Ongoing changes in climate and land use are widely considered to pose the largest threats to biodiversity worldwide. As humans actively and passively convert and degrade natural and semi-natural land, valuable habitats are destroyed. Those that remain are often small and increasingly isolated. At the same time, warming temperatures and changing patterns of precipitation provide another pressure on species and ecological communities.
As local environments change, individuals and species can show one of three responses. They can stay where they are, either persisting in, or adapting to, their new conditions. Another option is to disperse to more suitable habitat or to higher altitudes and latitudes where climatic conditions are more appropriate. If neither persistence nor dispersal are possible, the species will eventually go locally extinct. The combination of these responses across all individuals and species will then determine biodiversity change and community shifts at local and landscape scales, as well as larger-scale changes in species distributions. Studying these responses to environmental change and their effects will help us to design effective conservation measures to prevent further biodiversity loss and predict how biodiversity may change in the future. This is especially important given the increasing rate and magnitude of environmental change that is occurring now and expected to continue in the future.
One way in which we can improve our understanding of the ecological effects of environmental change is to look to the past. Studying how patterns of biodiversity today are influenced by the past, and how known changes in land use and climate have already affected species and communities are among the only ways in which we can see how nature responds to environmental pressures in real-world conditions.
In my lecture, I will describe different aspects of my research in which I use a number of historical data sources – most prominently historical maps and species observations – to try to document and understand what has happened, and what is happening to biodiversity today. I will show how local- and landscape-level changes in land use manifest at regional and national scales, and how this has driven species and community shifts over time. By developing new methods and using historical sources in novel ways, I aim to broaden the understanding of biodiversity responses to environmental change. Especially important is to understand how climate and land use interact to drive biodiversity change, as well how these environmental changes combine with the characteristics of different species and taxonomic groups to determine the winners and losers of global change in the Anthropocene.