Many ecological processes in the terrestrial environment rely on fungal communities: fungi recycle and provide nutrients; they are an important dietary component for some animals; and fungi can have large impacts on ecosystem composition through plant pathogens and animal diseases. Research has indicated that the abundance and behaviour of fungi may be changing in response to climate change. However, long-term records from which to investigate fungal population changes, community dynamics and interactions with host species are rare: the longest record available is a 67-year record started in 1950 but there is limited spatial coverage of similar long-term records. If preserved in anoxic sediments, fungal spores can be analysed to generate records of changing abundance and composition covering hundreds – thousands of years, thus significantly extending monitoring records. Fossil records may also provide insights into past environmental conditions such as the distribution of vegetation ecotones, impacts of herbivores on ecosystems, and incidences of animal and plant disease. This project will take a novel approach using modern and past records of fungal populations to understanding long-term fungal population changes in response to changing environments and climate. By understanding how fungi have responded to past climatic changes, we will be better able to predict how they will react in the near future, enabling us to anticipate population changes and predict outbreaks of pathogens.