福建农林大学学报（自然科学版）2016，Vol.45Issue(5)：536-543,8.DOI:10.13323/j.cnki.j.fafu(nat.sci.).2016.05.010
不同优势度胖大海林分林木直径分布特征
Tree diameter distribution patterns in Sterculia lychnophora Hance forest stands under different dominance levels
摘要
Abstract
The objective of this study is the natural secondary forest at Dongnai Natural and Cultural Reserve in Vietnam, the tree diameter distribution patterns of Sterculia lychnophora Hance forest stands under different dominance levels were analyzed by using skewness, kurtosis and alteration coefficient as the indexes, which were simulated by three probability density functions: Weibull distribution, exponential distribution and distance distribution, and then the three distribution functions were tested through χ2 test. To study the diameter distribution pattern of Sterculia lychnophora Hance forest stands at Dongnai Natural and Cultural Reserve in Vietnam, diameters at breast height (DBH) of S.lychnophora at 3 dominance levels (>25%, 15%-25% and<15%) were collected and simulated by distribution functions (i.e., Weibull distribution, exponential distribution and distance distribution) to formulate 3 types of probability density indicators, including skewness, kurtosis and alteration coefficient. Then the distribution functions were e-valuated by χ2 test to select function with the highest fitting effect.The results showed that:the stand diameter structure was different in S.lychnophora forest stands under the three different dominance levels. The average diameter at breast height (DBH) in the third dominance levels was 35.7 cm, the span of diameter class ranked 13.1 to 86.5 cm, the diameter distribution curve was left skew-ness, which mainly was medium and small diameter class, being 22-46 cm, the accumulating tree number percentage was more than 80.10%.Results showed that diameter structure of forest stands varied among different dominance levels (DLs). Average DBH in DL3 (>25%) was 35.7 cm, ranging from 13.1 to 86.5 cm. The diameter distribution curve was left skewed, indicating medium tolower diameter class (22-46 cm), which accounted for 80.10% of total plants in DL3.The average DBH in the first dominance lev-els and the second dominance levels were the same, which followed by 22.31 and 20.63 cm, the span of diameter class ranked 7 to 70 cm and that were not larger, the diameter distribution curves were left skewness and diminishing, which mainly were small diam-eter class, being 10-22 cm with the accumulating tree number percentage was over 67.63%, and the number of trees in medium and big diameter classes was fewer. Averages DBH for DL1 (<15%) and 2 (15%-25%) were almost the same, being 22.31 and 20.63 cm. Span of diameter class varied between 7 and 70 cm. Both diameter distribution curves for DL1 and 2 were left skewed and dimin-ishing. And diameters in smaller class, being from 10 cm to 22 cm, made up 67.63% of the total plants in DL1 and 2. Among the whole distribution models, the exponential distribution function had the best fitting effect for tree diameter distribution of the S.lych-nophora forest stands under different dominance levels. It is useful for forecasting diameter distribution and growth of natural second-ary forest, then providing fundamental basis for scientific management, sustainably using and conservation to the S.lychnophora for-est stands under different dominance levels. Among the 3 distribution models, exponential distribution function had the best fitting effect for tree diameter distribution of the S. lychnophora forest stands under different DLs. To summarize, exponential distribution function can be applied to predict diameter distribution and growth of natural secondary forest, and provide fundamental basis for sci-entific management, sustainable utilization and conservation of S.lychnophora forest stands.关键词
胖大海/直径分布/分布函数/优势度林分/越南同奈省Key words
Sterculia lychnophora Hance/diameter distribution/distribution function/dominance forest stands/Dongnai-Vietnam分类
农业科技引用本文复制引用
张巧巧,PHAM Van Huong,陈昌雄,LE Thi Hien,NGUYEN Ba Trieu,NGUYEN Huu Duy..不同优势度胖大海林分林木直径分布特征[J].福建农林大学学报（自然科学版）,2016,45(5):536-543,8.基金项目
中国政府奖学金项目( CSC No 2012704021) . （ CSC No 2012704021）
