干旱区生态环境知识资源中心(Arid): Competition suppresses shrubs during early, but not late, stages of arid grassland-shrubland state transition

Arid

DOI	10.1111/1365-2435.13336
	Competition suppresses shrubs during early, but not late, stages of arid grassland-shrubland state transition
	Pierce, Nathan A.1; Archer, Steven R.1; Bestelmeyer, Brandon T.2
通讯作者	Pierce, Nathan A.
来源期刊	FUNCTIONAL ECOLOGY
ISSN	0269-8463
EISSN	1365-2435
出版年	2019
卷号	33 期号:8 页码:1480-1490
英文摘要	Transitions from grass to woody plant dominance, widely reported in arid systems, are typically attributed to changes in disturbance regimes in combination with abiotic feedbacks, whereas biotic mechanisms such as competition and facilitation are often overlooked. Yet, research in semi-arid and subhumid savannas indicates that biotic interactions are important drivers in systems at risk for state transition. We sought to bridge this divide by experimentally manipulating grass-on-shrub and shrub-on-shrub interactions in early and late stages of grassland-shrubland state transition, respectively, and to assess the extent to which these interactions might influence arid land state transition dynamics. Target Prosopis glandulosa shrubs had surrounding grasses or conspecific neighbours left intact or killed with foliar herbicide, and metrics of plant performance were monitored over multiple years for shrubs with and without grass or shrub neighbours. Productivity of small shrubs was enhanced by grass removal in years with above-average precipitation, a result not evident in larger shrubs or during dry years. Proxy evidence based on nearest neighbour metrics suggested shrub-shrub competition was at play, but our experimental manipulations revealed no such influence. Competition from grasses appears to attenuate the rate at which shrubs achieve the size necessary to modify the physical environment in self-reinforcing ways, but only during the early stages of shrub encroachment. Our results further suggest that at late stages of grassland-to-shrubland state transitions, shrub-shrub competition will not slow the rate of shrub expansion, and suggest that maximum shrub cover is regulated by something other than density-dependent mechanisms. We conclude that grass effects on shrubs should be included in assessments of desert grassland state transition probabilities and rates, and that desertification models in arid ecosystems that traditionally focus on disturbance and abiotic feedbacks should be broadened to incorporate spatial and temporal variations in competitive effects. A plain language summary is available for this article.
英文关键词	Chihuahuan Desert competition grassland shrubland state transition woody plant encroachment
类型	Article
语种	英语
国家	USA
开放获取类型	Bronze
收录类别	SCI-E
WOS记录号	WOS:000479317100010
WOS关键词	CHIHUAHUAN DESERT ; SPATIAL-PATTERNS ; SOIL NUTRIENTS ; HONEY MESQUITE ; PROSOPIS-GLANDULOSA ; JORNADA BASIN ; ACACIA-KARROO ; ROOT SYSTEMS ; N-2 FIXATION ; SAVANNA
WOS类目	Ecology
WOS研究方向	Environmental Sciences & Ecology
来源机构	University of Arizona ; New Mexico State University
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/215846
作者单位	1.Univ Arizona, Sch Nat Resources & Environm, Tucson, AZ 85721 USA; 2.New Mexico State Univ, USDA ARS, Jornada Expt Range, Jornada Basin Long Term Ecol Res Program, Las Cruces, NM 88003 USA
推荐引用方式 GB/T 7714	Pierce, Nathan A.,Archer, Steven R.,Bestelmeyer, Brandon T.. Competition suppresses shrubs during early, but not late, stages of arid grassland-shrubland state transition[J]. University of Arizona, New Mexico State University,2019,33(8):1480-1490.
APA	Pierce, Nathan A.,Archer, Steven R.,&Bestelmeyer, Brandon T..(2019).Competition suppresses shrubs during early, but not late, stages of arid grassland-shrubland state transition.FUNCTIONAL ECOLOGY,33(8),1480-1490.
MLA	Pierce, Nathan A.,et al."Competition suppresses shrubs during early, but not late, stages of arid grassland-shrubland state transition".FUNCTIONAL ECOLOGY 33.8(2019):1480-1490.