DOI: 10.1007/s10533-016-0200-1
Scopus记录号: 2-s2.0-84962022987
论文题名: Low soil moisture during hot periods drives apparent negative temperature sensitivity of soil respiration in a dryland ecosystem: a multi-model comparison
作者: Tucker C.L. ; Reed S.C.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2016
卷: 128, 期: 2018-01-02 起始页码: 155
结束页码: 169
语种: 英语
英文关键词: Bayesian model comparison
; Biological soil crust
; Islands of fertility
; Plant litter decomposition
; Semiarid shrublands
; Soil respiration
Scopus关键词: Bayesian analysis
; carbon cycle
; carbon dioxide
; carbon flux
; decomposition
; litter
; semiarid region
; shrubland
; soil crust
; soil moisture
; soil respiration
; soil temperature
; temperature effect
; vascular plant
; United States
; Utah
; Tracheophyta
英文摘要: Arid and semiarid ecosystems (drylands) may dominate the trajectory of biosphere-to-atmosphere carbon (C) exchange, and understanding dryland CO2 efflux is important for C cycling at the global-scale. However, unknowns remain regarding how temperature and moisture interact to regulate dryland soil respiration (Rs), while ‘islands of fertility’ in drylands create spatially heterogeneous Rs. At a site in southeastern Utah, USA we added or removed litter (0–650 % of control) in plots associated with either shrubs or biological soil crust-dominated interspaces between vascular plants. We measured Rs, soil temperature (Ts), and water content (θ) repeatedly from October 2013 to November 2014. Rs was highest following rain in late summer at Ts ~30 °C, and lowest mid-summer at Ts > 40 °C, resulting in apparent negative temperature sensitivity of Rs at high temperatures, and positive temperature sensitivity at low-moderate temperatures. We used Bayesian statistical methods to compare models capturing a range of hypothesized relationships between Ts, θ, and Rs. The best model indicates that apparent negative temperature sensitivity of Rs at high Ts reflects the control of water content, not high temperatures. Modeled Q10 ranged from 2.7 to 1.4 between 5 and 45 °C. Litter addition had no effect on Q10 or reference respiration (Rref = Rs at 20 °C and optimum θ) beneath shrubs, and little effect on Rref in interspaces, yet Rref was 1.5 times higher beneath shrubs than in interspaces. Altogether, these results suggest reduced Rs often observed at high Ts in drylands is dominated by the control of θ, and, on shorter-timescales, variable litter inputs exert minimal control over Rs. © 2016, US Government. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83408
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: US Geological Survey, Southwest Biological Science Center, 2290 SW Resource Blvd, Moab, UT, United States
Recommended Citation:
Tucker C.L.,Reed S.C.. Low soil moisture during hot periods drives apparent negative temperature sensitivity of soil respiration in a dryland ecosystem: a multi-model comparison[J]. Biogeochemistry,2016-01-01,128(2018-01-02)