桂东南常绿混交林林窗形成原因与分析

Cause and Analysis of Gap Formation of Evergreen Mixed Forest in Southeast Guangxi

(广西苍梧县岭脚镇林业工作站,广西苍梧543100)摘要:[目的]研究广西苍梧县常绿混交林林窗形成的原因。[方法]采用样方调查及每木检尺方法对受冰冻灾害的林分进行研究。[结果]形成林窗的林隙木及灌木种类较为丰富,已鉴定的种类有19种148株,占总形成木的56.92%,林窗形成的方式为翻蔸、干中折断、干基折断及枯立,其中翻蔸、干中折断为主要形式。不同径级林隙形成木的死亡方式以15~30 cm径级为主,小径级占比最少,大径级的树木受灾后比小径级的更容易形成林窗。[结论]林隙边缘木因冰冻灾害受损形成林窗比例比林内高,冰冻灾害及大冠幅是形成林窗的主要原因。

[Objective] To study the causes of the gap formation of evergreen mixed forest in cangwu county,guangxi. [Method] The method of quadrat investigation and per tree measuring ruler was used to study the forest affected by freezing disaster. [Result] The results showed that there were abundant species of gap trees and shrubs that formed gaps,and 148 of 19 species were identified,accounting for 56.92% of the total number of trees formed. The forms of gaps were turning over stumps,breaking in the trunk,breaking in the trunk,and standing dry,among which turning over stumps and breaking in the trunk were the main forms. The death mode of gap forming trees of different diameter classes is mainly 15-30 cm diameter class,and the small diameter class accounts for the least. The trees of large diameter class are easier to form gaps than those of small diameter class after disaster. [Conclusion] The percentage of gap edge trees damaged by freezing disaster is higher than that in the forest,and the freezing disaster and large canopy are the main reasons for the formation of gap.