Huang Yao, Cai Hongyue, Jian Shuguang, Wang Jun, Kollmann Johannes, Hui Dafeng, Zhang Lei, Lu Hongfang, Ren Hai
CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones & Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; College of Ecology and Environment, Hainan University, Haikou, 570228, China.
School of Architectural Engineering, Shenzhen Polytechnic, Guangdong, Shenzhen, 518055, China.
J Environ Manage. 2023 Oct 15;344:118512. doi: 10.1016/j.jenvman.2023.118512. Epub 2023 Jun 27.
Poor regeneration of natural vegetation is a major factor contributing to the degradation of tropical coral islands. Soil seed banks (SSB) are important for maintaining the resilience of plant communities. However, the community characteristics and spatial distribution of SSBs and the controlling factors along human disturbance on coral islands are unclear. To fill this gap, we measured the community structure and spatial distributions of forest SSBs on three coral islands in the South China Sea, with varying degrees of human disturbance. The results showed that strong human disturbance increased the diversity, richness, and density of SSBs, as well as increased the richness of invasive species. With increased human disturbance, the heterogeneity pattern of SSBs spatial distribution changed from difference between forest east and west to forest center and edge. The similarity between the SSBs and above-ground vegetation also increased, and the distribution of invasive species extended from the edge to the central area of the forests, demonstrating that human disturbance limited the outward dispersal of seeds of resident species but increased the inward dispersal of seeds of invasive species. Interaction between soil properties, plant characteristics, and human disturbance explained 23-45% of the spatial variation of forest SSBs on the coral islands. However, human disturbance reduced the correlations of plant communities and spatial distribution of SSBs with soil factors (i.e., available phosphorus and total nitrogen) and increased the correlations of the community characteristics of SSB with landscape heterogeneity index, road distance, and shrub and litter cover. Resident seed dispersal on tropical coral islands might be enhanced by reducing building height, constructing buildings in down-wind locations, and preserving corridors that support animal movement among forest fragments.
天然植被再生不良是导致热带珊瑚岛退化的主要因素。土壤种子库（SSB）对于维持植物群落的恢复力很重要。然而，珊瑚岛上土壤种子库的群落特征、空间分布以及人类干扰对其的控制因素尚不清楚。为填补这一空白，我们测量了中国南海三个受不同程度人类干扰的珊瑚岛上森林土壤种子库的群落结构和空间分布。结果表明，强烈的人类干扰增加了土壤种子库的多样性、丰富度和密度，同时也增加了入侵物种的丰富度。随着人类干扰的增加，土壤种子库空间分布的异质性模式从森林东西部的差异转变为森林中心和边缘的差异。土壤种子库与地上植被之间的相似性也增加了，入侵物种的分布从森林边缘扩展到了森林中心区域，这表明人类干扰限制了本地物种种子的向外扩散，但增加了入侵物种种子的向内扩散。土壤性质、植物特征和人类干扰之间的相互作用解释了珊瑚岛上森林土壤种子库23%-45%的空间变异。然而，人类干扰降低了植物群落和土壤种子库空间分布与土壤因子（即有效磷和全氮）之间的相关性，并增加了土壤种子库群落特征与景观异质性指数、道路距离以及灌木和凋落物覆盖之间的相关性。通过降低建筑物高度、在顺风位置建造建筑物以及保留支持动物在森林片段之间移动的廊道，可能会增强热带珊瑚岛上本地种子的扩散。
