Changes Of Soil Respiration Across Eurasian Continent During 1982-2013

Global climate of continuous heating and increasing in the proportion of greenhouse gases in the atmosphere,makes people pay much attention on the process of releasingCO₂ from soil into the atmosphere.Soil respiration is the second largest flux of the global carbon cycle which counts 60-90%of total global ecosystem respiratory volume,thus the small changes in soil respiration can lead to great changes in atmospheric CO₂ concentration.In the past to quantified the regional soil respiration,often treated the soil temperature sensitivity coefficient of Q₁₀0 value as a constant.But the study found that Q₁₀ value changes over the ecosystem,and the Q₁₀ value in same ecosystem is different,often greater in the non-growing season than the growing season.This research is based on the statistical model of soil respiration,according to the GIMMS NDVI data,a year is divided into the growing season and non-growing season.And access to the Q₁₀ values,will be a part of the model about Q₁₀ value,input other climate raster data to establish 1982-2013 monthly soil respiration data set of Eurasia.Through the analysis of the time and space,found that:1)In Eurasia,Monthly soil respiration of shows obvious seasonality during 1982 and 2013.And mean 22.48 Pg C is released to atmosphere by soil respiration.Total soil respiration of Eurasia increased by 0.81 Pg C with 20cm soil temperature rising per 1?.2)On the spatial distribution of years mean soil respiration rate,the north of western Siberia and the Eastern plains located the north of latitude 60°,the soil respiration rate is as high as 800-1000 gC m^-22 yr^-1 in addition to bigger soil respiration in the eastern China caused by high temperature and high precipitation.3)Latitude zonal of soil respiration rate is more significantly than lontitude zonal,soil respiration rate in low latitudes is highest(1189.3 gC m^-2 yr^-1).And soil respiration shows as 675.3gC m^-2 yr^-1 due to higher carbon density in 65-75°of high latitude.Azonality is more pronounced on elevation change:High respiration in the plain,and decrease of soil respiration rate with rapidly temperature decrease resulted by higher altitudes.4)The soil respiration rate of Eurasia increase by speed of 1.16,0.94,0.44 gC m^-2 yr^-2 in 1982-1990,1991-2000,2000-2013 respectively.5)Forest,shrubs,grassland,farmland and bare land 5 vegetation types,which makes contribution to the total soil respiration by 28.74±0.39%,20.43±0.33%,32.03±0.4%,14.94±0.23,3.86±0.05%,respectively.Eurasia released 8.41 Pg C through soil respiration in non-growing season,accounting for 37%of the annual amout of soil respiration,thus non-growing season has huge relese potential and it can't be ingnored.6)When 20 cm soil temperature rise per 1?,the increase situation of soil respiration rate in12 vegetation types shows:evergreen coniferous forest?32.02?>woodland?28.24?>cropland?27.76?>wooded grassland?27.56?>mixed forest?27.39?>deciduous broad-leaved forest?26.29?>deciduous coniferous forest?25.50?>closed shrubs?22.37?>evergreen broad-leaved forest?21.31?>open shurbs?19.39?>grassland?17.80?>bare land?6.46?(unit:gC m^-2 yr^-1);When precipitation increase every 100 mm,soil respiration rate increases:closed and shrubs?39?>bare land?34?>woodland?28?>deciduous coniferous forest?26?>wooded grassland?25?>grassland?21?>evergreen coniferous forest?18?>mixed forest?16?>cultivated land?12?>evergreen broad-leaved forest?10?>deciduous broad-leaved forest?5?(unit:gC m^-2 yr^-1).