伊犁地区土地覆被变化及其对植被碳储量的影响

以伊犁地区为研究对象，以2005、2010年和2015年的土地覆被类型数据和植被功能型分类方案为依据，并利用植被固碳模型，分析了近10 a伊犁地区土地覆被变化特征及其对植被碳储量的影响。结果表明:1）伊犁地区土地覆被变化主要表现为农业用地、林地和建筑用地呈增加趋势，年变化率分别为0.007%、0.031%和0.001%，草地和灌木呈减少趋势，年变化率分别为0.003%和0.1%。2）10 a增加农业用地的面积为923.9 km²，主要的转化来源为草地，占转化总量的83.9%，同时也有78.8%的农业用地转化为草地。3）由于土地覆被的变化、植被净初级生产力以及不同土地覆被类型之间碳转化系数的影响，导致植被的碳储量总体上减少了2.48×10⁵ t。从整体上来看，伊犁地区的农业用地和草地的变化最为显著，土地覆被的变化导致的植被碳储量整体呈减少的趋势。由此可以得出，近10 a伊犁地区草地和农业用地的变化是影响植被碳储量的重要因素。

Changes of Land Coverage and the Impact on Vegetation Carbon Storage in Yili Region

This paper took Yili region of Xinjiang as the research object,based on the data of land cover types and vegetation functional classification schemes in 2005,2010 and 2015,the vegetation carbon fixation model was adopted to analyze the land cover change characteristics and its impact on vegetation carbon reserve volume in Yili area in the past 10 years.The results showed that 1) Yili the agricultural land,forest land and construction land presented an increasing trend,with the annual change rates of 0.007%,0.031% and 0.001%,respectively.Grassland and shrubs showed a decreasing trend with the annual change rates of 0.003% and 0.1% respectively.2) In the past 10 years,the area of increased agricultural land was 923.9 km².The main source of conversion was grassland,accounting for 83.9% of the total conversion.At the same time,78.8% of agricultural land was converted into grassland.3) The carbon reserves of vegetation decreased by 2.48×10⁵ t due to changes in land cover,net primary productivity (NPP) and carbon conversion coefficient between different land cover types.On the whole,the changes in agricultural land and grassland in Yili area were the most significant,and the overall carbon reserves of vegetation caused by the changes in land cover tended to decrease.It could be concluded that the change of grassland and agricultural land in Yili area in the past decade was an important factor affecting the carbon reserves of vegetation.