D (David) Kleijn D (David) Kleijn

Professor/Chair Plant Ecology and Nature Conservation


Nature is dynamic. Ecosystems change constantly and species are continuously being exposed to altering environmental conditions that may result in population decline or increase. However, currently the activities of mankind drive the decline of a disproportionate number of species. My main drive is to understand the causes of these declines and find conservation strategies that maintain sustainable population sizes and diverse ecosystems.


Because most of the European countryside is farmed in one way or another, the central theme of my research is best described as biodiversity and nature conservation in agricultural habitats. I aim to do this through applied ‘cause-effects’ studies (e.g. evaluating the effectiveness of agri-environment schemes) as well as more fundamental studies that examine underlying mechanisms and processes. This question-driven approach has resulted in the use of a wide range of different approaches (molecular studies, physiological studies, laboratory experiments, garden experiments, large-scale descriptive studies, biogeochemical studies, palaeo-ecological studies, behavioural studies) on plants, invertebrates and/or birds.


Lately my research has focused on the pros and cons of using ecosystem services as the justification for biodiversity conservation. On one hand I’m exploring whether we can internalize biodiversity conservation on farms by quantifying the benefits of ecosystem services for farmers, with the ultimate goal being that farmers start enhancing (functional) biodiversity because this benefits them economically. On the other hand I’m examining what proportion of species is covered by the ecosystem services conservation paradigm (i.e. what part of biodiversity is functionally important) and what this means for the design of cost-effective conservation strategies.


I have come to realize that effective conservation is just as much about people as it is about wild species of plants and animals. I’m therefore investing more and more time in trying to transfer my fascination for the beauty of nature to the general public.