蛟河阔叶红松林林冠干扰及林隙更新研究

CANOPY DISTURBANCE REGIMES AND GAP REGENERATION IN A KORENA PINE-BROADLEAVED FOREST IN JIAOHE,NORTHEAST CHINA

研究了吉林蛟河实验林场阔叶红松林的林冠干扰状况及林隙更新的基本规律。结果表明，扩展林隙（ＥＧ）和冠空隙（ＣＧ）在阔叶红松林中所占的面积比例分别是１８．０９％和１２．５１％，林冠干扰的返回间隔期为７００ａ左右；ＣＧ的大小平均为ＥＧ的６９％，ＥＧ的面积变化在１７—２８４ｍ２之间，平均为７５．４９ｍ２，而ＣＧ的面积变化在１０—２３４ｍ２之间，平均为５１．９８ｍ２，大多数林隙的平均直径仅为主林层树高的２０—６０％；大多数的林隙是由单株形成木形成的，形成林隙最重的方式是干基折断和掘根风倒；林隙形成木主要是由红松、沙松、枫桦和鱼鳞松四个树种组成，林隙形成木的胸径大都在４０—８０ｃｍ之间，树高在２５—３０ｍ之间；林隙的空间分布格局是均匀型的。不同树种在林隙内外的数量特征不同，随着林隙与非林隙的交替变化，不同树种的优势地位亦发生相应的变化，根据不同树种在林隙内外重要值位序差值的大小，可将蛟河阔叶红松林内树种对林隙的更新反应划分为三种类型。

This paper deals with the canopy disturbance regimes and gap regeneration in a Korean pine-broadleaved forest in the nature reserve of Jiaohe Forest Farm, northeast China. The results showed that the percentages of expanded and canopy gaps in the forest landscape is 18.09% and 12.51% respectively. The return interval of canopy disturbance is about 700a. The average size of CG is about 69% of EG size. The range of EG size is 17～284m 2, with an average of 75.49m 2. The range of CG size is 10～234m 2, with an average of 51.98m 2. The average diameter of most gaps are about 20-60% of the average height of canopy trees. Most gaps were formed by one gap maker, and the most important manners of gap formation were breakage at trunk base and uprooting. Major gap makers in the forest were Pinus koraiensis, Abies holopylla, Betula costata and Picea jezoensis. The DBH of most gap makers were 40～80cm, and their heights 25～30m. The distribution pattern of gaps in the forest landscape belongs to the uniform type. The quantitative characteristics of different tree species in gaps and non-gap stands are different. With the alternation of gaps and non-gap stands, the relative dominance of different species changed correspondently. Tree species were classified into three regeneration response types according to the difference of orders of importance values in gaps and in non-gap stands. Diversity characteristics of species were also different in gaps and non-gap stands.