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Effects of climate change on Arctic arthropod assemblages and distribution

PhD defence by Rikke R Hansen

2016.08.30 | Susanna Pakkasmaa

Date Mon 14 Nov
Time 13:00 15:00
Location AIAS, Høegh-Guldbergs Gade 6B, Aarhus University

MSc Rikke Reisner Hansen will defend her PhD thesis "Effects of climate change on Arctic arthropod assemblages and distribution" on Monday 14 November 2016.

Climate change is expected to affect future arthropod diversity. Deciphering of past and contemporary distribution patterns can provide valuable insight on important drivers of local and regional variation in community and population differences of Arctic terrestrial arthropods.

The focus of Rikke R Hansen’s project is on Greenland, yet the results are discussed in a wider geographical context. The research shows that Arctic arthropod assemblages vary over very short distances and that patterns in composition and diversity are dictated by local to landscape scale habitat features. Large geographical features, such as fjords, glaciers and mountain ranges, fragment species pools and create distinct site specific arthropod communities.

While heterogeneity of the sampled habitat and the size of the study area are positively correlated with species diversity, less attention has been given to the temporal accumulation of species within and between years. Rikke demonstrates a non-uniform seasonal development of Arctic arthropod community composition throughout the season along with peaking richness patterns during parts of the season, where conditions are optimal. These patterns are repeated across multiple Arctic sites, spanning a large climatic gradient, but with significant inter-annual and habitat variation.

Changes in traits like body size and phenology can alter species occurrences, and ultimately the whole community compositions. The species specific investigations have revealed that body size variation as a response to climate change may be masked by local habitat heterogeneity and depend on trophic level of the study organism.

Rikke R Hansen investigated also phenological and body size responses of two Arctic butterfly species to recent warming. Butterfly body size can decrease as a response to increasing temperatures. Furthermore, ecological events, such as flight time and the peak abundance of floral resources, can become decoupled due to climate change.

The opponents are Jane Uhd Jepsen from Norwegian Institute for Nature Research and Peter Convey from British Antarctic Survey, and the chair of the PhD committee is Annette Baattrup-Pedersen from Aarhus University.­

Arctic Research Centre
Tags: Arctic arthropods, climate change