Yu Fei, Shi Xiaoxiao, Yi Xianfeng, Ma Jianmin
College of Life Sciences, Henan Normal University, Xinxiang, China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
Front Plant Sci. 2018 Dec 20;9:1911. doi: 10.3389/fpls.2018.01911. eCollection 2018.
Ecotones are considered unique environments, and the concepts of edge effects and ecotonal species have been applied widely. Our understanding of the mechanisms that underlie population and community responses to edge effects has been advanced by recent studies. However, little evidence exists to support an increased density and species richness in ecotones regarding rodent-mediated seed dispersal in response to edge plots between communities. and communities are typical of the Qinling Mountains, China. To elucidate what shapes tree species composition and recruitment dynamics in ecotones, we compared the differences in secondary and tertiary seed dispersal as well as predation in pine and oak by scatter-hoarding rodents as well as the regeneration characteristics of both species in their ecotones with different plots (i.e., 5-8, 15-18, and 27-30 m widths) in the eastern Qinling Mountains. We found that the seeds of pine and oak were removed rapidly, with no differences in the seed removal rates in their ecotones with different plots. Moreover, 13.0 and 36.0% of the scatter hoards of pine and oak, respectively, were established by small rodents in ecotones with a width of 5-8 m, and 3.67 and 7.33% in ecotones with a width of 27-30 m. The seedling densities of pine and oak were significantly higher in ecotones at widths of 5-8 m compared with widths of 15-18 and 27-30 m. According to the seed dispersal and seedling recruitment patterns of pine and oak, the disproportionate abundance of seedlings in ecotones may be due at least partly to patterns of seed caching by rodents.
生态交错带被视为独特的环境，边缘效应和生态交错带物种的概念已得到广泛应用。近期的研究推进了我们对种群和群落对边缘效应响应机制的理解。然而，关于群落间边缘样地中啮齿动物介导的种子传播，几乎没有证据支持生态交错带中密度和物种丰富度会增加。[具体群落名称1]和[具体群落名称2]是中国秦岭地区的典型群落。为了阐明是什么塑造了生态交错带中树种组成和更新动态，我们比较了东部秦岭地区松属和栎属植物种子的二次和三次传播差异以及分散贮藏啮齿动物对其的捕食情况，以及这两个物种在不同样地（即5 - 8米、15 - 18米和27 - 30米宽度）的生态交错带中的更新特征。我们发现松属和栎属植物的种子被迅速移除，不同样地的生态交错带中种子移除率没有差异。此外，在宽度为5 - 8米的生态交错带中，分别有13.0%和36.0%的松属和栎属植物的分散贮藏是由小型啮齿动物完成的，在宽度为27 - 30米的生态交错带中这一比例分别为3.67%和7.33%。与宽度为15 - 18米和27 - 30米的生态交错带相比，松属和栎属植物在宽度为5 - 8米的生态交错带中的幼苗密度显著更高。根据松属和栎属植物的种子传播和幼苗更新模式，生态交错带中幼苗数量过多可能至少部分归因于啮齿动物的种子贮藏模式。
