Complex Relationships between Competing Guilds along Large-Scale Environmental Gradients.
Complex Relationships between Competing Guilds along Large-Scale Environmental Gradients.
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沿着大尺度环境梯度竞争的行会之间的复杂关系。
DOI：
10.1086/690765
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Vergnon R
中科院分区：
文献类型：
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作者：
Vergnon R
尽管在过去30年中进行了大量研究，但对于相互作用的结果如何沿着环境梯度变化，特别是在大的地理尺度上，仍然缺乏普遍的了解。一个简单的预期是，环境质量的下降应该会减少竞争者的密度，因此竞争的影响在更差的环境中应该会减弱。一个违反直觉的结果是，随着环境质量的下降，竞争者密度之间的关联可能会从负面变为正面。在这里，我们在一组维管植物群落中测试这些预测，多年生植物与竞争力较低的一年生植物共享空间和资源。我们调查了9个灰色沙丘群落每年沿着欧洲纬度梯度的栖息地质量。我们发现，一年生和多年生物种的密度呈负相关，在高质量的梯度端，而在低质量的一端，公会密度不相关或呈正相关，与竞争减弱，增加环境限制相一致。我们的研究结果表明，即使是简单的相互作用，可以引起不明显的变化，物种协会沿着环境梯度。他们强调，了解物种相互作用的结果可能需要明确的特征，其变化的强度与环境质量和限制物种的共分布的因素可以随环境梯度沿着变化。
Despite much research over the past 30 years, there is still little general understanding of how the outcomes of interactions vary along environmental gradients, particularly at large geographic scales. A simple expectation is that decreasing environmental quality should reduce densities of competitors and hence the effects of competition should weaken in poorer environments. A counterintuitive consequence is that associations between densities of competitors might change from negative to positive as environments decrease in quality. Here we test these predictions in a set of vascular plant communities where perennial species share space and resources with less competitive annuals. We surveyed nine gray dune communities annually for 5 years along a cross-European latitudinal gradient of habitat quality. We find that densities of annual and perennial species are negatively correlated at the high-quality end of the gradient, while at the low-quality end, guild densities are uncorrelated or positively correlated, consistent with a weakening of competition linked to increasing environmental limitations. Our results suggest that even simple interactions can give rise to nonobvious changes in species associations along environmental gradients. They highlight that understanding the outcome of species interactions may require explicit characterization of their changing intensity with environmental quality and that the factors limiting species’ codistribution can vary along environmental gradients.