| Being the main body of terrestrial ecosystem,the forest plays an important role in human’s survival and daily life.As the biggest and richest ecosystem in land,forest plays special role in maintaining the structure,functions and ecological processes of natural ecosystems,and provide the resource for human.The forest’s ecosystem services refer to the natural environmental conditions and their effectiveness.As a result of the limitation of the experimental data and the experimental conditions,and on the basis of relative data gathering,field investigation and the laboratory analysis,3S technology and ecological model was combined and used to study the economic valuation of forest ecosystem service and analysis of its spatial-Temporal variations in Enshi in 2002,2007 and 2013 by using the economic measurement of environment and natural resources such as substitute cost method and commercial method.The Carbon sequestration and Oxygen releasing,nutrient accumulation,water conservation and soil conservation and air purification 5 categories of economic service are valued,and displayed in the form of a map.The primary results are as follows:(1)Forest resources mainly distributed in northwest,southwest and eastern mountain area of Enshi,the area of forest has been increased from 2334.15 km2 in 2002 to 2796.04 km2 in 2013,up to 19.79%;among them,coniferous forest accounted for continuous maximum,followed by the evergreen broad-leaved forest and shrub forest,the three together accounted for 40% above,while the smallest proportion is deciduous coniferous forest,the proportion is less than 1%;(2)Average net primary productivity(NPP)of forest vegetation in Enshi increased from 524.35 g·m-2·a-1 in 2002 to 568.11 g·m-2·a-1 in 2007,then decreased to 514 g·m-2·a-1 in 2013,the net primary productivity of forest vegetation increased first and then decreased,in 2007 is the strongest;from NPP grade,the NPP of most area between 200~800 g·m-2·a-1;Due to the different degree of human disturbance,spatial distribution of NPP were high in the northwest town board and Long feng Town,southwest of the Bai Guo Xiang and the eastern region of the Xin Tang area and Cui Ba Xiang,central city were low.(3)The quantity of soil and water conservation of forest ecosystem in Enshi in three periods was 2402.07 million tons in 2002,2226.29 million tons in 2007 and 2373.04 million tons in 2013,which showed a trend of decreasing first and then rising.In the performance space for the northwest,southwest and east of the high altitude mountain high,characteristics of Enshi city and Enshi City,the northeast region is low;the modulus of soil erosion and soil erosion potential was increased at first and then decreased,soil erosion risk generally increased first and then decreased.(4)Valuing the 5 kinds of forest ecosystem services in Enshi city during the period of the three results showed that the spatial distribution,the high value area of water conservation and air purification two service is mainly the northwest,southwest and East high altitude mountain area,low concentrated in the city area and the northeast region,high price and with this low-cost regional distribution of nutrients,carbon fixation and oxygen release and soil conservation services such as three accumulation quantity,on the contrary;the three period of Enshi city forest service value per unit area size of the order is always the value of water conservation service > value of accumulation of nutrients of soil conservation service > value of carbon fixation oxygen service > value air purifying service;change trend,from 2002 to 2013,the ecosystem service value per unit area,water conservation,nutrient accumulation and The value of three services,carbon fixation and oxygen release,increased first and then decreased,while the value of the purified air service continued to decrease,while the conservation service value of the soil decreased first and then increased.(5)In all,the total value of forest ecosystem services in Enshi increased from 8.571 billion yuan in 2002 to 9.795 billion yuan in 2007,later reduced to 9.384 billion yuan in 2013,showing the variation of first increase and then decrease.The total ecosystem service value of coniferous forest and evergreen broad-leaved forest are provided to occupy most of the total value,followed by Bush,and the relative contribution of coniferous forest relatively small.The forest ecosystem service in Enshi average price per unit area is mainly distributed in the areas of high Sun River Longfeng town-Bai Guo Xiang Tunbao Xiang in this area,and the sun is always the highest price per unit area of township;and the city and west of the township,in addition to the new Tang Xiang are all low,the city of Wuyang dam and six corner Pavilion two the office of the streets was the lowest level.In 2002-2007 and 2007-2013,the overall size of the two regional changes was small,but the increase and decrease of the service value in the region was opposite in the spatial distribution. |
