研究人员分析了历经27年，超过500个属的生物多样性和组合的组成，它们的分布地点包括美国森林、草原、城市和农业用地的6131个溪流点。在这个数据集中显示，相对而言，27年以来，大型无脊椎动物密度下降了11%和丰度增长了12.2%，昆虫密度和丰富性分别下降了6.8%和23.3%。
此外，随着时间的推移，城市和农业溪流与森林和草原溪流之间的丰度和组成差异也在增加。城市和农业溪流失去了它们曾经拥有的少数对干扰敏感的分类群，而获得了耐干扰的分类群。研究结果表明目前保护和恢复河流的努力不足以减轻人类活动的影响。
据介绍，大型溪流无脊椎动物的生物多样性受到挑战，因为生物监测通常具有有限的空间时间和分类范围。
附：英文原文
Title: Density declines, richness increases, and composition shifts in stream macroinvertebrates
Author: Samantha L. Rumschlag, Michael B. Mahon, Devin K. Jones, William Battaglin, Jonny Behrens, Emily S. Bernhardt, Paul Bradley, Ethan Brown, Frederik De Laender, Ryan Hill, Stefan Kunz, Sylvia Lee, Emma Rosi, Ralf Schfer, Travis S. Schmidt, Marie Simonin, Kelly Smalling, Kristofor Voss, Jason R. Rohr
Issue&Volume: 2023-05-03
Abstract: Documenting trends of stream macroinvertebrate biodiversity is challenging because biomonitoring often has limited spatial, temporal, and taxonomic scopes. We analyzed biodiversity and composition of assemblages of >500 genera, spanning 27 years, and 6,131 stream sites across forested, grassland, urban, and agricultural land uses throughout the United States. In this dataset, macroinvertebrate density declined by 11% and richness increased by 12.2%, and insect density and richness declined by 23.3 and 6.8%, respectively, over 27 years. In addition, differences in richness and composition between urban and agricultural versus forested and grassland streams have increased over time. Urban and agricultural streams lost the few disturbance-sensitive taxa they once had and gained disturbance-tolerant taxa. These results suggest that current efforts to protect and restore streams are not sufficient to mitigate anthropogenic effects.
DOI: adf4896
Source: https://www.science.org/doi/10.1126/sciadv.adf4896