广西不同林龄马尾松碳储量及分配格局

Carbon storage and distribution in Pinus massoniana plantations at different stand ages in Guangxi Province

在生物量调查的基础上,对广西5 a、15 a、21 a、32 a和60 a马尾松(Pinus massoniana)人工林生态系统碳储量及其分配特征进行了研究。结果表明:马尾松人工林生态系统碳储量为60 a(277.04 t/hm^2)>32 a(250.05 t/hm^2)>21 a(208.05 t/hm^2)>5 a(130.35 t/hm^2)>15 a(128.02 t/hm^2);马尾松人工林植被层碳储量为31.18-159.52 t/hm^2,占总碳储量的23.92%-57.58%,随着林龄的增加而增加;凋落物层为1.42-3.59 t/hm^2,占0.51%-2.80%,随林龄的增加呈"M"型变化趋势。土壤层碳储量为32 a(136.52 t/hm^2)>60 a(116.09 t/hm^2)>21 a(115.28 t/hm^2)>5 a(96.66 t/hm^2)>15 a(78.58 t/hm^2),随林龄的增加呈倒"N"型变化趋势。马尾松人工林5 a、15 a、21 a、32 a林龄阶段碳储量均表现为土壤>植物>地被物,地下>地上,60 a阶段碳储量则表现为植物>土壤>地被物,地上>地下。植被层碳储量以乔木层最大(28.30-157.79 t/hm^2),占90.76%-98.92%,其中乔木层碳储量主要分布在树干(20.51-120.32 t/hm^2),占乔木层总碳储量的71.52%-76.25%,随林龄的增加而增加。桂东南马尾松平均年净固碳量为7.91 t/(hm^2·a),其中32 a(10.37 t/(hm^2·a))最大,固碳能力强,是一种优良的碳汇林树种。

Based on the data of biomass at five different stand ages （5 a. 15 a, 21 a. 32 a. 60 a） collected from the main Pinus massoniana areas in Guangxi, the carbon storage and its characteristics of dynamic change were studied. The results showed that the total carbon storage of Pinus massoniana plantation ecosystem was in the order of 60 a （277.04 t/hm^2）〉32 a （250.05 t/hm^2）〉21 a （208.05 t/hm^2）〉5 a （130.35 t/hm^2）〉15 a （128.02 t/hm^2）; Carbon storage of the vegetation layer was 31.18-159.52 t/hm^2, contributing 23.92%-57.58% to the total carbon storage of the ecosystems, as it grew with age; The carbon storage of litter layer was 1.42-3.59 t/hm^2, which contributed 0.51%-2.80% to the total carbon storage of the ecosystems, with the increase of forest age degrees showing a trend of a ＂M＂ type. The order of carbon storage of soil layer was 32 a〉60 a〉21 a〉5 a〉15 a, with the increase of forest age degrees falling under the ＂N＂ type. The carbon storage of Pinus massoniana plantation 5 a, 15 a, 21 a, 32 a stage characterized by soil layer 〉 plant layer 〉 ground layer cover, underground〉aboveground, while 60 a stage is characterized by plant layer 〉 soil layer 〉 ground layer, aboveground 〉underground. The biggest carbon storage of the vegetation layer was the tree layer （28.30-157.79 t/hm^2）, about 90.76%- 98.92%, in which the trunk dominants （20.51-120.32 t/hm^2） of 71.52%-76.25%, and the carbon storage increased with the forest age. The average annual net carbon fixation of Pinus massoniana plantation is 7.91 t/（hm^2·a）, where 32 a （10.37 t/（hm^2·a） ） forest had the highest carbon storage. Therefore Pinus massoniana was a better species for carbon sequestration forestry with high capability of carbon deposition.