Study On Management Design Of Betula Platyphylla-Larix Gmelini Mixed Forest

In this paper,Betula platyphylla-Larix gmelini primitive forest,clear cutting regeneration forest and gradual cutting regeneration forest in Daxinganling,Inner Mongolia were taken as the research object.Based on the theory of multifunctional near-natural forest operation method system,the present situation characteristics of real forest were analyzed,and the target forest phase was designed according to the present situation characteristics of real forest.Finally,the operation measures for adjusting management were designed.It provides a reference for the management of Bai Hua-Xingan larch mixed forest.The main results are as follows:1.Among the three forest types,the average DBH,tree height and volume per hectare were larger than those of clear cutting regeneration forest and gradual cutting regeneration forest,but the plant number density of original forest was smaller than that of clear cutting regeneration forest and gradual cutting regeneration forest.The tree species composition of the original forest is 7 larch and 3 white birch,the number of diameter plants is inverse "J"type,q value is between 1.2-1.5.The proportion of diameter grade accumulation of the three forest types is different,the proportion of small and large diameter grade accumulation of the original forest is 1:3:6,the clear cutting regeneration forest lacks large diameter grade wood,the small diameter grade accumulation proportion is too large,and the proportion of large diameter grade accumulation is large in the gradual cutting regeneration forest.Standard strip according to forest layer division in China The original forest can satisfy all the conditions,and can be divided into 3 forest layers in the upper,middle and lower layers.However,the upper and lower forest layers can not be divided.2.Through the above research,the primary forest is selected as the target forest phase,and the core factors of the target forest phase are set.The tree species composition of real forest was adjusted to7 larch and 3 white birch,the distribution of stand diameter structure was reversed by "J" curve,and the q value was adjusted to 1.2-1.5 range;the volume was adjusted to?185.8m3/hm2;the accumulation ratio of small medium and large diameter grade was adjusted to 1:3:6;the number density of stand number density of 950-1050 trees/hm2,stand was set to 50 trees/hm2;forest layer to be divided into upper,middle and lower layers.3.In order to realize the objective forest phase of real forest,taking the divided years of Xingan Larix gmelinii age group as the characteristics of management time,the individual wood cutting of target wood was adopted,and the corresponding adjustment measures were designed in each stage.