亚热带红壤丘陵区湿地松人工林生态系统碳素贮量与分布研究

Carbon Storage and Distribution of the Pinus elliotti Forest Ecosystem in Subtropical Red Soil Hilly Area

利用标准样方法对19a生湿地松人工林生物量、碳素含量、贮量及其空间分布进行测定。结果表明，湿地松各器官的碳素含量在50．92％-54．38％波动，排列顺序为树叶〉树枝〉树根〉树干〉树皮，且各器官的碳素含量随树龄增长而提高。林冠上层与下层叶的碳素含量比中层叶的碳素含量低，但差别不大；下层枝条碳素含量明显比上、中层枝条高。灌木层、草本层、凋落物层的碳素含量依次为45。16％、42．28％、40．88％；土壤层碳素含量平均为0．43％，且随土壤深度的增加而明显递减。湿地松各器官碳贮量与其生物量成正比例关系。排列顺序为树干〉树根〉树皮〉树枝〉树叶。随着树高的增大，树干碳贮量在乔木层中所占比例逐渐下降，树皮碳贮量所占比例处于一个缓慢上升的状态，枝叶碳贮量所占比例在10～12nl段出现最大值。湿地松林生态系统碳贮量（C）为121．94×10^3kg／hm^2，其中乔木层为86．78×10^3kg／hm^2，占整个生态系统总贮量的70．67％。下木层为0．6×10^3kg／hm^2，占0．49％，凋落物层为8．86×10^3kg／hm^2，占7．27％，林地土壤（0-60cm）为26．3×10^3kg／hm^2，占21．57％。根据以上数据，得出湿地松林年净生产力约为7．61×10^3kg／hm^2·a，有机碳年净固定量（C）为4．54×10^3kg／hm^2·a。

The biomass, carbon content, storage and distribution in Pinus elliottii plantation were studied by means of sample plot. The results showed that the carbon contents in different organs of P. elliottii trees ranged from 50.92% to 54.38% ,and decreased in the order of leaf〉 branch 〉 root 〉 bole 〉 bark. The carbon contents varied with layers in the canopy and increased with development of trees. The carbon content in the leaves of upper and lower layer was lower than that in the leaves of the middle, and the carbon content in the branch of the lower layer was higher than that of the middle and the upper. The carbon contents in shrub, herb and litter floor were 45.16% was 0.43% and declined with 42.28% and 40.88% , respectively. The average of carbon content in the soil soil depth. The carbon storage in different organs was positively related to the biomass of corresponding organs and decreased in the order of bole 〉 root 〉 bark 〉 branch 〉 leaf. The carbon storage accumulated by stem declined with the increase of height. The bark carbon storage ratio showed a trend of slow increase with the increase of height. The proportion occupied by the carbon storage in branch and leaf reached maximum between 10 m and 12 m in the canopy. The total carbon storage in P. elliottii plantation e- cosystem amounted to 121.94 × 10^3 kg·hm^-2, of which overstorey stored 86.78 × 10^3 kg·hm^-2, accounted for 70.67%. The understorey, litter floor and soil within the depth from 0 to 60 cm accounted for 0.49% , 7.27% and 21.57% , respectively. The annual net productivity of P. elliottii trees was 7.61 × 10^3 kg·hm^-2 ·a^-1 and annual carbon storage was up to 4.54 × 10^3 kg·hm^-2·^-1.