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作 者:朱灵益[1] 于九如[1] 杨忠信[1] 王北 韦少敏[1] 王葆芳[1]
机构地区:[1]中国林业科学研究院林业研究所,天津大学,陕西省榆林地区治沙研究所,宁夏自治区农科院林业研究所
出 处:《林业科学研究》1994年第1期54-60,共7页Forest Research
基 金:"七五"国家重点攻关专题
摘 要:应用两种方法编制了毛乌素沙区常见的8种灌木的数量化表。第一种方法用数量化理论(Ⅰ)模型,直接编制灌木生物量对各立地因子的数量化表,第二种方法应用经济计量学中联立方程模型的建模思想,将数量化理论(Ⅰ)模型与多元回归模型结合起来,先分别编制灌木种的冠幅、灌高对各立地因子数量化表,然后将其所得数值代入各灌木种生物量(单株/丛干重)对冠幅、灌高的多元回归模型中。最后通过理论值与实际值计算出相对误差值。结果是第一种方法编制的8个灌木种数量化表,相对误差为10%~19%,第二种方法编制的8个灌木种数量化表相对误差为46%~359%。Two different methods were used to establish the quantitative tables of site quality for 8 common species of shrubs: Caragana intermedia;Caragana korskinskii; Hedysarum scoparium; Hedysarum laere;Salix spammo-phila; Artemisia ordosica; Artemisia sphaerocephala and Hippophae rhammoi-des. Weight of biomass of the shrubs was used as an index to establish the tables.The model of quantitative theory (Ⅰ) was used to establish the first table. The second table was established by using the combination of model of quantitative theory (Ⅰ) and model of multiple regression. At first,the quantitative tables of the crown width and shrub height were worked out,then the data was used in the model of multiple regression. Finally, the relative errors were calculated through theoretic values and realistic values.The relative errors of the first table was 10%~19%, while those of the second one 46%~359%.
分 类 号:S758.6[农业科学—森林经理学]
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