乌兰布和沙漠7种灌木生物量的预测模型

The Prediction Model of Biomass of 7 Shrubs in Ulanbuh Desert

【目的】通过分析判别系数R2和估计值标准误差SEE筛选出乌兰布和沙漠7种灌木中最佳的生物量估测模型。【方法】灌木生物量模型是目前预测灌木生物量的重要方法之一,以乌兰布和沙漠7种灌木作为研究对象,每种灌木各取100个样本,实测其生物量。依据株高(H)和冠幅(M)的复合因子HM作为自变量,以实测生物量(W)为因变量构建回归分析模型。【结果】调查共获得700个灌木样本,每个样本分别包括植株高度(H)、基径(D)、冠幅(M)及其生物量(W)等因子。【结论】7种灌木中,油蒿生物量估算最优模型为W=a+b(HM)+c(HM)^2;猫头刺、矮脚锦鸡儿、红砂、盐爪爪、珍珠猪毛菜和四合木的生物量估算最优模型为W=a+b(HM)+c(HM)^2+d(HM)^3。经验证模型的预测值与实测值拟合率在67.05%~88.03%,其预测效果较好。利用W-HM生物量估算模型测定乌兰布和沙漠7种灌木生物量,操作方法简单快速易行,对于日后乌兰布和沙漠地区上区域尺度的生物量估算具有重要的意义。

【Objective】The optimal biomass estimation model of 7 shrub species in Ulanbuh Desert was selected by analyzing the discriminant coeffi cient R^2 and the standard error of the estimated value SEE.【Method】Shrub biomass model is one of the important methods to predict shrub biomass at present.Seven shrub species from Ulanbuh Desert were taken as research objects,and 100 samples of each shrub were taken to measure their biomass.The regression analysis model was constructed based on the compound factor HM of plant height(H)and canopy width(M)as the independent variable,and the measured biomass(W)as the dependent variable.【Result】A total of 700 shrub samples were obtained,each including plant height(H),basal diameter(D),canopy width(M)and biomass(W).【Conclusion】In 7 shrubs,the optimal biomass estimation model of artemisia oleracea was W=a+b(HM)+c(HM)^2.The optimal model for biomass estimation of cat's thorn,corgi,red sand,salt claw,pearl pigtail and sihemu was W=a+b(HM)+c(HM)^2+d(HM)^3.The forecast results are good after testing the models whose fi tting rate of predicable value and measured value is between 72.08-88.72%.The W-HM biomass estimation model was used to measure the biomass of 7 shrub species in ulanbuh Desert.The method was simple,quick and feasible,and it was of great signifi cance for the biomass estimation on regional scale in the future.