Aims

 为明晰陕西省森林生态系统碳储量分布格局, 基于2009年森林资源清查资料和2011年调查所得样地实测数据, 对陕西省森林生态系统碳储量、碳密度及其空间分布特征进行了研究分析。结果表明: 陕西省森林生态系统总碳储量为790.75 Tg, 土壤层、植被层和枯落物层碳储量分别占总碳储量的72.14%、26.52%和1.34%; 其中, 栎类碳储量在各森林类型中所占比重最大(44.17%), 中、幼龄林是陕西省森林生态系统碳储量的主要贡献者, 约占总碳储量的49%。陕西省森林生态系统平均碳密度为123.70 t·hm^–2, 土壤层最大, 枯落物层最小, 植被层居中; 碳密度均随龄级增加而升高, 同一龄级表现为天然林高于人工林生态系统。此外, 陕西省森林生态系统碳储量、碳密度分布格局不尽一致, 反映了森林覆盖面积及森林质量对碳储量的影响。未来应加强林地抚育管理水平, 增加造林再造林面积以增加碳储存, 应对全球气候变化。

Analysis on carbon stock distribution patterns of forest ecosystems in Shaanxi Province

Aims The objective of this study was to understand the distribution patterns of carbon stock in forest ecosystems in Shaanxi Province following the implementation of the ecological restoration project―the Grain for Green―in the 90’s of 20th century for combating the severe soil erosion and other environment problems. Methods Based on forest resources inventory data and field measurements, we estimated carbon storage of tree, shrub, herb, litter, and soil layer within each forest ecosystem of Shaanxi Province. Important findings Forest ecosystems in Shaanxi Province stored a total of 790.75 Tg C, and the proportion occupied by soil, vegetation and litter carbon were 72.14%, 26.52% and 1.34%, respectively. Carbon storage within Quercus spp. was the highest (44.17%) among all forest types. Given the large proportion of the areas occupied, the young and middle-aged forests accounted for almost half of the total carbon stores in forest ecosystems. The average carbon density of forest ecosystem was 123.70 t·hm^–2. Similar to the patterns among carbon pools, carbon density was also highest in soil, lowest in litter, and medium in vegetation for each forest type. Carbon density increased with stand age for natural and planted forest ecosystems, and was higher in the natural forest ecosystems than in the planted forests within the same stand ages. Differences in the spatial patterns between carbon stores and density indicate that carbon storage is related not only to forest quality, but also to forest areas. Therefore we could select tree species with high carbon concentration for reforestation and afforestation, and improve forest management practices to increase carbon sequestration potential, which would be beneficial to mitigation of global climate change.