| It is a quite weak link that grassland ecosystem carbon ability and carbon formation mechanism in the grass research by far.With the grassland from the north slope of Tianshan Mountains in Xinjiang as the research object, using conventionalanalysis method and statistical analysis method, the article analysed and revealed the level, spatial distribution pattern andforming mechanism of grassland biomass density, vegetation carbon density and soil carbon density, probed into therelationship among the density of the grassland biomass, vegetation carbon and soil carbon with environmental factors.,andevaluated the carbon sensitive factors and carbon number of various of grassland. The conclusions were as follows.1. Carbon sequestration characteristics of each types of grassland in the north slope of Tianshan mountains（1）The biomass densities of eight types of grassland in studied area, from big to small in the order, temperate mountainmeadow, temperate meadow steppe, alpine meadow, lowland saline meadow, temperate steppe, temperate desert steppe,temperate steppe desert, temperate desert.The corresponding carbon densitys of vegetation aerial layer and root system isalpine meadow(678.9g·m-2,61.9g·m-2), lowland saline meadow(497.8g·m-2,203.2g·m-2), temperate meadow steppe(632.8g·m-2,42.2g·m-2), temperate desert steppe (375.2g·m-2,47.8g·m-2), temperate steppe(333.2g·m-2,22.1g·m-2), temperatesteppe desert(273.2g·m-2,25.5g·m-2), temperate mountain meadow(241.6g·m-2,39.9g·m-2), temperate desert(163.6g·m-2,57.3g·m-2), respectively.（2）Shrub of both prairie grassland and desert grassland, carbon density of species individual plant performs:Ceratoideslatens(16.1-33.3g·m-2)> Caragana fruten(14.0-16.3g·m-2)>Salsola laricifolia,Reaumuria soongorica,Herbaephedrae(3.2-13.6g·m-2)> Nitraria tangutorum,Ajania fruticulosa,Convolvulus tragacanthoides(0.03-4.2g·m-2);Howevercarbon density of Haloxylon ammodendron in the two types of grassland changes larger.（3）The root-shoot ratio of different grassland types is in the range of3.2-20.0.And the vertical distribution pattern of rootsystem for all types of grassland is just like the “T” number.（4）Soil carbon density （section depth） is alpine meadow, low-lying saline meadow, temperate mountain meadow,temperate meadow steppe, temperate steppe, temperate desert steppe, temperate desert, temperate steppe desert, from big tosmall, respectively. Soil carbon content in the depth of0to10cm holds28.4-72.7percent of that in section depth.And withthe increasing of soil thickness, the spatial differences of soil carbon densities will decrease.2. Spatial distribution pattern of carbon sequestration for researched grassland areaIn the east of the north slope of Tianshan mountains, both alpine meadow in western part （west of Urumqi city）andlowland saline meadow in the eastern part （southeast of Barkol province） hoil a high density carbon for grassland (>25kg·m-2)；carbon density for prarie grassland and desert grassland in the north-central part（northwest of Barkol province and most of Qitai province） is relatively low (<10kg·m-2).3. Impact factor for the grassland carbon sequestrationAmong all the factors, the annual precipitation is the main factor for spatial differentiation of grassland carbonsequestration. Among them, the aboveground biomass density and carbon density is corelated with annual precipitation andhuman using, while belowground biomass density and carbon density is corelated with annual precipitation, annual averagetemperature, terrain and soil physical-chemical properties; Soil carbon density has a correlation with annual precipitation,annual average temperature and soil physical-chemical propertie4. Evaluation of the carbon sequestration ability for grasslandCarbon sequestration ability of grassland has a matching relationship with altitude, temperature, precipitation, soil pHand bulk density, soil nitrogen, soil type and human using of certain. Carbon sequestration ability,on the whole,meadow class> prairie class> desert class. |
PDF Full Text Request