鼎湖山南亚热带常绿阔叶林碳素积累和分配特征

Carbon accumulation and allocation of lower subtropical evergreen broad-leaved forests in a MAB reserve of China

研究了鼎湖山南亚热带常绿阔叶林 40 0多年林龄的锥栗 (Castanopsis chinensis)、黄果厚壳桂 (Crypto-carya concinna)和 50多年林龄的黄果厚壳桂、鼎湖钓樟 (Lindera chunii)两个群落碳素积累和分配特征。结果表明 ,两林分间植物碳素含量在不同器官和不同层中的分配格局均十分相似 ,总平均分别为 41 .980 %(锥栗、黄果厚壳桂群落 )和 40 .377% (黄果厚壳桂、鼎湖钓樟群落 )。锥栗、黄果厚壳桂群落生态系统碳总贮量为 2 4 4 .998t/ hm2 ,其中植被部分为 1 54.2 89t/ hm2 ,土壤为 89.1 2 8t/ hm2 ,地表凋落物层为 1 .581 t/ hm2。黄果厚壳桂、鼎湖钓樟群落植被碳总贮量为 84.1 51 t/ hm2。在两林分植被碳总贮量中 ,乔木层分别占了97.47% (锥栗、黄果厚壳桂群落 )和 98.0 4 % (黄果厚壳桂、鼎湖钓樟群落 ) ,而在乔木层碳总贮量中 ,干器官则分别占 47.93% (锥栗、黄果厚壳桂群落 )和 44.66% (黄果厚壳桂、鼎湖钓樟群落 )。锥栗、黄果厚壳桂群落植被碳年积累量为 3.1 4 9t/ (hm2· a) ,黄果厚壳桂、鼎湖钓樟群落植被碳年积累量则为 3.42 5 t/ (hm2· a)。

The accumulation and distribution of carbon were st udied for two communities of Castanopsis chinensis, Cryptocarya concinna (CC CC, > 400 year old) and of Cryptocarya concinna, Lindera chunii (CCLC, > 5 0 year old) in a lower subtropical evergreen broad-leaved forest of a MAB bio sp here reserve of China. Carbon concentrations distributed among plant organs and layers in a similar pattern for these two communities, with a mean value (%) of 41 980 in CCCC community and 40 377 in CCLC community. The total carbon standi ng stock in the ecosystem of CCCC community was estimated to be 244 998 t/hm 2. The vegetation component accounted for 62 96 percent of the total (154 289 t/hm 2), while soil (to 60 cm depth) and the standing litter components accou nted for 36 38 percent (89 128 t/hm 2) and 0 66 percent of the total (1 58 1 t/hm 2), respectively. The total carbon standing stock in the vegetation com ponent of CCLC community was estimated to be 84 151 t/hm 2 and was about 54 54 percent of that for CCCC community. In both communities, however, the total c arbon standing stock in the vegetation component was mostly in the tree layer, w ith 97 47 percent of total (150 385 t/hm 2) in CCCC community and 98 04 per cent in CCLC community (82 504 t/hm 2), and woody tissues contained almost ha lf of the total carbon standing stock in the tree layer (47 93% and 44 66% in CCCC and CCLC communities, respectively). Although the community of CCCC was old er than 400 years, its vegetation was still accumulating carbon every year. The total annual carbon accumulation of vegetation component was 3 149 t/(hm 2·a ) in CCCC community and slightly lower than that in CCLC community (3 425 t/(hm 2·a)).