濁口溪集水區天然林林分結構與樹種組成之研究

Study on the Stand Structure and Composition of Species in Natural Forests of Cho-Kou Watershed

李久先(Joou-Shian Lee) ； 陳朝圳(Chaur-Tzuhn Chen)

《臺灣省立博物館年刊》 34卷 (1991/12) Pp. 11-32

https://doi.org/10.6548/ATMB.199112_34.0002

摘要

本研究以濁口溪集水區之115個地面樣區之天然林資源調查資料為材料，以Weibull機率函數分別配置林分及樹種之宜徑分布，並以相關及迴歸分析探討Weibull統計介量與地理因子間之關係，研究結果可知二介量之Weibull機率函數可有效的配置研究範圍之全林分及各樹種之直徑分布。對全林分而言，地理因子中僅有海拔高會影響分布之形狀及徑級比例，其中Weibull直徑分布之C值隨海拔高之增加有下降之勢，而B值則隨著海拔高之增加而增加。林分性態因子中，除每公頃立木株數與直徑分布變化不具相關性外，其他如每公頃胸高斷面積、平均胸徑、平均林分高皆與Weibull直徑分布之B值量正相闕，而與C值則量負相關。研究範圍內之天然林主要以楠木類及櫧櫟類為主，其出現率約79.1%~82.6%。各樹種不同徑級在林分蓄積級中之變化依Kendall's等級相關分析，僅海拔高梯度與立木蓄積級呈正相關。樹種別之立木胸徑資料亦可以Weibull機率函數配置之，各樹種因其樹性不同，其於林分族群中具有不同類型之直徑分布，Weibull直徑分布之C值可供解釋之用。

關鍵字

濁口溪集水區 ； 天然林 ； 林分結構 ； 樹種組成 ； Weibull機率函數 ； 直徑分布 ； 地理因子

並列摘要

The data of this study are from 115 temporary sample plot s of natural forest resource in Cho-Kou watershed. Diameter distribution of standand species is fitted by Weibull probability function and geographic factors are developed by correlation and regression analysis. The results obtained are summarized as follows: Diameter distribution of stand and species in natural forests of Cho-Kou watershed is fitted effectively by two-parameter Weibull distribution. For stand, elevation is the only factor to effect the shape and scale of diameter distribution in all geographic factors. C-value of two-parameter Weibull distribution is decreased by increasing the elevation gradients, but B-value of two-parameter Weibull distribution increases along with the increase of the elevation gradients. In the characteristics of stand except per hectare stand numbers, per hectare basal area, average diameter at basal height, average stand height are positive correlation with the B-value of two-parameter Weibull distribution. The major tree species of natural forest in the study area are Oak spp. and Machilus spp.; their presence is about 79.1%- 82.6%. Both geographic factors and stand volume classes are tested by the nonparametric method of Kendall's correlation analysis. The result show, that there is a negative correlation between the elevation classes and stem volume classes. DBH distribution for every species can be fitted by the Weibull probability function, which has different distribution type for stand population in the characteristic of species. The trend can be explained by the C-value parameter of Weibull diameter distribution.

並列關鍵字

Cho-Kou watershed ； natural forests ； stand structure ； species composition ； Weibull probability function ； diameter distribution ； geographic factors