桂西北岩溶区苏木人工林生物量及碳储量

Biomass and Carbon Storage of Caesalpinia Sappan plantation in Northwest Guangxi

2017年,采用标准样地法对桂西北岩溶区5年生苏木人工林生态系统的生物量、碳储量及其分配特点等进行研究。结果表明:苏木人工林生态系统植被层生物量为17.46 t·hm^-2,各组分由大到小排序为乔木层(80.2%)>凋落物层(10.8%)>灌草层(8.9%);乔木层各器官生物量达极显著差异(P<0.01),由大到小排序为树干>树枝>根兜>树叶>侧根>果。乔木层年净生产力为2.81 t·hm^-2·a^-1,乔木层各器官碳含量差异不显著(P>0.05),平均碳含量介于465.49~504.40 g·kg^-1之间,由大到小依次为树枝>树叶>树干>根兜>果>侧根;灌草层碳含量为423.00 g·kg^-1;凋落物层碳含量为487.77 g·kg^-1;土壤层(0~20 cm)碳含量为56.13 g·kg^-1,土壤层具有相对较高的碳吸附能力。苏木人工林生态系统总碳储量为135.36 t·hm^-2,各组分由大到小排序为土壤层(93.7%)>乔木层(5.1%)>凋落物层(0.7%)>灌草层(0.5%)。乔木层年净固碳量为2.14 t·hm^-2·a^-1,苏木在岩溶区适应生长能力及固碳潜力相对较高,可作为岩溶区石漠化治理和碳汇树种。

In 2017,the standard sample plot method was used to study the biomass,carbon storage and spatial distribution characteristics of 5-year-old Caesalpinia sappan plantation ecosystem in karst area of Northwest Guangxi.The results showed that:the biomass of vegetation layer in Caesalpinia sappan plantation ecosystem is 17.46 t·hm^-2,sort from big to small as arbor layer(80.2%)>litter layer(10.8%)>shrub grass layer(8.9%).The biomass of each organ in the arbor layer is very significant difference(P<0.01),sort from big to small as stem>branch>root tip>leaf>lateral root>fruit.The net productivity of arbor layer is 2.81 t·hm^-2·a^-1.The carbon content in different organs in arbor layer is no obviously different,the average content is between 465.49~504.40 g·kg^-1,sort from big to small as branch>leaf>stem>root tip>fruit>lateral root.The carbon content in understory shrub grass layer is 423.00 g·kg^-1,in litter layer is 487.77 g·kg^-1,and soil layer(0~20 cm)is 56.13 g·kg^-1,the soil layer has relatively high carbon adsorption capacity.The total carbon storages of Caesalpinia sappan plantation ecosystem is 135.36 t·hm^-2,each component sort from big to small as soil layer(93.7%)>arbor layer(5.1%)>litter layer(0.7%)>shrub grass layer(0.5%).The annual carbon fixation of arbor layer is up to 2.14 t·hm^-2·a^-1,Caesalpinia sappan has relatively high adaptability and carbon sequestration potential in karst areas,can be used as an ideal rocky desertification control and carbon sink species in karst areas.