Linking stoichiometric homeostasis of microorganisms with soil phosphorus dynamics in wetlands subjected to microcosm warming.
Soil biogeochemical processes and the ecological stability of wetland ecosystems under global warming scenarios have gained increasing attention worldwide. Changes in the capacity of microorganisms to maintain stoichiometric homeostasis, or relatively stable internal concentrations of elements, may serve as an indicator of alterations to soil biogeochemical processes and their associated ecological feedbacks. In this study, an outdoor computerized microcosm was set up to simulate a warmed (+5°C) climate scenario, using novel, minute-scale temperature manipulation technology. The principle of stoichiometric homeostasis was adopted to illustrate phosphorus (P) biogeochemical cycling coupled with carbon (C) dynamics within the soil-microorganism complex. We hypothesized that enhancing the flux of P from soil to water under warming scenarios is tightly coupled with a decrease in homeostatic regulation ability in wetland ecosystems. Results indicate that experimental warming impaired the ability of stoichiometric homeostasis (H) to regulate biogeochemical processes, enhancing the ecological role of wetland soil as an ecological source for both P and C. The potential P flux from soil to water ranged from 0.11 to 34.51 mg m(-2) d(-1) in the control and 0.07 to 61.26 mg m(-2) d(-1) in the warmed treatment. The synergistic function of C-P acquisition is an important mechanism underlying C∶P stoichiometric balance for soil microorganisms under warming. For both treatment groups, strongly significant (p<0.001) relationships fitting a negative allometric power model with a fractional exponent were found between n-HC∶P (the specialized homeostatic regulation ability as a ratio of soil highly labile organic carbon to dissolved reactive phosphorus in porewater) and potential P flux. Although many factors may affect soil P dynamics, the n-HC∶P term fundamentally reflects the stoichiometric balance or interactions between the energy landscape (i.e., C) and flow of resources (e.g., N and P), and can be a useful ecological tool for assessing potential P flux in ecosystems.
College of Natural Resource and Environmental Sciences, China Academy of West Development, Zhejiang University, Hangzhou, Zhejiang Province, China.
Hang
H
Wang
College of Natural Resource and Environmental Sciences, China Academy of West Development, Zhejiang University, Hangzhou, Zhejiang Province, China.
Hongyi
H
Li
College of Natural Resource and Environmental Sciences, China Academy of West Development, Zhejiang University, Hangzhou, Zhejiang Province, China.
Zhijian
Z
Zhang
Curriculum for the Environment & Ecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
Jeffrey D
JD
Muehlbauer
Department of Civil & Environmental Engineering, University of Tennessee, Knoxville, Tennessee, United States of America.
Qiang
Q
He
College of Natural Resource and Environmental Sciences, China Academy of West Development, Zhejiang University, Hangzhou, Zhejiang Province, China.
Xinhua
X
Xu
Institute of Ecology, Zhejiang Forestry Academy, Hangzhou, China.
Chunlei
C
Yue
Department of Earth and Environmental Engineering, Henry Krumb School of Mines, Columbia University, New York, New York, United States of America.
Daqian
D
Jiang
D055669:Ecological and Environmental Phenomena; D057232:Global Warming; D006706:Homeostasis / Q000502:physiology*; D008954:Models, Biological; D010758:Phosphorus / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D013696:Temperature; D053833:Wetlands
D012987:Soil; D010758:Phosphorus