Novel method to compare long-term wood decomposition rates featured as ‘Editor’s Choice’ paper in centenary volume of Journal of Ecology
A 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
http://www.journalofecology.org/view/0/edchoice1001.html
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)
Rien 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
The 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
http://ukcatalogue.oup.com/product/9780199594696.do
18th Benelux Congress of Zoology 2011
November 2011
Sexual conflict and behavioural traits: steps towards a mechanistic integration
During 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: http://www.zoology2011.com
Life Watch in the Netherlands
October, 2011
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 www.lifewatch.eu
Toby Kiers authors Science paper on the fair transfer of resources between plants and mycorrhizal fungi
August, 2011
The 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.
http://www.sciencemag.org/content/333/6044/880.full.pdf
The mighty reach of community ecology
July 2011
Symposium 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’
De 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 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
How 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 http://onair.ncrv.nl
VSB grant awarded to Oscar Franken
June, 2010
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 (http://www.bugsinthepicture.com), 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
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
Under 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
A 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
On 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
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
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 http://www.naturalis.nl), 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
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
In 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
In 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 http://www.collembase.org/, 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
Joris 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
On 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
On 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
Joris, 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 http://www.beneluxcongress.com/.
Official launch of Collembase: An online repository for soil quality testing
25 September, 2007
It 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 (http://www.collembase.org/) 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
Animal 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
In 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
Recently 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
Rully 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
From 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
A 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
On Wednesday March 8th Nico van Straalen and Dick Roelofs launched their new book "An Introduction to Ecological Genomics", published by Oxford University Press (see http://www.oup.co.uk/isbn/0-19-856671-9). 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
As 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)
