Data from: Carbon stocks in the Guinea savanna of Ghana: estimates from three protected areas

Savannas are widespread in sub-Saharan Africa (SSA) and unarguably play major role in the global carbon balance. Extensive quantification of carbon stocks of the savannas in SSA will therefore contribute significantly to the global carbon budget in the era of climate change. In this study, we investigated the spatial distribution of carbon stocks of different soil fractions from the dominant tree species (Vitellaria paradoxa) of three forest reserves in the Guinea savanna of Ghana as well as the tree and non-tree carbon stocks. The study was carried out in Kenikeni, Sinsablegbinni and Klupene forest reserves using nested plot design. Higher soil carbon stock (SCS) was associated with the silt +clay fraction than the microaggregates and small macroaggregates of all three protected areas. Soil carbon stocks ranged from 2.99 to 15.89 Mg C /ha in the surface soil of 0-10 cm depth. The highest SCS was recorded at the sub-canopy (SC), drip line (DL) and 2(SC + DL) zones from the dominant tree of the Klupene, Sinsablegbinni and Kenikeni forest reserves, respectively. The highest tree carbon stock of 60.57 Mg C/ha was recorded in Kenikeni as compared to 26.98 Mg C/ha of Sinsablegbinni, which had the highest stocking density. Average carbon capture by a single tree ranged from 0.04 to 0.34 Mg C. Grass C stock in the above- ground biomass ranged from 0.09 to 0.29 Mg C /ha whilst the below ground carbon stock ranged from 0.03 to 0.44 Mg C /ha. Accumulation of carbon in the aboveground grass biomass increased with decreasing forest cover, whereas that of the below ground biomass increased with increasing forest cover with implications for forest management in the savanna.

热带稀树草原（savanna）广泛分布于撒哈拉以南非洲（sub-Saharan Africa, SSA），毋庸置疑在全球碳平衡中发挥着关键作用。因此，对撒哈拉以南非洲热带稀树草原的碳储量开展全面量化研究，将在气候变化时代为全球碳预算做出重要贡献。本研究以加纳几内亚热带稀树草原带的3处森林保护区为研究区域，针对区域优势树种牛油果树（Vitellaria paradoxa），探究其不同土壤组分的碳储量空间分布特征，同时分析乔木与非乔木碳储量。本研究采用嵌套样地设计，在凯尼凯尼（Kenikeni）、辛萨布莱格宾尼（Sinsablegbinni）与克鲁佩内（Klupene）3处森林保护区开展野外调查与采样工作。三处保护区中，粉粒+黏粒组分的土壤碳储量（soil carbon stock, SCS）显著高于微团聚体与小型大团聚体组分。0~10cm表层土壤的碳储量范围为2.99~15.89 Mg C/ha。克鲁佩内、辛萨布莱格宾尼与凯尼凯尼保护区的优势乔木冠下（sub-canopy, SC）、滴水线（drip line, DL）以及2(SC+DL)区域，分别为对应保护区土壤碳储量最高的位点。凯尼凯尼保护区的乔木碳储量最高，达60.57 Mg C/ha；辛萨布莱格宾尼保护区虽拥有最高的立木密度（stocking density），但其乔木碳储量仅为26.98 Mg C/ha。单株乔木的平均固碳量范围为0.04~0.34 Mg C。地上草本生物量的碳储量范围为0.09~0.29 Mg C/ha，地下草本生物量的碳储量范围为0.03~0.44 Mg C/ha。地上草本生物量的碳累积量随森林覆盖率降低而升高，而地下草本生物量的碳累积量则随森林覆盖率升高而增加，该结论对热带稀树草原的森林管理具有重要指导意义。