The number and size of seeds in common versus restricted woodland herbaceous species in central Iowa, USA
The number and size of seeds in common versus restricted woodland herbaceous species in central Iowa, USA
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DOI：
10.1111/j.0030-1299.2004.13314.x
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发表时间：
2004-12-01
期刊：
影响因子：
3.4
通讯作者：
Mabry, CM
中科院分区：
文献类型：
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作者：
Mabry, CM
很少有植物分布广泛，出现在任何有合适栖息地的地方。由于有限的定居能力，大多数物种都没有出现在看似合适的地点。在景观规模上，由于缺乏种子或合适的微型场地，殖民受到限制，而目前人类对景观的改变可能会加剧这一限制。为了验证这样一个假设，即与常见物种相比，分布受限的物种的扩散能力更有限。我比较了7种常见林地草本植物的种子数量，并与分布更受限的同一属或科的7种物种进行了比较。与密切相关的普通物种相比，受限制物种的种子数量几乎少了一个数量级。它们还产生了超过一个数量级的更大的种子。这些结果支持扩散限制。当不包括分类信息时，检测这些差异的能力会降低。这些数据表明，这些物种不能同时最大化种子大小和种子数量。这些结果是根据人类干扰历史来解释的，人类干扰历史对爱荷华州的景观产生了压倒一切的影响，而且可能有利于种子丰富的物种，而不是种子少得多的物种。
Few plants have widespread distributions and occur wherever there is suitable habitat. Most species are absent from seemingly suitable sites because of limited colonizing ability. At a landscape scale colonization is limited by lack of seeds or suitable microsites, and this limit is likely to be exacerbated by current human alteration of the landscape. To test the hypothesis that species with restricted distributions have a more limited capacity for dispersal compared to common species, I compared seed number in a group of seven common woodland herbaceous species compared to seven species in the same genus or family with more restricted distributions. Restricted species had nearly an order of magnitude fewer seeds compared to closely related common species. They also produced over an order of magnitude larger seeds. These results support dispersal limitation. The ability to detect these differences was reduced when taxonomic information was not included. The data suggest that these species can not maximize both seed size and seed number. The results are interpreted in light of the human disturbance history that has had an overriding influence on the Iowa landscape and has likely favored species with an output advantage of abundant seeds over species with far fewer seeds.