DOI: 10.1007/s10533-017-0412-z
Scopus记录号: 2-s2.0-85038387905
论文题名: Threshold responses of soil organic carbon concentration and composition to multi-level nitrogen addition in a temperate needle-broadleaved forest
作者: Cheng S. ; Fang H. ; Yu G.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2018
卷: 137, 期: 2018-01-02 起始页码: 219
结束页码: 233
语种: 英语
英文关键词: Aggregate size distribution
; Atmospheric N deposition
; Microbial community abundance
; Nonlinear responses
; SOC physical fractionation
Scopus关键词: bacterium
; broad-leaved forest
; community structure
; concentration (composition)
; forest ecosystem
; microbial community
; nitrogen
; nonlinearity
; old-growth forest
; organic carbon
; particulate organic carbon
; relative abundance
; soil carbon
; threshold
; China
英文摘要: Responses of soil organic carbon (SOC) cycling and C budget in forest ecosystems to elevated nitrogen (N) deposition are divergent. Little is known about the N critical loads for the shift between gain and loss of SOC storage in the old-growth temperate forest of Northeast China. The objective of this study was to investigate the nonlinear responses of SOC concentration and composition to multiple rates of N addition, as well as the microbial mechanisms responsible for SOC alteration under N enrichment. Nine rates of urea addition (0, 10, 20, 40, 60, 80, 100, 120, 140 kg N ha−1 year−1) with 4 replicates for each treatment were conducted. Soil samples in the 0–10 cm mineral layer were taken after 3 years of N fertilization. Soil aggregate size distribution and SOC physical fractionation were performed to examine SOC dynamics. Phospholipid fatty acid (PLFA) technique was used to measure the abundance and structure of microbial community. Three years of N addition led to significant increases in the concentrations of soil particulate organic C and aggregate-associated organic C fractions only. The responses of total N and each labile SOC fraction to the rates of N addition followed Gaussian equations, with the N critical loads being estimated to be between 80 and 100 kg N ha−1 year−1. The change in SOC concentration (ΔSOC) was positively correlated with the changes in aggregate associated OC (r2 > 0.80) and POC concentrations (r2 > 0.50). Significant correlations among the concentrations of labile SOC fractions, the percentages of soil aggregates, and the abundances of microbial PLFAs were observed, which implies a close linkage between microbial community structure and SOC accumulation and stability. Our results suggest that increase in soil moisture and shift of microbial community structure could control the critical N load for the switch between C accumulation and loss. The current N deposition rate (~ 11 kg N ha−1 year−1) to the northeast China’s forests is favorable for soil C accumulation over the short term. © 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/83201
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: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Chaoyang District, Beijing, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
Recommended Citation:
Cheng S.,Fang H.,Yu G.. Threshold responses of soil organic carbon concentration and composition to multi-level nitrogen addition in a temperate needle-broadleaved forest[J]. Biogeochemistry,2018-01-01,137(2018-01-02)