Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.2307/3071818 |
Interspecific competition and resource pulse utilization in a cold desert community | |
Gebauer, RLE; Schwinning, S; Ehleringer, JR | |
通讯作者 | Gebauer, RLE |
来源期刊 | ECOLOGY
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ISSN | 0012-9658 |
出版年 | 2002 |
卷号 | 83期号:9页码:2602-2616 |
英文摘要 | In desert ecosystems a large proportion of water and nitrogen is supplied in rain-induced pulses. It has been suggested that competitive interactions among desert plants would be most intense during these pulse periods of high resource availability. We tested this hypothesis with three cold desert shrub species of the Colorado Plateau (Gutierrezia sarothrae, Atriplex confertifolia. and Chrysothamnus nauseosus), which differ in their distribution of functional roots. In a three-year field study we conducted a neighbor removal experiment in conjunction with simulated 25-mm precipitation events and the addition of a nitrogen pulse. in either spring or summer. We measured predawn water potential (Psi), gas exchange, leaf delta(15)N, carbon isotope discrimination (Delta), and growth of target plants for the duration of the study. We found that G. sarothrae used resource pulses to a larger extent than A. confertifolia, which has more functional roots at depth. In all species, the addition of a water or nitrogen pulse did not significantly affect maximal rates of photosynthesis or branch growth. Contrary to our initial hypothesis, we did not find that pulse use was reduced by the presence of neighboring plants. Nevertheless, there was strong evidence for competitive interactions, which were more likely mediated by water at depth than by nitrogen. in the more deep-rooted species A. confertifolia, neighbor removal affected T, gas exchange, Delta, percentage of carbon, and growth. G. sarothrae, which has a much smaller proportion of roots at depth, was less affected by the removal of neighboring shrubs, and not at all when only predominantly shallow-rooted herbaceous species were removed. These results suggest that shrubs in this cold desert community may primarily compete for water in deeper soil layers, where water depletion is slow and dominated by plant water uptake. There appeared to be little competition for water in shallow soil layers, where depletion is fast and dominated by evaporation. |
英文关键词 | Atriplex confertifolia Chrysothamnus nauseosus Colorado plateau, desert, Gutierrezia sarothrae, neighbor removal, plant competition resource pulses, stable isotopes, water uptake |
类型 | Article |
语种 | 英语 |
国家 | USA |
收录类别 | SCI-E |
WOS记录号 | WOS:000178153900023 |
WOS关键词 | CARBON-ISOTOPE DISCRIMINATION ; N-15 NATURAL-ABUNDANCE ; SHORTGRASS STEPPE ; SUMMER PRECIPITATION ; CHIHUAHUAN DESERT ; ARID ECOSYSTEM ; SOIL-MOISTURE ; ROOT SYSTEMS ; WATER-UPTAKE ; PLANTS |
WOS类目 | Ecology |
WOS研究方向 | Environmental Sciences & Ecology |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/142486 |
作者单位 | (1)Univ Utah, Dept Biol, Salt Lake City, UT 84112 USA;(2)Univ Utah, Stable Isotope Ratio Facil Environm Res, Salt Lake City, UT 84112 USA |
推荐引用方式 GB/T 7714 | Gebauer, RLE,Schwinning, S,Ehleringer, JR. Interspecific competition and resource pulse utilization in a cold desert community[J],2002,83(9):2602-2616. |
APA | Gebauer, RLE,Schwinning, S,&Ehleringer, JR.(2002).Interspecific competition and resource pulse utilization in a cold desert community.ECOLOGY,83(9),2602-2616. |
MLA | Gebauer, RLE,et al."Interspecific competition and resource pulse utilization in a cold desert community".ECOLOGY 83.9(2002):2602-2616. |
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