川西高山松林火烧迹地天然更新研究

Studies on Natural Regeneration of Pinus densata in Burned Forestlands in Western Sichuan Province

[目的]研究川西高山松林火烧迹地的天然更新状况。[方法]通过＂空间序列＂代替＂时间序列＂的研究方法对川西高山松林火烧迹地进行了调查研究。[结果]火烧迹地上高山松天然更新效果较好,一般火烧的次年即有大量幼苗发生,同时一定频率低强度的火烧有利于高山松纯林的维持和稳定,这主要是因为该地区高山松分布于阴坡和半阴坡;灌木高山松林火烧迹地天然更新状况较好,草类高山松林火烧迹地次之,高山栎高山松林火烧迹地最差;分布在海拔2 800~3 600 m的高山松林火烧迹地自然恢复良好,但海拔4 000 m以上的火烧迹地上更新的幼苗幼树较为稀少;阴坡、半阴坡迹地天然更新状况优于阳坡迹地,这是因为周围的温度、湿度等环境条件变动幅度直接影响着高山松更新幼苗的成活率。[结论]该研究为加快当地植被恢复、改善环境及建设长江上游生态屏障提供了理论依据。

[Objective] The aim was to study the natural regeneration of Pinus densata in burned forestlands in Western Sichuan Province.[Method] Natural regenerations of Pinus densata in burned forestlands in Western Sichuan Province at different ages were investigated through the method of space sequence instead of time sequence.[Result] The natural regeneration of Pinus densata was better than the other species;generally a large amount of seedlings emerged during the first post-fire year;and the fire of appropriate frequency and low intensity was helpful the stabilization and maintaining of pure forests of Pinus densata,mainly because Pinus densata was distribution on northern and eastern slopes.The natural regeneration of shrub-Pinus densata forests in the burned areas were better;the herb-Pinus densata forests took second place;and the Quercus aquifolioides-Pinus densata forests were the worst.The natural regeneration of Pinus densata forests in the burned areas at an elevation from 2 800 to 3 600 m restore were well,while the seedlings density in the burned forestlands at an elevation of above 4 000 m was small.The natural regeneration of Pinus densata forests on northern and eastern slopes in burned areas was better than that on southern slopes,mainly because the changeable range of environmental conditions like temperature and humidity would directly affect the survival rate of renewal seedlings.[Conclusion] The research provides theoretical basis for accelerating local vegetation restoration,improving environment and constructing the Changjiang river headwater＇s ecological barrier.