实验三林分密度对直径（Experiment three stand density versus diameter）.docVIP

实验三林分密度对直径（Experiment three stand density versus diameter） Personal arrangement, feel very good, upload to the library, and share with you Experiment three: effect of stand density on diameter, tree height, volume and crown growth Purpose and significance of experiment Forest is an ecological system composed of many forest trees. It has population structure and density is the main factor affecting forest growth The aim of this experiment is to stand the investigation, analysis of density influence on tree growth, understanding of the role of density, has an important role in guiding the choice of tree species, forest structure adjustment, forest thinning, Afforestation Planning and design etc. This experiment deals with tree growth, afforestation density and intraspecific interspecific relationship in classroom teaching Two experimental principle In the forest ecosystem, each tree growth needs a certain nutrient space Under the condition of sufficient nutrient space, the growth and development of trees are good, the nutrient space is insufficient, and the growth and development of trees are poor Stand density increases (or decreases the average distance between trees), means that each tree nutrition space decreases, the competition between the trees, resulting in a single tree diameter and volume decrease or narrowing of the crown Therefore, from the level of forest stand density or average distance and tree growth indicators (such as diameter, volume and crown width) relationship, can get the effect of density on forest growth, determine the intraspecific and interspecific competition degree Three experiment content 1 different density (distance) on a tree diameter, tree height, volume and crown change; 2 calculate the internal competition index of a tree and analyze the intraspecific competition index at different distances; 3 the influence of density on growth was analyzed from the change of growth index and competition index of tree species in different density