鳞毛蕨(Dryopteris filix-mas)天山云杉林倒木更新分析

Analysis on the Effect of Fallen Woodss in Regeneration of the Forests of Picea schrenkiana-Dryopteris filix-mas

对西天山国家级自然保护区1 hm2典型鳞毛蕨天山云杉林临时标准地内,倒木对更新的影响进行了研究。结果表明:①研究区中所有倒木的平均倾倒方向为西北方向,具有更新个体存在的倒木平均倾倒方向为东北方向;②倒木的倾倒方向对倒木的更新没有显著影响(F3,51=0.645,P=0.589),而倒木的腐朽等级对倒木的更新存在显著影响(F2,51=3.215,P=0.048);③不同腐朽等级倒木上幼苗、幼树的出现概率不同,能为幼苗、幼树生长提供生境的倒木只有腐朽等级高的Ⅲ,Ⅳ,Ⅴ级倒木,且倒木腐朽等级越高,对幼苗、幼树的生长越有利。

In all forest ecosystems, large numbers of fallen woods are brought about with the occurrence of disturbance. Then, fallen woods become as a kind of important factors affecting forest structure. They play a particular ecological role in forest ecosystems and affect the balance or stability of forest ecosystems. In all of these, the role of fallen woods in the regeneration of forests is extraordinarily considerable. This paper analyzes the effect of fallen woods in regeneration in a 1-hm^2 temporary plot of the forest ofPicea schrenkiana-Dryopterisfilix-mas in the Western Tianshan National Nature Reserve. The nature reserve （43°03＇ - 43°15＇N, 82°51＇- 83°06＇E） is located in the western section of the central Tianshan Mountains, its south-north length and east-west width are 28 km and 14 km respectively, and its area is 31 217 km^2, in which the areas of woodlands and shrubbery lands are 1 1701 km^2 and 380 km^2 respectively, and the forest coverage is 39%. all fallen woods is northwest, and the average orientation The results are as follows： （1） The average orientation of of fallen woods with regeneration is northeast; （2） The effect of fallen wood orientation on the regeneration of individual trees is not so significant （ F3,51 = 0. 645, P = 0. 589）, but that of decomposition grade is significant （F2.51 =3. 215, P =0. 048） ; （3） The emergence frequency of seedling and sapling in different decomposition grades is different. Seedlings and saplings occur only on the fallen woods in third, forth and the fifth grades of decomposition. Furthermore, the higher the decomposition grade of fallen woods is, the more favorable the regeneration of individual trees will be.