Our recent study, led by postdoc researcher Félix, examines the functional genes of stream microbes on the mountainsides in Norway, Spain and China, and further predicts the continental-scale variations of stream functional diversity under future climate change. Our findings indicate that climate change increases the functional diversity of microbes living in streams. Consequently, climate change may, in certain cases, be beneficial to ecosystems.
Here comes the abstract.
Background: Understanding the large-scale patterns of microbial functional diversity is essential for anticipating climate change impacts on ecosystems worldwide. However, studies of functional biogeography remain scarce for microorganisms, especially in freshwater ecosystems. Here we study 15,289 functional genes of stream biofilm microbes along three elevational gradients in Norway, Spain and China.
Results: We find that alpha diversity declines towards high elevations and assemblage composition shows increasing turnover with greater elevational distances. These elevational patterns are highly consistent across mountains, kingdoms and functional categories and exhibit the strongest trends in China due to its largest environmental gradients. Across mountains, functional gene assemblages differ in alpha diversity and composition between the mountains in Europe and Asia. Climate, such as mean temperature of the warmest quarter or mean precipitation of the coldest quarter, is the best predictor of alpha diversity and assemblage composition at both mountain and continental scales, with local non-climatic predictors gaining more importance at mountain scale. Under future climate, we project substantial variations in alpha diversity and assemblage composition across the Eurasian river network, primarily occurring in northern and central regions, respectively.
Conclusions: We conclude that climate controls microbial functional gene diversity in streams at large spatial scales; therefore, the underlying ecosystem processes are highly sensitive to climate variations, especially at high latitudes. This biogeographical framework for microbial functional diversity serves as a baseline to anticipate ecosystem responses and biogeochemical feedback to ongoing climate change.
This study, published in the Microbiome journal, is detailed as below:
Picazo, F., Vilmi, A., Aalto, J. et al. Climate mediates continental scale patterns of stream microbial functional diversity. Microbiome 8, 92 (2020). [Full text]