关键词: 蛛网模型 马铃薯 供求分析, 蛛网模型 马铃薯 供求分析

Abstract: Using trunk analysis to collect lumber disc sample to measure the wood material property, chemical composition and calorific value for thrity-three years old planted forest of Castanopsis fissa in Huaihua Hunan Province. The wood density, fiber length, fiber width, fiber aspect ratio, calorific value, cellulose content and acid insoluble lignin content in the strain longitudinal variation law were studied in this paper. The results showed that the density of wood with tree height increased gradually declined, an average of 0.421 g/cm3, the variation range of 0.356-0.497 g/cm3, longitudinal differences reached significant level. And wood fiber length, fiber content and acid insoluble lignin content with the increase of tree height firstly increased, then decreased, the mean respectively 1174.529 μm, 53.177% and 23.661%, and the range of variation were 1063.653-1278.946 μm, 47.135%-56.654%, 21.99%-26.226%, longitudinal differences significant. Wood calorific value with tree height increased, the average value was 17474.76 kJ, variation range of 16036.06-18491.86 kJ.