Age structure and growth pattern of an endangered species, Amentotaxus formosana Li
Age structure and growth pattern of an endangered species, Amentotaxus formosana Li
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DOI：
10.1111/j.1744-7909.2007.00429.x
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发表时间：
2007-02-01
影响因子：
11.4
通讯作者：
Wang, Ya-Nan
中科院分区：
文献类型：
--
作者：
Lin, Chinsu;Chan, Ming-Hsun;Wang, Ya-Nan
台湾穗花杉是台湾特有的林下树种。本种仅分布于察合雅莱山和大乌山一带。由于其稀有性，以及该物种的濒危和本土特性，我们探索了该物种在本土环境中的再生过程。因此，本文旨在概述的年龄分布和生长特性的A。利用树木年轮分析技术，对台湾相思在原生林分的分布进行了研究。2004年至2006年在Chachayalaishan地区的一个地点进行了清查。经调查，样地共有乔木67株，其中16株为A.台湾的树木被计算在内。这大约占总人口的24%。这种特殊的物种分布在林下空间，而其他物种，如木姜子属，结果表明，该林地乔木层的年龄以31 ~ 90年生为主，平均年龄为56年。对于濒危物种，A.年龄14 ~ 126岁，平均58岁。使用Weibull概率密度函数对物种的年龄分布进行建模，并使用Sigmaplot统计软件进行统计评估。形状参数的估计值为1.4045，表明中等再生情况。A.在样地的26种植物中，台湾竹的平均高度为0.32 cm，居第20位。以年龄为回归变量，可以预测杉木直径生长量。福尔摩沙效率。决定系数R-2为0.8322。林下和林上乔木层间的直径生长具有竞争性。生长变化率与A.福尔摩沙及周边硬木则为负值。
Amentotaxus formosana Li is a native, tolerant, and under-wood species in Taiwan. This particular species is only distributed around the Chachayalaishan and Dawushan areas. Because of its rarity, and the endangered and native properties of the species, we explored the regeneration process of the species in the native environment. This paper, therefore, aims to outline the age distribution and growth characteristics of A. formosana in the native stand using the techniques of tree ring analysis. An inventory was conducted in a site at the Chachayalaishan area from 2004 to 2006. According to the inventory, there are 67 trees in the sampling plot among which 16 individual A. formosana trees were counted. This is roughly 24% of the total population. This particular species is distributed around the understory space, while other species such as Litsea spp., Meliosma squamulata Hance, Schefflera octophylla Harms, Elaeocarpus japonicus Sieb et Zucc and Cleyera japonica Thunb are the major species whose canopy occupying the upperstory space of the stand. Results of tree-ring analysis suggest that the age of most of the trees in the sampling plot is between 31 and 90 years old with an average of 56. For the endangered species, A. formosana, age of the individuals varied from 14 and 126 years old and the average was 58 years old. Age distribution of the species was modeled using the Weibull probability density function and was statistically assessed using Sigmaplot statistical software. The estimate of shape parameter is 1.404 5 indicating a medium regeneration situation. The diameter growth rate of A. formosana is 0.32 cm and ranks 20th among the 26 species in the sampling plot. Using the age as a regressor variable, we can predict the diameter increment of A. formosana efficiently. The coefficient of determination, R-2, is 0.832 2. The diameter growth among the trees of the upperstory and understory was competitive. Relationship between the growth change percentage of A. formosana and the surrounding hardwoods is negative.