Limiting similarity between invaders and dominant species in herbaceous plant communities?
Limiting similarity between invaders and dominant species in herbaceous plant communities?
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DOI：
10.1111/j.1365-2745.2007.01274.x
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发表时间：
2007-09-01
影响因子：
5.5
通讯作者：
Emery, Sarah M.
中科院分区：
文献类型：
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作者：
Emery, Sarah M.
1.有限相似性理论预测，成功的入侵者应该在功能上不同于社区中已经存在的物种。这一理论已经通过操纵社区的功能丰富度进行了测试，但没有功能多样性的其他方面，如优势物种的身份。由于优势种对生态系统功能有很强的影响，我假设成功的入侵者在功能上应该与群落优势种不同。为了验证这一假设，我在两个不同的实验中加入了17种不同物种的种子：一个是在一个自然的老田群落中，该群落由不同的植物物种占主导地位，另一个是在草原生态系统中，优势物种的身份不同，但物种丰富度或均匀度不变。利用指示种分析法检验入侵种在优势种功能不同的样地中是否有较高的建群成功率.在两个实验中，大部分入侵物种（47-71%）在不同的优势处理中没有表现出亲和力差异，尽管三分之一的物种确实表现出一些限制相似性的证据。外来入侵者比本地入侵者有更高的入侵成功率，并似乎被功能相似的优势种抑制。然而，即使这些入侵模式在两个实验中也不一致。从这项研究的结果表明，有一些证据表明，优势种抑制入侵功能相似的物种，超出了简单的存在或不存在的物种在社区的影响，虽然它不是唯一的因素影响入侵成功。入侵成功的模式是不一致的物种和实验，表明其他研究只使用一个单一的物种的入侵者作出结论，社区入侵应谨慎解释。
1. Limiting similarity theory predicts that successful invaders should differ functionally from species already present in the community. This theory has been tested by manipulating the functional richness of communities, but not other aspects of functional diversity such as the identity of dominant species. Because dominant species are known to have strong effects on ecosystem functioning, I hypothesized that successful invaders should be functionally dissimilar from community dominants.2. To test this hypothesis, I added seeds of 17 different species to two different experiments: one in a natural oldfield community that had patches dominated by different plant species, and one in grassland mesocosms that varied in the identity of the dominant species but not in species richness or evenness. I used indicator species analyses to test whether invaders had higher establishment success in plots with functionally different dominant species.3. A large percentage of invader species (47-71%) in both experiments showed no difference in affinity across the different dominant treatments, although one-third of species did show some evidence for limiting similarity. Exotic invaders had much higher invasion success than native invaders, and seemed to be inhibited by dominant species that were functionally similar. However, even these invasion patterns were not consistent across the two experiments.4. The results from this study show that there is some evidence that dominant species suppress invasion by functionally similar species, beyond the effect of simple presence or absence of species in communities, although it is not the sole factor affecting invasion success. Patterns of invasion success were inconsistent across species and experiments, indicating that other studies using only a single species of invader to make conclusions about community invasibility should be interpreted with caution.