南京林业大学学报（自然科学版）2017，Vol.41Issue(2)：198-202,5.DOI:10.3969/j.issn.1000-2006.2017.02.030
基于GIS几何计算的杉木树干横断面面积模型构建
Retrieving the basal area of Cunninghamia lanceolata based on GIS geometric calculations
摘要
Abstract
[Objective]Basal area is one of the most important forest structure variables, since it is highly correlated with growth and yield at both tree and stand levels. In this study, four methods that are commonly used to estimate basal area were evaluated and compared to create basal area models, and to determine an optimal estimation method.[Method]Measurements of basal areas, perimeters and diameters at different heights of the stem were collected from Chinese fir trees ( Cunninghamia lanceolata) using GIS geometrical calculation functions. Models of basal area and perimeter were then created to retrieve the circumference ratio, which was combined with the optimal statistical method for practical ap?plications.[Results]The statistical relationship between basal area ( G) and perimeter ( C) was G = 0.0776663C2 with a coefficient of determination ( R2 ) of 0.9985. The circumference ratio ( F) of Chinese fir was 3.21889932, which was found to be larger than the circumference ratio of an ideal circle (π=3.1415926) . The accuracy of the geometric mean diameter was shown to be highest among the four methods. The statistical relationship between basal area and the geomet?ric mean diameter ( d) was fitted as G = 0.8177 d1.9902( R2= 0.9905) . Basal areas calculated using F were larger than those calculated using π. The bias of the former method was positive, and that of the latter method was negative. Using the mean of F andπas the circumference ratio, we achieved the highest accuracy and stability of basal area predictions.[Conclusion]We concluded that estimating basal area with a combination of geometric mean diameter and the mean value of F and π is preferable for practical forestry applications.关键词
杉木/断面积/圆周率/几何平均直径/GISKey words
Cunninghamia lanceolata/basal area/circumference ratio/geometric mean diameter/GIS分类
农业科技引用本文复制引用
梅光义,陈玲,曹元帅,孙玉军,王明初..基于GIS几何计算的杉木树干横断面面积模型构建[J].南京林业大学学报（自然科学版）,2017,41(2):198-202,5.基金项目
国家林业局"948"项目(2015-4-31) （2015-4-31）
林业科学技术推广项目([2014]26) （[2014]26）
