WATER-STRESS AND USE OF SUMMER PRECIPITATION IN A GREAT-BASIN SHRUB COMMUNITY
WATER-STRESS AND USE OF SUMMER PRECIPITATION IN A GREAT-BASIN SHRUB COMMUNITY
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DOI：
10.2307/2389821
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发表时间：
1994-06-01
影响因子：
5.2
通讯作者：
EHLERINGER, JR
中科院分区：
文献类型：
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作者：
DONOVAN, LA;EHLERINGER, JR
1.在大流域灌丛群落中，水分胁迫的季节模式(由黎明前木质部压力势决定)和夏季降水的相对利用(由氢同位素组成决定)在种内和种间有所不同。6~7月旱季水分胁迫的发展与8月夏季降水的利用呈正相关。最小的植株通常会产生最大的水分胁迫，并吸收最多的夏季降水，这可能是因为它们更依赖于浅根。在所研究的成熟灌木中，夏季降水中的水分被黄花金鱼和三齿蒿所吸收，而不被反胃毛虫、杜松和四齿草所吸收。对于成熟时根深蒂固的灌木物种，如恶心草，与繁殖成熟的大型植物相比，小型宿根植物的有效土壤水分的数量和时间是不同的。
1. Seasonal patterns of water stress (determined from predawn xylem pressure potentials) and relative use of summer precipitation (determined from hydrogen isotope composition) varied intraspecifically and interspecifically in a Great Basin shrub community.2. The development of water stress during the dry season from June to July was positively correlated with the use of summer precipitation in August. The smallest plants generally developed the greatest water stress and took up the most summer precipitation, presumably due to being more dependent on shallow roots.3. Among mature shrubs examined, moisture from summer precipitation was taken up by Chrysothamnus viscidiflorus and Artemisia tridentata, but not by C nauseosus, Juniperus osteosperma and Tetradymia canescens.4. For shrub species that are deeply rooted at maturity, such as C nauseosus, the quantity and timing of available soil moisture is different for small establishing plants as compared to large reproductively mature plants.