Temperature response of soil respiration largely unaltered with experimental warming

Proceedings of the National Academy of Sciences of the United States of America
By: , and 

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Abstract

The respiratory release of carbon dioxide (CO2) from soil is a major yet poorly understood flux in the global carbon cycle. Climatic warming is hypothesized to increase rates of soil respiration, potentially fueling further increases in global temperatures. However, despite considerable scientific attention in recent decades, the overall response of soil respiration to anticipated climatic warming remains unclear. We synthesize the largest global dataset to date of soil respiration, moisture, and temperature measurements, totaling >3,800 observations representing 27 temperature manipulation studies, spanning nine biomes and over 2 decades of warming. Our analysis reveals no significant differences in the temperature sensitivity of soil respiration between control and warmed plots in all biomes, with the exception of deserts and boreal forests. Thus, our data provide limited evidence of acclimation of soil respiration to experimental warming in several major biome types, contrary to the results from multiple single-site studies. Moreover, across all nondesert biomes, respiration rates with and without experimental warming follow a Gaussian response, increasing with soil temperature up to a threshold of ∼25 °C, above which respiration rates decrease with further increases in temperature. This consistent decrease in temperature sensitivity at higher temperatures demonstrates that rising global temperatures may result in regionally variable responses in soil respiration, with colder climates being considerably more responsive to increased ambient temperatures compared with warmer regions. Our analysis adds a unique cross-biome perspective on the temperature response of soil respiration, information critical to improving our mechanistic understanding of how soil carbon dynamics change with climatic warming.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Temperature response of soil respiration largely unaltered with experimental warming
Series title Proceedings of the National Academy of Sciences of the United States of America
DOI 10.1073/pnas.1605365113
Volume 113
Issue 48
Year Published 2016
Language English
Publisher Proceedings of the National Academy of Sciences
Contributing office(s) Woods Hole Coastal and Marine Science Center, John Wesley Powell Center for Analysis and Synthesis
Description 6 p.
First page 13797
Last page 13802