太子河洛氏鱥幼鱼栖息地适宜度评估

基于对太子河流域鱼类及栖息地的调查研究,选择该流域的优势种洛氏鱥(Phoxinus lagowskii)作为指示生物,建立洛氏鱥幼鱼对水深、流速、溶解氧、总溶解颗粒物和河岸带植被指数的栖息地适宜度曲线,并借鉴河道内流量增量法计算各采样点河段的洛氏鱥幼鱼栖息地适宜度指数。结果表明:洛氏鱥幼鱼栖息地适宜度指数在太子河上游较高(>0.5),中游次之(0.2-0.5),下游较低(<0.2)。洛氏鱥幼鱼栖息地适宜度指数与10项栖息地调查指标和土地利用类型的相关性分析表明:太子河流域内限制洛氏鱥幼鱼生存的因素不是水文条件,而是河流水质及河岸带等环境因素;洛氏鱥幼鱼栖息地适宜度指数受人类活动影响较大,随着太子河中下游人类开发强度加大,洛氏鱥栖息地质量呈下降趋势。

Assessment of Habitat Suitability of Juvenile Phoxinus lagowskii in Taizi River

According to the research on habitat of fish in Taizi River,the dominant species Phoxinus lagowski was selected as a biological indicator.Indexes of the habitat suitability curves of Phoxinus lagowski,including depth,velocity,dissolved oxygen,total dissolved solid and vegetation index of riparian zone,were established.Meanwhile,the habitat suitability index(HSI) of juvenile P.lagowskii at each site was calculated using instream flow incremental methodology.The results indicated that HSI was >0.5 in upstream,0.2-0.5 in midstream and <0.2 in downstream.The combined analysis on HSI and 10 indicators of habitat and land use types,revealed that the water quality and riparian zone conditions had more important effect than hydrological conditions on the survival of juvenile P.lagowskii.Furthermore,the human activities had a great effect on habitat suitability index of juvenile P.lagowskii.The index decreased with the increase of human developments in the midstream and downstream of Taizi River.