SURVIVAL OF WINTER ANNUALS IN NORTHERN MOJAVE DESERT
SURVIVAL OF WINTER ANNUALS IN NORTHERN MOJAVE DESERT
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DOI：
10.2307/1933732
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发表时间：
1967-01-01
期刊：
影响因子：
4.8
通讯作者：
BEATLEY, JC
中科院分区：
文献类型：
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作者：
BEATLEY, JC
1963-64年，在内华达州南部3个流域的13个样地（总样本量16.4 m2）上取样的莫哈韦沙漠冬季年群（53个分类群），初秋萌发后成活率为38%（样地范围10 ~ 63%）。死亡发生在早春，在从冬季营养生长缓慢到茎伸长开始转变的时候。尽管在7- 8个月的生长季节没有明显的降水不足，但在植株体积增加数倍的生命周期中，土壤湿度不足以满足所有幼苗的需求显然是导致死亡的原因。在7个流域62个样地（总样本量62 m2）取样，3-5.5 in降雨后春季发芽后幼苗的平均成活率（58个分类群）。1965年3月至arpil为60%（按流域范围，44-83%）。这些种群的生命周期在6-10周内完成，其死亡率不能归因于湿度不足。在大多数季节，无论降水情况如何，大多数沙漠一年生植物的幼苗可能无法存活到成熟。
Following early autumn germination in Mojave Desert winter annual populations (53 taxa) sampled on 13 plots (total sample size, 16.4 m2) in 3 drainage basins in southern Nevada, 1963-64, there was 38% survival to maturity (plot ranged 10-63%). Death occurred in early spring, at the time of shift from the slow vegetative growth of vinter to the beginning of stem elongation. Despite no marked precipitation deficiencies during the 7- to 8-month growing season, mortality apparently resulted from inadequate soil moisture to meet the demands of all seedlings at the point in the life cycle of a manyfold increase in plant volume. Mean percentage survival to maturity of seedlings (58 taxa), sampled on 62 plots (total sample size, 62 m2) in 7 drainage basins, following spring germination after rains of 3-5.5 in. in March -Arpil 1965, was 60% (range by basin, 44-83%). Mortality in these populations, whose life cycles were completed in 6-10 weeks, could not be attributed to inadequate moisture levels. In most seasons, regardless of precipitation regimes, the majority of seedlings of desert annuals probably do not survive to maturity.