Research Highlights

Lake response to natural and cultural impacts at the landscape scale in Western Uganda 

There is an increasing need to integrate a range of long-term records to provide a comprehensive environmental understanding of human-environment and spatial-temporal interactions within a landscape. This approach to understanding modern landscape change in a palaeolimnological framework is important when developing management strategies for ecosystems in regions most susceptible to future changes.

For this research, diatom records from two Ugandan crater lakes, (pristine Lake Kyogo and heavily impacted Lake Nyamogusingiri), spanning the last 50-150 years, were used to compare the palaeolimnological records of environmental change to establish the potential impact of humans on the record of climate history contained within the lake sediments. The research was undertaken by Dr Keely Mills (Centre for Environmental Management, University of Ballarat) and Dr David Ryves (Centre for Hydrological and Ecosystem Science, Loughborough University) in collaboration with ANSTO’s Dr Atun Zawadzki and involved the analysis of changes in the diatom assemblages in two sediment cores and 210Pb radiometric dating.

The results show that even near-pristine lakes in protected areas of western Uganda demonstrate a significant shift in water quality, as inferred from the diatom assemblages, over the last 25-50 years. This switch is coincident with an increase in the delivery of catchment-derived sediments. A similar response is seen across a number of other lakes in the area, and suggests that a regional driver is responsible for the observed recent changes, perhaps related to the onset of significant human activity, overprinted on known regional (wet vs dry) climatic fluctuations.

Lake in western Uganda