作者机构：
中南林业科技大学理学院,长沙410004;数字洞庭湖南省重点实验室,长沙410004;中南林业科技大学经济学院,长沙410004;[刘峰; 杨志高] College of Science, Central South University of Forestry and Technology, Changsha, 410004, China<&wdkj&>Key Laboratory for Digital Dongting Lake Basin of Hunan Province, Changsha, 410004, China;[李建军] Key Laboratory for Digital Dongting Lake Basin of Hunan Province, Changsha, 410004, China
通讯机构：
College of Science, Central South University of Forestry and Technology, Changsha, China
作者机构：
[Yang, Zhi-gao; Zhang, Gui; Liu, Feng] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Peoples R China.;[Yang, Zhi-gao; Zhang, Gui; Liu, Feng] Cent South Univ Forestry & Technol, Key Lab Digital Dongting Lake Basin Hunan Prov, Changsha 410004, Peoples R China.
通讯机构：
[Zhang, Gui] C;Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Peoples R China.;Cent South Univ Forestry & Technol, Key Lab Digital Dongting Lake Basin Hunan Prov, Changsha 410004, Peoples R China.
关键词：
Canopy gap;Disturbance;Spatial point pattern;Influence factors;Silviculture
摘要：
The divergent gap characteristics and spatial patterns of canopy gaps created by natural or artificial disturbances can exert a dominant influence on forest structure and composition. However, little research has been conducted on the effects of ice storm damage on canopy gaps in subtropical mature forests of South China. In this study, one semi-natural site was dominated by a broad-leaf forest and two managed sites were representative of plantations with coniferous forests. Based on airborne laser scanning data and field evidence across sites, statistical analyses were used to examine gap characteristics following ice storms of moderate severity. Generalized Ripley's K-function analysis was applied to test gap spatial patterns at a range of scales, and spatial point pattern analysis was used to quantitate the relative importance of specific influences on patterns of gap occurrence. The results revealed that the average gap size was 75.7 m~2 and that 12.2 gaps occurred per hectare. Most gaps were single-tree fall events. In addition to more gaps, the mean gap size was smaller and the shape was more complex in the semi-natural site than in two managed sites. Large differences in gap characteristics were observed among snapped, uprooted, snag, and artificial gap damage types. Gaps generally showed a clustered distribution at large scales (e.g. 70m), whereas spatial patterns varied with gap damage types at different sites. The occurrence of gaps was strongly related to slope and topographic position at the semi-natural site, whereas slope, stem density, and human accessibility (proximity to pathways) were the most important factors affecting gap occurrence at the managed sites. We suggest that gap-based silvicultural treatments and natural disturbances regimes conjoin, highlighting interactions with other factors such as microsite conditions, non-tree vegetation and more.
