| The purpose of this study is to take Larix gmelinii in the cold temperate zone as the object of study,and to establish a fixed plot of one hectare in the National Field Scientific observation and Research Station of Daxinganling Forest ecosystem in Inner Mongolia.The interspecific competition intensity and forest competition status of Larix gmelinii natural forest were studied,the competition mechanism of Larix gmelinii was revealed,and the inter-species and inter-species relationships of Larix gmelinii were clarified,and the relationship between species and species of Larix gmelinii was studied.Effects of tree species on ecosystem function.Based on the determination of target tree and competition tree and the selection of competition index,the prediction model of DBH and competition intensity was established,and the compatibility between Larix gmelinii tree species was discussed.The competition between the mechanism and the forest.And finally,a single-wood competition model of the larix gmelinii is obtained.The following results are mainly obtained:1.The intraspecific and interspecific competition intensity of Larix gmelinii natural forest in the northern part of Daxing'an Mountains was analyzed by means of the Hegyi competition model of single tree on a hectare sample plot of Larix gmelinii primordial forest.The intraspecific competition intensity of Larix gmelinii natural forest accounted for 56%and 44%of the competition intensity respectively,indicating that the interspecific competition of Larix gmelinii was small,and the main competition came from the intraspecific competition of Larix gmelinii.There are few species associated with Larix gmelinii,and the order of competition between species and main associated trees is as follows:Larix gmelinii intraspecific>interspecific Larix gmelinii>Bai Hua intraspecific>interspecific birch.Intraspecific competition intensity of Larix gmelinii and intra-species competition intensity of Betula birch against target wood However,the interspecific competition intensity of Larix gmelinii and the interspecific competition intensity of Betula birch have a power function relation to the DBH of the target tree.With the increase of DBH of Larix gmelinii,the competition intensity decreased gradually.2.According to the combination of mathematics and theory,the competitive circle of Larix gmelinii in cold temperate zone was determined by gradually expanding the mathematical method.8 m was determined as the most suitable radius of sample circle for Larix gmelinii.A 2m buffer is set up in the four sides of the sample plot to ensure that the object tree is in the sample plot,not in the edge of the sample plot or in the buffer zone,and that the buffer can only be used as a competition tree.3.The results show that the single tree model of Larix gmelinii is CI=-0.6749D 1.556 decision coefficient is 0.85,the tree crown model is CI=-2.5437C 2.5779 decision coefficient is 0.79,the tree height model is:CI=-0.8327H 1.7513 decision coefficient is 0.62.According to the error percentage method,the accuracy of the model is 82.354.4.Through the study on the relationship between the competition for cool sing-an larch wood,hold the competitive relationship between the tree species not only to choose appropriate proportion of mixed,mixed density and when taking the cradle has important guiding significance,also to understand the community composition and ecological function,and promote the efficiency of the forest ecosystem health stable and has important theoretical and practical significance,to utilize modern larch provide theoretical basis for the structure adjustment,optimization. |
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