Historical Climate Controls Soil Respiration Responses to Current Soil Moisture. Hawkes, C. V., Waring, B. G., Rocca, J. D., & Kivlin, S. N. 114(24):6322–6327.
Historical Climate Controls Soil Respiration Responses to Current Soil Moisture [link]Paper  doi  abstract   bibtex   
[Significance] Ecosystems' feedback to climate change remains a source of uncertainty in global models that project future climate conditions. That uncertainty rests largely on how much soil carbon will be lost as microbial respiration and how that loss varies across ecosystems. Although there has been a large emphasis on microbial temperature responses, how soil microorganisms respond to changes in moisture remains poorly understood. Here we show that historical rainfall controls soil respiration responses to current moisture. This finding was robust, with historical climate repeatedly limiting current respiration regardless of alterations to soil moisture, rainfall, or the arrival of new taxa. This study highlights the importance that legacies in microbial responses to climate change can have in future ecosystem responses. [Abstract] Ecosystem carbon losses from soil microbial respiration are a key component of global carbon cycling, resulting in the transfer of 40-70 Pg carbon from soil to the atmosphere each year. Because these microbial processes can feed back to climate change, understanding respiration responses to environmental factors is necessary for improved projections. We focus on respiration responses to soil moisture, which remain unresolved in ecosystem models. A common assumption of large-scale models is that soil microorganisms respond to moisture in the same way, regardless of location or climate. Here, we show that soil respiration is constrained by historical climate. We find that historical rainfall controls both the moisture dependence and sensitivity of respiration. Moisture sensitivity, defined as the slope of respiration vs. moisture, increased fourfold across a 480-mm rainfall gradient, resulting in twofold greater carbon loss on average in historically wetter soils compared with historically drier soils. The respiration-moisture relationship was resistant to environmental change in field common gardens and field rainfall manipulations, supporting a persistent effect of historical climate on microbial respiration. Based on these results, predicting future carbon cycling with climate change will require an understanding of the spatial variation and temporal lags in microbial responses created by historical rainfall.
@article{hawkesHistoricalClimateControls2017,
  title = {Historical Climate Controls Soil Respiration Responses to Current Soil Moisture},
  author = {Hawkes, Christine V. and Waring, Bonnie G. and Rocca, Jennifer D. and Kivlin, Stephanie N.},
  date = {2017-06},
  journaltitle = {Proceedings of the National Academy of Sciences},
  volume = {114},
  pages = {6322--6327},
  issn = {1091-6490},
  doi = {10.1073/pnas.1620811114},
  url = {http://mfkp.org/INRMM/article/14376315},
  abstract = {[Significance]

Ecosystems' feedback to climate change remains a source of uncertainty in global models that project future climate conditions. That uncertainty rests largely on how much soil carbon will be lost as microbial respiration and how that loss varies across ecosystems. Although there has been a large emphasis on microbial temperature responses, how soil microorganisms respond to changes in moisture remains poorly understood. Here we show that historical rainfall controls soil respiration responses to current moisture. This finding was robust, with historical climate repeatedly limiting current respiration regardless of alterations to soil moisture, rainfall, or the arrival of new taxa. This study highlights the importance that legacies in microbial responses to climate change can have in future ecosystem responses.

[Abstract]

Ecosystem carbon losses from soil microbial respiration are a key component of global carbon cycling, resulting in the transfer of 40-70 Pg carbon from soil to the atmosphere each year. Because these microbial processes can feed back to climate change, understanding respiration responses to environmental factors is necessary for improved projections. We focus on respiration responses to soil moisture, which remain unresolved in ecosystem models. A common assumption of large-scale models is that soil microorganisms respond to moisture in the same way, regardless of location or climate. Here, we show that soil respiration is constrained by historical climate. We find that historical rainfall controls both the moisture dependence and sensitivity of respiration. Moisture sensitivity, defined as the slope of respiration vs. moisture, increased fourfold across a 480-mm rainfall gradient, resulting in twofold greater carbon loss on average in historically wetter soils compared with historically drier soils. The respiration-moisture relationship was resistant to environmental change in field common gardens and field rainfall manipulations, supporting a persistent effect of historical climate on microbial respiration. Based on these results, predicting future carbon cycling with climate change will require an understanding of the spatial variation and temporal lags in microbial responses created by historical rainfall.},
  keywords = {*imported-from-citeulike-INRMM,~INRMM-MiD:c-14376315,~to-add-doi-URL,climate,constraints,feedback,historical-perspective,respiration,soil-moisture,soil-resources},
  number = {24}
}
Downloads: 0