云杉落针病防治指标的研究

对甘肃白龙江林区人工云杉林落针病发生严重地区,采用均匀典型整群抽样法调查40块样地,分不同病级进行树干解析40株,利用计算机辅助设计计算,获得了病级与树高、胸径、材积平均生长量、损失量和损失率的关系,各病情指数与材积损失量、损失率的相关关系。从病害群体的角度推导出云杉落针病材积损失率估测模型,建立了经济危害允许水平、防治指标的估测模型,确定经济危害最高稳定阈值,以及与其对应的材积损失率。模型预测准确,精度高。

Study on the control indices of spruce needle cast

Forty plots of spruce lands with serious pine needle dropping disease were selected by even and typical principles in artificial forests of Bailongjiang. Forty strains at different degrees of disease severity were sectioned and analyzed. The relations between the disease severity and the height, the diameter, the average growth rate of log cubage, the total loss of log cubage and loss proportion were studied respectively. The indices of disease severity were correlated to both the total loss and loss proportion of log cubage. Based on the population levels of the disease, the evaluation models of the loss proportion of log cubage from pine needle dropping disease were established. The estimation based on the model was accurate.