鱼类生物群落对太子河流域土地利用、河岸带栖息地质量的响应

河流生态系统的退化是多空间尺度环境因子作用的结果。探讨不同尺度环境因子及水生生物之间的作用关系,识别影响水生生物群落完整性的尺度问题,是有效开展水生生物保护的基础。基于2009年对太子河流域15个样点的鱼类、河岸带栖息地质量评价,结合遥感影像解译的太子河流域土地利用情况(包括流域尺度和河段尺度),研究鱼类完整性指数(F-IBI)与两种尺度土地利用、栖息地质量参数之间的关系。结果表明太子河上游地区河岸栖息地质量较好,下游地区由于农业用地、城镇用地比例的增加河岸栖息地质量明显下降。F-IBI与自然用地比例呈正相关,与农业、城镇用地比例呈负相关。农业用地对F-IBI的影响体现在流域尺度,而城镇用地在两种尺度上都存在显著影响。相比于农业用地,城镇用地相同比例的增加会导致F-IBI更快的下降。底质、水质状况、人类活动强度是显著影响F-IBI的栖息地质量评价参数。3项参数均随农业和城镇用地比例增加而降低,农业用地主要在流域尺度上对3项参数产生影响,城镇用地主要影响底质和水质状况2项参数,而在两种尺度上的影响相差不大。

Exploring the relationship among land-use, riparian habitat quality, and biological integrity of a fish community

River ecosystems are being degraded by various environmental factors across multi-spatial scales. In general, aquatic organism conservation aims to explore the relationship between aquatic organisms and environmental factors across multi-spatial scales, and to discern the scale at which the biological integrity of aquatic organisms is affected. We collected data about fishes and riparian habitat conditions at 15 sampling sites in the Taizi River basin during August, 2009. In parallel, we collected data on land use at the both of catchment and reach scales by interpreting the satellite images. We explored the relationship among the fish index of biotic integrity (F-IBI), land use at two scales, and riparian habitat condition. The results showed that riparian habitat condition is relatively better in the upper regions than the lower regions of rivers, due to a percentage increase in farmland and urban areas in the lower regions. F-IBI showed a positive correlation with the proportions of natural areas, but showed a negative correlation with the proportions of farmland and urban areas. F-IBI exhibited a stronger response to the proportion of farmland at the catchment scale, and to the proportion of urban areas at both scales. Compared to farmland, the same percentage increase in urban area resulted in a faster decrease of F-IBI. Substrate, water quality, and anthropogenic disturbances were three key riparian habitat parameters that significantly degraded F-IBI. These three parameters decreased with increasing proportions of farmland and urban areas. Farmland showed a significant effect on the three parameters at the catchment scale, whereas urban areas only significantly affected substrate and water quality at both scales.