Characteristics of typhoon disturbed gaps in an old-growth tropical montane rainforest in Hainan Island, China  

作　　者：Huai Yang Shirong Liu Kunfang Cao Jingxin Wang Yide Li Han Xu 

机构地区：[1]Research Institute of Tropical Forestry, Chinese Academy of Forestry [2]Key Laboratory of Forest Ecology and Environment of State Forestry Administration, Institute of Forest Ecology,Environment and Protection, Chinese Academy of Forestry [3]State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, and College of Forestry,Guangxi University [4]Division of Forestry and Natural Resources, West Virginia University

出　　处：《Journal of Forestry Research》2017年第6期1224-1232,共9页林业研究（英文版）

基　　金：supported by the Ministry of Science and Technology(2012BAD22B01 and 2006BAD03A04);special funds of Research Institute of Tropical Forestry,Chinese Academy of Forestry(RITFYWZX2012-02;CAFYBB2014QA010)

摘　　要：Disturbances that create gaps can shape the structure and function of forests. However, such disturbance regimes in Asian tropical montane rainforests remain largely unquantified. Least studied are typhoon disturbances that are attributable to climate change. We investigated gap characteristics in terms of size, age, and gap-maker to quantify the gap disturbance regimes in an intact old-growth tropical montane rainforest on Hainan Island, China. The intensity of typhoons has increased since 1949, and typhoon winds blow mostly (45.5%) from the northeast corner of Hainan Island, resulting in a higher frequency of gaps in the northeast. A total of 221 gap-makers (trees that fell to create canopy gaps) and 53 gaps were observed in a 3.16 ha old-growth rainforest. Most canopy gaps (85%) were < 200 m(2). The average size of canopy gaps was smaller in the rainforest than in other tropical forests, while the average size of expanded gaps was similar to those in other tropical forests. The maximum age of gaps was 23.5 years indicating that gaps had more rapid turnover than other parts of tropical forests. The frequency distribution of gap-makers followed a lognormal distribution with a distinctive peak at three gap-makers, which was different from the inverse J-shaped curve typical of other tropical forests. Gaps were recorded mainly on slopes between 20A degrees and 35A degrees and wood density of gap-makers was between 0.6 and 0.7 g cm(-3). Our results suggest that small-scale disturbance was the dominant agent of gap formation in this old-growth rainforest that is subject to increasing typhoon disturbances.Disturbances that create gaps can shape the structure and function of forests. However, such disturbance regimes in Asian tropical montane rainforests remain largely unquantified. Least studied are typhoon disturbances that are attributable to climate change. We investigated gap characteristics in terms of size, age, and gap-maker to quantify the gap disturbance regimes in an intact old-growth tropical montane rainforest on Hainan Island, China. The intensity of typhoons has increased since 1949, and typhoon winds blow mostly (45.5%) from the northeast corner of Hainan Island, resulting in a higher frequency of gaps in the northeast. A total of 221 gap-makers (trees that fell to create canopy gaps) and 53 gaps were observed in a 3.16 ha old-growth rainforest. Most canopy gaps (85%) were < 200 m(2). The average size of canopy gaps was smaller in the rainforest than in other tropical forests, while the average size of expanded gaps was similar to those in other tropical forests. The maximum age of gaps was 23.5 years indicating that gaps had more rapid turnover than other parts of tropical forests. The frequency distribution of gap-makers followed a lognormal distribution with a distinctive peak at three gap-makers, which was different from the inverse J-shaped curve typical of other tropical forests. Gaps were recorded mainly on slopes between 20A degrees and 35A degrees and wood density of gap-makers was between 0.6 and 0.7 g cm(-3). Our results suggest that small-scale disturbance was the dominant agent of gap formation in this old-growth rainforest that is subject to increasing typhoon disturbances.

关 键 词：Gap characteristics Gap-makers OLD-GROWTH Slope Tropical montane rainforest Typhoon disturbance Wood density 

分 类 号：S718.5[农业科学—林学] S761.2