Question 2. How does climate variability affect key consumers and their influence on ecosystems?

Consumers in ecosystems span the range from heterotrophic microbes to small and large herbivores to omnivores and predators.  Prior ARC-LTER research has shown the importance of consumers in arctic ecosystems. We also have shown that mean climate trends, primarily warming, influence consumers. However, we know very little of how climate variability affects consumers.

A better understanding of how climate variability affects consumers will help predict the abundance, species composition, or in some cases even persistence of consumers as climate changes, and in turn their impacts on ecosystem function.  Our ongoing research includes observations, experiments, and models that complement and expand on our long-term datasets and understanding gained from ongoing ARC-related research and is focused around three questions:

How does variability in climate affect key consumer communities?

How does variability in climate affect the influence of higher trophic levels on ecosystem function?

How does variability in climate affect the genomic potential and metabolic functioning of microbial communities as species move from soils to streams to lakes?

Net Ecosystem Exchange (NEE) after 21 years of exclusion of large (brown bar) and large and small (gray bar) herbivores in dry heath tundra.  Herbivory causes the ecosystem to shift from a C sink (negative NEE) to a C source (positive NEE). Adapted from Min et al. (2021).