Long-term trends in carabids over 25 years – community and population level analyses

In times of insect decline, long-term data become more and more important. Such data allow insights into long-term trends and an analysis of possible drivers underlying temporal changes of community and population structure. Using data from 25 years of continuous ground beetle trapping in an ancient woodland located in a large nature reserve in Northern Germany, we analysed temporal changes at both community and population level and identified potential underlying drivers. Ground beetle species significantly declined over time but biomass and number of trapped individuals remained constant. As the habitat was kept stable und unchanged in the last 25 years we also study the influence of external drivers such as climatic variables on phenology and population trends of the most-abundant species. We discuss our results in light of the ongoing insect decline and climate change.