Climate change affects Lepidoptera families in different ways

Abstract

Climate change and habitat conversion are major drivers of biodiversity loss and community shifts at local scale. The majority of terrestrial biodiversity is represented by insects, which are thought to be especially affected by climate change as their life cycles strongly depend on temperature. Within the insects Lepidoptera is a diverse order, which has been shown to react to global warming. However, most of the studies on changes of Lepidoptera communities are either temporally or spatially limited and miss therefore reliable information on development of diversities and communities at broader landscape levels and time ranges. We used data on macro-moths (Lepidoptera) in Bavaria (southern Germany), sampled over a period of about 40 years in order to detect changes in species diversities and community properties. Light trapping was applied at 2751 plot-dates on 373 unique forest plots spread over the whole geographic and elevational range of Bavaria. We caught about 800000 specimens from about 850 different macro Lepidoptera species. The two most dominant families were the Geometridae and Noctuidae with about 350000 specimens of 343 species and about 240000 specimens of 345 species, respectively. While overall species diversity remained constant before the 1990s and before the 2000s, it decreased significantly after the year 2000. The same pattern occurred with the Noctuidae subset while Geometridae showed an inferior diversity decline after the year 2000, where diversity was significantly lower than before 2000, but not than before 1990. This phenomenon may be due to the different biology of the two families. We conclude that conservation measures should first identify species or species groups which are especially threatened by global change and focus actions on these. Furthermore, this talk presents different aspects macro-moth community development such as mean color lightness and mean body size, linking changes to climate change.