【摘要】 神农架林区气候复杂,森林类型多样,巴山冷杉林生境复杂,生物量估算难度较大。本研究首先将神农架林区植被细分类,提取出研究区巴山冷杉林分布范围,然后使用换算因子连续函数法对外业调查的研究区22块巴山冷杉样地进行样地生物量估算;最后利用逐步多元回归分析方法,估算巴山冷杉生物量。回归方程的拟合优度检验R值为0.851,决定系数R2为0.725,显著性检测值F为11.20。主要结论有:1)研究区提取出巴山冷杉面积为8 347.41 hm2,巴山冷杉生物量总量为102.51×104t,平均值为122.8 t/hm2。与前人的研究成果相比,估算平均值基本一致,实验结果可信。2)巴山冷杉林生物量出现了从边缘向内部的递减现象,巴山冷杉在林区呈现"离散化"分布,生物量也存在空间上的"退化"现象。更多还原

【Abstract】 Shennongjia Forest district belongs to the northern subtropical monsoon climate zone with vegetation distributed in different vertical belts. Because of its high altitude,complicated climate,rich forest types and fragmented landscape,it is difficult to classify the vegetation types and estimate the biomass of Abies fargesii in forest region of Shennongjia district. First,seven categories were classified in Shennongjia forest district which are cold-temperate,coniferous forest,temperate coniferous and broad-leafed mixed forest,temperate deciduous broad-leafed forest,broad-leafed evergreen and deciduous mixed forest,north-subtropical ever green broadleaved forest,scrub and meadow. Second,using the Biomass Expansion Factor(BEF) methods to estimate the biomass of the 22 Abies sample plots which were surveyed in the Shennongjia Forest district; at last,choosing 15 variable parameters to fit with the biomass of the sample plots and obtain the biomass’ s regression equation of the Abies fargesii. The R value of the goodness of fit tests is 0.851,the decisive coefficients R2 is 0.725,the significance test is 11.20. The main conclusions are as follows:(1) Basing the extracted area of the Abies fargesii(8 347.41 ha),the biomass of Abies fargesii is estimated by the most suitable model,the total biomass is 102.51×104 t,and the mean value is 122.8 t/ha. The biomass estimated in the study is similar to the former study,thus the experiment results are reliable.(2) The spatial pattern of the biomass distribution of the Abies fargesii showed a decrease of biomass from the edge to the inside. The biomass distribution of the Abies fargesii in three typical districts presents a trend of disintegration. What’s more,the poor reproduction of the over mature forest lead to the invasion of the under-story trees and the degeneration of the distribution of the Abies fargesii which also results in the degeneration of its biomass.更多还原