黄土高原丘陵区退耕还林地油松人工林碳储量及分配特征研究

以黄土高原丘陵区主要退耕还林树种油松为研究对象,对甘肃省庆阳市合水县采用样地调查与生物量实测方法,分析不同坡向（阳坡、阴坡）及退耕年限（退耕6年、9年和12年）油松人工林的乔木不同器官、灌草层、枯落物层和土壤层的碳含量,以及油松人工林乔木层、灌草层、枯落物层和土壤层碳储量及其分配特征,探讨甘肃黄土高原丘陵区生态林的固碳作用。结果表明:（1）油松不同器官碳含量为48.15%~53.90%,各器官碳含量大小为树干>叶>细枝>粗枝>根桩>粗根>树皮>大根>中根>小根>细根>球果;灌木层碳含量为茎>叶>根;草本层碳含量为地上部分>地下部分。（2）油松人工林的枯落物层碳含量为未分解层大于半分解层。（3）0~100 cm土壤层的碳含量随退耕年限增加而增大,随土壤深度的增加而下降;0~10 cm、10~20 cm土壤层不同坡向间碳含量差异显著。（4）阳坡和阴坡退耕6年、9年和12年油松林总碳储量分别为42.90、50.50、59.22 t·hm^-2和45.08、53.77、65.70 t·hm^-2。研究认为,黄土高原丘陵区阳坡和阴坡均适宜油松林发挥固碳效益,且阴坡要优于阳坡,是甘肃黄土高原丘陵区的理想树种。

Characteristics of Carbon Storage and Sequestration of Pinus tabulaeformis Forest Land Converted by Farmland in Loess Hilly Area

In order to understand the carbon sequestration of ecological forests in Loess Plateau of Gansu Province,we toke the different slopes (sunny and shady slope)and restoration duration(conversion of 6 years,9 years and 12 years) of Pinus tabulaeformis plantations as test objects and by the methods of plot investigation and biomass measurement.We studied the carbon content in different plant organs,shrub layers,grass layers,litter layers and soil layers and the carbon storage and its allocation in tree layer,shrub layer,grass layer,litter layer and soil layer.For the test plantations,the carbon storage content in different P.tabulaeformis organs ranged from 48.15%~53.90%,which in the order as follows:stem>leaf>fine-branch>thick-branch>stump>thick-root>bark>large-root>medium-root>small-root>fine-root>cone;in shrub layer was stem>leaf>root;in grass layer was abovegrond>underground;in litter layer was fresh>decomposing.The carbon storage in the soil profiles(0~100 cm) increased with plantation age but decreased with soil depth.There are significant different of difference slope positions in 0~10 cm and 10~20 cm.The total carbon storage in sunny and shady slopes of the 6-,9-and 12-year plantations was 42.90,50.50,59.22 t·hm^-2 and 45.08,53.77 and 65.70 t·hm^-2.It was considered that P.tabulaeformis had a good carbon sequestration function in sunny slope and shady slope.The shady slope was better than sunny slope and being able to be an ideal tree species in Loess Plateau of Gansu Province.