Assessing the Long-Term Impacts of Research Facilities on Soil Ecosystems of the McMurdo Dry Valleys, Antarctica

Understanding how human activities affect Antarctic ecosystems is essential for both environmental management and the interpretation of ecological change. This is particularly important in Antarctica's ice-free areas, which contain most of the continent's terrestrial biodiversity and host the majority of scientific infrastructure. While work has been done to understand short-term impacts of research stations and scientific activity, little is known about the persistence of these impacts on soil ecosystems. Here, we examine the long-term ecological legacy of historical research infrastructure in the McMurdo Dry Valleys, East Antarctica. We collected soil samples from sites of historical research facilities that have since been removed, extracted and identified soil invertebrates and conducted statistical and geospatial analyses to identify spatiotemporal trends and evaluate patterns of abundance relative to distance from disturbance centres and time since abandonment. Soils closer to former infrastructure consistently had lower nematode abundances than soils further away, indicating long-lasting impacts of human activities on soil ecosystems. We also found evidence of potential recovery in some nematode populations, which appears to depend on the type of disturbance and the surrounding environmental setting. At several sites, surface disturbance from historical infrastructure is no longer readily apparent but biological recovery remains incomplete, demonstrating that visual restoration of the landscape does not necessarily correspond to ecological recovery. Measuring the impacts of human activities in these areas is important because they may confound our ability to interpret the subtle but significant effects of climate change and ecosystem responses more generally. This is particularly pressing as research and tourism are expected to increase in these regions. We offer ecological explanations for these patterns and discuss their implications for environmental management and conservation in the McMurdo Dry Valleys and other ice-free areas of Antarctica.