DOI: 10.1007/s10533-017-0415-9
Scopus记录号: 2-s2.0-85039703287
论文题名: Exudation rates and δ13C signatures of tree root soluble organic carbon in a riparian forest
作者: Gougherty S.W. ; Bauer J.E. ; Pohlman J.W.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2018
卷: 137, 期: 2018-01-02 起始页码: 235
结束页码: 252
语种: 英语
英文关键词: Isotopes
; Non-structural carbon
; Organic matter
; Riparian
; Root exudation
Scopus关键词: air temperature
; carbon dioxide
; carbon flux
; carbon isotope
; exudation
; forest soil
; net ecosystem exchange
; net primary production
; nutrient uptake
; organic carbon
; rhizosphere
; riparian forest
; root
; soil carbon
; soil organic matter
; soil respiration
; temperate environment
英文摘要: Tree root exudation (TRE) of water soluble organic carbon (WSOC) is an important but under-assessed component of net primary production, and is thought to strongly influence rhizosphere biogeochemistry. Riparian systems in particular are often viewed as biogeochemical hot spots fueled partially by root exudate WSOC. However, TRE rates have not been previously reported for these systems. The δ13C signatures of exudates may provide important insights into plant physiology and inform isotope-based methods to identify sources of soil CO2 fluxes, but this information is also generally lacking. In the present study, root exudate WSOC was collected in situ to assess both net exudation rates and exudate δ13C values in a temperate riparian forest. Net TRE rates were found to be most strongly related to a combination of tree species, root characteristics and net ecosystem exchange (Adj. R2 = 0.73; p < 0.001). In contrast, exudate δ13C values were correlated to time-lagged vapor pressure deficit (Adj. R2 = 0.21; p < 0.05) and air temperature (Adj. R2 = 0.43; p < 0.05), suggesting a rapid transfer of photosynthate from the canopy to the rhizosphere. Extrapolation of mean net TRE rates (13 µmol C g root−1 day−1) from a root mass basis to the entire sampling area suggests that TRE may account for as much as 3% of net annual C uptake and represents an important input of organic matter to riparian soils. Our findings of predictable TRE rates and exudate δ13C values in the present study suggest that future studies examining δ13C values of different plant components, soil organic matter and respired soil CO2 would benefit by accounting for the impact of root exudates. © 2017, Springer International Publishing AG, part of Springer Nature. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83199
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Aquatic Biogeochemistry Laboratory, Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, United States; US Geological Survey, Woods Hole Coastal & Marine Science Center, Woods Hole, MA, United States; W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, United States
Recommended Citation:
Gougherty S.W.,Bauer J.E.,Pohlman J.W.. Exudation rates and δ13C signatures of tree root soluble organic carbon in a riparian forest[J]. Biogeochemistry,2018-01-01,137(2018-01-02)