根据宁夏回族自治区森林资源清查资料以及野外调查和室内分析的结果,研究了宁夏地区森林生态系统固碳现状,估算了该区森林生态系统的碳密度、碳储量,并分析了其空间分布特征.结果表明:宁夏森林各植被层生物量大小顺序为:乔木层(46.64Mg·hm^-2)〉凋落物层(7.34Mg·hm^-2)〉细根层(6.67Mg·hm^-2)〉灌草层(0.73Mg·hm^-2).云杉类(115.43Mg·hm^-2)和油松(94.55Mg·hm^-2)的单位面积植被生物量高于其他树种.不同林龄乔木层碳密度中,过熟林最高,但由于幼龄林面积所占比例最大,其乔木层碳储量(1.90Tgc)最大.宁夏地区森林生态系统平均碳密度为265.74MgC·hm^-2,碳储量为43.54Tgc,其中,植被层平均碳密度为27.24MgC·hm^-2、碳储量为4.46TgC,土壤层碳储量是植被层的8.76倍.宁夏地区的森林碳储量整体呈南高北低分布,总量较低.这与其森林面积小和林龄结构低龄化有很大关系.随着林龄结构的改善和林业生态工程的进一步实施,宁夏森林生态系统将发挥巨大的固碳潜力.
Based on the data of Ningxia Hui Autonomous Region forest resources inventory, field investigation and laboratory analysis, this paper studied the carbon sequestration status of forest ecosystems in Ningxia region, estimated the carbon density and storage of forest ecosystems, and analyzed their spatial distribution characteristics. The results showed that the biomass of each forest vegetation component was in the order of arbor layer (46.64 Mg . hm^-2 ) 〉 litterfall layer ( 7.34 Mg . hm^-2) 〉 fine root layer (6.67 Mg. hm^-2 ) 〉 shrub-grass layer (0.73 Mg.hm^-2 ). Spruce ( 115.43 Mg. hm^-2) and Pinus tabuliforrnis (94.55 Mg. hm^-2 ) had higher vegetation biomasses per unit area than other tree species. Over-mature forest had the highest arbor carbon density among the forests with different ages. However, the young forest had the highest arbor carbon storage ( 1.90 Tg C) due to its widest planted area. Overall, the average carbon density of forest ecosys- tems in Ningxia region was 265.74 Mg C ~ hm-2, and the carbon storage was 43.54 Tg C. Carbon density and storage of vegetation were 27.24 Mg C ~ hm-2 and 4.46 Tg C, respectively. Carbon storage in the soil was 8.76 times of that in the vegetation. In the southern part of Ningxia region, the forest carbon storage was higher than in the northern part, where the low C storage was mainly related to the small forest area and young forest age structure. With the improvement of forest age structure and the further implementation of forestry eeoengineerin, the forest ecosystems in Ninaxiaregion would achieve a huge carbon sequestration potential