The effect of experimental warming and precipitation change on proteolytic enzyme activity : positive feedbacks to nitrogen availability are not universal

• Published in: Global Change Biology
• Main Authors: Brzostek, Edward R., Blair, John M., Dukes, Jeffrey S., Frey, Serita D., Hobbie, Sarah E., Melillo, Jerry M., Mitchell, Robert J., Pendall, Elise (R17757), Reich, Peter B. (R16861), Shaver, Gaius R., Stefanski, Artur, Tjoelker, Mark G. (R16688), Finzi, Adrien C.
• Other Authors: Hawkesbury Institute for the Environment (Host institution), (Host institution)
• Format: Article in Journal/Newspaper
• Language: English
• Published: U.K, Blackwell Science 2012
• Subjects: global change; organic nitrogen; proteolytic enzymes; soil nitrogen; soil organic matter; decomposition; Arctic; Climate change; Tundra
• Online Access: http://handle.uws.edu.au:8081/1959.7/512477; https://doi.org/10.1111/j.1365-2486.2012.02685.x

Nitrogen regulates the Earth's climate system by constraining the terrestrial sink for atmospheric CO2. Proteolytic enzymes are a principal driver of the within-system cycle of soil nitrogen, yet there is little to no understanding of their response to climate change. Here, we use a single methodology to investigate potential proteolytic enzyme activity in soils from 16 global change experiments. We show that regardless of geographical location or experimental manipulation (i.e., temperature, precipitation, or both), all sites plotted along a single line relating the response ratio of potential proteolytic activity to soil moisture deficit, the difference between precipitation and evapotranspiration. In particular, warming and reductions in precipitation stimulated potential proteolytic activity in mesic sites – temperate and boreal forests, arctic tundra – whereas these manipulations suppressed potential activity in dry grasslands. This study provides a foundation for a simple representation of the impacts of climate change on a central component of the nitrogen cycle.