DOI: 10.1007/s10533-017-0342-9
Scopus记录号: 2-s2.0-85019550047
论文题名: Nitrogenase activity by biological soil crusts in cold sagebrush steppe ecosystems
作者: Schwabedissen S.G. ; Lohse K.A. ; Reed S.C. ; Aho K.A. ; Magnuson T.S.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 134, 期: 2018-01-02 起始页码: 57
结束页码: 76
语种: 英语
英文关键词: Acetylene reduction
; Biological soil crusts
; Cold steppe ecosystems
; Critical zone
; Critical zone observatory
; Grazing
; Nitrogenase activity
; Reynolds Creek Critical Zone Observatory
; Reynolds Creek Experimental Watershed
Scopus关键词: acetylene
; climate change
; climate effect
; disturbance
; ecosystem function
; ecozone
; enzyme activity
; grazing
; herb
; nitrogen fixation
; precipitation (climatology)
; reduction
; seasonal variation
; shrub
; soil carbon
; soil chemistry
; soil crust
; soil nitrogen
; soil stabilization
; steppe
; Idaho
; Intermountain West
; United States
; Artemisia tridentata
; Bryophyta
英文摘要: In drylands worldwide, biological soil crusts (BSC) form a thin photosynthetic cover across landscapes, and provide vital benefits in terms of stabilizing soil and fixing nitrogen (N) and carbon (C). Numerous studies have examined the effects of climate and disturbance on BSC functions; however, few have characterized these responses in rolling BSCs typical of northern ecosystems in the Intermountain West, US. With temperature increases and shifts in precipitation projected, it is unclear how BSCs in this region will respond to climate change, and how the response could affect their capacity to perform key ecosystem functions, such as providing ‘new’ N through biological N2 fixation. To address this important knowledge gap, we examined nitrogenase activity (NA) associated with rolling BSCs along a climatic gradient in southwestern Idaho, US, and quantified how acetylene reduction rates changed as a function of climate, grazing (using exclosures), and shrub-canopy association. Results show that warmer, drier climates at lower elevations hosted greater cover of late successional BSC communities (e.g., mosses and lichens), and higher NA compared with colder, wetter climates at higher elevations. Highest NA (0.5–29.3 µmol C2H4 m−2 h−1) occurred during the early summer/spring, when water was more available than in late summer/autumn. Activity was strongly associated with soil characteristics including pH and ammonium concentrations suggesting these characteristics as potentially strong controls on NA in BSCs. The relationship between grazing and NA varied with elevation. Specifically, lower elevation sites had lower NA at grazed locations, whereas higher elevation sites had higher NA with grazing. At both low and high ends of the elevation gradient, shrub-canopy associated BSCs maintained two to three times higher NA compared to BSCs in the interspace among shrubs. Taken together, our findings indicate that the controls and rates of NA in BSCs vary seasonally and strongly with climate in the Intermountain West, and that drier springs are likely to influence rates of NA more than warmer summers. © 2017, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83261
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: Department of Biological Sciences, Idaho State University, 650 Memorial Drive, Pocatello, ID, United States; Southwest Biological Science Center, United States Geological Survey, Moab, UT, United States
Recommended Citation:
Schwabedissen S.G.,Lohse K.A.,Reed S.C.,et al. Nitrogenase activity by biological soil crusts in cold sagebrush steppe ecosystems[J]. Biogeochemistry,2017-01-01,134(2018-01-02)