【摘要】 湿地生态健康评价对于掌握湿地的健康状况、理解人类活动干扰对其影响及实施生态预警等有重要意义。鄱阳湖对于维持其流域甚至长江中下游的生态平衡十分重要,目前尚未建立起其较完善的生态健康评价指标体系。大型底栖无脊椎动物完整性指数(benthic macroinvertebrate-based index of biotic integrity, B-IBI)是广泛应用的湿地生态健康评价方法。基于30个采样点(7个参照点,23个受损点)的大型底栖无脊椎动物采样数据,构建鄱阳湖湿地的B-IBI指数,采用自然断点法划分非常健康、健康、一般、差和极差5个健康等级标准,据此评价湿地生态健康状况。研究表明:(1)基于B-IBI指数的鄱阳湖湿地生态健康评价结果为一般;(2)就采样点B-IBI分值而言,呈现出西部健康状况优于东部的格局,其中国家级自然保护区内状况较好,而工业区、城镇、农田及河流入湖口附近状况较差;(3)B-IBI指数与前期构建的景观发展强度指数(LDI)、栖息地环境质量指数(QHEI)以及植被完整性指数(V-IBI)具有显著相关性,表明基于不同指数的评价结果较为一致。本研究构建的B-IBI指数能为鄱阳湖湿地的生态健康评价和监测提供重要方法。更多还原

【Abstract】 Assessing the status of wetland health can provide critical information for the protection and management of wetland ecosystems. The benthic macroinvertebrate-based index of biotic integrity(B-IBI), is a comprehensive method for assessing the ecological health of wetlands. Benthic macroinvertebrates are the most widely used biological indicators owing to their distinct advantages for freshwater biomonitoring, including bottom-dwelling habits, their relatively immobile nature, and huge species diversity. In this study, we aim to develop a benthic macroinvertebrate-based index of biotic integrity(B-IBI) to assess the health condition of Poyang Lake wetland. Field surveys of 30 sampling sites were conducted in the autumn of 2015. We collected data covering benthic macroinvertebrate species identity, abundance, water quality parameters, soil properties, and land use surrounding the sampling sites. We tested 49 candidate metrics with respect to the diversity, structure, and disturbance tolerance of benthic macroinvertebrate communities, for their discriminatory ability between the least disturbed and impaired sites. Five metrics were finally selected as the B-IBI metrics: number of taxa, number of Ephemeroptera, Trichoptera, and Odonata(ETO) taxa, Simpson′s diversity index, number of Diptera individuals, and number of predator taxa. Values of these metrics were scaled between 0 and 1. The B-IBI score of a sampling site was calculated as the sum of the scaled values of each individual metric. B-IBI scores were judged as five categories: excellent, good, fair, poor, and very poor. The results showed that four sites were rated as excellent(3.75 ≤ B-IBI); six were good(2.51 ≤ B-IBI ≤ 3.74); two were fair(1.92 ≤ B-IBI ≤ 2.50); eight were poor(1.02 ≤ B-IBI ≤ 1.91); and ten were very poor(B-IBI ≤ 1.01). Sampling sites rated as excellent and good were mostly located in western sections, especially within the national nature reserves, while those rated as poor and very poor were mostly located in northern, eastern, and southern sections, where wetland health was impaired by dense population and intensive agriculture practices. Wetland areas where rivers discharge into Poyang Lake were generally rated as poor, suggesting that pollutants brought in by rivers have negative impacts on wetland health. B-IBI assessment was significantly correlated with values generated from other methods(Pearson′s r ranging between 0.43 and 0.57, P<0.05), including the index of landscape development intensity(LDI), the qualitative habitat evaluation index(QHEI), and the vegetation-based IBI(V-IBI), suggesting that the results of these methods are generally consistent but not identical. Using multiple methods may generate more comprehensive results for the assessment of the wetland health status of Poyang Lake.更多还原