Next Nature of Life Seminar with Prof. Dr. Bertrand Boeken at 10 October

October 2017

Prof. Dr. Bertrand Boeken, Ben-Gurion University of the Negev, Israel, will talk about:

Land degradation and resilience of semi-arid shrubland under grazing and drought
Read more


Dr. Aniek Ivens in 'Met het Oog op Morgen' on radio NPO 1

July 2017

On 29 July Dr. Aniek Ivens gave an interview in 'Met het Oog op Morgen' on radio NPO 1 about the invasive Red Fire Ant.


Prof. Hans ter Steege on 'Roads threaten biodiversity' on radio NPO 1 in Nieuws en Co

January 2017

The global road building is shattering natureRoads are a major threat for biodiversity because they fragment the landscape and thus the ecosystems. Worldwide there are some 600.000 fragments. An international team of scientists made a worldmap and published it in academic journal Science. Hans ter Steege, researcher of tree diversity in the Amazone and connected to Naturalis and the Vrije Universiteit Amsterdam explains in 'Nieuws en Co' about the consequences of this fragmentation for the biodiversity in the Amazon region and overhere in The Netherlands. Listen here [Dutch]. View the map here.


Toby Kiers and Anouk van 't Padje on NPO2 in 'De Kennis van Nu'

December 2016

Fungal KingdomThe age old special relationship between plants and fungi is a world in itself. Our scientists Professor Toby Kiers and Anouk van 't Padje talk about the impressive fungal kingdom in the NPO2 broadcast De Kennis van Nu [Dutch] on December 1st. It turns out that not only humans are fighting for the best deal, fungi and plants do too.

Hans Cornelissen on the Highly Cited Researchers 2016 List of Thomson Reuters

November 2016

Hans Cornelissen is again – just as in 2015 – among the 1 percent most cited scientists of the world.

This is according to the Highly Cited Researchers 2016 List of Thomson Reuters. This yearly overview  is put together based on the number of citations of individual researchers in scientific journals. The citation list of 2016 shows about 3000 scientists. Together with Hans Cornelissen another scientist of the faculty of Earth and Life Sciences is listed and another three reseachers from other faculties at Vrije Universiteit Amsterdam or VU University. Five researchers of the VU Medical Center are in the list as well.

Hans Cornelissen Highly Cited Researcher 2016Hans Cornelissen is a full professor at our department in the section Systems Ecology. Cornelissen studies the effects of climate warming on ecosystems. “I study how changes in vegetation in the Arctic and in other areas of the world can have effects on the soil and even on the climate.” This year Cornelissen co-authored two Nature articles on the role of plant traits on the composition of vegetation globally.

Different butterfly or wasp species coming due to climate change?

October 2016

Changes in species composition can be predicted when using the new ‘Handbook of protocols for standardized measurement of terrestrial invertebrate functional traits.'

Butterfly-Handbook of protocols for standardized measurement of terrestrial invertebrate functional traitsWhy are there so many reportings of hornets in the Netherlands this year? Why have species like the wasp spider and the large damselfly increased so much over the past 20 years? The composition of insects and other invertebrates in The Netherlands varies because of climate change and changes in land use. But can we also predict which species will increase or decrease?

That is only possible if we have information on the traits of these animals, e.g. how they survive in their environment. We therefore look at their choice of food, how well they can stand heat and drought, their body size, the number of their offspring or their ability to disperse. Until now reliable information on these traits was lacking for many species because there was not a standardised protocol to measure them. That now has changed because of the recent publication of the ‘Handbook of protocols for standardized measurement of terrestrial invertebrate functional traits’ which describes how the 29 most important traits of insects and related animal species can be measured.

This handbook, to which Jacintha Ellers and Matty Berg contributed, makes it possible to determine for a great many insects and other arthropods how they differ in traits important for survival. This new approach makes it possible to predict for different landscapes which species will be found there in the future, e.g. when considering new nature conservation measures or climate scenarios. At the same time the handbook offers a handle on the management of different areas. By creating urban areas or farmland in which useful species thrive it is possible to benefit from the services that the invertebrates offer, such as pollination by bees or a soil amelioration by earthworms.

Hans ter Steege appointed as Honorary Professor at Systems Ecology

October 2016

Hans ter Steege has been appointed per October 1st as Honorary Professor in Tropical Forest Diversity and Tree Traits

Hans ter Steege
Hans ter Steege making a selfie in the marsh forest, his research area in Brasil

Tropical forests are very important for the preservation of global biodiversity and their role in the carbon cycle. The Amazone, the world's largest tropical forest, is the centre of Ter Steege's research. "How can it be that only one hectare of Amazone forest can contain 300 different kinds of trees?" he wonders.

Ter Steege will investigate the role of the various functional traits of tree species in the preservation of biodiversity and the functioning of the ecosystem especially under the influence of a changing climate. The research has an interdisciplinary nature. Ter Steege: "I am looking forward to cooperate with the members of the group and the colleagues within the domain Earth, Ecology and Environment." The appointment opens new possibilities for the use of 40 million collections of plants and animals that Naturalis owns. Ter Steege will be active as well in the BSc Biology and MSc Ecology and Evolution curricula.

Hans ter Steege works at the Naturalis Biodiversity Center, where he leads the group Biodiversity Dynamics. He studied and obtained his doctorate at the University of Utrecht. subsequently he lived and worked in Guyana for ten years within the framework of the Topenbos-Guyana Programme. He coordinates a network of around 180 researchers, the 'Amazon Tree Diversity Network' which researches the origin and regulation of diversity of tropical forests in particular the Amazone. The results give for the first time a detailed insight into the numbers of tree species in the Amazone, their populations and the threat caused by deforestation. These research outcomes have been published in international journals, such as Nature, Science, Science Advances and Ecology Letters.

In the media

September 25, 2016
Wouter Halfwerk was interviewed by the radio program 'Vroege Vogels' on noise, urbanisation and adaptation. Listen to the interview here.

September 16, 2016
Wouter Halfwerk was interviewd on the research that he and his colleagues conducted on how bats change how they hunt when hunting in noise. Their article was published in Science. Listen to the broadcast here [Dutch]

August 31, 2016
Mark Lammers, Evolutionary Entomologist:
Gave an explanation on Radio 1 why entomologists start a collection and what can be done with it. Listen to the broadcast here [Dutch]


Wouter Halfwerk published a paper in Science on bats hunting in noisy conditions

September 2016

Frog-eating bats evolved a perceptual strategy to hunt in noisy environments
Animals that rely on sound to attract mates, avoid predators or find prey are often confronted with high levels of background noise, in particular in human-impacted environments such as cities or along highways. Some bats, such as the fringe-lipped bat (Trachops cirrhosus) are specialized to use prey-generated sounds, for example frog mating signals to detect and localize their prey. This capacity can however be compromised by increased levels of background noise, produced by insect or, recently by humans.

Dylan Gomes, a bachelor intern at the Smithsonian Tropical Research Institute was interested in the potential negative affects of anthropogenic noise on hunting bats and together with Wouter Halfwerk and Rachel Page designed an experiment to test whether and how bats adapt when hunting for frogs in noise. The team, helped by researchers from the University of Texas and Salisbury set out to test bats on specially designed robotic frogs and found that, when confronted with noise overlapping the sound of the frog, bats would crank up their echolocation to compensate the masking impact.

A fringe-lipped bat attacking the robotic frog setup. Image by Rachel Moon
A fringe-lipped bat attacking the robotic frog setup-Image by Rachel Moon
The team used two robotic frogs that mimic the calls and vocal sac expansion of the túngara frog, Physalaemus pustulosus. The robofrogs were placed inside a flight cage with a fringe-lipped bat, Trachops cirrhosus. One robofrog played the frog's distinct mating call, with the other playing the call and expanding its robotic vocal sac. When they played a masking noise over the call, the hunting bat's echolocation activity increased and it proportionally attacked the frog emitting both signals. Without the masking sound, it attacked both frogs without a statistical difference. Furthermore, bats were faster when attacking the model with the dynamic vocal sac compared to the control model, albeit not as fast when no noise was added to the scene.

A novel perceptual mechanism to deal with noise
The ability to increase the use of information from one sensory system when an other systems is confronted with noise was so far only known to be used by humans. When talking to someone in a bar or busy train humans also suffer from noise masking and have to rely on lip movements to be able to communicate with each other. This strategy to deal with the so-called cocktail-party-problem is also used by bats, although for obvious different functions.

All animals have multiple senses and the interesting questions remains whether and to what extend they can flexibly use them when sensory conditions change. The findings are not just important for bats but have also implications for other animals that rely heavily on sounds to survive and reproduce.

Multisensory community ecology
Different animals have different sensory systems and are thus likely to deal with changes to their sensory environment in different ways. Human activities may therefore have a big impact on the interaction between species, such as predators and prey, or parasites and their host and thereby affect community composition.

Journal Reference:
D. G. E. Gomes, R. A. Page, I. Geipel, R. C. Taylor, M. J. Ryan & W. Halfwerk. Bats perceptually weight prey cues across sensory systems when hunting in noise. Science, 2016; 353 (6305): 1277 DOI: 10.1126/science.aaf7934

Loglife research program highlighted in Het Parool

July 2016

Hans Cornelissen's research program Loglife was highlighted in Het Parool. The article [Dutch] explaines how the research on the decomposition of logs in various environments gives insight on the effects on climate.

Heineken Young Scientist award for Wouter Halfwerk

June 2016

Wouter Halfwerk Heineken Young Scientist AwardWouter Halfwerk, assistant professor and lecturer at the Department Animal Ecology (Faculty of Earth and Life Sciences), receives the 2016 Heineken Young Scientists Award for Environmental  Sciences for his creative research on how humans alter communication  between animals in nature.
The Royal Netherlands Academy of Arts and Sciences (KNAW) grants the Young Heineken Scientists Award to five young scientists, 10.000  Euro for each of them. Halfwerk: “I am very honoured and glad to receive this reward. The money will be used to buy solar panels as a start to a climate neutral household.”

Frogs and birds
Wouter Halfwerk studied biology at Utrecht University and received his PhD in 2012 at Leiden University for his research on the evolution and ecology of birdsong. He was especially interested in the influence of human noise pollution on communication between great tits. After graduation, he spent three years working outside the Netherlands and grew interested in other senses and species. For example, while he was stationed at the Smithsonian Tropical Research Institute in Panama, he used robotic frogs to study calling male túngara frogs and how predatory bats and parasitic midges perceive the associated cues and signals. A male frog that makes more sound and also generates more ripples on the surface of the water not only attracts more females but also more enemies.

Currently, Halfwerk is studying whether and how environmental variables influence the perception of animal and how this might influence the relation between species such as predator and prey. “With a team of Master students I’m investigating the effect of noise and air pollution on the relationship between frogs and predatory bats in the tropics. With a PhD candidate I look at the influence of wind and human activities, such as heavy traffic and building projects, on insects that depend on vibration signals for their survival. Caterpillars for instance react on vibration of parasitical wasps by letting themselves drop on the ground to avoid a certain death. Vibration caused by wind or traffic can disturb this delicate survival mechanism and thereby affect  species interactions.”

Wouter Halfwerk has published in prestigious journals as Science. He has received an NWO VENI grant, an EU Marie Curie research grant, and a Smithsonian Fellowship. He is also actively involved in popularising science, for example by giving lectures and cooperating in television documentaries.

Scientific talent
The Heineken Young Scientists Awards, handed out every two years, offer important encouragement to talented young scientists who set an example for other young researchers and scientists. The scientists will receive the Award on Thursday, September 29th, in the "Beurs van Berlage" in Amsterdam.

Photo: Jussi Puikkonen/KNAW

Andries Temme interviewed by 'de Volkskrant'

May 2015

Andries Temme was interviewed by the Dutch newspaper Volkskrant on the conclusion of his thesis that he defended on Tuesday May 24 at this university. Andries concluded that carbondioxide in the air is currently so high that an extra dose has hardly any influence on the growth of trees and plants. Here is a link to the interview [in Dutch]. A link to his thesis will be made available shortly.

Oscar Franken on Radio 1 in 'Dit is de Nacht'

April 2016

Oscar Franken was on Dutch Radio 1 in 'Dit is de nacht' with a live talk on insects and other arthropods for a full hour. The program included a nice chat with the presenter and a Q&A with listeners. Here is a link to listen to the program [in Dutch], and here is the link to the webcam [in Dutch] version.

Human Science Frontier Program award for Wouter Halfwerk

March 2016
An international research team consisting of Wouter Halfwerk (FALW, DES) and two international collaborators were awarded a Human Science Frontier Program (HSFP) grant for their proposal  ‘Seeing voices’: the role of multimodal cues in vocal learning

The project 
Multimodal communication
is ubiquitous in biology: animals court with visual displays and sounds and plants lure pollinators with colour and fragrance. Yet, while the human literature has long recognised that multimodal communication requires intersensory integration, this issue has received less attention in biology. As many animal signalling systems are modifiable by experience or wholly learned, experience-dependent changes of multimodal communication may be general features of human and non-human animal communication.

Robot frog communication
Robot communication. The use of robotics in animal communications allows full control over independent signal components. This robotfrog is for example used to understand how different receivers make use of both the sound of a calling male as well as the visual movement of the vocal sac that inflates and deflates during calling. Image courtesy of R. Taylor.
Humans and songbirds are both vocal learners that can copy their communication signals from other individuals. Sound is essential for the development of vocal communication but visual cues, such as moving lips in speech, or moving beaks in birdsong also play an important role. Young songbirds are thought to learn song better when using sound and sight than when only sound is available. But why is this so? Does simultaneous hearing and seeing improve learning because beak movements are learned together with the sound of song? Or is simply seeing a social companion improving a bird's learning performance? And how is the brain integrating multimodal information during development? To investigate these questions the team aims to develop a robot that can teach young birds to sing. A robot tutor provides full control over visual and acoustic cues and allows searching for neuro-molecular correlates for auditory-visual song integration in candidate neural networks. Songbirds, and zebra finches in particular, are the prevalent animal model for molecular, neural and developmental aspects of human speech. Human and songbird brains exhibit for example important functional brain circuits and findings in either system often can inform research in the other. 

The team
The project combines the expertise and infrastructures of three laboratories with signature research approaches. Dr. Wouter Halfwerk (DES, VU Amsterdam) is an Ecologist who studies multimodal signalling and the evolution of communication signals using robotics. Behavioural Biologist Katharina Riebel(IBL, LeidenUniversity) has long standing experience of avian vocal learning and operant paradigms that function as ‘avian questionnaires’. The work will receive a neurobiological complement provided by Prof. Constance Scharff (FU Berlin). All three parties share a passionate research interest in the development and evolution of communication systems and have long felt that single discipline approaches cannot captivate the complexity of these systems. All three are eager to embark on this new synergistic research line optimally combining expertise and infrastructure of three laboratories to answer long-standing questions in communication research. 

Human Frontier Science Program
The Human Frontier Science Program (HFSP) funds cutting edge innovative research in the life sciences, promoting international collaboration in the spirit of science without borders. 34 million USD were awarded to the 32 winning teams. Applicants went through a rigorous year- long selection process in a global competition that started with 871 submitted letters of intent involving scientists in 64 different countries around the world. This year 7 Young Investigator Grants and 25 Program Grants were awarded. Each team receives on average 330,000 -375,000 USD per year for three years.

For more information, see the HFSP-website

Full list of the 2015 HFSP awards available here

Links Team
Dr. Wouter Halfwerk
Dr. Katharina Riebel
Prof. Constance Scharff      

M Ecology alumna Mirte Bosse interviewed by VUmagazine

M Ecology alumna Mirte BosseM Ecolgy alumna Mirte Bosse was interviewed [Dutch] by VUmagazine. Her thesis research at Wageningen University led her to a postdoc position at NIOO as of September 2015. At NIOO she is involved in a genomic study of the genetic differentiation between populations and selctions in Great Tits.

Hans Cornelissen coauthored 2 papers in Nature

Christmas 2015

The world of plant traits – plant traits of the world
Systems ecologist Hans Cornelissen coauthored two papers in Nature on the worldwide spectrum of plant traits and its ecological significance.
PlantDespite the overwhelming diversity of evolutionary adaptations in the world’s flora,  all evolutionarily successful plants have to manage with a limited variation of six key traits to make a living: the Global Spectrum of Plant Form and Function. This spectrum, a kind of fundamental ‘Bauplan’, has two main dimensions: the quality of leaves and the size of plants and their parts. This follows from a study conducted by an international research team led by Sandra Diaz (Cordoba, Argentina). By comparing thousands of plant species, the researchers discovered that the characteristics plants need to possess to be able to survive, like seed and leaf size and leaf and stem quality, tend to combine with each other in only a few ways. This is because of physical and physiological limits to plant form and function. Hans Cornelissen: “In other words, there is no such thing as a ‘super plant’ that has the traits to disperse well, grow fast, compete with neighbours vigorously and be tough enough to withstand harsh environmental conditions or herbivores. Different environments require different plant strategies”. Large area and nitrogen concentration per leaf mass as well as low stem tissue density help plants to grow quickly, but at the expense of toughness, defense against herbivores and life span. The mass of seeds is linked to dispersal and regeneration; small seeds travel far while large seeds contain food stock for the new plant that grows from it. The maximum height a plant can reach says much about its access to light for photosynthesis. Leaf size is linked to climate; small leaves possess a low leaf area to leaf mass ratio  and are therefore better able to withstand stress caused by drought, heat or cold. Which combinations of these six traits are successful depends on climate, land use (disturbance regime) and soil. The global spectrum of plant form and function will help to feed Dynamic Global Vegetation Models and Earth System Models with ecological information to better predict future vegetation properties and climate. This is because variation in the six traits is important for the climate response, CO2 uptake (through photosynthesis) and CO2 release (through litter decomposition and fire) of the world’s biomes. The spectrum will also help to put more ecology into evolutionary studies. Hans Cornelissen: “In that sense it is both amusing and disconcerting that the geneticists’ pet model plant, Arabidopsis thaliana, is functionally an outlier at global scale, being very fast growing and small and occupying the very fringe of the 2-dimensional plant spectrum.”  
Second Nature publication
A different team in which Hans Cornelissen also participated, led by Georges Kunstler (IRSTEA, France), took three of these six traits (leaf area per mass, maximum height and wood density) to demonstrate that easy-to-measure traits can help us to predict which are the winners and

Hans Cornelissen bij BNR Duurzaam
Hans Cornelissen in Radio BNR Duurzaam
losers of competition among trees. To show this the researchers combined species’ trait data with growth data for 3 million trees in 140,000 plots worldwide. This study also demonstrated that competition within tree species is generally stronger than between species, that it helps a bit to be different (in trait values) from one’s neighbours, and that certain traits (high wood density, low leaf area per mass) help tree species to compete in denser forest while other traits (maximum height) are more helpful in more open woodland. This finding makes generalization possible across forest ecosystems at global scale, despite the great variation in other traits of the many tree species.

The results of both studies were published in the Christmas edition of Nature (Diaz et al., Kunstler et al.).

Hans Cornelissen was interviewed about this research in Radio BNR Duurzaam [Dutch]

Gijsbert Werner awarded Newton International Fellowship

November 2015

Gijsbert Werner awarded Newton International FellowshipDoctoral researcher Gijsbert Werner is one of the 47 leading international researchers to be awarded with a Newton International Fellowship. The Fellowships provide an opportunity for some of the most talented post-doctoral researchers  working overseas to carry out world class research in UK institutions across all disciplines of humanities, engineering, and natural and social sciences. Fellows will receive support in the region of £100,000 each for a two year placement in the UK. Gijsbert Werner intends to spend two years of research into the Deep History of Mutualistic Cooperation at the University of Oxford.

Gijsbert Werner published interview in Nature with Nobel Laureate Richard Roberts

October 2015
Gijsbert Werner interviewed Nobel laureate Richard Roberts, published in Nature 526, S58–S59This week in the journal Nature, Gijsbert Werner, Phd student in Animal Ecology, has published an interview with Nobel laureate Richard Roberts. Werner was chosen by KNAW (Royal Academy of Sciences) as one of seven promising young scientists from the Netherlands to meet with seventy Nobel laureates at the 65th Lindau Nobel laureate meeting. He then was chosen by the editorial team at Nature to conduct an interview with Roberts in which he asks him about microbes, GMOs, and the problems with Nobel prizes.

Read the full interview

Wouter Halfwerk awarded the Dutch Zoology prize

October 2015
On October 9 Wouter Halfwerk received the Dutch zoology prize at the annual Royal Dutch Zoology Society conference. He was awarded the prize for his innovative research on multimodal communication of male túngara frogs. You can read the jury report (in Dutch) here.
The prize is awarded every year by the Royal Dutch Zoology Society to a Dutch scientist that recently published outstanding zoological work using a highly integrative approach. The prize can be rewarded to any scientist that combines knowledge and techniques from the moleculair level to the level of animal communities. Wouter received his prize for the work he conducted on the interaction between male frogs and their rivals as well as predators and his focus on the morphology, ecology, perception and behaviour of the different species involved.
Zoology price Wouter Halfwerk presentation

Wouter presenting his research at the Royal Dutch Zoology Society 2015 Conference

Stef Bokhorst in Klokhuis

October 2015

In the television program 'Klokhuis' ecologist Stef Bokhorst explained how the effects of climate change are studied on Antarctica. To view the item, klik here [Dutch].

Stef Bokhorst Klokhuis Antartica

Researchers Bokhorst and Rozema part of Sees expedition

August 2015

SEES.nlDr. Stef Bokhorst and Prof. Jelte Rozema, researchers at the section Systems Ecology, were part of the SEES expedition that voyaged to the island of Edgeøya in the Spitsbergen archipelago from 19 to 28 August 2015. The largest Dutch polar expedition ever investigated an area that was last investigated 40 years ago to map the consequences of climate change. The  expedition closed with a symposium that was attended by several Norwegian and Dutch VIPs.

More information on the international participants and aim of the SEES expedition can be found on the website of NWO.

Wouter Halfwerk received a Veni-grant

August 2015

Wouter Halfwerk VeniWouter Halfwerk, recently appointed on a tenure track at animal ecology, received a prestigious Veni-grant to continue his work on sensory ecology. He will look at the effects of anthropogenic noise on the interaction between predators and prey. His focus will be on birds that rely heavily on their vision to find caterpillars and he will assess whether their perceptual capacities will be reduced by noise exposure. He will carry out his research in collaboration with the NIOO as well as Leiden University.

The 2015 Bio-Art and Design award won by Toby Kiers in collaboration with Isaac Monte

May 2015

Toby Kiers and Isaac Monte Bio-Art and Design Award 2015In collaboration with Isaac Monte from Belgium, Toby Kiers of Animal Ecology has won the 2015 Bio-Art and Design (BAD) award. Their project, along with two others, was selected by an international jury to win 25,000 euros and an exhibition in November at the gallery MU in Eindhoven. The project titled "The Art of Deception" explores how biological interventions and aesthetic manipulation can be used as tools for the ultimate deception: the transformation of inner beauty.

Kees van Gestel awarded the EEA at SETAC Europe

May 2015
Kees van Gestel was awarded the Noack-Laboratories Environmental Education Award at the SETAC-Europe congress in Barcelona.
Kees van Gestel EEA winner at SETAC Europe 2015The Society of Environmental Toxiology and Chemistry in Europe awards an annual price worth 1000 Euros, sponsored by Dr. U. Noack Laboratories, to a person with exceptional achievements in the field of environmental education. The 2015 price went to Kees van Gestel, who gratefully accepted the award during the opening ceremony of the congress in Barcelona, in front of an audience of 2600 delegates.

In his speech Kees acknowledged his PhD students and post-docs (of which several were in the hall), his technician Rudo Verweij and his own “teacher” Nico van Straalen. Kees’ contributions to environmental education not only cover many years of teaching environmental toxicology at VU University Amsterdam, but also include supervision of – up to now – 35 PhD students, distributed over the world as the “Van Gestel” school of soil ecotoxicology. All of them are proud to have been guided and trained by Kees.

Photograph courtesy SETAC-Europe office

Hans Cornelissen's radio interview on 'tree cemetery' (research program Loglife)

April 2015
Hans Cornelissen was interviewed in the radio program VARA Vroege Vogels broadcasted on 19 April 2015. He explained about the tree cemetery experiment LOGLIFE taking place in two forest sites in the central part of the Netherlands. 
Interview Hans Cornelissen on Loglife by Vroege Vogels
In the forest plots tree logs are left to rest for sixteen years to investigate their biodiversity and their potential for storing carbon, which the trees take up as CO2 from the air. Researchers from VU University Amsterdam, Utrecht University and Wageningen University work together on the project LOGLIFE, which compares the natural decomposition of different tree species and the biodiversity of small animals on the different logs.
Logs of various varieties with a diameter of 25 cm were sawn into pieces of exactly one meter long. Next they were put to rest on the soil to be broken down naturally. Every couple of years the logs are examined. From every log slices are taken to analyse for growth rings, moisture level, wood density, other structural and chemical wood quality properties, diversity of fungi and other factors that can influence the decay. On two locations in the Netherlands a 1 km of log of 25 species of trees are being researched.

Matty Berg explains about millipedes on NPO2 TV

April 2015
Matty Berg veldwerk  Matty Berg explains about millipedes on TV, April 14th at 19:20 on NPO2
  in the program "Vroege Vogels" (explanatory text in Dutch with a link to
  the Dutch millipede determination card). The broadcast is to help celebrate
  2015: the Year of the Soil.

  The new millipede identification key is available for download as pdf (Dutch).

Jelte Rozema on Saline Agriculture on NPO Radio 5

April 2015

Jelte RozemaJelte Rozema discussed solutions on growing crops on saline soils in the Dutch radio program De Kennis van Nu [Today’s knowledge] broadcasted on April 7 by NPO Radio 5. Soil salinity is rising worldwide owing to climate change. Not many crops can be grown on saline soils. Jelte Rozema, professor of systems ecology, just returned from China where he runs a research project aimed at improving the cultivation of salt-tolerant beets for sugar production. Listen to the broadcast [Dutch].
Rozema et al. recently published this paper:
Rozema, J., Cornelisse, D., Zhang, Y., Li, H., Bruning, B., Katschnig, D., Broekman, R.A., Ji, B. & Bodegom, P.M. van (2015). Comparing salt tolerance of beet cultivars and their halophytic ancestor: consequences of domestication and breeding programs. AOB Plants, 7. 10.1093/aobpla/plu083
More information on Rozema's research and research partners [Dutch]

Gijsbert Werner to meet Nobel laureates at 65th Lindau Nobel laureate meetings

March 2015

Gijsbert Werner   After a rigorous selection process, Gijsbert Werner (Phd-
   candidate) was chosen by KNAW (Royal Dutch Academy
   of Sciences) as one of seven promising young scientists
   from the Netherlands to meet with seventy Nobel laureates
   at the 65th Lindau Nobel laureate meetings.

Concerns about earthworms

February 2015

In an interview in the daily newspaper 'Trouw' Kees van Gestel expressed his concerns over the effects of agrotoxics on earthworms. The agrotoxics-neonicotinoïds-intended to protect crops against insects, end up in the soil and thus in the earthworms.

Exactly how neonicotinoïds damage the worms is not yet clear. However it has been found that earthworms take in the poison in various ways: via the thin skin, by eating plant remains and also via soil moisture in which the poison is dissolved. Experiments exposing earthworms to these toxics resulted in a signifant decrease in off spring: this reduces the population and this directly affects the soil. What the effect is under natural conditions is impossible to say.

Van Gestel fears that the longterm effects may be severe. To research these effects for earthworms but also springtails, the research is expanded by adding Dutch and foreign students. Two new bachelor students and a Brazilian PhD-student will continue reseach done by two earlier students. Van Gestel expects to write an article based on the results found in the research by the first two students.

Next to neonicotinoïds climate change combined with pollution with heavy metals can be a threat for soil organisms. Due to the higher temperatures earthworms are more affected by the heavy metals; this became apparent in reseach in heavily polluted soils in Spain. A combination of higher temperatures and dry soil is disastrous for earthworms: they are less active, eat less and are more affected by the pollution. A paper on this subject was published in Environmental Chemistry and Toxicology.

Interview in the newspaper Trouw: 'Zorgen om de regenworm' [Dutch]

Snail is a true cupid

February 2015

Joris Koene's research on love darts in land snails was covered in the Valentine's issue of Trouw. The interview highlights how studying different mating systems, like hermaphroditism, is important for the general understanding of evolutionary processes. Read the article (Dutch).

Gijsbert Werner awarded best student paper of 2014

February 2015

Congratulations to Gijsbert Werner who was awarded the best student paper of 2014 at the Netherlands Annual Ecology Meeting on 11 February. The contest had a record number of entries this year and a prize award of 750 euros. The winning paper, "A single evolutionary innovation drives the deep evolution of symbiotic N2-fixation in angiosperms" was published in Nature Communications.

Nieuw: Component

Climate Change in the Antarctic

February 2015

The Dutch television program 'de kennis van nu' followed Stef Bokhorst on a trip to the Antarctic to find out what the impact of climate warming is on the Antarctic terrestial plants and soil animals. To find out more and view the documentary, please click here.

      Stef Bokhorst op Antarctica-2       Stef Bokhorst op Antarctica-1

VU-collaboration with Guangxi University in China started in our department

November 2014

A delegation from Guangxi University, Nanning headed by their rector, Professor Zhao Yanlin, visited our rector, Professor Frank van der Duyn Schouten, at VU University on 13 November. They signed a Memorandum of Understanding to formally celebrate and reinforce  the fresh and promising collaboration between both universities in research and education.

This was a follow-up to an initial visit by a delegation from this South Chinese university last year. This new VU-China link arises from the current fruitful collaboration of Hans Cornelissen with forest ecologist Professor Cao Kunfang. They work together on the role of termites in the breakdown of dead wood of many (sub-)tropical bamboo and broadleaved tree species. This research is important because of the key contribution of dead wood to the carbon cycle and thereby to climate. Coming January Hans will visit Guangxi University to start new joint projects on forest ecology and carbon dynamics. 

During this visit of the Chinese delegation to VU University there was also much opportunity for informal discussion at grass-root level. This already led to new plans for collaboration in organic chemistry (Prof. Romano Orru), business administration (Dr. Peter Peverelli) and mechanical engineering (Prof. Dirkjan Veeger). The vision is  that  this kind of small scale collaboration in research and exchange of (MSc, PhD) students will lay the foundation for university-wide joint activities such as student exchange programs.

       VU-collaboration with Guangxi University 283x660.jpg

Matt made it to the cover of Nature

September 2014

140929 Cover Nature

Matt Helmus, employed by the Amsterdam Global Change Institute and working in our department 2012-2014 published his work in Nature this week: Nature 513 (25 September 2014), Vol. 513, pp. 543-546. Congratulations, Matt!

According to the theory of island biogeography, the number of species (richness) is determined by how an island's area and isolation govern rates of colonization, extinction and speciation. There is a long history of human introduction of anole lizards to Caribbean islands, hitching a ride on crops such as pineapple and recently on ornamental plants for hotel gardens.

Matt took advantage of this spread of exotic species to conduct a large-scale direct test of the theory of island biogeography. His results confirm some theoretical predictions — geographic area remains a good positive predictor of species richness, for instance. But in a world dominated by humans, geographic isolation as a negative predictor of richness has been replaced by economic isolation. For example, shipping traffic among islands is unrelated to geographic isolation and is instead linked to trade policy — illustrated by the fact that the US embargo has reduced the number of exotic anoles established on Cuba.

The photograph shows Cuban green anole (Anolis porcatus) established in the Dominican Republic. Photo by Miguel Landestoy, from the website of Nature.

Hans Cornelissen among the world’s most highly cited researchers

June 2014

Hans Cornelissen is among the three thousand scientists worldwide to have been formally listed as a Highly Cited Researcher by Thomson Reuters. The 2014 list, the first in ten years, ranks Costa Rica-June 2014citation scores over the period 2002-2012 among scientists within each discipline. Marten Scheffer and Hans are the only Dutch scientists in the Environment/Ecology discipline to join this prestigious list. Especially a range of his papers on plant species effects on soil and ecosystem functioning have been cited heavily in international journals, but also his contributions to plant strategy theory based on plant traits and to global change impact on arctic and alpine ecosystems have been more than noticed internationally. One of Hans’s new research lines involves evolutionary lines in plant effects on biogeochemical processes (e.g. decomposition, fire, productivity) and applying this both to reconstructing the past and predicting the future of carbon, nutrient and water cycles. No doubt his papers on this research will keep him cited and excited rather than ex-cited for the foreseeable future.


Kees van Gestel and Nazaret González visit Sierra Minera

May 2014     

In the context of a joint project involving experts of VU Amsterdam and the School of Agriculture of UPCT (Universidad Politécnica Cartagena) Kees van Gestel paid a visit to Sierra Minera last week, a vast deserted mining area in Southern Spain. Nazaret González In Alcaraz, presently a guest in Amsterdam, investigates the toxicity risks of various contamination pathways arising from the mining area with regard to forests, marshes, water courses and agricultural land. Kees van Gestel, co-supervisor of the project used the excursion also to make a contribution to the UPCT Master program of AdvancedTechniques in Agricultural Research and Development and Food, and gave lectures to students and researchers of the School of Agriculture. The visit attracted quite some attention from the Spanish news media.


On the photograph from left to right: Jose Alvarez Rogel, Héctor Conesa Alcaraz, Kees van Gestel, Nazaret González Alcaraz and Isabel Párraga Aguado


Matty Berg honorary professor at Groningen University

March 2014

A new level in the collaboration with Groningen University has been established through an honorary chair supported by the Uyttenboogaart-Eliasen Foundation. Matty Berg, appointed as a professor of “Soil fauna and natural ecosystem dynamics” will be investigating the evolutionary changes of keystone soil invertebrates living in salt marshes, in response to changing climatic conditions. Because of adaptation, the ecological traits of these animals will change and this may lead to effects on the ecosystem, e.g. due to changes in activity, bioturbation and feeding. These eco-evolutionary feed-backs loops may come to involve the whole salt-marsh community with consequences for nutrient cycles and vegetation composition.

Matty 4-hgl Matty will remain associate professor at VU University and will spend one day a week in the Centre for Ecological and Evolutionary Studies of Groningen University to supervise MSc and PhD students working at the field station of Schiermonnikoog, in collaboration with prof.dr. Han Olff. Like Groningen University, our department has a long tradition of field research on the Wadden Islands, which is now intensified with the honorary chair. We look forward to the new opportunities for MSc and PhD projects that are enabled by Matty’s professorship. Matty will also collaborate with volunteer entomologists to map changes in ranges of invertebrate communities and to identify the underlying factors.

Valentine’s day in the animal kingdom

February 2014

Joris Koene lectures on the shooting of a love dart and other tricks to find your valentine on February 14th, Museon, The Hague (in Dutch).

News-februari 2014-Koene-1       

Wetenschapslezing met Dr. Joris Koene – Vrije Universiteit Amsterdam.
Een lezing over het klassieke baltsgedrag van landslakken: het schieten van de liefdespijl.

Op Valentijnsdag denken we natuurlijk vooral aan dozen bonbons en bossen rozen voor geliefden. Is de mens daarin uniek, of zijn er ook andere dieren die hun partners cadeaus geven? Wat proberen dieren hiermee te bereiken? En hoe zit dat als je een tweeslachtig dier bent? Om deze vragen te beantwoorden, zullen we tijdens deze lezing naar een aantal voorbeelden uit het dierenrijk kijken. Daarbij zal in meer detail worden gekeken naar het zeer tot de verbeelding sprekende gedrag van landslakken, het schieten van de liefdespijl. Hiermee zal geïllustreerd worden dat er vaak een conflict bestaat tussen de bedoelingen van beide paringspartners.

Aanvullende literatuur: het artikel "Slakken schieten met scherp" uit Natura.

Wilt u vooraf reserveren voor deze lezing? Klik dan hier.

Wanneer?: 14 februari 2014; 14.00 uur

Gijsbert Werner in PNAS: microbes and plants play in an evolving biological market

January 2014

Mycorrhiza-picture Ph.D. student Gijsbert Werner last week published a paper in PNAS on the evolution of biological markets. He argues that for a biological market to evolve, the only condition is that participants can reward partners that provide them with more resources in return. So not only higher organisms like social mammals can participate in a biological market, also markets with only microorganisms can evolve. Toby Kiers earlier discovered that plants form complex underground trading networks with fungi, by which they exchange nutrients and sugars. Some fungi can even withhold resources and store them until they get a better deal from the plant. Microbial traders can be tough and even use chemicals to eliminate competitors from the market. The social behaviour of microorganisms is also important because of potential useful applications. For example in an agricultural system the transfer of nutrients from soil to plants might be maximized by deploying cooperative interactions empty with symbiotic fungi, which will decrease the need for synthetic fertilizers.

Gijsbert’s paper even made it to the cover of PNAS, see

Two hoppers on one picture

December 2013

Two hoppers on one picture

In the last week of December 2013 Matty Berg reported a new species of Collembola for the NetherlaFasciominthurus quiquefasciatusnds, called Fasciosminthurus quinquefasciatus (Ned. Faun. Med. 40:1-6, 2013). The way in which this record was established is remarkable. Nature photographer André van den Ouden had taken a picture of a species of grasshopper, Oedipoda caerulescens. Coming home and studying the photographs he noted that close to the left leg of the grasshopper a tiny little animal was sitting. Because the photograph was of excellent quality quite a number of details could be discerned. André placed a notification on the website “”. Matty recognized the tiny animal immediately as a new springtail, known as a European species but not yet recorded in the Netherlands. It is unmistakable due to the zebra-like stripes on it body and its beautiful colour. With some effort he was also able to retrieve the animal in its natural habitat, a former shunting yard of a railway station in the East of the country close to the village of Mook. To discover a new species of hopper on a photograph of another hopper, what an astonishing coincidence!

For more information (in Dutch) see:

Photograph copyright André van den Ouden

New paper on phosphorus availability in Nature by VU University researchers and their colleagues

November 2013

Little investment in sexual reproduction proves fatal to species

Phosphorus threatens existence of endangered plants

Plant species that persist in areas with low availability of phosphorus invest little in sexual reproduction. Due to the increase of phosphorus in their habitats by eutrophication and the fragmentation of low-phosphorus areas, these plant species, which already are on the ‘red list’, are under threat of going extinct. This issue was raised by VU University researchers and their colleagues, in a study coordinated by Utrecht University in their publication in Nature of  November 18th 2013.

                   Nature-Beemd ooievaarsbek            Nature-Gras
                    Photos taken by Jerry van Dijk (UU)

This study is part of a larger research programme at VU University to predict future distributions and functioning of plant species based on their species characteristics. This information is used to improve global climate models. A VU-study describing these aspects will be published soon in Proceedings of the National Academy of Sciences USA.

Low investment in sexual reproduction threatens plants adapted to phosphorus limitation
DOI: 10.1038/nature12733
Yuki Fujita1, Harry Olde Venterink, Peter M. van Bodegom2, Jacob C. Douma3, Gerrit W. Heil, Norbert Hölzel, Ewa Jabłońska, Wiktor Kotowski, Tomasz Okruszko, Pawel Pawlikowski, Peter C. de Ruiter, Martin J. Wassen

1 Yuki Fujita obtained her doctorate degree on this subject at Utrecht University and is currently working as a researcher at the KWR Watercycle Research Institute
2 VU University, Department of Ecological Science
3 VU University, Department of Ecological Science. Currently working at Wageningen University.

More information

The paper was also mentioned in de Volkskrant:

Ken Kraaijeveld appointed post-doc in Jacintha’s Vici project

October 2013

Ken KraaijeveldWe are very happy to have Ken Kraaijeveld attracted to our department. He will work in the Vici project of Jacintha on evolutionary loss of essential traits in biological interactions. Such trait losses are not uncommon in evolution. For example, primates (including humans) have lost the ability to synthesize vitamin C de novo, because of excess vitamin C in their diet. Similarly, multiple insect lineages have lost the ability to convert carbohydrates to lipids after switching to a parasitoid lifestyle. Jacintha and Ken are elucidating the molecular changes underlying the loss of lipid biosynthesis in parasitoid insects. Detailed studies on the wasp Nasonia vitripennis are combined with whole-genome sequencing of selected parasitoids in unrelated families to assess whether the loss of lipogenesis has evolved repeatedly on the moelcular level.

Ken has a broad-ranging interest in evolutionary biology and has worked on topics such as sexual selection, sexual conflict and speciation. Recently, he focused on the evolutionary consequences of Wolbachia-induced parthenogenesis in insects. After cataloguing phenotypic effects and population genetic signatures, he has now begun to investigate the effects on the genome of the host.

Working at the Leiden Genome Technology Center, Ken has become an expert in the application of next-generation sequencing technology in the study of evolutionary questions. This technology is rapidly changing biological and medical research, a fact that the general public should also be aware of. He contributes to this effort through the activities of the LeveDNA! Foundation. Guest researcher at the Leiden Genome Technology Center at the Leiden University Medical Center.

Hans Cornelissen joins TOP-100 of influential ecology papers

September 2013

autumn colours Hans Cornelissen’s paper on linking plant traits and litter decomposition in Journal of Ecology was elected as one of the 100 most influential publications in British Ecology Society (BES) journals over the past century. The election marked the centenary of the BES, which publishes Journal of Ecology, Journal of Animal Ecology, Functional Ecology, Journal of Applied Ecology and Methods in Ecology and Evolution. The recommendations for each of the 100 elected most influential papers have been briefly summarised in a special (on-line) booklet, from which the papers themselves can be downloaded as well:

Read more:

In 1996, Hans Cornelissen pioneered a new approach to compare plant species for their litter decomposition rates in a standardised way.  His ‘common garden’ approach involves simultaneous incubation of fresh leaf litter of multiple species in litterbags, in an outdoor litter medium. This ‘litterbed’ somewhat resembles a natural litter layer with its typical decomposing organisms (fungi, bacteria, small invertebrates). The relative mass loss of each litter species over a given time period is the ‘decomposability’ of that species.  This research also showed, for the first time,  that the litter decomposability of a range of species could be predicted from the functional traits of these species, for instance their growth form and leaf lifespan – with for instance leaf litter from deciduous trees or herbs  decomposing fast and that of evergreen shrubs slowly. For deciduous shrubs and trees even autumn leaf colour turned out to be a good functional predictor of decomposition rate. For instance, brown leaf litter of chestnut trees, still full of the tannins that protected the living leaves, is decomposed slowly, while dead leaves of ‘wasteful’ ash or alders, dropped while still green without first recycling their green chlorophyll and other ‘goodies’, undergo fast decomposition.
This litterbed approach has since been applied all over the world (see Cornwell, Cornelissen et al. 2008 in Ecology Letters) and has stimulated a new hot field of ecological research on the effects of plant species on carbon and nutrient cycling in ecosystems worldwide. Hans Cornelissen and colleagues are now doing new experiments where this common garden approach has been extended to other parts of the plants than just leaves, including roots and stems, even the big logs of large trees.

Citation:    Cornelissen, J.H.C.  (1996) An experimental comparison of leaf decomposition rates in a wide range of temperate plant species and types.  Journal of Ecology 84: 573-582.


Towards a full integration of Earth Observation products and concepts in land surface models

July 2013

view Bern-klein Understanding climate and projections of likely future behaviour relies to a great extent on mathematical models of the Earth System that consider the dynamics of mass and energy transport around the system. An important part of such models is a land surface scheme, that deals with the interface between the land and atmosphere, for example, by modelling processes on the land such as vegetation dynamics and the Terrestrial Carbon Cycle. Such models increasingly make use of Earth Observation (EO)‐products to help constrain their behaviour to what we actually 'see' from spaceborne satellite instruments, as well as to test these models. However, a full exploitation of EO‐products is currently hampered by the different definitions, assumptions and algorithms applied by the scientific communities involved. Moreover, it seems that the radiative transfer schemes applied in land surface models are frequently internally inconsistent, even though concepts on consistent radiative transfer schemes are available. There is a strong need for improved communication and integration of the scientific communities involved.

A new project 'Towards a full integration of Earth Observation products and concepts in land surface models" led by Dr Peter van Bodegom of VU Amsterdam has been funded by the International Space Science Institute (ISSI) ( and the first team meeting was held in Berne, Switzerland 24-27 June, 2013. The team consists of scientists from the modelling and EO communities as well as space agency and other relevant representatives. This first meeting involved discussing consistency in radiative transfer in the various communities, data assimilation approaches, funding and setting the agenda for this form of integrated approach within the space agencies.

For further information, see

Gijsbert Werner and Piero Morseletto Win PBL Award

May 2013

PhD student team win award for best IPCC review by Netherlands Environmental Assessment Agency (PBL).

IPCC-award Gijsbert Werner Gijsbert Werner (Ecological Science) and Piero Morseletto (IVM) from VU University Amsterdam are the two best reviewers of the draft version of the Fifth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC). The Netherlands Environmental Assessment Agency (PBL) invited approximately 90 young scientists from around the world to review a chapter of the report. The VU PhD students were selected to present their conclusions to a PBL jury in Utrecht on 13 May 2013. They won the Award for Best Review.

The PBL is in charge of coordinating the Dutch government response to the draft version of the upcoming IPCC report, the final version of which is due to appear beginning 2014. In order to be able to review the 30 chapters of the concept report, PBL enlisted the help of about 90 PhD students from around the world. Carefully reviewing the upcoming report is of great importance, as in the most recent version of the IPCC report, which appeared in 2007, some clear errors were left. These errors greatly damaged the IPCC's credibility with the public and impeded the IPCC's mission to raise awareness on climate change issues. A  committee led by professor Robbert Dijkgraaf, at the time president of the Royal Dutch Academy of Sciences, published a report in 2010 arguing that a more thorough review process of the report should be implemented. This PBL project is part of such a process.

In Dutch:
Gijsbert Werner en Piero Morseletto winnen PBL Award Team van twee VU-promovendi wint award voor beste IPCC review van het Planbureau voor de Leefomgeving (PBL).

Gijsbert Werner-foto PhD-onderzoekers Gijsbert Werner (Ecologische Wetenschappen) en Piero Morseletto (IVM) van de Vrije Universiteit Amsterdam zijn de twee beste reviewiers van de conceptversie van het vijfde rapport van het Intergovernmental Panel on Climate Change (IPCC). Het Planbureau voor de Leefomgeving (PBL) heeft ongeveer 90 jonge wetenschappers van over de hele wereld gevraagd een hoofdstuk van het rapport te reviewen. De VU-promovendi werden geselecteerd om hun conclusies te presenteren aan een jury van PBL in Utrecht op 13 mei 2013. Daar wonnen zij voor hun review the Award for Best Review.

Het PBL leidt de reactie van de Nederlandse overheid op de conceptversie van het volgende IPCC-rapport. De definitieve versie verschijnt volgens planning begin 2014. Om de 30 hoofdstukken van het rapport the kunnen reviewen, heeft PBL de hulp ingeroepen van 90 promovendi van over de hele wereld. Het is van groot belang het volgende rapport grondig te reviewen, aangezien in de meest recente versie van het IPCC-verslag, uit 2007, een aantal duidelijke fouten was achtergebleven. Deze fouten tastten de geloofwaardigheid van het IPCC bij het publiek ernstig aan en hinderden de doelstelling om het bewustzijn over klimaatsverandering te vergroten. Een commissie onder leiding van prof.dr. Robbert Dijkgraaf, toentertijd voorzitter van de KNAW, stelde in 2010 in een rapport dat een grondiger review-proces van het IPCC-rapport zou moeten worden ingesteld. Dit PBL-project is onderdeel van een dergelijk proces.

A short movie about the use of Folsomia candida gene expression

May 2013

MSc student Simone Vink made a short movie about the use of Folsomia candida gene expression to evaluate soil quality at contaminated sites. See

KNDV-Zoology Prize 2013: Bertanne Visser

April, 2013

Bertanne Visser, winner of KNDV Zoology Prize 2013, organizes symposium in Artis Zoo, Amsterdam, May 7th 2013

poster Zoology Prize 2013 Former Animal Ecology PhD student Bertanne Visser, now post-doctoral fellow at IRBI, University of Tours, France, has been elected for the Zoology Prize, an annual award for outstanding work in zoology presented by the Royal Dutch Zoological Society. Bertanne will accept the award on May 7th, 2013 in a symposium on “Evolutionary physiology. Linking gene to function”. This exciting new area links physiology, behaviour, ecology and evolution. The system that Bertanne herself studies is the evolutionary loss of lipid synthesis in parasitoid insects, as an example of evolutionary traits loss compensated by mutualism. The symposium takes places in the atmosphere of Artis Zoo in Amsterdam.

More information

NWO VICI-grant for Jacintha Ellers

February 2013

Jacintha Ellers-photoJacintha Ellers has obtained a highly prestigious VICI grant from the Netherlands Organisation for Scientific Research (NWO). With this grant of 1,5 million euro she will expand her work on evolutionary loss of traits in ecological interactions.

At present, the prevalence of trait loss is likely to be grossly underestimated because trait loss is not always accompanied by loss of function, due to provision of resources by ecological interactions. If resources are supplied by a symbiotic partner or by dietary intake, the underlying trait becomes redundant and is prone to loss or degradation. However, the evolutionary dynamics driving such compensated trait loss are poorly understood, despite its potential importance for long-term stability of ecological interactions.

Jacintha will use multiple model systems including parasitoid insects and bacterial endosymbionts to elucidate the driving forces and underlying mechanisms of trait loss.

Folsomia candida made it to the Volkskrant

January 29, 2013

Folsomia candida-Volkskrant
Folsomia candida made it to the Volkskrant

Last week the publication by Dick Roelofs in Molecular Biology and Evolution(
) received quite some press attendance. Dick was interviewed in the science programme Labyrinth( ) and a picture of Folsomia candida even made it to the national newspaper Volkskrant. Springtails, due to their small size and soil-living habit are not the kind of animals that easily make it to the general public, however, Dick’s demonstration that there is a functional isopenicilline-N-synthase in the genome of Folsomia suddenly placed these cute animals into the spotlights. The case of horizontal gene transfer into an animal genome is already exciting, but what made it even more astonishing is the possibility that not only certain bacteria and fungi but also at least one animal can make beta-lactam antibiotics.


Matty Berg will be on the TV program ‘t Klokhuis talking about isopods

November, 2012

All you always wanted to know about isopods but were afraid to ask

Tuesday, the 20th of November at 18:25 on Nederland 3, the episode of the TV programme Het Klokhuis will be dedicated to these nice creatures called emptyisopods (or pissebedden in Dutch). Matty Berg will explain how and where these animals live and what are their importance to soil ecosystems.

 Picture 1     Picture 2     Picture 3
Photo © Theodoor Heijerman

Paper on the evolutionary loss of traits published in Ecology Letters

September 2012

Species lose functions when others work for them!
Effects of co-evolution more widespread than previously assumed. A parasitic wasp which cannot reproduce independently because a bacterium has taken over its egg production; such loss of function occurs is more widespread in nature than scientists previously assumed. This was shown in a new evolutionary theory formulated by researchers at VU University Amsterdam and the University of Wisconsin. They publish their findings in the journal Ecology Letters.

Species take advantage of others
When two species have a prolonged ecological relationship, one species sometimes loses an essential function because it is provided by the other. “As a result of natural selection, species stop producing a compound if an ecological partner in their environment is already producing it,” says VU University professor Jacintha Ellers. “Species therefore take advantage of others working for them. Such compensated trait loss is a result of co-evolution of species. However, dependence on others can become a major disadvantage if the ecological partner disappears, for example due to climate change. Without the partner the chance of survival is small,” says Ellers.

Genome analysis shows loss of function
For a long time scientists have underestimated the scale of compensated trait loss because its effects remain hidden as long as one species works for the other. Ellers: “But now there is an increasing number of species whose entire genome has been sequenced. That makes it easier to find genes that have lost their function. Therefore, more and more cases of compensated loss of function will come to light.” The scientists reviewed the scientific literature and found evidence for over forty cases of compensated trait loss in ecological interactions such as mutualism, parasitism and herbivory.

Humans no longer produce vitamin C
Apart from no longer being able to reproduce independently, parasitic wasps also cannot produce fat anymore because they eat the fat from their host. Corals do not produce certain amino acids anymore because a bacterium provides them. And leaf cutter ants are unable to digest proteins because they grow a fungus that provides them with amino acids. It has been known for many years that humans and other primates no longer produce vitamin C because the fruit they consume already contains enough of it.

Applying scientific knowledge to agricultural pestcontrol
Compensated trait loss is common in parasites and pathogenic fungi. The researchers therefore believe that their findings can be used for agricultural pest control. “Pest control should not only focus on the parasite or fungus, but also on other species that have taken over their lost function,” says Ellers. “For example, the blight fungus Rhizopus microspores is dependent on a bacterium for its reproduction. So by controlling the bacteria the fungus will be unable to reproduce, which may be a promising way to slow its spread.”

For more information, please contact Jacintha Ellers.
Ellers J, Toby Kiers E, Currie CR, McDonald BR, Visser B (2012) Ecological interactions drive evolutionary loss of traits. Ecology Letters 15:1071-1082.


Article Frida Keuper in Nature Climate Change

May 2012

Article by Frida Keuper on thawing of permafrost highlighted in Nature Climate Change

Foto Frida Keuper in veld The article ‘A frozen feast: thawing permafrost increases plant-available nitrogen in subarctic peatlands’ by Frida Keuper and co-authors,  which appeared in Global Change Biology, is highlighted in Nature Climate Change

Release from the cold

Nitrogen is often in short supply for plant growth in northern peatlands. But will it become more available to plants if and when climate warming causes thawing of the long-term frozen (permafrost) soil layer?

Frida Keuper and colleagues compared plant-available nitrogen pools and fluxes in near-surface permafrost (0–10 cm below the thawfront) with those taken from the current-rooting-zone layer (5–15 cm depth) across five representative peatlands in subarctic Sweden. They revealed  up to seven times more plant-available nitrogen in near-surface permafrost soil compared with that in the layer where plants put their roots currently. Furthermore, a supplementary experiment showed an eightfold greater plant nitrogen uptake from thawed permafrost soil than from soil in the current rooting zone or in fresh litter substrates. These results demonstrate that near-surface permafrost soil of subarctic peatlands can release a biologically relevant amount of plant-available nitrogen, which may have impacts on plant productivity and species composition.

Frida Keuper, Peter van Bodegom, Ellen Dorrepaal James Weedon,Jurgen van Hal, Richard SP van Logtestijn and Rien Aerts. (2012) A frozen feast: thawing permafrost increases plant-available nitrogen in subarctic peatlands. Global Change Biology Vol 18 (6): 1998-2007.

Rob Hengeveld: we must curb the precipitous path towards a wasted world – quickly

May 2012

Wated World-Hengeveld VU University emeritus professor of Nature Conservation Rob Hengeveld just published his book “Wasted World” with The University of Chicago Press. In this book, which received praise from Bill McKibben, Gretchen Daily, Dan Simberloff and David Goodall, Hengeveld reveals how a long history of human consumption has depleted natural resources and left us drowning in waste. Rather than analysing each of the current environmental problems separately (climate change, energy shortage, food shortage, salinization, deforestation, environmental pollution), Rob provides a comprehensive overview of all of them and shows how they are interconnected and relate to a single underlying cause: we are with too many people on this world.
All systems produce waste. When the human population was still limited the waste streams could be absorbed and recycled in the same way as nature does, organisms feeding upon each other, the waste of one organism being the feed for another. Energy from the sun has kept those cycles in perpetual motion. However, the human population has grown to such an extent that natural processes cannot supply enough energy and nutrient sources to turn the enormous amount of waste generated quickly enough into nutrients. We are like a plumber who tries to fix a pipe leak by taking away parts of other pipes, thereby creating bigger and bigger holes and even greater spills.
In his book Rob Hengeveld calls for a new strategy for worldwide population growth control, in order to prevent wasting not only the natural, biological and geological world, but also our unique cultural world, which we have built over a few thousand years at the end of an evolutionary development that in itself took 4 billion years.

Hengeveld, R. (2012) Wasted World. How Our Consumption Challenges the Planet. The University of Chicago Press, Chicago, U.S.A. ISBN-13: 978-0-226-32699-3, ISBN-10: 0-226-32699-3, 337 pp., hard cover $ 30,-.

Kees van Gestel te beluisteren op Radio Amsterdam FM

May 2012

Op 6 mei was Kees van Gestel te beluisteren op radio Amsterdam FM in het wetenschappelijk programma Swammerdam; wetenschap te Amsterdam. Het thema van de uitzending was milieuverontreiniging. De uitzending is terug te horen op


Wetenschappers herontdekken waardevolle plantendatabase

May 2012

(english version below)

Glasnost dringt diep door tot onder de grondNadia foto-klein-2

Een groep Nederlandse en Russische wetenschappers van de Vrije Universiteit Amsterdam, Moscow State University en de Universiteit van Perm hebben een enorme hoeveelheid gegevens over symbiose tussen planten en schimmels uit de voormalige Sovjet-Unie nieuw leven ingeblazen. De dataset is ongeveer even groot als alle gegevens op dit gebied die buiten de Sovjet-Unie zijn verzameld en is dus van grote waarde voor wetenschappers wereldwijd. De gemoderniseerde dataset is gepubliceerd in het internationale ecologische tijdschrift Ecology .

Schimmel en plant kunnen niet zonder elkaar

Van 1950 tot 1980 verzamelde een Russisch onderzoeksteam (Universiteit van Perm, Rusland) onder leiding van Ivan Aleksandrovich Selivanov een enorme hoeveelheid gegevens over symbiose tussen planten en schimmels uit de voormalige Sovjet-Unie. De dataset bestaat uit 2970 plantensoorten van 155 plantenfamilies uit 154 plaatsen. De gegevens zijn essentieel omdat ze een belangrijke ecologische symbiose documenteren. De schimmel neemt water en voedingsstoffen uit de bodem op voor de plant en in ruil daarvoor geeft de plant suikers aan de schimmel. Deze symbiotische relatie wordt mycorrhiza genoemd. De symbiose is van groot belang: de meeste planten kunnen niet groeien zonder hun schimmel-partners, maar omdat het zeer arbeidsintensief is om te bestuderen is de aard van de symbiose bij de meeste planten in de wereld niet bekend.

Planten in verschillende klimaatzones begrijpen

Enkele bevindingen zijn gepubliceerd in een boek in het Russisch, maar de dataset zelf, alleen beschikbaar op papier, werd verstopt in de bijlage van een proefschrift verborgen in verschillende Russische bibliotheken. De gegevens werden nog slechter toegankelijk toen professor Selivanov in 1998 overleed. Nederlandse en Russische wetenschappers vertaalden en digitaliseerden deze enorme schat aan gegevens, zich bewust van het belang ervan voor de wetenschap. Het zal wetenschappers helpen om voeding en groei van planten in verschillende klimaatzones en de evolutie van deze bijzondere symbioses beter te begrijpen.

Namen van contactpersonen:
Hans Cornelissen/Nadia Soudzilovskaia/Will Cornwell
020-5986962 / 06-43051830 / 06-44567203


Glasnost even penetrates below ground: Dutch and Russian scientists give a new life to a huge Soviet-era ecological dataset

From 1950 to 1980 a Russian research team (University of Perm, Russia) under lead of professor Ivan Aleksandrovich Selivanov collected an enormous amount of data on plant-fungus symbioses from all across what was then the Soviet Union. The dataset includes 2970 plant species from 155 families in 154 sites. Together this is approximately equal to all of the data that had been collected outside the Soviet Union, and as such it is of tremendous value to scientists worldwide. 

These data are crucial because they document an important economic and ecological symbiosis.  The fungus acquires water and nutrients from the soil, and, in exchange, the plant provides the fungus with sugars. Together, the symbiotic relationship is called mycorrhiza. The symbiosis is of great importance: most plants cannot grow without their fungal partners; but because it is very laborious to study, the nature of the symbiosis for most of the world’s plants is unknown. 

Some of the findings were published in a book in Russian language, but the dataset itself, available only in paper form, was deposited in the appendix of a doctoral thesis hidden in several Russian libraries.  The data became even less accessible when Prof. Selivanov himself died in 1998.

The group of Russian and Dutch scientist including researchers from Moscow State University, VU University of Amsterdam and University of Perm, gave a new life to this dataset.  Recognizing its importance to the scientific community, they translated and digitized this huge data treasure. The modernized dataset will be published in the international ecological journal “Ecology” in 2012. It will help scientists to better understand plant nutrition and growth in different climate zones as well as the evolution of these special symbioses.

Hans Cornelissen / Nadia Soudzilovskaia / Will Cornwell
020 5986962/ 06 43051830 / 06 44567203



VU-ecologen: Toendravegetatie verandert sterk door klimaatsopwarming

April 2012

Een internationaal team van ecologen, waaronder Hans Cornelissen van de Vrije Universiteit Amsterdam, analyseerde voor het eerst op wereldschaal de gevolgen van klimaatsopwarming voor toendravegetatie. Deze veranderingen zijn belangrijk door de grote rol van toendravegetatie voor het vastleggen van koolstof op aarde. Vegetatie remt immers het broeikaseffect. De ecologen publiceerden hun bevindingen in het gerenommeerde tijdschrift Nature Climate Change.

Op 46 koude locaties vergeleken de onderzoekers hoe de afgelopen 30 jaar de belangrijkste plantengroepen in boomloze toendra veranderden. Dit deden zij door herhaalde metingen. De ecologen toonden aan dat de toendravegetatie over het algemeen hoger en dichter is geworden door de bijna overal sterk toegenomen struikvegetatie. Dit gaat ten koste van de kleintjes onder de planten, zoals mossen, die belangrijke zijn in koude en vaak natte gebieden.

De ecologen toonden bovendien in Ecology Letters aan dat ook bij kunstmatige toendraopwarming in veldexperimenten de struiken toenemen ten koste van mossen en korstmossen. Ook sluiten hun resultaten aan bij het grootschalige ‘opgroenen’ van de toendra door aardmetingen vanuit satellieten. Voor het goed voorspellen van de toekomstige toendravegetatie zijn ook regionale en lokale verschillen in bodem en klimaat belangrijk.

De onderzoekers ontdekten dat vooral in nattere gebieden en in de minder koude poolstreken de struiken sterk en evenredig toenamen met de mate van zomeropwarming. Ook maakte het veel verschil voor de vegetatieverandering  of de bodem al dan niet een permanent bevroren laag (permafrost) had.  Om vegetatieverandering in koude gebieden beter te kunnen voorspellen, bevelen de onderzoekers aan om met gestandaardiseerde methodes de vegetatieveranderingen te blijven meten en vooral in te zetten op de koude regio’s die nu nog slecht onderzocht zijn, zoals Siberië, Canada en Groenland.

Vegetatiemeting-april 2012-Hans

Hans Cornelissen meet toendravegetatie op in Noord-Zweden, een van de locaties in de wereldwijde analyse. Op de achtergrond zijn ‘dakloze’ tentjes te zien die de toendra opwarmen in een experiment dat gekoppeld is aan deze metingen.

Two papers on trait modeling in one issue in Ecography

April 2012
Photo Bob Douma

Last week, two related papers about plant trait modelling appeared in the same issue of Ecography. Douma en co-authors are the first to show the potential of plant traits in predicting vegetation distribution. They successfully developed a new vegetation distribution model that makes a functional link between the vegetation and environmental drivers by plant traits. In the first paper, Douma en co-authors explore which traits can best be used to distinguish vegetation types from each other. In the second paper, they explore other factors that determine model performance. Ecography (Volume 35, Issue 4, pages 294-305, 364-373).

Matty Berg - VARA's Vroege Vogels

April 2012

Matty Berg  featured on radio in a VARA’s Vroege Vogels  documentary (by broadcaster VARA on Radio 1) about the soil fauna of gardens, on April 1th. Gardens are more species rich in soil fauna than you might expect. Almost all major groups of soil fauna can be found in an average garden, such as isopods, millipedes, centipedes, many beetle families, fly larvae, earthworms, snails and slugs, spiders, daddy longlegs, and many more.  Most of these groups are present with many different species. There are plenty of possibilities to enlarge the diversity of soil fauna in your garden. For instance, by placing dead wood and stones along walls and in flower beds. Or stop mowing, litter removal, and hoeing. Species rich gardens have a high soil fertility and are disturbed as less as possible.[tt_news]=360065&tx_ttnews[backPid]=66&cHash=a69fefe7ddd16384c9b45681f7190676


Nabehandeling van RWZI-effluent?

March, 2012

Symposium RWZI-effluent-Waterharmonica

Symposium 15 jaar praktijkervaringen Waterharmonica

On Thursday March 29nd, a national symposium is organized on natural systems for the after-treatment of sewage effluent according to the “Waterharmonica” philosophy introduced by Ruud Kampf. Over the last years several of these systems have been laid out in the Netherlands and abroad (incl. Empuriabrava, Spain). The symposium will discuss the positive experiences gained, plus the latest developments, and will also include a site visit to the Waterharmonica system of the amusement park “Efteling”. The project was conducted under the auspices of STOWA, the association of collaborating water boards, which organizes the symposium at Kaatsheuvel.

For more information:


February 2012

Joris Koene - foto 2 FALW-bioloog Joris Koene schrijft mee aan boek over seksueel conflict
In een inleidend hoofdstuk geeft Koene opvallende voorbeelden uit het dierenrijk.

In The Oxford Handbook of Sexual Conflict in Humans hebben wetenschappers de gevolgen van seksueel conflict voor de mens voor het eerst overzichtelijk in kaart gebracht. VU-bioloog Joris Koene schreef een inleidend hoofdstuk met opvallende voorbeelden uit het dierenrijk.

“Seksueel conflict ontstaat doordat mannetjes een grote hoeveelheid sperma produceren terwijl vrouwtjes veel energie steken in een beperkt aantal eitjes,” legt Koene uit. “Daardoor zijn vrouwtjes selectief in hun partnerkeuze, terwijl mannetjes met hun sperma juist zoveel mogelijk eitjes willen bevruchten. Voortplanting is natuurlijk een gezamenlijke activiteit van beide seksen, maar evolutionair gezien betekent dat niet dat de belangen van beide overeenkomen. In het dierenrijk kan dat leiden tot bizar gedrag.”

Koene beschrijft hoe slakken ‘liefdespijlen’ op hun partner afvuren om te voorkomen dat hun sperma wordt afgebroken zodat de kans op bevruchting met dat sperma toeneemt. En hoe bedwantsen hun sperma onderhuids in de buikholte van een vrouwtje injecteren. Het sperma vindt uiteindelijk zelf zijn weg naar de eitjes. Daarmee omzeilen de mannetjes de selectie op spermacellen die normaal in het voortplantingsstelsel van de vrouwtjes plaatsvindt. Daarnaast komen ook conflicten rondom broedzorg en zwangerschap aan bod.

In 21 hoofdstukken leggen vooraanstaande experts in de evolutionaire psychologie en antropologie vervolgens uit welke gevolgen seksueel conflict heeft voor seks bij mensen. Onderwerpen die aan bod komen zijn jaloezie, echtelijke ruzie, seksuele intimidatie, de menstruatiecyclus, het vrouwelijk orgasme en de chemische oorlogvoering tussen sperma en het vrouwelijk geslachtsorgaan.

Schimmelkennis brengt risico’s gentech-gewassen in kaart

February 2012

Photo Erik Verbruggen Schimmelkennis brengt risico’s gentech-gewassen in kaart
Voor een goede plantengroei zijn plantenschimmels onontbeerlijk.

Onderzoeker Erik Verbruggen van de FALW-afdeling Dierecologie ontdekte dat fosfaat en grasklaver effect hebben op de diversiteit en variatie in soortensamenstelling van die schimmels. Zijn onderzoeksresultaten zijn bruikbaar om mogelijke risico’s van genetisch gemodificeerde gewassen voor de natuurlijke schimmelgroei in kaart te brengen.


Tachtig procent van alle planten op aarde leeft samen met mycorrhiza-schimmels. Deze schimmels groeien vanuit de wortels de bodem in, en helpen de plant met het opnemen van voedingsstoffen. De planten groeien hierdoor over het algemeen beter. Andersom profiteert de schimmel ook van de plant. Deze voorziet hem van suikers – het product van bovengrondse fotosynthese – die vanuit de plant naar de wortels stromen.

Ecoloog Erik Verbruggen ging op zoek naar factoren in landbouwvelden die invloed hebben op de schimmelsamenstelling. Doel was om in kaart te brengen wanneer er sprake is van verstoring van de natuurlijke variatie. De uitkomst zou bruikbaar moeten zijn bij het testen van mogelijke effecten van genetisch gemodificeerde gewassen op de schimmeldiversiteit en hiermee op de natuurlijke plantengroei.

Grote natuurlijke variatie
Allereerst legde Verbruggen de soortenrijkdom van mycorrhiza-schimmels onder verschillende omstandigheden vast. ‘Pas als je de natuurlijke variatie kent, kun je uitspraken doen over wat hiervan afwijkt’, legt hij uit. Onderzoek naar de diversiteit in plantenschimmels is in Nederland nog niet eerder zo grootschalig aangepakt. Verbruggen bestudeerde 23 biologische velden en evenveel gangbare velden met maïs of aardappelen, twee veel voorkomende gewassen in Nederland. In totaal kwam hij zo’n veertig schimmelsoorten tegen. De diversiteit lag in de biologische landbouw vijftig procent hoger dan bij de gangbare landbouw. ‘Dat klopt met eerdere studies’, zegt Verbruggen. ‘Maar in beide typen landbouwvelden kwam ik twee tot twaalf schimmelsoorten tegen. Dit betekent dat de natuurlijke variatie behoorlijk groot is.’

Fosfaat en grasklaver
Verbruggen onderzocht daarna welke factoren de schimmeldiversiteit bepalen. Fosfaat en vruchtwisseling kwamen als belangrijkste uit de bus. Hoe minder fosfaat in de bodem, hoe hoger de diversiteit. En ook het na elkaar telen van verschillende gewassen zorgt voor een grote variatie aan schimmels, met grasklaver als belangrijke stimulans voor de schimmelrijkdom. Verbruggen ontdekte dat gangbare landbouwvelden met een laag fosfaatgehalte en regelmatige verbouw van grasklaver toch een hoge diversiteit aan schimmels kunnen hebben. Dezelfde factoren zorgden er in beide landbouwvormen voor dat de ene schimmelsoort de andere niet ging overheersen, wat een teken zou zijn voor verstoring van het natuurlijk evenwicht.

Transgene mais
Deze studie biedt aanknopingspunten om mogelijke effecten van genetisch gemodificeerde gewassen op bodemschimmels te testen. Zelf deed Verbruggen een test met transgene maïs. Deze maïs had geen sterk verstorend effect op de soortensamenstelling van schimmels. In de toekomst kunnen dankzij meer schimmelkennis nieuwe gewasvarianten getest worden. Gentech-gewassen worden in Nederland niet voor commerciële doeleinden verbouwd, maar er zijn wel proefvelden en laboratoria die zich met de ontwikkeling van dergelijke gewassen bezighouden.

Verbruggen promoveert op donderdag 9 februari op zijn studie naar plantenschimmels, die hij uitvoerde in het kader van het onderzoeksprogramma Ecology Regarding Genetically modified Organisms (ERGO). Dit programma wil de ecologische kennis aanvullen die nodig is om te bekijken of de te verwachten ecologische invloed van genetisch gemodificeerde gewassen maatschappelijk aanvaardbaar is of niet. De vraag naar deze kennis komt voort uit het feit dat vóórdat een genetisch gemodificeerd gewas in Europa geteeld of verwerkt mag worden, een uitgebreide toelatingsprocedure moet worden doorlopen. Het onderzoeksprogramma wordt gefinancierd met FES-gelden. NWO-gebied Aard- en Levenswetenschappen heeft het programma opgezet en is verantwoordelijk voor de uitvoering ervan.

KNAW Grant for joint research with China

January 2012
China Grant-afbeelding 1 Ni hao? Hans Cornelissen and Will Cornwell obtained a KNAW (Dutch Royal Academy of Sciences) grant for a 3-year joint research project on ‘The Tree of Life of Carbon Cycling’ with Chinese partners. These partners are Professor Ming Dong and his team at the Institute of Botany in Beijing and Professor Kunfang Cao and his team at the Xishuangbanna Tropical Botanical Garden; both institutes belong to the Chinese Academy of Science. The project builds on the fruitful collaboration between Hans Cornelissen and Ming Dong over almost three years, and on Hans’ longer-term enthusiastic research links with China.

The joint work will focus on how evolutionary relationships between plant species are expressed in China Grant-afbeelding 2 their leaf characteristics (traits) and especially how these characteristics then determine whether the dead leaves (litter) of the different species are decomposed slowly or fast. How fast dead leaves are broken down in a certain standard soil environment is called ‘decomposability’. In this project the Chinese-Dutch team will do large experiments in which the litter decomposition rates of hundreds of species are compared simultaneously in ‘litter beds’. In Beijing and tropical Xishuangbanna hundreds of species of some groups of special interest are already rotting away happily and this spring Hans and Will will join their Chinese project partners to set up a large experiment on the litter decomposability of grasses and bamboos, the latter woody members of the grass family being a highlight of China’s flora.

China Grant-afbeelding 4 This work will also help us to reconstruct the role of different evolutionary plant groups (clades) in carbon cycling and climate in the past, going back as far as the time of the dinosaurs with its cycad palms, ginkgo’s and early flowering plants. Extensions of this approach, also part of this KNAW project, are fire experiments with multiple Chinese species, in our fire laboratory FLARE. By studying the flammability of different plant groups we hope to reconstruct the role of plants in fire regimes in the past, also very important for the carbon cycle and its effect on climate. Finally, with PhD student Andries Temme, the project will also study how Chinese species from different evolutionary groups grow and perform at low atmospheric CO2 concentrations of long gone eras; concentrations much below current levels and even much below those just before the Industrial Revolution. These experiments are done at Utrecht University, which hosts walk-in growth chambers with low, current and (future) high CO2 concentrations. China Grant-afbeelding 5

The KNAW grant, which will be supplemented by travel money from the Chinese Academy of Sciences, will pay mostly for frequent mutual research visits of a large Chinese-Dutch team for three years; and for running these experiments together. The presence of Chinese young and established researchers in our department has already been on the rise with CSC fellows and others joining both Systems Ecology and Animal Ecology, but this presence is set to increase even much more the coming years.

Novel method to compare long-term wood decomposition rates featured as ‘Editor’s Choice’ paper in centenary volume of Journal of Ecology

January 2012
News-Gregoire Freschet-sealing dead wood samplesA group of Systems Ecologists published a new rapid method to compare long-term breakdown rates of rotting tree logs of different species. They combined short-term dead wood incubations in a standard field environment with modelling. This way they could reveal how differences in wood characteristics (traits) of different tree species resulted in different ways and rates of breakdown (decomposition), without differences in moisture or temperature upsetting their comparisons. Because the paper was recognised as very novel as well as important and promising for understanding global carbon cycling, Journal of Ecology selected it as their show-piece paper to accompany its centenary celebration.

Photo: Gregoire Freschet sealing dead wood samples into litterbags

For details see

The importance of wood decay for the global carbon balance is widely recognized, as dead wood tends to rot slowly and therefore stores much carbon. When it builds up on the soil surface, it can also work as fuel and stimulate fire. Climate modellers find it important to incorporate dead wood accurately in their carbon cycling models. However they find it hard to separate the different factors that determine wood decomposition rates, as in the forest different tree species with different wood characteristics break down under different moisture and temperature conditions.  PhD student Gregoire Freschet together with James Weedon, Jurgen van Hal and supervisors Rien Aerts and Hans Cornelissen, successfully developed a rapid method involving (1) sampling wood from several decay stages for several species, (2) incubating these in the same field environment simultaneously for two years and then (3) using a new optimisation model to estimate the long-term decay pattern of each species.  This way they could show that coarse wood rotted at a rate that was specific for each species in subarctic North Sweden. They could also predict these species decomposition rates from the initial lignin contents and pH of the dead wood.  The new method can be applied to compare wood or other slow-rotting plant material among species anywhere and will greatly help our understanding of what drives wood breakdown in different regions of the world.

Freschet, G.T, J.T. Weedon, R. Aerts, J.R. van Hal & J.H.C. Cornelissen (2012). Interspecific differences in wood decay rates: insights from a new short-term method to study long-term wood decomposition. Journal of Ecology 100: 161-170.


Documentary on the already infamous new nature policies (Natuurwet)

December 2011

Rien Aerts - brandpuntRien Aerts featured prominently on television in a Brandpunt documentary (by broadcaster KRO) about the already infamous new nature policies (Natuurwet) announced by deputy minister Henk Bleker. Rien, together with colleague Professor Han Olff from Groningen University, argued convincingly that these policies would have disastrous consequences for nature and biodiversity in Holland. Although Bleker argues that his ‘nature policies are not barbaric', the effects of his deeds will prove him wrong. The problem is not only the overall drastic cuts in the budget for nature conservation schemes; he also wants to take nature areas away from organisations who have carefully managed them for decades, often with great benefits to biodiversity and people, millions of whom depend on the many important natural services of  these areas for their well-being.  Bleker thinks that simply abolishing much legislation and financial investment, and handing nature areas to private land managers like farmers, will not damage their nature value. However, as Rien Aerts argued, a green field with a horse in the middle and barbed wire around it is not the same as nature. He insists that the new policy would not lead to nature management but simply to nature demolition.

New edition of “An Introduction to Ecological Genomics”

November 2011

Cover Ecological GenomicsThe textbook “An Introduction to Ecological Genomics” saw its second edition this week. Nico and Dick have been working hard to update the first edition which was published in 2006. The few years that have elapsed since then have not only seen the introduction of next-generation sequencing technology, but as the publication of many excellent studies on comparative genomics, phylogenomics and population genomics. In the new edition, particular attention is paid to the frontiers created by these new fields. In a completely new chapter on “Variation and Adaptation”, an overview is given of the new field of population genomics, an area of increasing popularity among ecologists, The reader may also find an extensive discussion as to the issue of neutrality in molecular evolution. Are the evolutionary changes in genome structure mostly due to neutral processes, dependent on population size, or does the reach of selection include the genome? The new chapter has expanded the scope of the book to include a wide variety of topics of interest to evolutionary ecologists.

The book remains the first and only synthetic treatment of this new field of science, giving a comprehensive summary of genomics-based approaches to current ecological questions. The authors hope that the use of this book will support graduate programmes in ecology and evolutionary biology worldwide and will stimulate students to proceed their career in the exciting field of ecological genomics, while it is – still – relatively new.

Van Straalen, N.M. & Roelofs, D. (2012) An Introduction to Ecological Genomics. Oxford University Press, Oxford, 363 pp, ISBN 978-0-19-959469-6, £ 37,50

18th Benelux Congress of Zoology 2011

November 2011

Sexual conflict and behavioural traits: steps towards a mechanistic integration

logo BSC-symposium 2011During the 18th Benelux Congress of Zoology, Bram Kuijper (Univ. Cambridge, UK; Univ Groningen, NL) and Joris M. Koene (VU Univ. Amsterdam, NL) will be organising a session that is sponsored by the NVG. The session is titled ‘Sexual conflict and behavioural traits: steps towards a mechanistic integration’ and will be kicked off by keynotes given by Ted Morrow (Uppsala University, Sweden) and Kate Lessells (NIOO, Wageningen, Netherlands)
In brief, the session will revolve around the role of sexual conflict as a driving force in shaping behaviour, such as courtship and mating. By also encouraging focus on genetic and neurobiological architecture of behaviours associated with sexual conflict, the organisers hope to stimulate the integration of different disciplines and approaches used to address this topic. Contributions will span a broad range of biological fields dealing with reproductive behaviour and sexual conflict.

For more information:

Life Watch in the Netherlands

October, 2011

Life Watch-picture LifeWatch is an overarching research infrastructure for biodiversity and ecosystem data in Europe that builds upon existing networks. A consortium of 23 leading Dutch institutes with expertise in biodiversity research and eScience submitted a proposal to NWO, with the aim to establish the LifeWatch Research and Innovation Center in The Netherlands. This will allow The Netherlands to take on the scientific lead for LifeWatch Europe. Matty Berg, from the Department of Ecological Science, was appointed as the contact person for the VU University Amsterdam.

LifeWatch rests on three pillars within this domain: (i) developing smart methods to integrate and analyze existing data and new data generated by modern sensor systems, (ii) improving the digital accessibility of (public) research data in Europe, and (iii) designing solutions to sustain essential ecosystem services, complying with internationally agreed targets in this field. Researchers expect to be able to tackle scientific breakthroughs using LifeWatch on the complex relations between on the one hand the behaviour of organisms in a dynamic world, and biodiversity and ecosystem functioning on the other.

A decision about funding of the proposal is expected in January 2012.

For more information please see

Toby Kiers authors Science paper on the fair transfer of resources between plants and mycorrhizal fungi

August, 2011

Toby Kiers-Science paper-september 2011The interaction between plants and arbuscular mycohrrizal (AM) fungi is one of the world’s most abundant mutualistic interactions. The vast majority of terrestrial plants benefit of this interaction by increased nutrient and/or water supply while providing the associated AM fungi with carbohydrates. In contrast to mutualistic interactions where one host interact with multiple partners, plants and AM fungi form a complex network of interactions where plant and fungi simultaneously interact with different individuals. This increases the opportunity for “cheaters”, which exploit the benefits provided by others while avoiding the costs of supplying resources.
Toby and co-authors manipulated the associations between plants and more- and less-cooperative fungi and traced the movement of resources between the plant roots and fungi. They showed that both plants and AM fungi are able to detect, discriminate and preferentially reward cooperative partners in comparison to less-cooperative ones. The two-way control of the interaction ensures a fair transfer of resources, selecting against cheaters. The mutualism between plants and AM fungi is evolutionarily stable due to this “biological marked”, where higher quality services (resource transfer) are better remunerated in both directions.


The mighty reach of community ecology

July 2011

HAV-puzzelstukjeSymposium in honour of Herman Verhoef and his contributions to science.

Thursday, July 7th, 2011 - room D107
10.30 hrs-15.45 hrs

Programme of the symposium

Twee vrouwelijke FALW-onderzoekers ontvangen NWO Meervoud-subsidie

January 2011

Toby Kiers (Dierecologie) en Heidi de Wit (CNCR-NCA) hebben beide een subsidie binnengehaald uit het NWO-programma Meervoud, oftewel MEER Vrouwelijke Onderzoekers als Universitair Docent.

Met de subsidie van maximaal 340.000 euro kunnen Kiers en De Wit de komende vier jaar een eigen onderzoeksprogramma opzetten. Beiden hebben de garantie dat zij na afloop van het project doorstromen naar een UD of UHD positie. Met het programma MEERVOUD wil NWO de doorstroom van vrouwen naar hogere wetenschappelijke posities in de bètawetenschappen stimuleren. Vrouwen zijn namelijk nog altijd sterk ondervertegenwoordigd in de UD-, UHD- en hoogleraarrangen. In deze ronde werden in totaal 17 voorstellen ingediend. Van de drie gehonoreerde voorstellen zijn er twee afkomstig van de faculteit Aard- en Levenswetenschappenr. Toby Kiers, afdeling dierecologie: ‘Cooperation and antagonism in resource rich environments’

Kiers-Meervoud subsidieDe mutualistische samenwerking tussen planten en symbiotische schimmels is een van de oudste en belangrijkste ecologische interacties op aarde. Maar de beschikbaarheid van voedingsstoffen is de laatste eeuw wereldwijd sterk toegenomen. In potentie kan dit leiden tot een verschuiving van mutualisme naar parasitisme binnen deze interactie. Dit onderzoek is gericht op de vraag hoe parasitisme evolueert vanuit mutualisme wanneer beschikbaarheid van voedingsstoffen verandert. Dit onderzoek zal zo bijdragen aan onze kennis over hoe voedingsstoffen de evolutie van samenwerking beïnvloeden.

NWO Vidi grant for Toby Kiers

October, 2010

Toby Kiers-fotoToby Kiers has obtained a highly prestigious Vidi grant from the National Science Foundation (NWO) for her work on the evolution of mutualisms. This will allow her to reinforce her already very succesful line of research on plant-microbe interactions in soil. Mutalistic relationships between organisms (in which two or more partners benefit) are abundant in nature, but they pose a problem for evolutionary theory since they represent an opportunity for cheating. Toby will investigate what mechanisms stabilize the initial evolution of mutualisms in plant-fungi-fungivore interactions in the rhizosphere.

As a consequence of the Vidi grant, the faculty of Earth and Life Sciences has decided to offer Toby a tenure track position. We are extremely happy that Toby will be able to establish her own group within the department.

Joris Koene live in NCRV's "On Air"

July, 2010

Koene-in-On-AIRHow do snails have sex? Joris Koene, the Dutch snail expert tells all about it live in NCRV's "On Air", which broadcasts on national television (Ned. 3). He just returned from a large international congress about molluscs that was held in Thailand, where he presented the latest findings of his research on snail sex.

You can watch the rerun at

VSB grant awarded to Oscar Franken

June, 2010

Kenya-Oscar Franken

Congratulations to master student Oscar Franken. He was awarded a grant from the VSB Fund 2010 to start, after his master graduation this summer, on a new project at the Mpala Research Centre located in the Laikipia District, central Kenya. Together with Dr. Toby Kiers and Dr. Todd Palmer, Oscar will travel to Kenya in December to begin the project which is entitled: Linking aboveground herbivory to below-ground ecosystem functioning in an African savannah.

Bertanne and Jacintha publish LOL in PNAS

May, 2010


When Bertanne started her PhD it was still a hypothesis, but her recent paper published in the prestigious journal Proceedings of the National Academy of Sciences shows that it is now a fact: the majority of adult parasitoid insects is incapable of de novo lipid synthesis.

Bertanne and Jacintha collected data on lipid biosynthesis for 94 species of insects, partly from the literature, and partly from newly conducted experiments. Phylogenetic analysis of these data showed that evolution of lack of lipogenesis is concurrent with that of parasitism. Environmental compensation, in this case the provision of lipids from the host, has allowed the loss of this seemingly essential trait without negative fitness consequences.

Photograph by Tibor Bukovinszky (, showing the hyperparasitoid wasp Gelis agilis (Ichneumonidae: Cryptinae)

Visser, B., Le Lann, C., Den Blanken, F.J., Harvey, J.A., Van Alphen, J.JM. & Ellers, J. (2010). Loss of lipid synthesis as an evolutionary consequence of a parasitic lifestyle. PNAS, doi 10.1073/pnas.1001744107


Simultanously Hermaphroditic Animal Meeting held at Animal Ecology group

11-12 February, 2010


A group of European scientists convened at the VU University for a workshop on the measurement of sexual selection in hermaphroditic animal species, organised by Joris Koene and Jeroen Hoffer of the Animal Ecology group of VU University. Hermaphrodites combine the two sexes in a single individual and therefore complicate the determination of the relative advantage of mating in either sexual roles. As this was the second Simultaneously Hermaphroditic Animals Meeting (SHAM, previously held in Montpellier, France) a new framework is developing to deal with the experimental and statistical problems associated with hermaphrodite male and female fitness. Importantly, the first experimental results were presented by groups from Nils Anthes (Germany) and Benjamin Pelissie and Patrice David (France). The informal setting also allowed to freely discuss ideas and important future topics. The success of these meetings will soon condense into a multi-authored paper, where achieved insights will be shared with the wider scientific community. All in all, participants considered the workshop highly enjoyable and everyone agreed to meet again next year in Basel, Switserland.

Community Ecology book published

February, 2010

Community Ecology-book

A new textbook on community ecology, edited by Herman Verhoef and Peter Morin was published by Oxford University Press. The book arose out of a course that was held in the Ph.D. programme of the SENSE Research School. A selection of the lecturers had developed their course contribution into a written text, and these texts, illustrated by many examples and graphs, together make up a state-of-the-art textbook for the rapidly progressing field of community ecology. In addition to a chapter by Herman on trophic dynamics of communities the book contains contributions by Matty Berg, Jacintha Ellers, Toby Kiers and Marcel van der Heijden, along with several international colleagues. The book emphasizes the importance of spatial and temporal scales as well as applications to emerging problems in human-dominated ecosystems. Also, the relationship between evolutionary and community ecology is discussed. The beautiful cover designed by Janine Mariën adds to the book attractiveness.

Verhoef, H.A. & Morin, P.J., eds. (2010).Community Ecology. Processes, Models, and Applications, pp 247. Oxford University Press, Oxford.

Bas Bruning hits the media with Australian toad

January, 2010

Toad-Bas BruningUnder the appealing title: “Turgid female toads give males the slip” VU master student Bas Bruning wrote a paper appearing in Biology Letters (doi: 10.1098/rsbl.2009.0938) about his work in Australia, at the university of Sydney (with Ben Phillips & Richard Shine). The work attracted a lot of media attention in the Netherlands.

Bas showed that females of the giant cane toad, Bufo marinus, can select the biggest and strongest males by inflating their body when in amplexus. A series of elegant experiments demonstrated that males differ in their capacity to hold on to females and that the male most likely to fertilize the eggs is the one holding on longest when the females makes herself as big as possible. This very simple physical mechanism of anuran mate choice, overlooked until now, may reflect the fact that females may co-opt already existing defensive traits for use in sexual selection.

Folsomia eggs require Wolbachia to develop

January, 2010

Plaatje Folsomia eggs require WolbachiaA recent paper by Martijn Timmermans and Jacintha Ellers published in Evolutionary Ecology, has shown that Folsomia eggs do not hatch if the females are cured of Wolbachia by application of the antibiotic rifampicine. Q-PCR screens for the Wolbachia-specific ftsZ gene showed that indeed Folsomia does not contain Wolbachia anymore after a diet with 1% rifampicine. This does not affect the size of a clutch, but suppresses any development of the eggs. With subsequent clutches the hatching rate increases again, which is in accordance with the bacterial dosage model, which argues that a certain number of cells is necessary for the biological effects of Wolbachia to become expressed. The study suggest that Wolbachia infection of the Folsomia egg is essential to initiate its development, a wonderful demonstration of the intricate evolutionary relationship between a parthenogenetic animal and its endosymbiont.

Timmermans, M.J.T.N. & Ellers, J. (2009) Wolbachia endosymbiont is essential for egg hatching in a parthenogenetic arthropod. Evolutionary Ecology 23: 931-942.

Egg of Folsomia candida in anaphase of tissue differentiation. Photograph from Y. Gao et al. (2006) Preliminary observations on the egg development of Folsomia candida (Collembola: Isotomidae). Zoological Research 27(5): 519-524.

Do humans still evolve?

October, 2009

Foto-Do humans still evolveOn October 9th, VU Connected organized a symposium in the NEMO theatre in Amsterdam, under the title: "The future of mankind". After presentations by Steph Menken, Jacintha Ellers, Cor Zonneveld and Mark van Vugt, two first-year students of Biomedical Science gave a lecture. They had just completed Nico's course Diversity and Evolution in which they had composed an essay about the question "Do humans still evolve?" Joske Ubels argued that humans indeed evolve, but that evolution is mostly limited to cognitive abilities, while the human body will degrade. She based her argument on evidence for heritability of intelligence and preferences in the human population for intelligent partners. Iris van Blitterswijk argued against the thesis of the London geneticist Steve Jones who had stated in 2008 that human evolution has reached the end of the line. Iris showed in three convincing examples that evolution in fact is still going on. The presentations by the two young students were greatly appreciated by the audience and a lively discussion followed.

On the photograph from left to right: Mark van Vugt (Psychology, VU), Koos Neuvel (VU Connected), Nico van Straalen (FALW), Iris van Blitterswijk, Joske Ubels, Steph Menken (University of Amsterdam), Cor Zonneveld (Amsterdam University College).

Public outreach in the Darwin year 2009

 June, 2009

Omslag Caleidoscopische ogen

As a consequence of the Darwin year 2009, the theory of evolution has attracted a tremendous attention. These months, Nico van Straalen has been very busy giving lectures on evolution for a variety of audiences. This was also stimulated by the publication of a booklet entitled "The girl with kaleidoscope eyes", a collection of Nico's newspaper columns over the years 2007 and 2008 (in Dutch: "Het meisje met caleidoscopische ogen"). Janine Mariën designed the cover for this book. In the series "Letters to Darwin", appearing in the national newspaper Volkskrant, Nico argued that the enormous attention for Darwin has a negative side-effect: the general public may get the impression that everything about evolution was already stated by Darwin. In fact it is only now, after the genomics revolution, that we are gaining insights into the molecular networks that relate genes to phenotype. Including genomics, developmental biology and epigenetics into evolution is necessary to understand why species evolve. Nico also argues that natural selection may not always be the most important factor in macro-evolution. To explain why body plans have changed, we must understand the tinkering in the genome, in addition to the selective forces in the environment.

Soil fauna on the map

 March, 2009

Verspreidingsatlas: M.P. Berg

On Saturday February 28th, Matty Berg gave a lecture on the distribution of soil fauna in the Netherlands at the annual meeting of the European Invertebrate Survey, division the Netherlands (EIS-NL). The reason for this lecture was the publication of the new distribution atlas (see photo) on Dutch isopods, centipedes and millipedes. The atlas brings together more than 43.800 records of 132 species of soil fauna and it describes the distribution and ecology of each of these species. The exact locations where species have been recorded are visualized by distribution maps, in relation to the four major soil types that occur in the Netherlands. Preceeding the species descriptions, chapters are included with basic information on the biology of isopods and myriapods, how and where to collect species, how to identify them, how to distinguish adults from juveniles, and males from females. These chapters are beautifully illustrated with drawings of various species made by Hay Wijnhoven. The first copy of the atlas was presented to Wim Dimmers, who is one of the most productive surveyors on soil fauna in the Netherlands, for the last decade. He contributed with many records to the atlas and kindly accepted a copy of the book, on behalf of all the 454 surveyors that have submitted records on soil fauna to the database since 1880. A copy of the new atlas (see below) can be purchased via EIS-NL (see, for the amount of € 12.50.
Title: Verspreidingsatlas Nederlandse landpissebedden, duizendpoten en miljoenpoten (Isopoda, Chilopoda, Diplopoda).  (In Dutch). Authors: Matty P. Berg, Martin Soesbergen, David Tempelman, Hay Wijnhoven (2008) Stichting European Invertebrate Survey – Nederland, Leiden & Vrije Universiteit, Afdeling Dierecologie, Amsterdam, 192 pp, ISBN 978-90-76261-07-2.

Discussion panel on animal experiments

January 8th, 2009

 Forum Dierproeven-1.1
On January 8th, the department organized a discussion panel on ethical issues associated with animal experiments for students in the course "Regulation and Defence in Animals". A member of parliament for the Animal Rights Party (PvdD), Esther Ouwehand, participated in the panel. The aim of the discussion was to increase awareness among biology students of ethical considerations associated with fundamental and applied research using animal experiments. Esther Ouwehand said that she wanted to further tighten the (already rather strict) regulation associated with animal experimentation for scientific purposes, including the use of invertebrates. Students asked questions on the safety testing of drugs, the use of products with chemical ingredients tested on animals, the availability of alternatives, etc. The discussion, chaired by Prof. Tjard de Cock Buning (Athena Institute), was very lively and attracted several faculty from outside the course. It helped to sharpen each student's personal opinion on the use of animal experiments, as part of developing a professional attitude as a biologist.

On the photo from left to right: Oliver Stiedl (VU University, Center for Neurogenomics and Cognitive Research), Bas Blaauboer (Utrecht University, Institute for Risk Assessment Sciences), Paul van Soest (VU University, Ethical Commission for Animal Experiments), and Esther Ouwehand (Member of Parliament, Animal Rights Party).

MuSA workshop attracts broad international participation

September 22 and 23, 2008

On September 22 and 23 the department organized a workshop on multiple-scale assessment of contaminated sites. The idea of the workshop was that two presently divergent fields of scientific activity, life-cycle impact assessment and ecological risk assessment, can learn from each other. The workshop discussed possible linkages between these two fields under four different topics: spatial differentiation of impacts, biodiversity assessment, ecotoxicity, and long-term mobility of trace metals. There was a remarkably broad international attendance; 13 different countries were represented among 32 delegates. This is illustrative of the widely felt urgency of finding new solutions for dealing with contaminated land, a problem which is high on the agenda not only in the Netherlands, but in many places elsewhere.
The workshop marked the end of the MuSA-project, which was sponsored by the European Snowman initiative. Hélène Beauchamp from our department, and Jerôme Payet from SETE MIP-Environnement have been working hard for about a year to explore a possible mariage between life-cycle impact assessment and ecological risk assessment when evaluating management options for contaminated land.

Toby Kiers authors Science paper on agricultural development

23 April, 2008

Toby-science.jpgIn the Science issue of 18 April (vol. 320, pp. 320-321), Toby Kiers has published a Policy Forum paper on "Agriculture at a crossroads". The paper came out of her work for the International Assessment of Agricultural Science and Technology for Development (IAASTD), a panel installed by the United Nations to address the challenges faced by agriculture to meet the needs of humanity now and in the future. The assessment found that changes in governance, development and delivery of science and technology are required to achieve an equitable distribution of agricultural benefits and a reduction of negative environmental impacts (eutrophication, pesticide contamination and loss of local crop varieties). Toby argues that agricultural science and technology must be redirected to develop concrete approaches that will capitalize on human ingenuity, farmer innovation, strengthening of rural communities and market access. The new path of development can be achieved using relatively simple technologies. Interestingly, the IAASTD assessment does not completely reject genetic modification of crops but demonstrates that GM crops may be appropriate in some contexts, although unpromising in many more. The discussion on GM crops is a timely issue in The Netherlands since the start of a national programme, supported by NWO, on "Ecology regarding genetically modified organisms" (ERGO), in which the department participates.

Hexapods monophyletic after all

18 March, 2008

Hexapoda.jpgIn recent years, uncertainty on the monophyly of Hexapoda has arisen after mitochondrial markers showed that crustaceans are more related to insects than six-legged collembolans are. Using the Folsomia candida EST data that is available on, we reassessed the position of Collembola. Our phylogenetic analyses clearly support a placement of Collembola in-between the Crustacea and Insecta. This suggests that Hexapoda is monophyletic after all (Timmermans et al., 2008, BMC Evolutionary Biology, 8: 83).

Joris Koene wins Zoology Prize 2008

29 January, 2008

JorisZoologyJoris M. Koene is the 2008 winner of the Dutch Zoology Prize of the Royal Dutch Zoological Society (KNDV). Joris receives the prize for his integrative research on sexual selection and sexual conflict in hermaphroditic animals. His research on pond snails has been very productive over the last years and has led to several exciting discoveries on the private life of these molluscs. For example, the so-called Coolidge effect, which refers to resurgence of sexual motivation in males when confronted with not-yet mated females, also holds for Lymnaea stagnalis (BMC Evolutionary Biology 7, 212, 2007).

The Zoology prize is awarded annually by an independent jury installed by the KNDV. Besides the honour and the encouragement to continue the work, the prize also consists of a sum of money. The prize will be presented in the spring during a symposium organized for this occasion by the winner and the KNDV.

50th Ph.D. thesis by Marina Bongers

19 December, 2007

Bongers-thesisOn December 18th, Marina Bongers defended her Ph.D. thesis on mixture toxicity of heavy metals to Folsomia candida. Counting from 1986, when our records started, this is the 50th thesis of the department of Animal Ecology.

Marina's thesis contains an extensive and detailed analysis of interactions between the heavy metals lead, zinc, copper and cadmium. Interactions were analysed in the soil itself, where they compete for binding places, in their uptake kinetics, where they compete for biotic ligands, and in their toxic action, where they influence each other's binding to targets and detoxification mechanisms.

In contrast to what most people think, metals do not always show simple interactions, such as additivity, in their action on biological targets. The same combination of metals may show a variety of combination effects, varying from antagonism to synergism, depending on the concentration of each metal and their relative proportions in the mixture. Marina also showed that the anionic moiety added when metal salts are spiked to soils must be removed by percolation before a correct analysis of metal mixture toxicity can be made.

Marina's work is another hallmark in the continuously high productivity of the ecotoxicology group headed by Kees van Gestel.

Marcel van der Heijden leaves the department

19 November, 2007

MarcelLeavesOn November 9th, Marcel van der Heijden held his farewell party (see photo). He has accepted a job at Agroscope, in Zürich, Switzerland. Marcel was in the department of Animal Ecology for about two years, following a re-organisation of the Institute in 2004. In this relatively short period he expanded his active research group, involving two PhD students (Susanne de Bruin and Erik Verbruggen), a post-doc (Toby Kiers) and a technician (Ludo Luckerhoff). His research enjoying world-wide reputation, he also attracted several students from abroad. Marcel's research is focused on the ecological significance of symbiotic soil organisms for ecosystem functioning and biodiversity. Luckily, we will keep contact with Marcel, because he remains officially appointed at VU University for 0,05 full-time equivalents. In this way we ensure able supervision, albeit from a distance, of the ongoing mycorrhyza projects.

14th Benelux Congress of Zoology at VU

5 November, 2007

BeneluxCongressJoris, Desirée, Jacintha and Nico have been busy over the last months in organizing the 14th Benelux Congress of Zoology on 1 and 2 November. This conference is held annually, on behalf of the Royal Dutch Society of Zoology, in collaboration with the Belgian and Luxemburg sister organisations, alternately in The Netherlands and in Belgium. The Amsterdam meeting attracted 181 delegates.

Behavioural ecologist Geoff Parker was awarded as the "Distinguished Zoologist 2007". In his lecture on Thursday evening Parker gave a caleidoscopic overview of his work on sexual conflict and sperm competition, analysed using game theory and the concept of evolutionary stable strategies. Parker's models have inspired a whole generation of experimental ecologists, including students of Jacintha's course Evolutionary Behavioural Ecology at Schiermonnikoog.

Other plenary lectures at the meeting were given by Patricia Beldade (Leiden University), Mike Ryan (University of Texas, Austin), and Jaap Koolhaas (Groningen University).

In his opening address Nico emphasized that exciting developments are taking place in modern animal biology. As an example he pointed out the genomic analysis of model species, which allows new insights in the adaptation of animals to their environment. Also new phylogenetic splits between the main lineages of invertebrates are being revealed by comparative genomics.

The 14th Benelux Congress of Zoology was a stimulating event with many high-quality presentations. Four prices were awarded for the best PhD en MSc oral and poster presentations (Marnix Gorissen from Radboud University Nijmegen, Hans Peter Vandersmissen from Catholic University Louvain, Fana Michilsen from the University of Antwerp and Judith Sitters from Wageningen University).

See also

Official launch of Collembase: An online repository for soil quality testing

25 September, 2007

LaunchingCollembaseIt is generally accepted in the scientific literature that genomic tools can be particularly valuable for environmental risk assessment. Recent developments in toxicogenomics suggest that pollution and environmental quality can be assessed by transcriptional profiling.

We proudly present new genomics-based tools for the Collembolan Folsomia candida (genome sequences and oligonucleotide microarray) that can be used to achieve a significant acceleration of soil quality risk assessment.

The Collembase-website ( was officially launched on September 25, 2007, and details are published in BMC Genomics (Timmermans et al., 2007).

Mohamed Khalil investigating oribatid mites

2 July, 2007

MohamedAnimal ecologist Mohamed Khalil from Tanta University, Egypt, came to visit our department for half a year. We have a special link with Tanta, since Mohamed worked here between 1992 and 1994 as part of his PhD. Later a colleague of his, Hala Abdel-Lateif, followed the same scheme. In the present project Mohamed samples a range of metal-polluted sites in France, Belgium, Germany and The Netherlands, to assess the effects of soil pollution on oribatid mite community structure.

Several literature sources suggest that oribatid mites are one of the most sensitive groups of arthropods as regards heavy metals, and this is confirmed by experiments with Platynothrus peltifer conducted earlier in our departement. However, only very few studies have been done on oribatid mite communities in metal gradients, which is due to the formidable taxonomic problems that this group poses to the non-specialist. Prof. Khalil, being an expert on oribatid mite identification and ecology is thus conducting one of the first large-scale surveys of soil arthropod responses to heavy metals, in which all mites are identified to species.

The presence of Mohamed Khalil did not remain unnoticed in the university; he was interviewed for the personnel magazine (25 June 2007), and portrayed as an example of somebody contributing to the multinational character of the VU (see photo).

Bilobella aurantiaca, a species from South-East Europe, found in the Netherlands

16 May, 2007

BilobellaAurantiacaIn his backyard in Westzaan Matty Berg found a species of springtail that has never been recorded in the Netherlands or even North-West Europe before, Bilobella aurantiaca (family Neanuridae). The springtails were thriving under tree-bark of an old popular trunk, in a layer of rotting faeces of woodlice, millipedes and earthworms. They were present with numerous juveniles as well as adults, so they clearly represented a viable population, not a rare case of immigration. The animals are very conspicuous and beautifully coloured (see photograph, made by Theodoor Heijerman). When Matty presented his find in the department's weekly meeting, Nico van Straalen admitted that among the prettiest springtails of the country, Bilobella aurantiaca comes close to his favourite, Orchesella flavescens.

A remarkable aspect of Matty's discovery is that B. aurantiaca has a typical South-East European range of distribution. The closest records are from the Balcan and Switzerland in the east and Italy, Spain and Portugal in the south. This illustrates that surprises are always around the corner in biogeography of soil invertebrates. It also shows how incomplete our present knowledge may be. Matty is working with the European Invertebrate Survey and Naturalis National History Museum to obtain updated overviews of the distribution of invertebrates, many of which presently show highly dynamic range shifts due to climate change.

Noted added (December 2009): Later investigations have shown that this
species is not Bilobella aurantiaca, but Bilobella braunerae. See Berg,
M.P. (2009) De springstaarten van Nederland: het genus Bilobella, nieuw
voor de fauna, en Neanura (Hexapoda: Entognatha: Collembola). Nederlandse
Faunistische Mededelingen 31, 101-112. 

New equipment for compound-specific stable isotope analysis installed

5 March, 2007

isotopeMSRecently the facilities of the department have been extended by the installment of an isotope ratio mass spectrometer, equiped with a gas chromatograph and a pyrolysis unit, designed to measure stable isotope ratios in fatty acid fractions of small animals. The equipment is operated by Dr. Roel Pel, formerly working at the Netherlands Institute of Ecology, who joined the department as a guest researcher by September 2006. Installation of the apparatus and its fixtures was completed in January 2007; the system is now operational. Compound-specific isotope ratios represent a dual chemical/isotopic signature indicative of the trophic position of an animal and so can be used to unravel food-webs. Another application is the analysis of adaptive responses to cold, which is often accompanied by changes in membrane lipid composition.

Another landmark in the VU-Indonesia collaboration

19 december 2006

ThesisRullyRully Adi Nugroho presents his PhD thesis on December, 21st, supervised by Herman Verhoef, Wilfred Röling and Anniet Laverman. After Bintoro Gunadi, Budhi Prasetyo, Budi Widianarko and Agna Krave, this is the fifth PhD thesis defended at the Faculty of Earth and Life Sciences, as an outgrowth of the collaboration between the Vrije Universiteit and its Indonesian sister university, Universitas Kristen Satya Wacana in Salatiga, Central Java. Two more projects are ongoing and are likely to lead to a PhD thesis defence in 2008. The collaboration between VU and UKSW in the field of biology dates back to 1989 and has been particularly fruitful over the years. Numerous MSc students have been exchanged and various staff members have paid short visits to the other university. Rully's thesis is evidence of a common field of interest, the intriguing biodiversity of soils, be it tropical or temperate. Rully's thesis focuses on ammonia oxidizers and unravels the community of microorganisms using modern molecular methods. There is a complex relationship between the diversity of this community, the dominant environmental factors and the overall rate of nitrification. The complexity of interactions explains why some soils do and some soils don't nitrify.

Search for Anurida at Apterygota seminar

11 September, 2006

AnuridaFrom August 27 to 30 Matty Berg, Kees van Gestel and Nico van Straalen organized the VIIth Apterygota seminar. This meeting is one of a series running over nearly three decades now. It is a meeting place for taxonomists, ecologists and evolutionary biologists who share their latest research on wingless hexapods (Protura, Diplura, Collembola, Microcoryphia and Zygentoma). The meeting was hosted by the Royal Netherlands Institute for Sea Research (NIOZ) on the island of Texel, and the PR staff of this institute took active part in the organization. One of the programme items was a field excursion into the mud slacks and dune ecosystems of the island. While most of the days had been cloudy and rainy, the excursion took place under a clear sky. When the company approached the sea-side hundreds of Anurida maritima were exposing themselves on the boulders and in the flood-mark. This springtail is one of the few truly salt-adapted hexapods. Later in the dunes many Podura aquatica were seen floating on freshwater pools. So the seminar not only staged the latest scientific presentations on Apterygota but also offered the opportunity to collect some of the typically Dutch Collembola from the wild.

Students discover high acute toxicity of Citronella oil to springtails in a school practical at the VU

31 May, 2006

CitronellaA few weeks ago Nico van Straalen was called by a national newspaper, The Volkskrant, and was asked for advice on a case of swarming Collembola on somebody's roof. A woman had complained that swarms of springtails developed on her flat roof; the animals (probably Bourletiella spp.) entered the house through ventilation slits. Nico recommended to clean the roof, remove plants and moss and rake the pebbles. However, a spokesman from Wageningen University advised differently and recommended application of Citronella oil to the ventilation slits. This product would act as an insect repellent. The issue was put to the test by BSc students Marcel Deken, Jeroen Castricum and Oscar Franken, who in that week happened to organize a practical for a secondary school class to the VU. The students compared Citronella oil with three other citrus products in preference carousels. They discovered that Citronella oil is acutely toxic to Collembola: Orchesella cincta died within a few seconds after coming into contact with a substrate to which one droplet per 4 g of sand was added. The same dose of freshly pressed lemon juice was not avoided, even preferred in most cases. However, bottled lemon juice was avoided by the springtails. The best repellent effect was seen with a cleaning product called Citronell. The experiments clearly show that for Citronella oil, it is not the repellent effect of the lemon smell that causes an effect on springtails, but some highly potent toxin. Citronella oil appears to be not a citrus product at all, but an extract from Cymbopogon citratus, a medicinal herb from South-East Asia with lemon fragrance and often used in Thai kitchen. Extracts from this plant contain a great variety of secondary metabolites, including several terpenoids, but the nature of the toxin remains unknown to date. Anybody who knows about toxicity of Cymbopogon extracts to insects, please let us know.

Book on Ecological Genomics presented

8 March, 2006

GenomicsBookCover.jpgOn Wednesday March 8th Nico van Straalen and Dick Roelofs launched their new book "An Introduction to Ecological Genomics", published by Oxford University Press (see The event was witnessed by some 60 people, after which a reception was held in Wim's inn.

Prof. Pier Vellinga, dean of the faculty of Earth and Life Sciences, Prof. Paul Brakefield (Leiden University) and Prof. Louise Vet (Netherlands Institute of Ecology) held introductory talks and praised the book, after which Nico handed out the first three copies. The "very first" copy was presented to Janine Mariën, who designed the cover and was praised for her marvellous artwork. The cover shows a fantasy world of biodiversity seen through the spots of a microarray scan. Janine's beautiful artistic rendering contributes greatly to the attractiveness of the book. The "really first" copy was presented to an "average student", because the book is going to be used in the MSc programme Ecology. Smiling Eva Krab, actually not an average student at all, kindly accepted a copy of the book. The "definitive first" copy was presented to an "average tax payer", because, as Nico argued, universities are ultimately supported by the tax payer. Hans Breeuwer, evolutionary biologist at the University of Amsterdam, was picked from the audience and accepted the definitive first copy. Now we are looking forward to the first reviews!

Dr. Jacintha Ellers appointed professor

1 December, 2005

ProfJacintha.jpgAs off 1 december 2005 Dr. Jacintha Ellers was appointed professor of Evolutionary Ecology. A special set of four chairs was installed on the occasion of the 125th anniversary of the Vrije Universiteit, to promote equal opportunities for men and women in leading positions. The chairs, allocated for female excellence in the different facultiews are named after Fenna Diemer-Lindeboom (1912-2004), a prominent fighter for female rights in protestant circles.

Jacintha develops a research programme on evolution of life-histories in variable envrionments, with emphasis on the role of phenotypic plasticity.

(Picture by Marijn Alders)