Study On Ecological Function And Benefits Of Three Public Welfare Forests In Qingyanghu National Forest Park

In recent years,the state has vigorously developed forestry,the area of public welfare forests has been continuously expanded,and the benefits have become more and more obvious,laying a solid foundation for the continuous development of the regional economy.In this study,three kinds of public welfare forests(P.massoniana broad-leaved mixed forest,broad-leaved mixed forest and pure pine forest)were studied in Qingyang Lake Forest Farm.The physical and chemical properties of different forest soils were determined by plot survey and laboratory analysis.Microclimatic factors,carbon fixation and oxygen release capacity,purification of atmospheric capacity and species diversity reveal the ecological functions of three public welfare forests,estimate their ecological benefits,and provide certain basic data for the construction and management of public welfare forests in China.The research results are as follows:(1)Broad-leaved mixed forest has the strongest moisturizing effect and cooling effect,while Pinus massoniana is the weakest.The cooling and humidifying effects of different forest types were positively correlated with the canopy density of forest stands.When the canopy closure is greater than 0.75,the cooling effect and humidification effect of the forest are significantly enhanced.(2)The ability of carbon fixation and oxygen release in mixed forests was stronger than that of pure forests.The broad-leaved mixed forest had the strongest ability to fix carbon and release oxygen.The mixed forest of Pinus massoniana was the second,while the pure forest of Pinus massoniana was the weakest.(3)Compared with the pure Pinus massoniana forest,the physical condition of the mixed forest of Pinus massoniana broad-leaved mixed forest and broad-leaved mixed forest has improved to some extent.The soil bulk density of the mixed forest is less than that of pure Pinus massoniana,while the capillary porosity and non-capillary porosity The total porosity is higher than that of pure Pinus massoniana forest.The lowest soil bulk density is broad-leaved mixed forest.The lowest non-capillary porosity is pure Pinus massoniana.The capillary porosity,non-capillary porosity and total void fraction are the highest.Mixed leaves.(4)Compared with pure pine forest of Pinus massoniana broad-leaved mixed forest and broad-leaved mixed forest,the content of soil nutrient elements increased to some extent.The content of organic matter in the broad-leaved mixed forest was the highest,followed by the mixed forest of Pinus massoniana and broad-leaved forest,and the lowest in the pure forest of Pinus massoniana.Comparing the soil layers,the nutrient content in the 0-10 cm soil layer changed the most,while the nutrient content in the 20~30 cm soil layer changed the least.(5)After the conversion from pure forest to mixed forest,the soil water storage capacity of the stand,the water holding capacity of the stand and the penetration capacity of the stand have been improved to some extent.Compared with the broad-leaved mixed forest of Pinus massoniana,the broad-leaved mixed forest has stronger ability to improve soil water status,and the water storage capacity of Pinus massoniana broad-leaved mixed forest is stronger than that of Pinus massoniana.Compared with the soil layer of 20~30 cm,the soil moisture condition of 0-10 cm soil layer improved greatly.After transforming pure forest into mixed forest,the soil is more mature,which is beneficial to increase the soil water permeation rate,and reduce the occurrence of surface runoff,which is conducive to the soil and water conservation effect of forest land.(6)Among the three forest stands,the litter holding rate of Pinus massoniana broad-leaved mixed forest was the highest,while the broad-leaved mixed forest had the highest water holding capacity.For the same type of stand,the canopy density and density showed a significant positive correlation with the water holding capacity of litter.(7)Compared with pure forest of Pinus massoniana,the ability of mixed forests to absorb organic pollutants(such as S02,N02,NO)has been improved to varying degrees.Among them,broad-leaved mixed forest has the strongest ability to purify the atmosphere.The mixed forest is second,and the pure pine forest is the weakest.(8)Among the three forest stands,the evenness index,richness index and Simpson index of broad-leaved mixed forest were the highest,and the three forest richness indices were arranged in broad-leaved mixed forest>Pinus massoniana broad-leaved mixed forest.>P.massoniana pure forest,Simpson index size is broad-leaved mixed forest>Masson pine broad-leaved mixed forest>Masson pine pure forest,evenness index is arranged as broad-leaved mixed forest>Masson pine broad-leaved mixed forest>Masson pine pure forest.(9)The main ecological benefit value of three types of public welfare forests in Qingyang Lake National Forest Park is 1.84 × 108 yuan.Among them,the improvement of microclimate 1.59 × 108 yuan,carbon and oxygen release 1.03 ×116 yuan,water conservation 1.44 ×107 yuan,water and soil 1.26 ×106 yuan,purification of the atmosphere 2.18 ×105 yuan,protection of biodiversity 7.94 × 106 yuan.The total benefit value of Pinus massoniana forest is 4.96 × 107 yuan,the benefit value per unit area is 2.73×105 yuan·hm-2·a-1,and the total benefit value of Pinus massoniana broad-leaved mixed forest is 6.19×107 yuan,the benefit value per unit area is 2.78×105yuan hm-2·a-1,broad-leaved mixed forest The total benefit value is 7.25 X 107 yuan,and the benefit value per unit area is 3.01×105yuan·hm-2·a-1,the ecological benefit value of the three kinds of public welfare forests is mainly to improve the value of microclimate benefits.