柠条生物量分配格局及可加性估测模型研究

灌木生物量的分配反映了植株对周围环境条件的适应,而灌木生物量模型是估算灌木生物量的重要方法。基于对宁夏灵武市柠条灌木各类生物量及因子的测定,分析了立地条件(SI)对灌木生物量分配的影响,建立了各器官(茎、叶、根)及总生物量的估测模型,并用SI改进,在改进基础上,构建可加性生物量模型。结果表明:1)立地条件对灌木生物量的分配影响显著,坡向的影响大于坡度的影响;2)以W=axb为基础,以体积(V、冠幅与株高的乘积)为自变量建立的生物量模型,拟合精度最高,且除叶生物量外,基于SI改进的生物量模型较原模型在精度上有显著提高;3)灌木的可加性生物量模型较改进后的基础模型在拟合效果上表现更优,预测值与实测值拟合率在58.99%~86.23%。

Biomass Allocation Patterns and Additive Models of Caragana korshinskii

Biomass allocation of shrub species reflects the adaptation of the shrub to the surrounding environments.Biomass estimation modelling is one of the most important methods to predict shrub biomass.This study was designed to analyze the effect of site conditions (slope and aspect) on the biomass allocation patterns and to establish the optimal estimation models for each organ (leaf,stem,and root) and total biomass of Caragana korshinskii .Furthermore,we improved the biomass models with site conditions as independent variable for better prediction precision.Finally,the additive models were built to resolve the unequal between in the amount estimated by the total model and the sums estimated by the component-models.The results showed that 1) site conditions had significant effect of biomass allocation and the effect of aspect was more obvious than the other.2) The biomass model with, W=ax b considering V as the independent variable showed the best prediction precision.SI as the independent variable was added to the biomass models could improve the performance significantly.3) The additive models showed better performance than the improved model with SI.The fitting rate of model equation between estimated value and actual value come to 58.99%-86.23% after verification.