Assessment On Regulating Functions Of Forest Ecosystem In The Kanas National Nature Reserve Based On InVEST Model

Kanas National Nature Reserve is located in the northwest of Xinjiang which is a typical distribution area of south Taiga Forest Regions.The dominant tree species includes Larix sibirica Ledeb.,Picea obovata Ledeb.,Abies sibirica Ledeb.,Pinus sibirica(Loud.)Mayr.,Betula pendula Roth..The forest ecosystem of the Kanas National Nature Reserve is an important barrier to maintain the regional and even the national ecological environment.Based on the spatial data and the measured data of the study area in 2015,using InVEST model and 3S technology to complete the valuation of Kanas National Nature Reserve`s ecosystem services,which has carbon storage,soil conservation,water conservation and biological diversity,and meanwhile to explore the different environmental factors impact on the ecosystem service function.The results showed that:(1)In the Kanas National Nature Reserve,the total carbon of the vegetation is 24.82 Tg/a,the value of carbon storage is 1.24 billion RMB.Arbor forest land area was 38629.99 hm2,carbon storage was 16.82 Tg/a,carbon density was 43.49 t/hm2;shrub land was 18861.27 hm2,carbon storage was 1.97 Tg/a,carbon density was 10.47 t/hm2;The area of the grass is not stable,carbon storage was about 6.01 Tg/a.The carbon storage of arbor forest is 8.54 times that of the shrub land and also is 2.79 times of the grassland.(2)Order of carbon sequestration value of different forest types was needle leaf forest land>broad leaf forest land> grassland > shrub land > needle broadleaf mixed forest land.The needle leaf forest land area was 33125.59 hm2,carbon storage was 15.15 Tg/a,the carbon density was 457.36 t/hm2,the value of carbon storage was 759 million yuan.The broad leaf forest land area was 1594.19 hm2,carbon storage was 1.38 Tg/a,the carbon density was 865.65 t/hm2,the value of carbon storage was 69 million yuan.The needle broadleaf mixed forest area was 3955.21 hm2,carbon storage was 0.29 Tg/a,the average carbon density was 73.34 t/hm2,the value of carbon storage was 14 million yuan.(3)Toatal water yield volume in Kanas National Nature Reserve was 425 million m3,and the value of the water yield is 285 million yuan,and the contribution of grassland,needle leaf forest land,broad-leaved forest land were all made the largest contribution to the water conservation,which was three fourths of the total water yield volume.(4)Solid earth 6.7405 million t,the value of the soil conservation is 1.469 billion yuan,the ULSE was 1260.78 t and rainfall factor is the most important factor which infecting the soil conservation distribution.(5)Soil conservation and water conservation functions of evaluation based on watershed area,Using the hydrological analysis tools ArcHydro to DEM data processing received 596 watersheds.The Kanas lake is the largest watershed,the water yield was about 2.234 million m3,and aslo was the strongest region.On the other hand,the soil loss of Kanas National Nature Reserve was 1260.78 t,the 243 watershed which are soil erosion between 0-5t is the main source of output,and meanwhile was 60% of the whole soil loss.These watersheds were mainly distributed in the above 3000 m and the annual precipitation of these area was above 700 mm.(6)The biodiversity of Kanas National Nature Reserve was mainly affected by the threat of roads and artificial buildings,the degradation ability of coniferous forest and shrub land was obviously better than that of grassland in the severe degraded area,but in the moderate degraded area and the mild degraded area,the anti-degradation ability of coniferous forest,broad-leaved forest,shrub and grassland were balanced.