MTA-DE Lendület Functional and Restoration Ecology Research Group, Egyetem tér 1, H-4032, Debrecen, Hungary.
University of Debrecen, Department of Ecology, Egyetem tér 1, H-4032, Debrecen, Hungary.
Sci Rep. 2018 Sep 12;8(1):13703. doi: 10.1038/s41598-018-32078-x.
Neutral theory of species assembly means that species assembly is governed by stochastic dispersal processes and fluctuations in established populations. An alternative theory suggests that assembly is strongly determined by functional trait filtering governed by abiotic and biotic filtering selecting species from the local species pool. To test these assumptions, in the current paper we analysed vegetation changes in the first 12 years of succession after heavy goose grazing on acidic sand. With trait-based analyses using permanent plots we addressed the following hypotheses: (i) High fluctuations in the trait values are typical in the first years; later a temporally divergent change in the trait patterns of sites with different vertical position became characteristic. (ii) In the functional diversity of regenerative and vegetative traits we expected different temporal patterns. We confirmed the first hypothesis, as in the first few years most traits displayed high fluctuations with no clear patterns. Our findings weakly supported the second hypothesis; while there were distinct patterns detected in the functional richness of traits, functional divergence and evenness displayed no clear distinctive patterns. We can conclude that both trait neutrality and filtering effects operate in the vegetation changes of the first period of secondary succession.
物种组装的中性理论意味着物种组装受随机扩散过程和已建立种群中的波动所支配。另一种理论则认为，组装受到强烈的功能性状过滤的决定，由非生物和生物过滤从本地物种库中选择物种。为了检验这些假设，在当前的论文中，我们分析了在强酸沙地上重度鹅放牧后最初 12 年的演替过程中的植被变化。利用永久样地进行基于性状的分析，我们提出了以下假设：（i）在最初几年，性状值的高波动是典型的；之后，不同垂直位置的样地的性状模式在时间上出现了明显的差异。（ii）在再生和营养性状的功能多样性方面，我们预计会有不同的时间模式。我们证实了第一个假设，因为在前几年，大多数性状表现出高波动，没有明显的模式。我们的发现结果弱支持第二个假设；虽然在性状的功能丰富度中检测到了明显的模式，但功能发散和均匀度没有显示出明显的独特模式。我们可以得出结论，中性理论和过滤效应都在次生演替的早期阶段的植被变化中起作用。
