From flowering to dispersal:: Reproductive ecology of an endemic plant, Astragalus australis var. olympicus (Fabaceae)
From flowering to dispersal:: Reproductive ecology of an endemic plant, Astragalus australis var. olympicus (Fabaceae)
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DOI：
10.2307/2656772
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发表时间：
1999-09-01
影响因子：
3
通讯作者：
Kaye, TN
中科院分区：
文献类型：
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作者：
Kaye, TN
奥林匹斯黄芪是美国华盛顿州奥林匹斯山脉的一种特有植物。它被美国鱼类和野生动物管理局视为受关注的物种。本研究着重研究了该植物从种子萌发到种子生产的生殖生物学，以确定可能导致其稀有和阻碍其保护的弱点。大多数植物平均产生的花和胚珠数量较多（分别为314.8和4106），但形成果实和种子的相对较少（分别为25.8和3.8%）。果实中胚珠因被捕食、种子败育和缺乏受精而丧失，其重要性依次递减。这些死亡的比例因地点和年份而异。通过套袋将传粉者排除在外，使坐果率降低了50%，但每个果实的坐果率和种子质量未受影响。萌发受割伤、温度和水分有效性的影响。被传播前种子捕食者（象鼻虫幼虫）破坏的种子约有11%仍能存活并从休眠状态中释放出来。我假设，在一个地点超过80%的分散前种子捕食对种群增长有负面影响。对该树种的保护可以从改善坐果和减少种子捕食中获益。
Astragalus australis var. olympicus is an endemic plant of the Olympic Mountains, Washington. It is considered a Species of Concern by the U.S. Fish and Wildlife Service. This study focused on the reproductive biology of the plant from Rower production through seed germination to identify possible weak points that might contribute to its rarity and impede its conservation. Most plants produced a large mean number of flowers and ovules (314.8 and 4106, respectively), but relatively few of these formed fruits and seeds (25.8 and 3.8%, respectively). In decreasing importance, ovules in fruits were lost to predation, seed abortion, and lack of fertilization. The percentages of these fates differed among sites and years. Excluding pollinators by bagging flowers reduced fruit set by similar to 50%, but seed set per fruit and seed mass were unaffected. Germination was affected by scarification, temperature, and moisture availability. About 11% of seeds damaged by predispersal seed predators (weevil larvae) remained viable and were released from dormancy. I hypothesize that predispersal seed predation (over 80% at one site) has a negative effect on population growth. Conservation of this species could benefit from improved fruit set and decreased seed predation.