干热河谷库区消落带植被恢复研究

    Research on vegetation restoration of water-level-fluctuating zone in reservoirs in dry-hot valleys

    • 摘要: 干热河谷库区消落带植物生长面临周期性水淹与出露高温的双重胁迫,区域植被恢复极其困难。为解决干热河谷库区消落带植被恢复难题,以金沙江干热河谷白鹤滩库区消落带为例,开展植被恢复试验研究。试验结合消落带特点和实地调查结果,筛选适宜的植被恢复物种,提出适用于干热河谷库区消落带植被恢复的植物梯级配置模式和土工格栅工程措施。通过系统调查试验区栽种植物生长存活情况,分析了植物物种筛选、梯级植被配置及应用工程措施的植被恢复效果。研究结果表明:干热河谷库区消落带植被恢复宜在消落带上段综合选配乡土植物银合欢、小桐子、桑树、美人蕉、狗牙根、苍耳和皇竹草;中段配置耐淹植物竹柳、枫杨、水桦、小梾木、秋华柳和狗牙根;下段配置耐淹草本植物狗牙根和苍耳,其中乔木树种宜配置胸径5 cm以上苗木。试验区植物对干热环境适应采取了不同生长策略,表现出新枝从树干下部萌发、树干顶端枯梢、基部萌芽或大量萌蘖等形态性状;土工格栅工程措施在干热河谷库区消落带中上段能有效保持水土,营造近自然生境。研究结果可为干热河谷库区消落带植被恢复提供实践参考。

       

      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.

       

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