Impacts of Climate Change on European Invertebrates, with reference to the vulnerability of Bern Convention species

Description

There is strong evidence that invertebrates have responded to recent climate change. This report summarises recent research on observed and projected impacts for this taxonomic group:

• Changes to phenology, demographic processes (mortality and fecundity), and habitat associations have been observed within populations of invertebrates. There is some evidence for evolutionary responses to dispersal capacity and diapause induction.
• Invertebrate species distributions have expanded at high latitude or elevation range margins, and have contracted at low latitude or elevation margins. Rates of leading edge range expansion are constrained by habitat availability or dispersal ability. For some species, rear edge range contractions do not appear to show a marked time delay following climate warming.
• Species richness has not increased as much at high latitudes as predicted by the biogeographic associations of species, because of constraints of habitat loss on range expansions. Wide-ranging or generalist species, and species associated with low latitudes or elevations, now represent a higher proportion of species in some invertebrate communities, compared with habitat specialists or species associated with cool high latitudes or elevations.
• The possible roles of biotic interactions on species responses to climate change are poorly resolved, with implications for the effects of emergent disease or invasive alien species.
• Climate change may have important effects on invertebrates which provide ecosystem services such as nutrient cycling or pollination, or “disservices” such as disease vectors and forestry pests.
• Bioclimate models applied to the potential distributions of European butterflies in 2080 suggest that 48-78% of species will suffer >50% reductions in distribution size, if they are unable to shift their distributions to track suitable climates. There are marked differences in projected distribution losses between scenarios based on 2.4ºC and 4.1 ºC temperature increases.
• Bern Convention invertebrates are characterised by high habitat specificity and narrow distributions. Their sensitivity and lack of adaptive capacity suggests high vulnerability to climate change.
• Planned adaptation may be vital to conserve Bern Convention invertebrates under climate change. The possible roles of landscape-scale conservation, assisted colonization, and management for habitat heterogeneity are considered, as are monitoring, research and policy implications.

Reference information