不同生境梭梭冠幅预测模型研究

Study on Crown Prediction Model of Haloxylon ammodendron in Different Habitats

冠幅是反映沙漠植被生长情况的重要变量,通过对不同生境沙漠植物冠幅预测,可为沙漠植被的科学经营提供参考。以古尔班通古特沙漠建群种梭梭为研究对象,选取常用的6种回归模型(M1、M2、M3、M4、M5、M6),以树高和地径为调查因子,建立高地、缓坡和平地不同生境中的梭梭冠幅模型。通过Origin和Anaconda软件对模型进行回归分析,根据4个拟合精度标准,决定系数(R2)、均方根误差(RMSE)、平均绝对误差(MAE)、平均绝对百分比误差(MAPE),选取最优模型。模型拟合结果表明,在树高-冠幅和地径-冠幅模型中,6种回归模型的R2均大于0.5,模型拟合效果较好。3种生境下(高地、缓地、平地)树高-冠幅和地径-冠幅均以M5(三次多项式)为最优模型。6个模型都具有统计学意义(Sig.<0.001),对古尔班通古特沙漠梭梭冠幅的预测具有重要的参考价值,为维护该地区生态和植被恢复提供一定的科学依据。

The canopy width is a necessary variable for the growth of desert vegetation.Predicting the crown width of desert plant in different habitats can provide reference for the scientific management of desert vegetation.Taking the species of Haloxylon ammo⁃dendron in the Gurbantunggut Desert as the research object,select 6 commonly(M1,M2,M3,M4,M5,M6)used regression models,using tree height and ground diameter as survey factors,establish a canopy model of H.ammodendron in different habitats of highlands,gentle slopes,and flat lands.Perform regression analysis on the model using Origin and Anaconda software,select the optimal model based on four fitting accuracy standards(R2,RMSE,MAE,and MAPE).The model fitting results indicate that:in the tree height-shrub crown width and shrub ground diameter models,the R2 values of the six regression models are all greater than 0.5,the model fitting effect is good.M5(cubic polynomial model)is the optimal model for tree height crown width and ground diameter crown width in three different habitats.All six models have statistical significance(Sig.<0.001),which has important reference value for predicting the crown size of H.ammodendron in the Gurbantunggut Desert,and provides a certain scientific basis for maintaining the ecology and vegetation restoration of the region.