DOI: 10.1111/gcb.13694
论文题名: High N, dry: Experimental nitrogen deposition exacerbates native shrub loss and nonnative plant invasion during extreme drought
作者: Valliere J.M. ; Irvine I.C. ; Santiago L. ; Allen E.B.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2017
卷: 23, 期: 10 起始页码: 4333
结束页码: 4345
语种: 英语
英文关键词: coastal sage scrub
; drought
; Mediterranean-type shrublands
; nitrogen deposition
; nonnative plant invasion
; shrub loss
; vegetation-type conversion
Scopus关键词: Poaceae
英文摘要: Hotter, longer, and more frequent global change-type drought events may profoundly impact terrestrial ecosystems by triggering widespread vegetation mortality. However, severe drought is only one component of global change, and ecological effects of drought may be compounded by other drivers, such as anthropogenic nitrogen (N) deposition and nonnative plant invasion. Elevated N deposition, for example, may reduce drought tolerance through increased plant productivity, thereby contributing to drought-induced mortality. High N availability also often favors invasive, nonnative plant species, and the loss of woody vegetation due to drought may create a window of opportunity for these invaders. We investigated the effects of multiple levels of simulated N deposition on a Mediterranean-type shrubland plant community in southern California from 2011 to 2016, a period coinciding with an extreme, multiyear drought in the region. We hypothesized that N addition would increase native shrub productivity, but that this would increase susceptibility to drought and result in increased shrub loss over time. We also predicted that N addition would favor nonnatives, especially annual grasses, leading to higher biomass and cover of these species. Consistent with these hypotheses, we found that high N availability increased native shrub canopy loss and mortality, likely due to the higher productivity and leaf area and reduced water-use efficiency we observed in shrubs subject to N addition. As native shrub cover declined, we also observed a concomitant increase in cover and biomass of nonnative annuals, particularly under high levels of experimental N deposition. Together, these results suggest that the impacts of extended drought on shrubland ecosystems may be more severe under elevated N deposition, potentially contributing to the widespread loss of native woody species and vegetation-type conversion. © 2017 John Wiley & Sons Ltd 资助项目: This work was supported by the National Park Service Air Resource Division (TASK AGREEMENT NO. J8C07110022) and an NSF Doctoral Dissertation Improvement Grant (DEB-1501110). We would like to thank the many NPS employees, volunteers, graduate and undergraduate students who assisted in the field and laboratory and made this research possible.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60779
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Botany and Plant Sciences and Center for Conservation Biology, University of California Riverside, Riverside, CA, United States; Santa Monica Mountains National Recreation Area, U.S. National Park Service, Thousand Oaks, CA, United States
Recommended Citation:
Valliere J.M.,Irvine I.C.,Santiago L.,et al. High N, dry: Experimental nitrogen deposition exacerbates native shrub loss and nonnative plant invasion during extreme drought[J]. Global Change Biology,2017-01-01,23(10)