湘西桤木人工林蓄积量模型及适宜经营密度研究

The Study of the Stand Volume Model and Appropriate Management Density for Artificial Stand of Alnus cremastogyne in Xiangxi,Hunan

密度是表达林分结构的重要指标,立地条件、树种及林龄不同时,其林分最佳密度也不相同。以湘西桤木人工林为研究对象,采用数量化方法I和非线性回归分析方法,对2009年和2010年调查的78块标准地数据进行数据分析处理与建模。结果表明:(1)平均高、公顷株数、土层厚度、龄组、坡向、坡位、自然灾害、海拔、树种组成8种因子中,平均高、公顷株数、土层厚度和龄组对湘西桤木人工林平均木材积和单位面积蓄积量均有显著性影响,而海拔和树种组成对湘西桤木人工林平均木材积和单位面积蓄积量均无显著性影响。这对建立桤木人工林蓄积量与密度、平均高收集数据时提供理论指导,同时既能节省外业调查费用,又能保证建模数据的科学性。(2)建立了湘西8～10年桤木人工林蓄积量与密度、平均高相关关系模型:,建模精度为96.8458%,平均相对误差为1.1334%。模型适应性检验表明,残差值呈对称均匀分布,其平均相对误差为-1.2156%。(3)该地区8～10年桤木人林的最佳经营密度为800～1000株/hm2。这对于合理地经营和管理湘西桤木人工林具有重要的理论和实际指导意义。

Density is an important criterion for stand structure. The best stand management density maybe change when the site condition or tree species or age of stands are different in different stands. In this study, using quantification theory type I and non-linear regression analysis theory, the data from 76 plots had been analyzed and simulated, which is collected in Xiangxi, Hunan in 2009 and 2010. Several conclusion had been gained： （1） stand mean height, tree number every hectare, soil thickness, age-group, slope orientation, slope situation, natural disaster, elevation, species composition, in these kinds of zoology factors, the factor of stand mean height, tree number every hectare, soil thickness and age-group could affect mean standard tree volume and stand volume every hectare significantly, the others almost had no influence to them. These results could not only be useful to field survey for saving cost, but also insure that the plot data was credible. （2） The stand volume and density model for artificial stand that were 8-10 years management of Alnus cremastogyne in Xiangxi, Hunan had been established, the model formula was M =0.000429× N ×H^2122159 -6.0×10^-8 × N2 ×^H^2.325915. The precision of it was high. The precision was 96.8458%, the relative error mean was 1.1334%, the accuracy test showed that residual error values were equally distributed around the prediction values, and the relative error mean was-1.2156%. （3） The best appropriate density for artificial stand that were 8-10 years management for Alnus cremastogyne in Xiangxi, Hunan was from 800 to 1000 trees every hectare. It was very important to sustainable management for artificial stand management for Alnus eremastogyne in Xiangxi, Hunan.