Background The River Basins in Southwest China, with its remarkable climate, topography and geology, is an important ecological security barrier in China’s "Three Zones and Four Belts"; the upper reaches of the rivers have large elevation differences and rich hydropower resources, making it an important hydropower energy base in China. The construction of hydropower projects inevitably produces slope destabilization, soil erosion and vegetation degradation, etc. The construction of hydropower projects in the Southwest Rivers has a great impact on the ecological degradation mechanism of hydropower projects under the extreme cold/drought conditions.

Methods employs field investigation, remote sensing interpretation, physical experiments, numerical simulation, and artificial intelligence methods to analyze the ecological effects of hydropower project disturbances in the upper reaches of River Basins in Southwest Region. It aims to identify the limiting factors of vegetation restoration and reconstruction, and to develop key technologies for the selection and breeding of stress-resistant plant species, the construction of stable plant communities, the formulation of vegetation substrates, and the integrated design of slope protection and ecological restoration. Ultimately, the project will establish a multi-objective, checklist-based ecological restoration technology system to support the sustainable management of disturbed alpine and arid ecosystems.

Results 1) Accurately identify the limiting factors of vegetation restoration and reconstruction, and to reveal the mechanisms of ecological degradation on disturbed slopes under the cold and arid conditions in the upper reaches of River Basins in Southwest Region. 2) Elucidate the response and diversity maintenance mechanisms of native plants under combined environmental stresses and hydropower project disturbances, and to develop technologies for the breeding of cold-, drought-, and infertility-tolerant native plant germplasm and the construction of stable plant communities. 3) Reveal the evolution and interaction mechanisms of disturbed slope soils under freeze–thaw and drought stresses, and establish a technological framework for the creation and adaptation of cold-, drought-, and erosion-resistant vegetation substrates suited to the upper reaches of River Basins in Southwest China. 4) Establish an evaluation index and methodological system for ecological restoration benefits, and to construct a multi-objective, constraint-based integrated technology system for slope protection and ecological restoration.

Conclusions Focus on cracking the key technical bottlenecks such as selection and breeding of excellent stress-resistant plants and stable community planting technology, creation of cold- and drought-resistant and erosion-resistant planting substrate and reconstruction of planting layer technology, and multi-dimensional synergistic technology of hydropower project-disturbed slope protection and ecological restoration, so as to provide integrated and systematic solutions for the ecological protection of slopes in disturbed areas of of the major hydropower projects in the upper reaches of River Basins in Southwest Region.