太行山丘陵区不同林龄核桃树固碳释氧量及冠下土壤碳储量

Carbon fixation and oxygen release amount and soil carbon storage under the canopy of walnut trees with different forest ages in hilly areas of Taihang Mountain

为了探明太行山丘陵区核桃树的固碳释氧量和不同部位的碳储量及冠下土壤碳储量随林龄的变化规律,以1年、3年、5年、9年、13年和16年生的核桃树为研究对象,测定其叶片面积、叶片净光合速率、不同部位的生物量以及土壤有机质含量。结果表明,不同林龄核桃树间存在较大差异。随着林龄的增加,核桃树的固碳释氧量呈现出先增加后降低的趋势,单株核桃树的固碳量、释氧量大小排序为9年生>5年生>13年生>16年生>3年生>1年生;随着林龄的增加,核桃树的树叶、树枝和树干的碳储量均呈先增加后降低的趋势,单株核桃树的碳储量大小排序为树枝>树干>树叶;就不同林龄的核桃树而言,其林地各土层(0~20 cm、20~40 cm、40~60 cm)的土壤碳储量均呈现出随林龄的增加而逐渐增大的趋势,而对于同一林龄核桃树,其土壤碳储量随土壤深度的增加而逐渐降低。

To find out the carbon fixation and oxygen release amount of walnut trees,carbon storage of different parts and change of soil carbon storage under the canopy with forest ages in hilly areas of Taihang Mountain,the walnut trees of one year old,three years old,five years old,nine years old,thirteen years old and sixteen years old were taken as the research objects,and the leaf area,net photosynthetic rate of leaves,biomass of different parts and soil organic matter content were determined.The results showed that there were significant differences between walnut trees of different ages.With the increase of forest age,the carbon fixation and oxygen release amount of walnut trees increased first and then decreased.The carbon fixation and oxygen release amount of a single walnut tree all showed the trend of nine years old>five years old>thirteen years old>sixteen years old>three years old>one year old.With the increase of forest age,the carbon storage of leaves,branches and trunks from walnut trees increased first and then decreased.The carbon storage of a single walnut tree showed the trend of branch>trunk>leaves.For walnut trees of different ages,the soil carbon storage of each soil layer(0-20 cm,20-40 cm,40-60 cm)in the forest land all increased with the increase of forest age,while for walnut trees of the same age,the soil carbon storage decreased with the increase of soil depth.The results of this paper can provide a theoretical basis for the accurate evaluation of ecological benefits of economic forest.