Distribution of carbon storage in a lower subtropical monsoon evergreen broad-leaved forest in Dinghushan Nature Reserve
Distribution of carbon storage in a lower subtropical monsoon evergreen broad-leaved forest in Dinghushan Nature Reserve
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作者：
Tang Xu
研究森林碳储量具有重要的理论意义。虽然对主要森林类型的研究较多，但大多数是针对北方半球热带、中高纬度地区的森林，对北回归线附近的森林研究较少。鼎湖山自然保护区的区域植被为季风万年青阔叶林。虽然位于北回归线，该地区覆盖着不同的森林类型，包括综合森林演替系列。此外，自1956年以来，该地区的背景数据已经有了很好的记录，这对本研究有利。根据1hm 2固定样地生物量和各高度级优势种碳含量数据，分析了不同垂直层次、不同胸径级和不同种群的立木碳储量及其分布。结果表明：（1）南亚热带季风万年青阔叶林的碳贮量为89.75t·hm-2，其中花、枝、叶和根的碳贮量分别占53.09%、25.36%、2.64%和18.31%;（2）胸径小于20 cm的个体占群落的绝对优势，约占群落总数的95%。个体数随径级的增加而显著减少。立木碳储量随径级增加呈“M”形分布。当胸径从1 cm增加到10 0 cm时，2 0 ~30 cm和70~90 cm的林分碳储量最大，分别为12.5 0 t·hm-2和14.14 t·hm-2，5 0 ~ 6 0 cm的林分碳储量最小，为1.6 9 t·hm-2;（3）固定碳储量的垂直分布仅随层高的增加而增加。其中，53.97%分配在第Ⅰ层（h≥ 20 m），31.37%分配在第Ⅱ层（10 m ≤ h20 m），11.26%分配在第Ⅲ层（5 m ≤ h10 m），3.40%分配在第Ⅳ层（h5 m）。树干、枝、根、叶的碳储量均随层高的增加而增加，但第Ⅱ层的叶碳储量最高;（4）微生物带优势种的碳储量大小顺序为：锥栗木荷厚壳桂树黄杞果木青果楠楠黄肾叶总体而言，成熟度较高的种群在群落的碳储量中占主导地位。
It is of theoretical importance to understand forest standing carbon storage. Although there have been many reports on it for major forest types, most of them refer to forests in tropics, medi- and high-latitude areas in the Northern Hemisphere, few focus on forests near the tropic of cancer. The regional vegetation in Dinghushan Nature Reserve (DNR) is monsoon evergreen broad-leaved forest (MEBF). Although located in the tropic of cancer, the area is covered with different forest types, including integrated forest succession series. Besides, the background data in this area have been well documented since 1956, which benefits this study. Based on biomass data in 1-hectare permanent plot and carbon contents of dominant species in each height class for MEBF, the paper analyzed standing carbon storage and its distribution according to vertical layers, DBH (diameter at breast height) classes and population. The results are showed as following: (1) Standing carbon storage in the lower subtropical monsoon evergreen broad-leaved forest amounts to 89.75t·hm -2, with the percentage of 53.09% , 25.36%, 2.64% and 18.31% in bloes, branches, leaves and roots, respectively; (2) Individuals with DBH less than 20 cm dominate the community, account for 95% of the total. The number of individuals decreases remarkably with DBH class increasing. Distribution of standing carbon storage with DBH class enhancement demonstrates an “M” shape tendency. When DBH increases from 1 cm to 100 cm, there are two maximum values of standing carbon storage occurring in the DBH classes of 20~30 cm and 70~90 cm, being 12.50 t·hm -2 and 14.14 t·hm -2, respectively, and there is a minimum value of standing carbon storage showing in the DBH class of 50～60 cm,being 1.69 t·hm -2; (3) Vertical distribution of standing carbon storage increases simply with layer height. Of the whole standing carbon storage, 53.97% is allocated in layerⅠ(h≥20m), 31.37% in layerⅡ(10m≤h20m), 11.26% in layer Ⅲ (5m≤h10m), and 3.40% in layer Ⅳ(h5m). Standing carbon storage in boles, branches, roots and leaves also increases with layer height except the leaves of layerⅡ, the standing carbon storage of which is the highest; (4) The amount of standing carbon storage of dominant species in MEBF is in this sequence: Castanopsis chinensisSchima superbaCryptocarya concinnaCryptocarya chinensisAcmena acuminatissimaEngelhardtia roxburghianaGironniera subaequalisPygeum topengiiCanarium albumPterospermum lanceaefoliumMachilus chinensisSchefflera octophyllaNephelium chryseum. In general, the population with higher maturation dominates the standing carbon storage of the community.