雅鲁藏布江流域杨树人工林优势种对高寒环境的生态适应性研究

雅鲁藏布江流域的造林工作对提升流域水土保持以及改善流域生态环境具有重要意义.北京杨(Populus×beijingensis)和银白杨(P.alba)作为该流域的主要造林树种,但这两树种对高寒环境的生态适应性研究较少.为深入探讨雅鲁藏布江流域主要杨树人工林的生态适应性,本文以青藏高原雅鲁藏布江流域不同海拔分布的北京杨和银白杨为对象,通过采集叶片并进行性状特征的测定,对该流域主要杨树人工林的生态适应性进行了深入研究.结果表明：(i)树种和海拔效应对北京杨和银白杨的可溶性总糖、淀粉、果糖和非结构性碳水化合物都具有显著影响;(ii)在高寒环境中,北京杨的渗透调节能力和抗氧化能力较银白杨更强.综上所述,北京杨在应对高寒胁迫时较银白杨具有更好的耐受性.未来在青藏高原杨树人工林的造林工作中,应主要考虑选择北京杨.

The ecological adaptability of dominant poplar species to alpine environments in the Yarlung Zangbo River Basin

Afforestation in the Yarlung Zangbo River Basin is of great importance for improving water and soil conservation and improving the ecological environment. Populus × beijingensis and P. alba are the main species used for plantation in the basin. However, there is a lack of research on their ecological adaptability to the alpine environment. To assess the ecological adaptability of the predominant poplar plantations within the Yarlung Zangbo River basin, this study takes P. × beijingensis and P. alba at different altitudes as the research objects and studies the ecological adaptability of the main poplar plantations by collecting leaves and measuring their trait.The results showed that: (i) tree species and altitude had significant effects on the total soluble sugars, starch, fructose and non structural carbohydrates of P. × beijingensis and P. alba; (ii) the osmotic regulating ability and antioxidant ability of P. × beijingensis were stronger than those of P. alba in the alpine environment. In conclusion, P. × beijingensis has better tolerance to alpine stress than P. alba. In summary, Populus × beijingensis has better tolerance to alpine stress than P. alba, and in the future afforestation work of poplar plantations on the Qinghai-Tibet Plateau, P. × beijingensis should be mainly considered.