Ecology and Zoology Department, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil.
Sci Rep. 2024 Oct 24;14(1):25240. doi: 10.1038/s41598-024-76747-6.
Riparian forests are crucial for biodiversity, but dam construction for hydroelectric power disrupts these ecosystems, causing habitat loss and altering river dynamics. Our study investigates the impacts of dams on tree diversity in the southern Brazilian Atlantic Forest. We sampled trees along riverbanks and uplands across 15 dam-affected fragments, analysing the relationship between habitat loss (i.e. loss of riparian zones by permanent flooding due to dam filling), elevation difference, fragment size, and dam implementation time with alpha and beta diversity using mixed models and redundancy analyses. Habitat loss had a more significant impact on beta diversity, leading to shifts in species composition and reduced uniqueness of communities as the impact's intensity, spatial extent, and duration increased. Alpha diversity only increased in response to local elevation differences between plots located on uplands and riverbanks. Our sampling design can be applied to other inadequately monitored systems to provide insights into beta diversity, a component often neglected in dam licensing and mitigation processes. Our findings reveal a transient local heterogenisation, transitioning into regional homogenisation due to dam-induced habitat loss in riparian forests of the Brazilian Atlantic Forest.
河岸林对生物多样性至关重要，但水坝建设用于水力发电会破坏这些生态系统，导致栖息地丧失和改变河流动态。我们的研究调查了水坝对巴西南部大西洋森林中树木多样性的影响。我们沿着河岸和高地在 15 个受水坝影响的片段中进行了树木采样，分析了栖息地丧失（即由于大坝蓄水导致永久性洪水淹没而丧失河岸带）、海拔差异、片段大小和大坝实施时间与 alpha 和 beta 多样性之间的关系，使用混合模型和冗余分析。栖息地丧失对 beta 多样性的影响更大，导致物种组成发生变化，随着影响的强度、空间范围和持续时间的增加，群落的独特性降低。alpha 多样性仅在位于高地和河岸的样地之间的局部海拔差异响应中增加。我们的采样设计可以应用于其他监测不足的系统，以提供对 beta 多样性的深入了解，这是大坝许可和缓解过程中经常被忽视的一个组成部分。我们的研究结果表明，由于巴西大西洋森林河岸林的水坝引起的栖息地丧失，暂时导致了局部异质化，然后过渡到区域同质化。
