Abstract:
Plant growth in the water-level-fluctuating zone of dry-hot valley reservoir is subject to periodic water flooding and high temperature, and regional vegetation recovery is quite difficult. To solve this problem, vegetation restoration of the water-level-fluctuating zone in the Baihetan Reservoir located in Jinsha River was conducted. We selected suitable plant species for vegetation restoration through hydrological analysis and field surveys, and proposed geogrid engineering measures and elevation-based plant arrangement. The application and effectiveness of vegetation restoration were analyzed by systematically investigating survival and growth of planted plants in experimental site. The results showed that vegetation restoration in the water-level-fluctuating zone of this dry-hot valley reservoir was recommended to allocate native plants such as
Leucaena leucocephala,
Jatropha curcas,
Morus alba,
Canna indica,
Cynodon dactylon,
Xanthium sibiricum and
Pennisetum sinese in the upper layer, arrange flood-tolerant plants such as
Salix hybrid,
Pterocarya stenoptera,
Betula nigra,
Cornus quinquenervis,
Salix variegata and
Cynodon dactylon in the middle layer, and prioritize flood-tolerant herbaceous plants such as
Xanthium sibiricum and
Cynodon dactylon in the lower layer. Saplings exceeding 5 cm in diameter at breast height were suitable for vegetation restoration. Plants in experimental area adopted different growth strategies to acclimate to the arid and hot environment, exhibiting distinct morphological adaptations such as new branches sprouting from the lower trunk, dieback at the upper trunk, basal budding, or many root sprouts. Geogrid engineering measures could create near-natural habitat and conserve water and soil effectively in middle and lower layer of the water-level-fluctuating zone in dry-hot valley. These results can provide practical reference for the ecological restoration in fluctuating zone of the dry-hot valley reservoirs.