旱柳生长快,繁殖容易,生命力、适应性强,是我市汶河沿岸林地主要造林树种之一。在汶河沿岸14万亩有林地中,旱柳林面积达3万余亩,占21.4％,总蓄积量12万立方米,此林分多为中幼龄林。为了提高旱柳林生长量,缩短培育期,明确不同林龄,不同立地条件上林分密度,制定合理经营措施,编制了旱柳林分密度管理图,作为间伐、生长预测、资源清查和造林设计的依据。 林分密度管理图是以林分密度效应规律为基础,用密度与各测树因子之间相关关系所建立的数学模型编制的,是由最大密度线、等树高线、等直径线、经营管理线和自然稀疏线所组成。这五组线既独立,又相互联系,同时,均受着林分密度限制。 一、材料收集和整理 编表材料均是取自我市汶河沿岸现有旱柳林分。基本上代表着各种林分生长状况。蓄积量按标准木解析材料计算。标准地调查因子有平均树高、优势木树高、平均直径、单位面积株数、单位面积蓄积量等。计算时, Willow grow fast, easy propagation, vitality, adaptability, is the city of Wenling, one of the main afforestation tree species. In 140000 acres of forest along the Wenhe River, the area of ​​Hanliu up to more than 30,000 acres, accounting for 21.4% of the total volume of 120,000 cubic meters, mostly in this stand for young forest. In order to increase the growth of the willow plantation, shorten the cultivation period, clarify the stand density at different stand ages and different site conditions and formulate reasonable management measures, the plot of the stand density management of the willow willow plantation is prepared for the thinning, growth prediction, resource inventory and afforestation Design basis. The stand density management chart is based on the law of stand density effect, and is based on the mathematical model established by the correlation between density and each test tree factor. It is composed of the maximum density line, tree height line and equal diameter line Management and natural sparse line composition. These five lines are both independent and interrelated, and at the same time are subject to the density of the stands. First, the material collected and collated Table materials are taken from the existing forest along the banks of Wenhe, Linhe. Basically represents the growth of a variety of stands. Volume calculated by standard wood analytical materials. The standard survey factors are the average tree height, the dominant tree height, the average diameter, the number of units per unit area, the amount of accumulation per unit area. When calculating,