大渡河流域川陕哲罗鲑分布与栖息地特征研究

在实地调查和资料分析基础上,对大渡河流域川陕哲罗鲑栖息地及分布进行了量化分析,并对其适宜栖息地保护河段进行了评估与划分。研究表明:(1)1950~2012年,大渡河流域川陕哲罗鲑分布范围持续减少,损失率高达91.4%,强烈的人类活动(如水电开发)成其主要影响因素;(2)川陕哲罗鲑对栖息地生境质量需求较高,适应水温范围较窄(4℃~14℃)。在不同生活史阶段川陕哲罗鲑对于生境的需求存在差异;(3)大渡河上游干流及众多支流对保护川陕哲罗鲑极为重要。在上游适宜划分为川陕哲罗鲑栖息地保护的河段总长度共计2 222.9 km。根据研究结果,我们建议:(1)川陕哲罗鲑栖息地有效保护,不仅应保护其现有分布区域,而且还应涵盖具有较高保护和恢复价值的历史分布和潜在分布空间;(2)尽快开展大渡河河源区川陕哲罗鲑栖息地保护相关规划和研究工作;(3)为协调流域保护和发展,建议建立完善生态补偿机制。

DISTRIBUTION AND HABITAT CHARACTER OF HUCHO BLEEKERI IN THE DADU RIVER BASIN

Hucho bleekeri is one of the species in the genera Hucho in China, and the only large salmon fish in the Tibetan Plateau area. During the past several decades, Hucho bleekeri lost its habitat severely as a result of anthropogenic changes. In this paper, a quantitative analysis on habitat ranges and characters of Hucho bleekeri in the Dadu River basin was made, and the suitable habitat areas for this fish species were evaluated and determined based on field investigation and history data collection. The results showed: 1) from 1950 to 2012, the habitat loss in the Dadu River basin was extremely high in the past 60 years and now the loss rate was 91.4%. Intensive human activities such as hydropower development were the main reasons for this tendency of habitat loss; 2) the habitat requirements for Hucho bleekeri was relatively high and the suitable water temperature was in a narrow range (ranged from 4℃ to 14℃). Meanwhile, there were differences in habitat requirments during its different life stages; 3) the upper Dadu River with its tributaries were very important for Hucho bleekeri habitat protection. The rivers which can be protected as suitable habitats for Hucho bleekeri mainly distributed in the upper reaches of the Dadu River, with a total length of 2 222.9 km. Based on our results, some helpful suggestions on Hucho bleekeri habitat protection can be given: 1)in order to protect the habitat effectively, it is vital that different types of habitats should be considered comprehensively. Not only the present distribution areas, but also the historical and potential distribution areas which can be recovered as suitable habitat for Hucho bleekeri should be included. 2) planning and research works on habitat protection for Hucho bleekeri should be carried out in the headwaters of Dadu River as early as possible; 3) for the coordination of watershed protection and development, mechanism of ecological compensation should be constructed and improved.