Evaluation And Study On The Ecological Benefits Of Main Forest Type In Daqing Mountain

Ecological benefit evaluation in domestic was in its starting stage, most used the macroscopic statistical data calculation the ecological benefit of forest, there was no perfect index system combined with practical ecological benefit evaluation in each area, majority study was single ecological function benefit, the ecological benefit evaluation theorys and methods were not perfect. The paper embodies the perfect combination from the single factor ecological benefit analysis to comprehensive ecological benefit evaluation. The paper using statistics and analytical hierarchy process and established the main vegetation(pinus tabulaeformis , larix prince rupprecht Btula platyphlla)ecological benefit index system in Daqing Mountain, using the weight coefficient reflects the contributing degrees of the indexes, through the density, biomass, water-physical properties, litter, artificial rainfall, forest microclimate, dry matter accumulation aspects analysis the ecosystem stability, water conservation, modified microclimate, soil and water conservation, soil improvement, carbon fixation and oxygen release six ecological benefit index, obtained the weight values of sub-benefits, finally using the fussy evaluation evaluate the level. The result indicate:1. The proper density of pinus tabulaeformis was small than 3200 stand/hm~2,and the competition of larix prince rupprecht is not serious when 1700stand/hm~2. The Btula platyphlla was influences by origin and ages, the influences of density was not notable.2. The above-ground biomass was Larix prince rupprecht(52225kg/hm~2)> pinus tabulaeformi(s34869kg/hm~2)> Btula platyphlla(26734kg/hm~2), the shrub layer biomass of Btula platyphlla(3251～4160kg/hm~2) was highest. The grass layer biomass of the pinus tabulaeformis (369～1146 kg/hm~2)was higher than Btula platyphlla and Larix prince rupprecht.3. In the physical properties aspect, the forestland was better than grass land, and Btula platyphlla was better than plantation forest. The change of soil water content was different with soil available water; the rain was more influence the pine plantation and grass land tha99n the other vegetation.4. Based on the total water-holding capacity of litter and soi(l0~60cm), the order of the water conservation function for the four forest types was natural secondary forest of Betula platyphylla(3687.172 t/hm~2)>Larix prince rupprecht plantation(3553.229 t/hm~2)>Ostry opsisdavidiana shrubs(3035.698 t/hm~2)>Pinus tabulaeformis plantation (2796.279 t/hm~2).5. The amounts of soil erosion of Larix prince rupprecht forest, Pinus tabulaeformis forest , Betula platyphylla, Ostry opsisdavidiana shrubs at forest farm were 1080t/a,10227.6t/a,1581.6t/a and 2323.2t/a.The soil erosion amount from big to small were Pinus tabulaeformis forest > Larix prince rupprecht forest > Ostry opsisdavidiana shrubs > grassland > Betula platyphylla, and the amount of Pinus tabulaeformis forest was 21.8 times larger than Betula platyphylla;6. The humidity in forest and out the forest have not obvious law at 1-2m , the tem9perature was effected by the season, the pinus tabulaeformis can be reducing wind speed 50% , the larix prince rupprecht was 40%, the Btula platyphlla reducing wind speed in july was two times of may.7. The fixed carbon dioxide benefit of pinus tabulaeformis, Larix prince rupprecht, Btula platyphlla was 29.47 t/hm~2,51.95 t/hm~2,26.93 t/hm~2, the Manufacturing Oxygen benefit was 21.70 t/hm~2,38.24 t/hm~2,19.82t/hm~2.8. The percent of every index was different in total ecological benefit, which makes the each ecological benefit and contribution rate obvious difference. The result indicated that compositive ecological benefit index of ecological forest were Btula platyphlla(1.0367)> larix prince rupprech(t1.036)> pinus tabulaeformi(s0.742). The ecosystem stability of Btula platyphlla was better than plantation, soil and water conservation was distinctly different of each vegetation , the water conservation effect of pinus tabulaeformi was poor , fixing carbon and making oxygen effect of larix prince rupprecht was best. The fuzzy evaluation result was the same to Analytic Hierarch process.