CONICET Laboratorio de Investigaciones en Ecología y Sistemática Animal-Universidad Nacional de la Patagonia San Juan Bosco, Argentina.
Sci Total Environ. 2011 Jan 1;409(3):612-24. doi: 10.1016/j.scitotenv.2010.10.034. Epub 2010 Nov 20.
Changes in land-use practices have affected the integrity and quality of water resources worldwide. In Patagonia there is a strong concern about the ecological status of surface waters because these changes are rapidly occurring in the region. To test the hypothesis that greater intensity of land-use will have negative effects on water quality, stream habitat and biodiversity we assessed benthic macroinvertebrates, riparian/littoral invertebrates, fish and birds from the riparian corridor and environmental variables of 15 rivers (Patagonia) subjected to a gradient of land-use practices (non-managed native forest, managed native forest, pine plantations, pasture, urbanization). A total of 158 macroinvertebrate taxa, 105 riparian/littoral invertebrate taxa, 5 fish species, 34 bird species, and 15 aquatic plant species, were recorded considering all sites. Urban land-use produced the most significant changes in streams including physical features, conductivity, nutrients, habitat condition, riparian quality and invertebrate metrics. Pasture and managed native forest sites appeared in an intermediate situation. The highest values of fish and bird abundance and diversity were observed at disturbed sites; this might be explained by the opportunistic behavior displayed by these communities which let them take advantage of increased trophic resources in these environments. As expected, non-managed native forest sites showed the highest integrity of ecological conditions and also great biodiversity of benthic communities. Macroinvertebrate metrics that reflected good water quality were positively related to forest land cover and negatively related to urban and pasture land cover. However, by offering stream edge areas, pasture sites still supported rich communities of riparian/littoral invertebrates, increasing overall biodiversity. Macroinvertebrates were good indicators of land-use impact and water quality conditions and resulted useful tools to early alert of disturbances in streams. Fish and birds having a greater ability of dispersion and capacity to move quickly from disturbances would reflect changes at a higher scale.
土地利用方式的变化已经影响到全球水资源的完整性和质量。在巴塔哥尼亚地区，人们非常关注地表水的生态状况，因为该地区的这些变化正在迅速发生。为了验证土地利用强度增加将对水质、河流生境和生物多样性产生负面影响的假设，我们评估了来自河岸带和环境变量的底栖大型无脊椎动物、河岸/湖岸无脊椎动物、鱼类和鸟类，这些变量来自 15 条河流（巴塔哥尼亚），这些河流经历了土地利用方式的梯度变化（未管理的原生林、管理的原生林、松林种植园、牧场、城市化）。总共记录了 158 种底栖大型无脊椎动物、105 种河岸/湖岸无脊椎动物、5 种鱼类、34 种鸟类和 15 种水生植物，考虑到所有的地点。城市土地利用对溪流产生了最显著的变化，包括物理特征、电导率、养分、生境状况、河岸质量和无脊椎动物指标。牧场和管理的原生林地点处于中间状态。受干扰的地点观察到鱼类和鸟类丰度和多样性的最高值；这可能是由于这些群落表现出的机会主义行为，使它们能够利用这些环境中增加的营养资源。不出所料，未管理的原生林地点显示出生态条件的最高完整性，同时也有底栖群落的高度生物多样性。反映良好水质的大型无脊椎动物指标与林地覆盖率呈正相关，与城市和牧场土地覆盖率呈负相关。然而，通过提供溪岸地区，牧场仍然支持丰富的河岸/湖岸无脊椎动物群落，增加了整体生物多样性。大型无脊椎动物是土地利用影响和水质状况的良好指标，是溪流受到干扰的早期预警的有用工具。鱼类和鸟类具有更大的扩散能力和快速从干扰中移动的能力，因此将反映更高尺度的变化。
