人工塑造生境条件下中华倒刺鲃的栖息偏好研究

Habitat Preference of Spinibarbus sinensis Under Artificial Habitat Conditions

为了促进受水电工程影响河段鱼类资源的恢复,选择中华倒刺鲃(Spinibarbus sinensis),依托大型生态试验场,人工塑造多种近自然微地形生境,营造适宜鱼类栖息的水文水动力环境,研究其栖息行为偏好特性。设置0.3、0.6、1.0、1.5、2.0、3.0 m^(3)/s共6种流量工况,分别进行多地形组合、沙洲地形局部偏好、深潭浅滩地形局部偏好鱼类栖息生境选择试验。采用PIT射频识别系统实时监测鱼类栖息行为,选取流速、涡量、湍流动能和床体切应力4个水动力指标,计算对应流场条件下的中华倒刺鲃栖息适宜度,并基于随机森林和CART算法筛选影响中华倒刺鲃栖息选择的主要水动力指标,探究其栖息行为的水动力选择机制。结果表明,深潭浅滩及沙洲河段的进出口是中华倒刺鲃喜好栖息场所,涡量和流速是影响其栖息的主要水动力指标。流速高于0.545 m/s、低于2.3 m/s,涡量高于0.72/m、低于15.7/m时的流场条件,为试验工况下中华倒刺鲃的最适宜栖息环境。研究结果为鱼类栖息地生态修复及生态调度提供了理论依据和技术支撑。

In this study,Spinibarbus sinensis was selected for study,and we explored the habitat preferences of S.sinensis in constructed multiple microtopographic habitats,simulating the hydrolog⁃ic and hydraulic conditions in natural rivers with large-scale ecological settings.Additionally,the principal hydrodynamic indicators influencing habitat selection and the hydrodynamic selection mech⁃anism of habitat behavior were analyzed based on Random Forest and Classification and Regression Trees(CART)algorithms.The aims of the study were to provide criteria for planning,designing and carrying out habitat restoration,to facilitate the recovery of fish resources in rivers affected by hydropower projects and to create a hydrodynamic environment suitable for S.sinensis.On August 7 and September 15,real-time monitoring of fish habitation behaviour was conducted in the ecologi⁃cal experimental field using a Passive Integrated Transponder(PIT)radio frequency identification system.Four hydrodynamic indicators(flow velocity,vorticity,turbulent kinetic energy,and bed shear stress)were selected to calculate the suitability index for S.sinensis under different microtopo⁃graphic environments(straight,meandering river sections and sections with a pool,shoal,or bars)and different flow conditions(0.3,0.6,1.0,1.5,2.0,3.0 m^(3)/s).Results show that river sections with pool-shoal and bars were the preferred habitat for S.sinensis.With increasing water flow,prefer⁃ence for river sections with bars increased,especially at the inflow and outflow of bars.Under high water flow conditions(2.0,3.0 m^(3)/s),over 60%of the S.sinensis displayed a strong prefer⁃ence for the river section with bars.Flow velocity and vorticity were the primary hydrodynamic pa⁃rameters affecting the habitat preferences of S.sinensis.Under test conditions,the most suitable field conditions for S.sinensis habitation is a velocity between 0.545 m/s and 2.3 m/s,and a vortici⁃ty between 0.72/m and 15.7/m.This research provides a theoretical foundation and technical support for ecological restoration and management of fish habitat.