Function And Value Evaluation Of Water Conservation, Soil Reinforcement And Fertility Maintenance Of Three Forestland In The Hilly Region Of Central Hunan Province

This study selects the forest ecological public welfare forest of pure stand of pinus massoniana、p pinus massoniana broadleaf mixed forest、broadleaf mixed forest in three different forest types as the research object, by the combination of field investigation and laboratory test, for the study area water retention fertilizer were studied as a function, and made the evaluation of its economic value. Provide certain theoretical basis and data support for the management of the ecological forest, provide effective reference for the formulation of policies related to the reservoir. The results show that:(1) There are great differences in the water conservation capacity of the three types of forest, which is showed that:broadleaf mixed forest> pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana. And the shrub grass layer, litter layer and soil layer between the three levels, soil water storage capacity accounted for more than 90% of the total water conservation.The maximum water holding capacity of the shrub layer in the three types of forest was significantly positively correlated with the biomass. The maximum water holding capacity of the shrub layer was between 2.10-2.59 t·hm-2, shown as:pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana> broadleaf mixed forest; The litter maximum water holding capacity, maximum interception amount and effectively storing volume changes are showed as:broadleaf mixed forest > pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana.Within 0-30cm soil, different forest types of effective storage amount and the maximum water storage changes in 417.27-492.09 t·hm-2 and 1397.76-1732.28 t·hm-2, are showed as:broadleaf mixed forest> pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana. The variance analysis showed that different forest sample plots, the differences in soil maximum water storage capacity was highly significant (P< 0.01), indicating forest tree species and structure of the different has a significant influence on soil water storage performance.(2)Within 0-30cm soil, the soil bulk density value of different soil is smaller, and increased with the increase of soil depth. Showed as:pure stand of pinus massoniana > pinus massoniana broadleaf mixed forest> broadleaf mixed forest. The water content of the surface soil was the highest, and gradually decreased with the increase of soil depth, are showed as:broadleaf mixed forest> pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana. Soil total porosity decreased with the increase of soil depth decreased, the forest soil total porosity and non-capillary porosity are showed as:broadleaf mixed forest> pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana.(3)The ability of soil reinforcement and soil fertility maintenance is different in the three types of forest. Are showed as:broadleaf mixed forest> pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana.Three kinds of forest soil pH, TK content were decreased with soil depth increase and increase, organic matter, TN, TP were with soil layer deepening reduced. Overall, the forest soil pH, TP, TK content are showed as:pinus massoniana broadleaf mixed forest> broadleaf mixed forest> pure stand of pinus massoniana. And organic matter, TN are showed as:broadleaf mixed forest> pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana.The variation range of soil reinforcement of three types of forest in 32.54-35.28 t·hm-2·a-1, are showed as:pinus massoniana broadleaf mixed forest> broadleaf mixed forest> pure stand of pinus massoniana. The soil nutrient content of each forest type was between 0.31-0.99 t·hm-2·a-1, are showed as:broadleaf mixed forest> pinus massoniana broadleaf mixed forest> pure stand of pinus massoniana. On the whole, the soil fixation ability and the ability to protect the soil of the pinus massoniana broadleaf mixed forest and the broadleaf mixed forest is much higher than that of the pure stand of pinus massoniana, which is directly related to the high nutrient content in the soil.(4)The average annual value of water conservation forests in pinus massoniana broadleaf mixed forest、broadleaf mixed forest and pure stand of pinus massoniana are 8.0995 million yuan、7.6881 million yuan and 5.9227 million yuan, illustrates the pinus massoniana broadleaf mixed forest and broadleaf mixed forest water conservation benefit is superior to the pure stand of pinus massoniana.The average annual value of solid earth protecting fertilizer in broadleaf mixed forest、pinus massoniana broadleaf mixed forest and pure stand of pinus massoniana are 9.07 million yuan、8.24 million yuan and 6.07 million yuan, illustrates that the mixed forest solid earth protecting fertilizer efficiency has great advantage.