Dr. J.A. (Joeri) Zwerts

Hugo R. Kruytgebouw
Padualaan 8
Kamer N308
3584 CH Utrecht

Dr. J.A. (Joeri) Zwerts

Universitair docent
Ecology and Biodiversity
030 253 6835

Growing global human populations and prosperity will require progressively more resources for the decades to come. This will put further pressure on our natural systems. At the same time, international pledges and legislation for sustainable production and nature conservation are also becoming more ambitious. To accommodate both resource production and nature conservation, we will need more effective ways to manage the landscapes in which resources are produced. These so called multifunctional landscapes are the main focus of my work. My research aims to develop an understanding of the linkages between land use change, climate change and biodiversity conservation in multifunctional landscapes. I do this by quantifying the implications of different land-use management strategies and landscape connectivity on conservation, behavior, and habitat use of wildlife.

Impact evaluations
One key focus of my research is evaluating the impacts of conservation efforts to determine if they are effective or need to be improved. New EU policies, commodity certification schemes, Payments for Ecosystem Services projects, all require rigorous evaluation of effectiveness to provide consumers, producers, legislators and NGOs with the information for evidence based decision making.

Agro-commodity (e.g. timber, palm oil, soy etc) certification schemes for example, require producers to respect a set of socio-economic and environmental standards, but the on-the-ground impacts often remain unvalidated, resulting in uncertainty on whether certification schemes should be adopted or improved.

For instance, I assessed the impacts of Forest Stewardship Council (FSC)-certified forestry on wildlife in the Congo Basin, such as African forest elephants, gorillas and chimpanzees. To do this, I set up partnerships with 14 forestry companies, three large conservation organizations, and worked closely with over 260 temporary employees from local communities. This study revealed, with 1.3 million camera-trap images of 55 mammal species in 14 logging concessions, greater animal encounter rates in FSC-certified than non-certified forest, especially for large mammals and species of high conservation priority. The results were published in Nature, strengthening the narrative for FSC-certification.

Landscape connectivity
I also focus on landscape connectivity in relation to agro-commodity production, and on the quantification of landscape connectivity requirements for the conservation of wildlife. Landscape connectivity plays a vital role in sustaining wildlife populations and fostering ecological health. By maintaining connectivity, wildlife can access resources, find mates, and colonize new areas, thus enhancing genetic diversity and resilience to environmental changes. Moreover, landscape connectivity promotes ecosystem functions like seed dispersal and pollination, contributing to overall biodiversity and ecosystem stability. Preserving and restoring connectivity through strategic conservation efforts not only benefit wildlife but also support human well-being by safeguarding ecosystems and the services they provide. Therefore, developing an evidence-based connectivity strategy is essential to ensure the long-term survival of many species.

A pillar of my research is to develop better ways to measure biodiversity, because better methods will be essential in quantifying the impacts of humans on the environment. This is instrumental for impact evaluations, ecological studies, but also for biodiversity credit schemes whereby organisations are rewarded for the conservation of biodiversity. To do this, we will require innovative tools and interdisciplinary partnerships. My research mainly focuses on the application of sounds, both through species specific detection and soundscapes, but innovative monitoring can include a whole array of natural cues, from vibrations to olfactory cues, that are yet beginning to be explored.

My work mainly focuses on mammals because they are highly vulnerable for anthropogenic disturbance and therefore are expected to be good indicators for the effectiveness of environmental management. Many of the larger mammal species have, furthermore, to a large extent been decimated over the last few decades, making their conservation a top priority and yet another reason to study the best way to realistically conserve the remaining populations.