Simião-Ferreira Juliana, Nogueira Denis Silva, Santos Anna Claudia, De Marco Paulo, Angelini Ronaldo
Laboratório de Pesquisas Ecológicas e Educação Científica, Universidade Estadual de Goiás, BR 153 n. 3105 Fazenda Barreiro do Meio Caixa Posta 459, Anápolis, GO, 75001-970, Brazil.
Instituto Federal de Educação, Ciência e Tecnologia de Mato Grosso-IFMT, Cuiabá, MT, Brazil.
Environ Manage. 2018 Apr;61(4):687-699. doi: 10.1007/s00267-017-0989-y. Epub 2018 Feb 5.
The multiple scale of stream networks spatial organization reflects the hierarchical arrangement of streams habitats with increasingly levels of complexity from sub-catchments until entire hydrographic basins. Through these multiple spatial scales, local stream habitats form nested subsets of increasingly landscape scale and habitat size with varying contributions of both alpha and beta diversity for the regional diversity. Here, we aimed to test the relative importance of multiple nested hierarchical levels of spatial scales while determining alpha and beta diversity of caddisflies in regions with different levels of landscape degradation in a core Cerrado area in Brazil. We used quantitative environmental variables to test the hypothesis that landscape homogenization affects the contribution of alpha and beta diversity of caddisflies to regional diversity. We found that the contribution of alpha and beta diversity for gamma diversity varied according to landscape degradation. Sub-catchments with more intense agriculture had lower diversity at multiple levels, markedly alpha and beta diversities. We have also found that environmental predictors mainly associated with water quality, channel size, and habitat integrity (lower scores indicate stream degradation) were related to community dissimilarity at the catchment scale. For an effective management of the headwater biodiversity of caddisfly, towards the conservation of these catchments, heterogeneous streams with more pristine riparian vegetation found within the river basin need to be preserved in protected areas. Additionally, in the most degraded areas the restoration of riparian vegetation and size increase of protected areas will be needed to accomplish such effort.
溪流网络空间组织的多尺度反映了溪流栖息地的层次结构，从子流域到整个水文盆地，其复杂性程度不断增加。通过这些多空间尺度，局部溪流栖息地形成了景观尺度和栖息地规模不断增大的嵌套子集，对区域多样性的α和β多样性贡献各不相同。在这里，我们旨在测试多嵌套层次空间尺度的相对重要性，同时确定巴西塞拉多核心地区不同景观退化程度区域中毛翅目昆虫的α和β多样性。我们使用定量环境变量来检验景观同质化影响毛翅目昆虫α和β多样性对区域多样性贡献的假设。我们发现，α和β多样性对γ多样性的贡献因景观退化而异。农业活动更密集的子流域在多个层面上的多样性较低，尤其是α和β多样性。我们还发现，主要与水质、河道大小和栖息地完整性相关的环境预测因子（分数越低表明溪流退化）与流域尺度上的群落差异有关。为了有效管理毛翅目昆虫源头生物多样性以保护这些流域，流域内具有更原始河岸植被的异质溪流需要在保护区内得到保护。此外，在退化最严重的地区，需要恢复河岸植被并扩大保护区规模来实现这一目标。
