Muti-function Evaluation For Over-cutting Coniferous And Broad Leaf Forests In Eastern Part Of Daxing’ An Mountain

Taken Larch Forest、coniferous and broadleaved mixed forest and Betula platyphylla forest of the over-cutting forest region in Daxing’an mountain of Heilongjiang province as research object, the particle analyzes the water conservation function、productivity function、carbon storage and the biological diversity of this region based on the investigation method of standardized plots. Based on the analytic hierarchy process, we also make comprehensive evaluation for the multifunction of the forest to analyze the relationship between the multifunction of the forest and the stand type. We intend to provide scientific foundation for the establishment of the multifunction test and demonstration of operation optimization and the sustainable management for the forest in the northern part of Daxing’an mountain.Viewed from the average value, the water conservation function and productivity of the forest of the different forest type shows the regularity of coniferous forest> coniferous and broadleaved mixed forest> broad-leaved forest. The score of the productivity evaluation with the carbon storage for the coniferous forest is significantly higher than coniferous and broadleaved mixed forest and broad-leaved forest, whereas there is no significant difference between the coniferous and broadleaved mixed forest and broad-leaved forest. As for biological diversity, coniferous and broadleaved mixed forest is the highest. On the whole, the evaluation value for the multifunction forest based on the average for the total gets the regularity of coniferous forest> coniferous and broadleaved mixed forest> broad-leaved forest.The water conversation function for the different forest type shows that:coniferous forest> coniferous and broadleaved mixed forest> broad-leaved forest. For the litter, variation range for the litter accumulation of three types of forest stand is21.70/hm2～33.74t/hm2, and the sequence is coniferous forest> coniferous and broadleaved mixed forest> broad-leaved forest. The maximal water holding capacity for the three kinds of forest type is varied between64.35t/hm2and134.68t/hm2. Based on the average value, the sequence is coniferous forest (100.99t/hm2)> coniferous and broadleaved mixed forest (92.70t/hm2)> broad-leaved forest (81.3t/hm2)1.As for soil layer, the soil bulk density for the three forest stand type varies between0.52and1.37g/cm3. With the average value of the soil bulk density for the different forest type, the sequence is coniferous forest (0.67g/cm3)<coniferous and broadleaved mixed forest (0.79g/cm3) broad-leaved forest (1.02g/cm3) and it has significant difference among the soil bulk density for the different forest types (F=4.781, P=0.028). The soil porosity of the different forest type varies between53.25%and79.81%and the regularity is coniferous forest (74.4%)> coniferous and broadleaved mixed forest (67.5%)> broad-leaved forest (65.6%). The variation range for maximal water holding capacity for different forest types is573.49t/hm2～1393.02/hm2. Meanwhile, based on the average of maximal water holding capacity, the sequence is coniferous forest (1112.28t/hm2)> coniferous and broadleaved mixed forest (1102.44t/hm2)> broad-leaved forest (850.431/hm2)2.The variation range for the tree layer and volume of the three kinds of forest stand in Xinlin Cuigang in Daxing’an mountain is72.88m3/ha～296m3/ha, the biomass of undergrowth vegetation is17.2t/hm2～81.42/hm2, and the diameter at the breast height is1.499～6.466. The carbon density varies between94.92t/hm2and265.93/hm2in which the tree layer is20.42t/hm2～75.16t/hm2, undergrowth vegetation is8.03t/hm2～67.38t/hm2, the litter layer is7.13t/hm2～19.74t/hm2and the organic carbon density of the soil is27.66t/hm2～197.55t/hm2. Shannon-Wiener index and evenness index are used to evaluate the diversity for the forest.3. The weight of the indexes established for the evaluation of the multifunction to the forest in Xinlin Cuigang farm in Daxing’an mountain varies a lot. And the weight for water conversation is0.557,0.179for forest productivity and carbon storage,0.0859for the biological diversity.4. The evaluation for forest multifunction with the different forest type in Xinlin Cuigang farm of Daxing’an mountain is:as for forest water conversation function and productivity is coniferous forest> coniferous and broadleaved mixed forest> broad-leaved forest. From the score of productivity evaluation we can conclude that the carbon storage of coniferous forest is significantly larger than coniferous forest and broadleaved mixed forest and broad-leaved forest. There is no significant difference between the broadleaved mixed forest and broad-leaved forest. With biological diversity, coniferous and broadleaved mixed forest is the largest. The sequence of the forest multifunction evaluation for Xinlin Cuigang farm in Daxing’an mountain is coniferous forest> coniferous and broadleaved mixed forest> broad-leaved forest. The forest function taken Larch as the main tree species is better than the forest taken Larch and Betula platyphylla forest and coniferous, broad mixed forest and Betula platyphylla as main tree species.