GELIFES Seminars - Fons van der Plas

Link to seminar

Fons van der Plas (WUR)

The scale-dependence of biodiversity loss in grasslands

Causes and consequences

We are living in a time of rapid biodiversity change, caused by various human activities. But changes in biodiversity are often scale-dependent: local biodiversity gains can coincide with a homogenization of plant or animal communities across sites (regional biodiversity losses) and vice versa. Given this scale-dependence of biodiversity change, two key questions are: 1) at what spatial scale is human-driven biodiversity loss most severe, and 2) what are the consequences of biodiversity loss for the functioning of ecosystems at different spatial scales? My research focuses on these questions using grassland plant communities as a model system. I will first discuss how local grassland management, including grazing and fertilization, as well as human pressures from surrounding landscapes, such as atmospheric nitrogen deposition, drive plant grassland plant diversity across various scales. One of the conclusions is that often-reported local-scale losses in plant diversity due to human pressures are often mirrored by homogenization at much larger spatial scales, whereby plant communities across different sites become increasingly similar over time. I will then discuss two types of consequences of different scales of biodiversity loss for ecosystem functioning. First, average levels of various ecosystem processes, such as biomass production, soil carbon storage and ecosystem stability, are affected by multiple scales of biodiversity loss, although not always predictable ways. Second, when ecological communities become increasingly similar to each other over time, the way how they function also becomes increasingly similar, resulting in ‘functional homogenization’ of ecosystems.

Biosketch:
Dr. Fons van der Plas is assistant professor in the Plant Ecology and Nature Conservation Group at Wageningen University. His main drive is to understand the causes and consequences of biodiversity loss. His research has focused mostly on grasslands, although recently he has become increasingly interested in biodiversity in urban environments.