DOI: 10.1007/s10533-017-0418-6
Scopus记录号: 2-s2.0-85039856189
论文题名: The effects of heating, rhizosphere, and depth on root litter decomposition are mediated by soil moisture
作者: Castanha C. ; Zhu B. ; Hicks Pries C.E. ; Georgiou K. ; Torn M.S.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2018
卷: 137, 期: 2018-01-02 起始页码: 267
结束页码: 279
语种: 英语
英文关键词: 13C labeling
; Decomposition
; Rhizosphere
; Root litter
; Soil depth
; Soil moisture
; Warming
Scopus关键词: dissolved organic carbon
; grass
; grassland
; growing season
; leachate
; litter
; lysimeter
; Mediterranean environment
; rhizosphere
; root
; soil depth
; soil moisture
; uncertainty analysis
; warming
; Avena fatua
英文摘要: The breakdown and decomposition of plant inputs are critical for nutrient cycling, soil development, and climate-ecosystem feedbacks, but uncertainties persist in how the rates and products of litter decomposition are affected by soil temperature, rhizosphere, and depth of input. We investigated the effects of soil warming (+ 4 °C), rhizosphere, and depth of litter placement on the decomposition of Avena fatua (wild oat grass) root litter in a Mediterranean grassland ecosystem. Field lysimeters were subjected to three environmental treatments (heating, control, and plant removal) and three 13C-labeled root litter addition treatments (to A horizon, to B horizon, and no-addition disturbance control) for each of two harvest time points. We buried root litter in February 2014 and measured loss of 13C in CO2 from the soil surface and in leachate as dissolved organic carbon (DOC) over two growing seasons. At the end of each growing season we recovered the 13C remaining in the soil. Loss of root litter C occurred almost entirely via heterotrophic respiration, with an estimated < 2% lost as DOC during the initial decay period. The added roots were broken down and incorporated into bulk soil material very quickly; only ~ 30% of added root was visible after 6 months. In the first growing season, decomposition occurred faster in the B than in the A horizon, the latter having greater moisture limitation. Subsequently, there was almost no further decomposition in the B horizon. After two growing seasons, less than 20% of the added root litter C remained in the A or B horizons of all environmental treatments. Heating did not stimulate decomposition, likely because it exacerbated the moisture limitation. However, while plots without plants dried down more slowly than plots with plants, their decomposition rate was not significantly greater, possibly due to the lack of rhizosphere processes such as priming. We conclude that in this Mediterranean grassland ecosystem, soil moisture, which is affected by season, depth, heating, and rhizosphere, plays a dominant role in mediating the effect of those factors on root litter decomposition, which after two seasons did not differ by depth or by treatment. © 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/83193
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: Climate and Ecosystem Sciences Division, Climate Sciences Department, Lawrence Berkeley National Laboratory, Berkeley, CA, United States; Department of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China; Department of Biological Sciences, Dartmouth College, Hanover, NH, United States; Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, United States; Energy and Resources Group, University of California, Berkeley, CA, United States
Recommended Citation:
Castanha C.,Zhu B.,Hicks Pries C.E.,et al. The effects of heating, rhizosphere, and depth on root litter decomposition are mediated by soil moisture[J]. Biogeochemistry,2018-01-01,137(2018-01-02)