乌鲁木齐南山森林生物量和碳储量空间分布特征

Spatial Distribution Characteristics of the Biomass and Carbon Storage of Forest in Nanshan Mountain,Urumqi

乌鲁木齐南山分布有大面积的雪岭云杉林,探究其生物量和碳储量的空间分布特征,能够为该地区碳储量的研究和森林生态系统管理提供依据。以2015年4—5月的Landsat TM遥感影像为主要数据源,结合样地实测数据,基于遥感统计模型法,利用逐步回归法建立模型估算了乌鲁木齐南山雪岭云杉林的生物量。以此为基础,分析了生物量的空间分布规律和碳储量的空间分布格局。结果表明:生物量模型估算值与实测值的平均相对误差为12.72%,精度较高。雪岭云杉林的平均生物量为91.21t/hm,生物量总量为8.2×10~6 t,山区生物量密度的分布总体呈现西南高、东北低的趋势。森林生态系统碳储量为4.1×106 t,平均碳密度为45.61t/hm,山区及其周边的森林碳密度分布不均衡。研究表明,乌鲁木齐南山生物量密度分布不均可能和人类活动有关,且碳储量主要集中在中高密度等级。

Forest vegetation in Nanshan Mountain constitutes main part of the forest in Urumqi.The spatial distribution characteristics of the biomass and carbon reserve are explored in order to provide the basis for the sustainable forest ecosystem management in this area.Landsat TM remote-sensing images in April and May of 2015 were used to calculate the vegetation index.Coupling with fields measured biomass data,we constructed stepwise regression models to estimate the biomass Picea schrenkianaforest in Nanshan Mountain.We converted the biomass to carbon stocks in the study area.The results indicated that the average relative error between the estimated biomass and the measured value was 12.72%;the total biomass of forest ecosystem in Nanshan was 8.2×10^6 t,spatial pattern of biomass showed a trend of high in southwest and low in northeast;the total carbon reserve stock was 4.1×10^6 t with an average carbon density of 45.61 t/hm^2;the spatial distribution of carbon showed the relative higher stock of carbon in mountainous areas.The study showed that the biomass density distribution may be related to human activities in Nanshan Mountain,and carbon stocks were mainly concentrated in medium and high density grades.