Scale-dependent caus es and consequences of biodiversity loss
We are living in a time of rapid biodiversity change, caused by various human activiti es. But changes in biodiversity are often scale-dependent: local biod iversity gains can coincide with a homogenization of plant or animal communities across sites (regional biodiversity losses) and vice vers a. Given this scale-dependence of biodiversity change, two key questi ons are: 1) at what spatial scale is human-driven biodiversity loss m ost severe, and 2) what are the consequences of biodiversity loss for the functioning of ecosystems at different spatial scales? My resear ch focuses on these questions, using grassland plant communities and forests as model systems. I will first discuss how management activit ies, as well as human pressures, drive plant grassland plant diversit y across various scales. One of the conclusions is that often-reporte d local-scale losses in plant diversity due to human pressures are of ten 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 scale-dependent conseque nces of biodiversity loss for ecosystem functioning. First, average l evels of various ecosystem processes, such as biomass production, soi l carbon storage and ecosystem stability, are affected by multiple sc ales of biodiversity loss, although not always predictable ways. Seco nd, when ecological communities become increasingly similar to each o ther over time, the way how they function also becomes increasingly s imilar, resulting in ‘functional homogenization’ of ecosystems. DESCRIPTION: Scale-dependent causes and consequences of biodiversity l oss We are living in a time of rapid biodiversity change, caused by v arious human activities. But changes in biodiversity are often scale- dependent: local biodiversity gains can coincide with a homogenizatio n of plant or animal communities across sites (regional biodiversity losses) and vice versa. Given this scale-dependence of biodiversity c hange, two key questions are: 1) at what spatial scale is human-drive n biodiversity loss most severe, and 2) what are the consequences of biodiversity loss for the functioning of ecosystems at different spat ial scales? My research focuses on these questions, using grassland p lant communities and forests as model systems. I will first discuss h ow management activities, as well as human pressures, drive plant gra ssland plant diversity across various scales. One of the conclusions is that often-reported local-scale losses in plant diversity due to h uman pressures are often mirrored by homogenization at much larger sp atial scales, whereby plant communities across different sites become increasingly similar over time. I will then discuss two types of sca le-dependent consequences of biodiversity loss for ecosystem function ing. First, average levels of various ecosystem processes, such as bi omass production, soil carbon storage and ecosystem stability, are af fected by multiple scales of biodiversity loss, although not always p redictable ways. Second, when ecological communities become increasin gly similar to each other over time, the way how they function also b ecomes increasingly similar, resulting in ‘functional homogenizatio n’ of ecosystems. END:VEVENT END:VCALENDAR