Abstract
Species responses to environmental change, such as habitat loss and fragmentation typically do not occur immediately, but after a certain time lag. The number of species that still persist but are expected to go extinct due to past environmental changes are referred to as “extinction debt”. We tested for the existence of an extinction debt in semi-natural grasslands after 50 years of landscape changes. In a European cross-country study, we found evidence for an extinction debt in grassland plants, but not in butterflies. However, in a study in Sweden, we found evidence of an extinction debt for plants, butterflies and hoverflies, but not for bees. Also the recovery of populations and communities after the restoration of degraded habitats takes time. We studied how the spatial isolation from existing source habitats influence the recovery of plant and insect communities in restored semi-natural grasslands. We found contrasting patterns in community recovery among plants and pollinating insects, with a slower change in community composition for plants than for pollinators. Instead, the composition of pollinators was more dependent on the connectivity to source habitats. This is likely to influence the recovery of plant-pollinator interaction networks.

Coffee and tea will be served after the seminar.

All are welcome, no registration.

Organiser
AIAS Fellow Toke T. Høye