Programa de Pós-Graduação em Ecologia, Universidade Federal do Pará, Belém, Pará, Brazil.
Laboratório de Ecologia e Conservação, Instituto de Ciências Biológicas, Universidade Federal Do Pará, Rua Augusto Corrêa, Rua Augusto Corrêa, nº.1, Bairro Guamá, Belém, Pará, CEP 66.075-110, Brazil.
Environ Monit Assess. 2021 Nov 2;193(11):763. doi: 10.1007/s10661-021-09553-6.
The increasing land use in the Amazon region has resulted in the widespread substitution of forest areas with pasture and bauxite mining. These land uses reduce the forest cover of streams and modify their characteristics, reducing the diversity of aquatic insect assemblages. In the present study, we aimed to identify the threshold of the assemblages of the larvae of insects of the orders Ephemeroptera, Plecoptera, and Trichoptera (collectively known as EPT), and adults of the order Odonata, along an environmental gradient of land use and land cover (LULC). We sampled 30 streams along an environmental gradient determined by the proportion of forest, pasture, and bauxite mining observed within the catchment of each stream. We identified 12 taxa associated with forest (nine positively and three negatively) and four negatively associated with pasture. However, no taxa were associated explicitly with the bauxite mining gradient. As forest is converted to pasture, the abundance and frequency of occurrence of the taxa sensitive to pasture are reduced, reflecting their environmental sensitivity and their potential as sentinels of preserved streams. The identification of the thresholds of the EPT and odonates taxa allowed us to determine which of these organisms are positively or negatively associated with the environmental gradient of LULC in Amazonian streams. We hope that the results of the present study can be applied in future biomonitoring programs, particularly for monitoring the response of aquatic insects to the degradation of streams.
亚马逊地区不断增加的土地利用导致森林地区广泛被牧场和铝土矿开采所取代。这些土地利用方式减少了溪流的森林覆盖面积，并改变了其特征，降低了水生昆虫组合的多样性。在本研究中，我们旨在确定沿土地利用和土地覆盖（LULC）环境梯度的幼虫和成虫的昆虫目（蜉蝣目、石蝇目和毛翅目）的集合的阈值。我们在每个溪流流域内观察到的森林、牧场和铝土矿开采比例的环境梯度上，对 30 条溪流进行了采样。我们确定了 12 个与森林有关的分类群（9 个为正相关，3 个为负相关），以及 4 个与牧场有关的负相关分类群。然而，没有分类群与铝土矿开采梯度明确相关。随着森林向牧场的转化，对牧场敏感的分类群的丰度和出现频率减少，反映了它们对环境的敏感性以及它们作为受保护溪流哨兵的潜力。EPT 和蜻蜓类生物的阈值的确定，使我们能够确定这些生物中哪些与亚马逊溪流的 LULC 环境梯度呈正相关或负相关。我们希望本研究的结果可以应用于未来的生物监测计划，特别是监测水生昆虫对溪流退化的反应。
