Increasing biological and chemical diversity in lake sediment due to climate change is likely to increase greenhouse gas emissions, according to a study. As the climate warms, vegetation cover increases in forests of the northern latitudes. This increase is likely to increase the amount of plant material falling into rivers and lakes, where the material can decompose. Andrew J. Tanentzap and colleagues examined the effects of increased organic matter on the thousands of organic molecules found in water as well as the biodiversity of microbial communities. The authors filled containers with varying ratios of artificial sediment and organic material, consisting of deciduous and coniferous litter from nearby forests. Next, the authors submerged these mesocosms in the shallow waters of 2 Canadian lakes that naturally varied in clarity. Analyzing the chemical and microbial diversity 2 months later, the authors found that chemodiversity and biodiversity were correlated, increasing together as the amount of organic matter increased. The resulting increases in chemodiversity were more strongly associated with concentrations of carbon dioxide and methane than biodiversity alone. According to the authors, the resulting increases in microbial decomposition could increase greenhouse gas emissions by a factor of 1.5 to 2.7, with implications for the global carbon cycle.
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Article #19-04896: "Chemical and microbial diversity covary in fresh water to influence ecosystem functioning," by Andrew J. Tanentzap et al.
MEDIA CONTACT: Andrew J. Tanentzap, University of Cambridge, UNITED KINGDOM; tel: +44 01223 748 982; e-mail: ajt65@cam.ac.uk
Proceedings of the National Academy of Sciences