Atmospheric pollution contributed to destabilizing a small mammal community amid four decades of environmental changes

Over the last four decades, the Black Triangle region of Europe has experienced significant changes in atmospheric pollution, climate, land use, and vegetation. These concurrent environmental shifts have led to a destabilization of a small mammal community in the Czechia area. Researchers analyzed 39 years of semiannual data on six small-mammal species, alongside monthly records of atmospheric pollution levels, vegetation index, meteorological conditions, and soil moisture.

By utilizing Empirical Dynamic Modelling (EDM), scientists were able to uncover chaotic relationships between species and their environment, identify causal links, and forecast potential future dynamics.

The research found that small mammal populations were directly impacted by atmospheric pollution, with a notable decline in pollution levels in the late 1990s coinciding with a delayed shift in community composition. The primary effect of reduced pollution was observed in the dominant omnivores, which intensified the interactions between species, contributing to overall instability within the ecosystem.

Additionally, the study revealed a secondary pathway to chaos involving vegetation dynamics and soil moisture, with a particularly pronounced effect on shrew populations.

By examining feedback loops, researchers were able to demonstrate how pollution, alongside other environmental changes, facilitated destabilizing positive feedbacks within the ecosystem. Incorporating the relevant environmental predictors into their forecasting models improved the accuracy of chaotic dynamics predictions, suggesting that identifying key drivers of interactions in complex ecosystems could enhance our ability to anticipate future ecological changes.

This retrospective study highlights the often-overlooked role of atmospheric pollution as a significant macro-ecological driver in the destabilization of small mammal communities.