Programa de Pós-Graduação em Biologia Comparada, Universidade Estadual de Maringá, Maringá, Paraná, Brazil.
Programa de Pós-graduação em Ciências Biológicas/Zoologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, São Paulo, Brazil.
PLoS One. 2022 Sep 9;17(9):e0274191. doi: 10.1371/journal.pone.0274191. eCollection 2022.
Human pressures have been intensely modifying freshwater ecosystems worldwide. We assessed the effects of human pressure on habitat diversity and primary productivity to understand the consequences on fish fauna in 25 tropical and subtropical streams of two globally important ecoregions: Iguassu and Upper Paraná. We hypothesized that the increased human pressure (urbanization and agriculture) on stream environments, both at the local and catchment scales, directly decreases habitat diversity. We also hypothesized that increased human pressure triggers changes in primary productivity and fish fauna composition and structure. We evaluated the human pressure intensity using the Integrated Disturbance Index and the Rapid Habitat Diversity Assessment protocol, which combines information about land use, land cover and environmental characteristics of the stream catchment and sampling sites. Streams with increased human disturbance had lower habitat diversity, higher primary productivity, and high non-native species abundance. Fish compositional turnover was associated with increased human disturbance. Native and degradation-sensitive fish species, especially endemic ones, were associated with streams with higher habitat diversity and forested cover. Degradation-resistant fishes, mostly non-native species, were associated with streams with higher human disturbance and urban land use. Although human pressure did not affect species richness, Shannon diversity, and Simpson dominance, there were significant effects on numerical abundance and fish species equitability. In this study, human pressure directly affected habitat structure, with indirect consequences for fish fauna, increasing the potential for local extirpation of rare species.
人类的压力已经强烈地改变了全球的淡水生态系统。我们评估了人类压力对栖息地多样性和初级生产力的影响，以了解在伊瓜苏和上巴拉那两个具有全球重要意义的生态区的 25 条热带和亚热带溪流中鱼类区系的后果。我们假设，溪流环境中的人类压力（城市化和农业）的增加，无论是在局部还是集水区尺度上，都会直接降低栖息地的多样性。我们还假设，增加的人类压力会引发初级生产力和鱼类区系组成和结构的变化。我们使用综合干扰指数和快速栖息地多样性评估方案来评估人类压力强度，该方案结合了关于土地利用、土地覆盖和溪流集水区和采样点的环境特征的信息。受人类干扰增加的溪流，其栖息地多样性较低，初级生产力较高，非本地物种的丰度较高。鱼类组成的更替与人类干扰的增加有关。本地和对退化敏感的鱼类物种，特别是特有物种，与具有较高栖息地多样性和森林覆盖的溪流有关。对退化有抵抗力的鱼类，主要是外来物种，与具有较高人类干扰和城市土地利用的溪流有关。尽管人类压力没有影响物种丰富度、香农多样性和辛普森优势度，但对数量丰富度和鱼类物种均匀度有显著影响。在这项研究中，人类压力直接影响了栖息地结构，对鱼类区系产生了间接影响，增加了稀有物种局部灭绝的可能性。
