中亚热带常绿阔叶林林隙及其自然干扰特征的研究

通过对福建万木林中亚热带常绿阔叶林中96个林隙的调查，研究了中亚热带常绿阔叶林的基本特征和自然干扰规律，结果表明，在中亚热带常绿阔叶林中，扩展林隙(EG)和冠空隙(CG)在中亚热带常绿阔叶林景观中的面积比例分别为50．86％和16．66％，每年干扰频率分别为0．85％·年^-1和0．28％·年^-1，林隙干扰的返回间隔期约为357年．林隙形成方式由树木折干形成的最为普遍，占形成木总数58．04％。其次是由于掘根风倒而形成的，占33．48％．林隙大多由两株树木形成，平均每个林隙拥有形成木2．33株．扩展林隙的大小多在100～300m^2之间，其中以200～300m^2者所占的面积比例最大，而以100～200m^2者所占的数量比例最大，冠空隙的大小多在100m^2以下，其中50m^2以下所占的数量比例和面积比例都是最大的．林隙形成木分布最多的径级在20～30cm之间。

Gaps and their natural disturbance characteristics in mid-subtropical evergreen broad-leaved forest in Wanmulin

Through field investigation on 96 gaps in some permanent plots of mid-subtropical evergreen broad-leaved forest in Wanmulin Natural Reserve of Fujian Province, this paper dealt with the gap characteristics and their natural disturbance. The results showed that the area percentage of expanded gap (EG) and canopy gap (CG) in the forest landscape was 50.86% and 16.66%, and the natural disturbance frequency for EG and CG was 0.85% x yr(-1) and 0.28% x yr(-1), respectively. The return interval of canopy gaps was about 357 years. The most popular manner of gap formation in the forest was stem breakage (58.04% of the total), and the second was uprooting (33.48%). Most gaps were formed by two trees, averaging 2.33 trees per gap. The size of most expanded gaps was in the range of 100 - 300m2, the gaps of 200 - 300m2 occupied the biggest percentage in area, and those of 100 - 200m2 occupied the biggest percentage in number. The size of most canopy gaps was under 100m2, and the gaps of < 50m2 had the biggest percentage in area and number. The diameter at breast height of most gap makers was 20 - 30cm.