|
Study on the Spatial Structure of the Broad-leaved Korean Pine Forest
|
The succession sequences of broad-leaved korean pine forest at Jiao He region, Ji Lin province, where the stands were disturbed in different ways ,were developed into species stages of pioneer, companion and climax. The data used in this paper are got by the total station to analyze the stand characters including the spatial structure of the broad-leaved korean pine. The information can be used for guiding the broadleaved korean pine sustainable management.There was a new method in the paper to correct border effectiveness during calculating the assemble index R. The succession makes the stand to be an assemble distribution at pioneer stage which develops to be a random distribution both at companion and climax stage. The average distances of nearest neighbourhood stand and structure unit increase gradually, at climax stage they are 1.59m and 2.70m respectively.A new parameter named stand level rate was innovated to express the spatial structure of the complex mixed stand in the paper. The rate makes the spatial structure parameter with other parameters such as mixed degree, neighborhood pattern, neighborhood comparison, more complete. The best stand spatial composition cell is the one that is made of 4 trees near the consulted one. The composition cell expressed completely the stand spatial composition information stand. Also the cell with meaningful character could be explained. The best angle of neighborhood trees is 72?. Spatial structure parameter of the korean broad leaf pine stand is changing at the different succession development stages , but the changes of the stand height and BDH go unite. Mixed degree and the rate of stand level at every stage increase along the succession. The rate of stand level is 0.53, 0.56 and 0.63 respectively at the three succession stages. The mixed degree is 0.70, 0.76 and 0.82,and stand neighborhood pattern is 0.575, 0.508 and 0.517 respectively. Accordingly the stand spatial distribution in compartment 53 (during pioneer stage), compartment 52 (during companion stage) and compartment 54 (during climax stage) is assemble, random and random at the three succession stages.The stand spatial structure parameter could be used to select the cutting trees. In pratice firstly according to the study of stand spatial structure parameter at differentstages, the modification plan of relative structure parameters is determined. Then the priority cutting unit is choosed and the intergrated assessment was needed before making the final cutting woods.It was found out that the value of the stand DBH at the succession stages appeared to be inclined to left side mountain-liking curve. The numbers of tree at the three different stand levels appeared to be a pyramid-liking schedule. The upper level stand at pioneer stage is dominated by companion species (43.34%) and pioneer species(42.84%), while being dominated by companion species (82.70%) at companion stage, companion species (48.74%) and climax species (43.34%) at climax stage.The stand spatial structure parameters should be studied by modern methods to draw up the best stand composition model in the future.