Knowledge Resource Center for Ecological Environment in Arid Area
A preliminary study of the responsiveness to seasonal atmospheric and rainfall patterns of wash woodland species in the arid Richtersveld | |
Wand, SJE; Esler, KJ; Rundel, PW; Sherwin, HW | |
通讯作者 | Wand, SJE |
会议名称 | Workshop on the Plant Ecology of Namaqualand |
会议日期 | JUL 17-18, 1997 |
会议地点 | CAPE TOWN, SOUTH AFRICA |
英文摘要 | Seasonal carbon and water relations were compared among seven tree or shrub wash woodland species in the winter rainfall desert of the Richtersveld National Park, South Africa. Plants were generally aseasonal with respect to gas exchange, but responsive to rainfall events with respect to water relations and phenology. Relatively narrow annual ranges in potential evapotranspiration due to the maritime influence could explain why these plants respond more to fluctuations in water acquisition potential than to evaporative demand. Two species were summer-deciduous, but one of them (Ozoroa concolor) responded to aseasonal summer rainfall by leafing out and flowering. These two species had high shoot xylem water potentials when in leaf. All other species were sclerophyllous evergreens with low water potentials, particularly the shallow-rooted shrub Zygophyllum prismatocarpum, and Boscia albitrunca which may have a different rooting pattern to the other phreatophytes. The latter species was also unique due to its high leaf nitrogen contents, photosynthetic rates and stomatal conductances, despite very low leaf water potentials. Leaf stable carbon isotope composition ((13)delta C) varied between species (-22 to -27 parts per thousand), but was lower than the mean for arid regions worldwide. The values indicated moderately high levels of water use efficiency, but a less conservative strategy in two species, including Boscia albitrunca. The affinities of these species to summer rainfall biomes, their apparent decline in the western arid regions in recent geological history following aridification, and their absence southwards in the winter rainfall regions, suggest that these wash species rely on sporadic summer rainfall events to some extent. They may be at risk if predicted increases in temperature and changes in rainfall patterns alter their effective moisture availability. |
英文关键词 | photosynthesis phreatophyte stable carbon isotope composition water relations winter rainfall desert |
来源出版物 | PLANT ECOLOGY |
ISSN | 1385-0237 |
出版年 | 1999 |
卷号 | 142 |
期号 | 1-2 |
页码 | 149-160 |
出版者 | KLUWER ACADEMIC PUBL |
类型 | Article;Proceedings Paper |
语种 | 英语 |
国家 | South Africa;USA |
收录类别 | CPCI-S ; SCI-E |
WOS记录号 | WOS:000082531800012 |
WOS关键词 | CARBON ISOTOPE DISCRIMINATION ; WATER RELATIONS ; SOUTHERN-AFRICA ; SONORAN DESERT ; PACHYPODIUM ; CALIFORNIA ; PHENOLOGY ; CAPE |
WOS类目 | Plant Sciences ; Ecology ; Forestry |
WOS研究方向 | Plant Sciences ; Environmental Sciences & Ecology ; Forestry |
资源类型 | 会议论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/292789 |
作者单位 | (1)Natl Bot Res Inst, ZA-7735 Cape Town, South Africa;(2)Univ Stellenbosch, Dept Bot, ZA-7602 Stellenbosch, South Africa;(3)Univ Calif Los Angeles, Dept Biol, Los Angeles, CA 90024 USA;(4)Univ Cape Town, Dept Bot, ZA-7700 Rondebosch, South Africa |
推荐引用方式 GB/T 7714 | Wand, SJE,Esler, KJ,Rundel, PW,et al. A preliminary study of the responsiveness to seasonal atmospheric and rainfall patterns of wash woodland species in the arid Richtersveld[C]:KLUWER ACADEMIC PUBL,1999:149-160. |
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