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作 者 ：董道瑞,李 霞 *,万红梅,林海军

期 刊 ：西北植物学报 2012年 2期 页码：384~390

关键词：柽柳灌丛；冠幅；丛高；生物量估测；塔里木河下游；

Keywords:Tamarix ramosissima Shrub, crown, height, biomass estimation, the lower reaches of Tarim River,

摘 要 ：根据划分的柽柳灌丛大、中、小等级，在塔里木河下游英苏至喀尔达依区段进行地表采样、称重，采用统计相关法对柽柳年龄及地径关系进行分析，构建柽柳直立枝与单丛地上生物量估测模型，对模型精度进行检验，筛选最佳模型，并对模型估测值与实测值进行卡方检验。结果表明：（1）输水后柽柳新萌直立枝地径随年龄增加而增大，但输水前柽柳萌生直立枝的地径随年龄增加未呈现规律性变化。在地下水条件非一致性的干旱荒漠区，柽柳地径大小不能作为判断其年龄的依据。（2）根据柽柳标准枝和灌丛因子实测数据，用一元线性函数、幂函数、指数函数、对数函数4种函数进行柽柳直立枝生物量估测模型拟合结果表明，幂函数w=2.007(d²h)^0.837估测模型最优，其总体估测精度达89.92%。（3）以冠幅面积单变量、冠幅周长与丛高双变量构建的柽柳单丛生物量估测模型的精度分别为78.95%和80.09%。（4）以全收获法实测数据为真值对估测模型进行精度检验,柽柳冠幅面积为自变量模型的估测精度为80.54%，柽柳冠幅周长和丛高估测模型的精度为66.85%。（5）对柽柳单株及单丛生物量模型估测值与实测值进行卡方检验结果表明两者之间无显著差异。研究认为，由于柽柳冠幅在高分辨遥感数据上容易获取，柽柳冠幅面积估测模型在传统生物量估测和遥感生物量估测都具有实用价值。

Abstract:Based on classes (including large,medium,small) of Tamarix ramosissima crown to select and weight samples from Yingsu to Ka’erdayi Section,the relationship between age and basal diameter of T.ramosissima was analyzed using statistical correlation method.In order to predict the above ground biomass of upright growth and single cluster of T.ramosissima,estimation models were established,then examined the accuracy and filtered the best at last and performed a Chi-Square test between measured value and estimated value of biomass estimation models.The result shows that:(1)After water supply,the basal diameter of sprouting upright growth increased with increasing age,while there was no regularity in the upright growth sprouted before the water supply.In the arid deserts with different groundwater conditions,basal diameter of T.ramosissima can’t be considered as the basis to determine its age.(2)By analyzing and comparing the estimation model which have four kinds of functional forms including linear function,power function,exponential functions,logarithmic functions,the power function model with the following w=2.007(d²h)^0.837 formula was the best,the accuracy reached 89.92%.(3)Single cluster biomass estimation models of T.ramosissima were built taking crown area,crown girth and height as independent variables,respectively,whose estimation accuracy was 78.95% and 80.09%.(4)Taking measured value acquired with harvest method as real value to analyze the accuracy of estimation models,the accuracy of biomass estimation models built taking crown area,crown girth and height as independent variables was 80.54% and 66.85%,respectively.(5)The differences between measured value and estimated value of biomass estimation models were analyzed by Chi-Square test,the result shows that:There was no significant difference between them.Because the crown area of T.ramosissima can be acquired easily form high resolution remote sensing data,the estimation model which take crown area as independent variables can provide a basis for biomass estimation.

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