Geert de Snoo



My aim is to contribute to science-based conservation of biodiversity in human-dominated landscapes


Geert de Snoo is director of the Netherlands Institute of Ecology of the Royal Netherlands Society of Arts & Sciences (NIOO-KNAW). He is also full professor of Conservation Biology at the Institute of Environmental Sciences (CML) of Leiden University.

His two main lines of research are:
- The effects of land use change on biodiversity and ecosystems. Here his focus is on nature conservation on farmland. How can we contribute to ecological recovery and transition to sustainable land use? Not only the impact of landscape elements, such as field margins, on biodiversity is examined, but also the socio-economic aspects are discussed.
- The impact of contaminants on biodiversity and ecosystems. More specifically, his focus is on the side effects of pesticides in both terrestrial and aquatic environments on invertebrates and vertebrates.
More recently, the conservation of large predators in human-dominated landscapes and the interaction between humans and wildlife have been added to his research portfolio.

Geert de Snoo studied biology at the Free University in Amsterdam and then became a researcher at the Centre of Environmental Sciences (CML) of Leiden University. During his PhD he investigated the potential of unsprayed field margins for enhancing environmental quality, promoting biodiversity and implications for agricultural practice. After his PhD, De Snoo acquired various grants from NWO, the EU, governments and the private sector. In 2003 De Snoo became a special professor in the field of nature conservation on farmland at Wageningen University. Since 2009 he is professor of Conservation Biology at Leiden University. So far, De Snoo has supervised about 35 PhD students.

Administrative positions:
Currently, De Snoo is member of the board of the Centre of Excellence for Netherlands Biodiversity Research. A combined research initiative of the Netherlands Institute of Ecology, Naturalis Biodiversity Center, the Royal Netherlands Institute for Sea Research and Westerdijk Fungal Biodiversity Institute. He is member of the Dutch Council on Animal Affairs, the independent council for multidisciplinary issues in the field of animal welfare and health for the Minister of Agriculture, Nature and Food Quality. He is chair of the supervisory board of Netherlands Centre for One Health (NCOH).

From 2012-2019 De Snoo has been Dean of the Faculty of Science of Leiden University. Between 2009 and 2012, he was Director of the Centre of Environmental Sciences at Leiden University. For five years he was member of the Board for the Authorisation of Plant Protection Products and Biocides (Ctgb).



  • 2019–Present
    Director Netherlands Institute of Ecology (NIOO-KNAW)
  • 2009–Present
    Professor Conservation Biology at the Institute of Environmental Sciences, Leiden University
  • 2012–2019
    Dean of the Faculty of Science, Leiden University
  • 2009–2012
    Director of the Institute of Environmental Sciences, Leiden University, and head of the Department of Conservation Biology
  • 2003–2012
    Professor, special chair Nature Conservation on Farmland, Wageningen University, Department of Nature Conservation and Plant Ecology
  • 2000–2008
    Associate professor and head of the Department of Environmental Biology of the Institute of Environmental Sciences, Leiden University
  • 1994–2000
    Assistant professor at of the Institute of Environmental Sciences, Leiden University, head of the Section Ecosystems and Environmental Quality
  • 1996–1997
    Postdoc NWO-STIMULANS-grant
  • 1990–1994
    Qualified researcher NWO, PhD project
  • 1986–1990
    Researcher at the Institute of Environmental Sciences at Leiden University


  • 1990–1995
    PhD Environmental Science, Leiden University, Leiden
  • 1979–1986
    MSc Biology (Ecology / Ecotoxicology), Free University, Amsterdam



Peer-reviewed publicaties

  • Ecological Indicators

    Distribution of ground-dwelling arthropods across landscapes with intensive agriculture in temperate areas

    C.J.M. Musters, J. M. R. Wiggers, Geert de Snoo
    The idea that land use in the surroundings may affect the abundance of arthropods on a location plays an important role in the argument that agriculture is the prime cause of the recently discovered general decline of insects. We studied the abundance of ground-dwelling arthropods in agricultural fields along a gradient of increasing distance from (semi)natural areas and in relation to landscape complexity in both the North America (Illinois, USA) and Europe (The Netherlands) using pitfalls. Our results showed that the total abundance did not change with distance when we controlled for vegetation height and landscape complexity around the sample locations. Vegetation height affected abundance positively in crop land and negatively in grassland. Landscape complexity only affected abundance when it was measured in a 6000 m radius around sample location, not at lower levels of scale. We conclude that an effect of increasing landscape complexity may be expected when that is done on a large enough scale.
  • PLoS One

    Importance of natural land cover for plant species’ conservation: A nationwide study in The Netherlands

    Kaixuan Pan, Merijn Moens, Leon Marshall, Ellen Cieraad, Geert de Snoo, Koos Biesmeijer
    While shifts to high-intensity land cover have caused overwhelming biodiversity loss, it remains unclear how important natural land cover is to the occurrence, and thus the conservation, of different species groups. We used over 4 million plant species’ observations to evaluate the conservation importance of natural land cover by its association with the occurrence probability of 1 122 native and 403 exotic plant species at 1 km resolution by species distribution models. We found that 74.9% of native species, 83.9% of the threatened species and 77.1% rare species preferred landscapes with over 50% natural land cover, while these landscapes only accounted for 15.6% of all grids. Most species preferred natural areas with a mixture of forest and open areas rather than areas with completely open or forested nature. Compared to native species, exotic species preferred areas with lower natural land cover and the cover of natural open area, but they both preferred extremely high and low cover of natural forest area. Threatened and rare species preferred higher natural land cover, either cover of natural forest area or cover of natural open area than not threatened and common species, but rare species were also more likely to occur in landscapes with 0–25% cover of natural open area. Although more natural land cover in a landscape will not automatically result in more native species, because there is often a non-linear increase in species occurrence probability when going from 0% to 100% natural land cover, for conserving purposes, over 80% natural land cover should be kept in landscapes for conserving threatened and very rare species, and 60% natural land cover is the best for conserving common native species. Our results stress the importance of natural areas for plant species’ conservation. It also informs improvements to species conservation by increasing habitat diversity.
  • Proceedings of the National Academy of Sciences of the United States of America

    Experimental evidence for neonicotinoid driven decline in aquatic emerging insects

    S. Henrik Barmentlo, Maarten Schrama, Geert de Snoo, Peter M. van Bodegom, André van Nieuwenhuijzen, Martina G Vijver

    There is an ongoing unprecedented loss in insects, both in terms of richness and biomass. The usage of pesticides, especially neonicotinoid insecticides, has been widely suggested to be a contributor to this decline. However, the risks of neonicotinoids to natural insect populations have remained largely unknown due to a lack of field-realistic experiments. Here, we used an outdoor experiment to determine effects of field-realistic concentrations of the commonly applied neonicotinoid thiacloprid on the emergence of naturally assembled aquatic insect populations. Following application, all major orders of emerging aquatic insects (Coleoptera, Diptera, Ephemeroptera, Odonata, and Trichoptera) declined strongly in both abundance and biomass. At the highest concentration (10 mg/L), emergence of most orders was nearly absent. Diversity of the most species-rich family, Chironomidae, decreased by 50% at more commonly observed concentrations (1 mg/L) and was generally reduced to a single species at the highest concentration. Our experimental findings thereby showcase a causal link of neonicotinoids and the ongoing insect decline. Given the urgency of the insect decline, our results highlight the need to reconsider the mass usage of neonicotinoids to preserve freshwater insects as well as the life and services depending on them.
  • Ecological Indicators

    Distribution of flying insects across landscapes with intensive agriculture in temperate areas

    C.J.M. Musters, Tracy R. Evans, J. M. R. Wiggers, Maarten van 't-Zelfde, Geert de Snoo
    The abundance of insects has been strongly decreasing over the last decades, at least in the temperate zones of North America and Europe. This decrease has generally been attributed to increased human activity, especially increased agricultural production. Therefore, one would expect that insect abundance is spatially distributed according to human land use, more specifically that the abundance of insects in agricultural fields should be affected by the distance to (semi)natural areas. We tested this expectation on an extensive dataset of flying insects from Illinois, USA, and the Netherlands, Europe. Flying insects were collected with yellow sticky boards in agricultural fields at distances up to 566 m from (semi)natural areas. We did not find any effect of distance to (semi)natural area on the abundance of flying insects, after correcting for the confounding variables ‘landscape complexity’, ‘vegetation height’ and ‘plot locations’ (interior vs edge of the field). One might prematurely infer from this that (semi)natural areas do not affect flying insect abundance. We argue that knowing that flying insects are highly mobile, both active and passive, although sticky boards sample local insect abundance, abundance may be homogenized over a relatively large area in open landscapes. Therefore, the study of the effect of nature conservation management on flying insects should be done on spatially large scales, e.g., the landscape level.