Castro E R, Veras D S, Lustosa G S, Azevêdo C A S, Juen L
Programa de Pós-Graduação em Biodiversidade, Ambiente e Saúde, Lab. de Entomologia Aquática, Univ. Estadual do Maranhão, Campus Caxias, Caxias, Brasil.
Lab. de Ecologia de Comunidades, Instituto Federal do Maranhão, Campus Caxias, Caxias, Maranhão, Brasil.
Neotrop Entomol. 2021 Feb;50(1):21-31. doi: 10.1007/s13744-020-00816-4. Epub 2020 Oct 26.
Alterations in the environmental gradients of streams have a direct influence on the structure of the insect communities of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT), which are extremely sensitive to changes in habitat. The present study evaluated how habitat integrity in streams influence the composition of EPT genera, by testing three hypotheses: (i) the composition of the EPT genera is modified along the gradient of environmental disturbance; (ii) the composition of the EPT genera is more homogeneous in gradients with a higher degree of anthropogenic disturbance, and (iii) the greatest degree of environmental disturbance along the gradient results in the reduction of the richness and abundance of EPT genera. The study focused on 14 tributaries of the middle Itapecuru River, within an area of ecotone between the Brazilian Cerrado and Caatinga biomes. Data on the structure and physicochemical traits of the streams were collected between September 2014 and July 2015, a period that covers both the dry and rainy seasons in the study region. The results of the present study indicate that the composition of the EPT genera is modified in accordance with the variation in the habitat integrity, although, in contrast with expectations, more impacted areas had a more heterogeneous composition than undisturbed ones. The areas with more integrated landscapes contribute positively to the richness and abundance of EPT genera of the streams of the Cerrado-Caatinga ecotone. Given this, habitat integrity provide an important predictor of EPT diversity in the streams of the Cerrado-Caatinga ecotone.
溪流环境梯度的改变对蜉蝣目、襀翅目和毛翅目（EPT）昆虫群落的结构有直接影响，这些昆虫对栖息地变化极为敏感。本研究通过检验三个假设来评估溪流中的栖息地完整性如何影响EPT属的组成：（i）EPT属的组成沿环境干扰梯度发生改变；（ii）在人为干扰程度较高的梯度中，EPT属的组成更为均匀；（iii）沿梯度最大程度的环境干扰导致EPT属的丰富度和丰度降低。该研究聚焦于伊塔佩库鲁河中游的14条支流，位于巴西塞拉多和卡廷加生物群落之间的生态交错带区域内。在2014年9月至2015年7月期间收集了溪流的结构和理化特征数据，该时间段涵盖了研究区域的旱季和雨季。本研究结果表明，EPT属的组成根据栖息地完整性的变化而改变，不过，与预期相反的是，受影响更大的区域比未受干扰的区域具有更不均匀的组成。景观更为完整的区域对塞拉多 -卡廷加生态交错带溪流中EPT属的丰富度和丰度有积极贡献。鉴于此，栖息地完整性是塞拉多 -卡廷加生态交错带溪流中EPT多样性的一个重要预测指标。
