DOI: 10.1111/gcb.12032
论文题名: Global change effects on Bromus tectorum L. (Poaceae) at its high-elevation range margin
作者: Concilio A.L. ; Loik M.E. ; Belnap J.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2013
卷: 19, 期: 1 起始页码: 161
结束页码: 172
语种: 英语
英文关键词: Arid
; Cheatgrass
; Great Basin Desert
; Invasive species
; Nitrogen deposition
; Rainfall frequency
; Sagebrush steppe
; Snow to rain shifts
; Snowpack
; Stress-gradient hypothesis
Scopus关键词: arid environment
; biomass
; climate change
; global change
; grass
; invasive species
; irrigation
; nitrogen
; precipitation (climatology)
; rainfall
; snowpack
; stoichiometry
; altitude
; article
; Bromus
; greenhouse effect
; physiology
; Altitude
; Bromus
; Global Warming
; California
; Great Basin
; Sierra Nevada [California]
; United States
; Artemisia
; Artemisia tridentata
; Bromus
; Bromus tectorum
; Poaceae
; Purshia tridentata
英文摘要: Global change is likely to affect invasive species distribution, especially at range margins. In the eastern Sierra Nevada, California, USA, the invasive annual grass, Bromus tectorum, is patchily distributed and its impacts have been minimal compared with other areas of the Intermountain West. We used a series of in situ field manipulations to determine how B. tectorum might respond to changing climatic conditions and increased nitrogen deposition at the high-elevation edge of its invaded range. Over 3 years, we used snow fences to simulate changes in snowpack, irrigation to simulate increased frequency and magnitude of springtime precipitation, and added nitrogen (N) at three levels (0, 5, and 10 g m-2) to natural patches of B. tectorum growing under the two dominant shrubs, Artemisia tridentata and Purshia tridentata, and in intershrub spaces (INTR). We found that B. tectorum seedling density in April was lower following deeper snowpack possibly due to delayed emergence, yet there was no change in spikelet production or biomass accumulation at the time of harvest. Additional spring rain events increased B. tectorum biomass and spikelet production in INTR plots only. Plants were primarily limited by water in 2009, but colimited by N and water in 2011, possibly due to differences in antecedent moisture conditions at the time of treatments. The threshold at which N had an effect varied with magnitude of water additions. Frequency of rain events was more influential than magnitude in driving B. tectorum growth and fecundity responses. Our results suggest that predicted shifts from snow to rain could facilitate expansion of B. tectorum at high elevation depending on timing of rain events and level of N deposition. We found evidence for P-limitation at this site and an increase in P-availability with N additions, suggesting that stoichiometric relationships may also influence B. tectorum spread. © 2012 Blackwell Publishing Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62572
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Environmental Studies, University of California, Santa Cruz, CA 95064, United States; U.S. Geological Survey, Southwest Biological Science Center, Moab, UT 84532, United States
Recommended Citation:
Concilio A.L.,Loik M.E.,Belnap J.. Global change effects on Bromus tectorum L. (Poaceae) at its high-elevation range margin[J]. Global Change Biology,2013-01-01,19(1)