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Xinjiang Agricultural University (2013)

The Spatial Distribution Characteristics of Biomass and Carbon Density of Temperate Desert Grassland in Northern Xinjiang

门学慧; Men Xue Hui

Titre : The Spatial Distribution Characteristics of Biomass and Carbon Density of Temperate Desert Grassland in Northern Xinjiang

Auteur : 门学慧; Men Xue Hui

Grade : Master’s Theses 2013

Université : Xinjiang Agricultural University

Résumé
This research surveys the temperate desert grasslands in Northern Xinjiang, and selects82representative sample plots, collect herbaceous, shrubs, litter, aboveground and underground biomass and100cm depth of soil samples. Statistics and analysis were carried on the biomass spatial distribution andcarbon stocks of temperate desert grassland in Northern Xinjiang by using software such as SPSS, ArcGISand so on. Main research results are as following:Firstly, through analyzing the biomass spatial distribution of temperate desert grassland in NorthernXinjiang, we found that the biomass spatial distribution of temperate desert grassland in Northern Xinjiangis highly heterogeneous. aboveground biomass of per unit area is28.18~592.02g m-2, undergroundbiomass45.60~1971.10g m-2, and total biomass35.52~2189.26g m-2. In the above-ground biomass,litter is an important part of the class of the temperate desert grasslands biomass carbon pools.Secondly, through analyzing the biomass spatial components of temperate desert grassland inNorthern Xinjiang, we found that shrubs is main in <400m aboveground biomass, of which herbaceousbiomass is the most.Temperate desert grassland are mainly distributed in the altitude400~1200m inNorthern Xinjiang. Herbaceous biomass and altitude was a significant positive correlation, but shrubbiomass and altitude was negative. Biomass gradually reduced affected by the terrain and climate fromwest to east, but not significantly.Thirdly, through analyzing biomass of different subtypes of temperate desert grassland in NorthernXinjiang, we found that the size order of them is that : sandy desert subgroup> soil desertification subgroup> solonchak desert subgroup. Among them, sandy desert subgroup of aboveground biomass are mainlyshrubs and soil desert subgroup are mainly herbs.Fourthly, analysis to the biomass of the temperate desert grassland in Northern Xinjiang, Theestimation value of the grassland aboveground biomass is3.01×1012g using the Kriging interpolation, theunderground biomass1.18×1014g, and the total biomass is1.21×1014g.Fifthly, Research to the carbon storage of temperate desert grassland in Northern Xinjiang, the valueto the carbon storage of above-ground vegetation is47.50g m-2, the root carbon storage is94.38g m-2,and the gross carbon storage of soil is4069.42g m-2. The result is that the carbon storage of soil issignificantly higher than vegetation., and the gross carbon storage of temperate desert grassland in NorthernXinjiang is4236.22g m-2.Sixthly, The soil carbon density of temperate desert grassland show a certain regularity in the verticaldirection, it decreased gradually along with the increase of soil depth. The soil carbon density of theshallow soil layer is higher than deeper. The root system has been identified as one of the source ofgrassland vegetation carbon storage, it has taken up75%. The order size in different temperate desert grassland in Northern Xinjiang is : soil desertification subgroup> sandy desert subgroup> solonchak desertsubgroup.Seventhly, through analyzing the carbon storage of temperate desert grassland in Northern Xinjiang,we found that vegetation carbon storage of temperate desert grassland is1.17Tg in Northern Xinjiang,underground root46.22Tg,soil carbon storage590.55Tg.Eighthly, based on the diversity and carbon density of temperate desert grassland in Northern Xinjiangstatistics obtained that the temperate grassland within the study area contains3subtypes,8groups and19types of grassland ; the species richness index is low ; the number of species is few ; the averaged richnessindex is2.5. In the temperate grassland shrubs, the carbon density of leaf is the least and the carbon densityof old branches is the largest in different organs and the carbon density of Calligonum mongolicum inshrubs is the largest. Carbon density of chenopodiaceae in the herbaceous community is414.49g kg-1.

Mots clés : Northern Xinjiang; the temperate desert; grassland; biomass; carbon stocks;

Présentation (CNKI)

Page publiée le 1er avril 2014, mise à jour le 16 avril 2018