论文部分内容阅读
以东北商品林中杨桦次生林为对象,采用固定标准地连续、定位观测与临时标准地调查点面结合的方法,综合分析与评价了经营密度对林地土壤水分动态变化和林分生长量的影响.结果表明:同一经营密度的林分,不同土层深度的土壤含水量的变化趋势基本一致,均随土层深度的增加而减少;同一土层深度的土壤含水量随经营密度的减少而降低.单位面积山杨次生林和白桦次生林林分的胸径年生长量随经营密度增大而减少;林分蓄积量的变化规律却不同,不随经营密度增大而增加,亦不随经营密度增大而减小,而以中等经营密度值(0.7)最大.“,”Birch forest,secondary forest products in the Northeast for the object,using a fixed standard in continuous,observation and positioning of entire areas of the temporary standard method of investigation,a comprehensive analysis and evaluation of forest management on density and soil moisture dynamics influence the amount of stand growth.The results showed that: the same business of stand density,soil water content in different soil depth trends are basically the same,both with the soil depth increases;the same soil water content with soil depth reduction and lower operating density.Bit area of secondary birch and aspen stands of secondary forest in diameter growth increased with the increase of the density operator reduced;forest stock volume variation is different,do not increase with the increase of the density operator,nor the density decreases with the business,and medium density operator(0.7) the maximum.