Hu Guang, Wilson Maxwell, Zhou Bing-Bing, Shang Chenwei, Yu Mingjian, Wu Jianguo
School of Civil Engineering and Architecture, Zhejiang Sci-Tech University, Hangzhou, China.
School of Life Sciences, Arizona State University, Tempe, Arizona, United States.
PeerJ. 2021 May 21;9:e11416. doi: 10.7717/peerj.11416. eCollection 2021.
Damming disrupts rivers and destroys neighboring terrestrial ecosystems through inundation, resulting in profound and long-lasting impacts on biodiversity and ecosystem processes far beyond the river system itself. Archipelagos formed by damming are often considered ideal systems for studying habitat fragmentation.
Here we quantified the island attributes and landscape dynamics of the Thousand Island Lake (TIL) in China, which is one of the several long-term biodiversity/fragmentation research sites around the world. We also synthesized the major findings of relevant studies conducted in the region to further ecological understanding of damming and landscape fragmentation.
Our results show that the vegetations on islands and the neighboring mainland were both recovering between 1985 and 2005 due to reforestation and natural succession, but the regeneration was partly interrupted after 2005 because of increasing human influences. While major changes in landscape composition occurred primarily in the lakefront areas and near-lakeshore islands, landscape patterns became structurally more complex and fragmented on both islands and mainland. About 80 studies from the TIL region show that the genetic, taxonomic, functional, and phylogenetic diversity on these islands were mainly influenced by island area at the patch scale, but fragmentation per se also affected species composition and related ecological processes at patch and landscape scales. In general, islands had lower species diversity but a steeper species-area relationship than the surrounding mainland. Fragmentation and edge effects substantially hindered ecological succession towards more densely vegetated forests on the islands. Environmental heterogeneity and filtering had a major impact on island biotic communities. We hypothesize that there are multiple mechanisms operating at different spatial scales that link landscape fragmentation and ecological dynamics in the TIL region, which beg for future studies. By focusing on an extensive spatiotemporal analysis of the island-mainland system and a synthesis of existing studies in the region, this study provides an important foundation and several promising directions for future studies.
筑坝会阻断河流，并通过淹没周边陆地生态系统对其造成破坏，从而对生物多样性和生态系统过程产生深远且持久的影响，其影响范围远远超出河流系统本身。由筑坝形成的群岛通常被视为研究栖息地破碎化的理想系统。
在此，我们对中国千岛湖的岛屿属性和景观动态进行了量化，千岛湖是全球几个长期生物多样性/破碎化研究地点之一。我们还综合了该地区相关研究的主要发现，以进一步从生态学角度理解筑坝和景观破碎化。
我们的结果表明，由于植树造林和自然演替，1985年至2005年间岛屿及邻近大陆的植被均在恢复，但2005年后由于人类影响增加，这种恢复部分被中断。虽然景观组成的主要变化主要发生在湖滨地区和近岸岛屿，但岛屿和大陆的景观格局在结构上都变得更加复杂和破碎。来自千岛湖地区的约80项研究表明，这些岛屿上的遗传、分类、功能和系统发育多样性在斑块尺度上主要受岛屿面积影响，但破碎化本身也在斑块和景观尺度上影响物种组成及相关生态过程。总体而言，岛屿的物种多样性低于周边大陆，但物种 - 面积关系比大陆更陡峭。破碎化和边缘效应严重阻碍了岛屿上向植被更茂密森林的生态演替。环境异质性和过滤对岛屿生物群落有重大影响。我们假设在不同空间尺度上有多种机制在起作用，这些机制将千岛湖地区的景观破碎化与生态动态联系起来，这有待未来研究。通过聚焦于对岛屿 - 大陆系统的广泛时空分析以及该地区现有研究的综合，本研究为未来研究提供了重要基础和几个有前景的方向。
