杉桤混交效果及机理分析

Research on Effects and Mechanism of Mixed Forest with Cunninghamia lanceoiata(Lamb.) Hook. and Alnus cremastogyne Burk

对20a生杉木、桤木混交林丰产效果和机理进行研究,结果表明:混交林内桤木自然保存率低于杉木;杉木单株材积、单位面积材积分别大于桤木4.44和28.1。混交林下生物量是纯林的2.41倍,且植被种类、覆盖率及高度都显著大于纯林。混交林提高了土壤的透水和透气性能,土壤中有机质含量和主要营养元素含量均有所提高。杉木、桤木光饱和点、光补偿点有明显的差异,两树种混交对利用自然阳光有相互补充的作用。

The study is carried out on high--yield effects and mechanism of the 20--year--old Cunninghamia lanceoiata （Lamb.） Hook. and Alnus crernastogyne Burk mixed forests. The result shows that survival percentages of Aluns cremastogyne Burk is lower than Cunningharnia lanceoiata （Lamb.） Hook. in the mixed forests; the volume of individual plant and the volume of unit area of Cunninghamia lanceoiata （Lamb.） Hook. are separately more 4.44% and 28.1% than that of Aluns cremastogyne Burk. Biomass distribution which is below the mixed forests is 2.41 times of that which is below the forests, and the vegetation kinds, the coverage rate and height are remarkably more than the pure forests. The mixed forests increase the water permeability and air permeability of the soil, the contents of organic matter and the main nutrition elements have both a little increase. Light saturation point and light compensation point of Cunninghamia lanceoiata （Lamb.） Hook. and Alnus cremastogyne Burk have obviously difference, the forest which is mixed these two species could have the complementary function in using the natural light.