桂西北光皮桦人工林生态系统碳储量及其分布格局

Carbon Storage and Distribution of Betula luminifera Plantation in Northwest Guangxi

森林生态系统碳储量是陆地森林生态系统碳库的重要组成部分,在全球碳循环和碳平衡中发挥着重要作用。本文采用样地测定方法对广西天峨县林朵林场12年生光皮桦人工林的碳素含量、储量及其空间分布格局开展了研究。结果表明,(1)光皮桦不同器官碳素含量为411.3~477.6g/kg,各器官碳素含量排序从大到小依次为干材、干皮、树根、树枝、树叶。灌木层碳素含量为455.4g/kg,草本层为427.2g/kg,凋落物层为427.1g/kg。0~80cm土层碳素含量为15.8g/kg,其中表土层(0~20cm)的碳素含量(31.0g/kg)明显高于其他土层。(2)光皮桦人工林生态系统碳储量为201.45t/hm^2,其中乔木层为51.86t/hm^2,占25.74%;灌木层为1.02t/hm2,占0.51%;草本层为0.51t/hm^2,占0.25%;凋落物层为1.81t/hm^2,占0.90%;土壤层为146.26t/hm^2,占72.60%。(3)光皮桦12年生人工林年净生产力为11.22t/(hm^2·a),年净固碳量为5.06t/(hm^2·a),折合成CO2的量为18.56t/(hm^2·a)。

Forest ecosystem carbon storage is an important part of the carbon pool of terrestrial forest ecosystem, and plays an important role in the global carbon cycle and carbon balance. In this paper, the content, storage and distribution of carbon in 12-year-old Betula luminifera plantation were investigated through biomass harvesting in Linduo Forestry Farm of TianE County, Guangxi Province. The results showed： 1 ） Carbon content in different organs of B. luminifera trees ranged from 411. 3 g/kg to 477. 6 g/kg, which was in order as stem〉bark〉root〉branch〉leaf. The carbon content in shrub, herb, litter floor were 455. 4 g/kg, 427. 2 g/kg and 427. 1 g/kg, re-spectively. Carbon content in the soil （0~80 cm） was 15. 8 g/kg, of which the carbon content of the top soil （0~20 cm） significantly higher than the other layers; 2） The total carbon storage in B. luminifera plantation eco-systems amounted to 201. 45 t/hm^2 . The tree-storey stored 51. 86 t/hm^2 with 25. 74% of the whole, the under-storey stored 1. 53 t/hm^2 with 0. 76%, the litter floor 1. 81 t/hm^2 with 0. 90%, and soil stored 146. 26 t/hm^2 with 72. 60%;3） The annual net productivity of B. luminifera trees was 11. 22 t/ （hm^2·a）, and annual net carbon fixation was up to 5. 06t/ （hm^2·a）, amounted 18. 56 CO2 t/ （hm^2·a）.