以海南岛为例,选择环岛东、西、南、北四个方向的典型红树林群落,对土壤进行取样,测定土壤有机碳含量,计算土壤有机碳密度.通过对比群落结构、土壤理化性质、不同区域的自然条件,探讨红树林土壤有机碳的分布规律以及影响碳储量的主要因素.研究表明,土壤有机碳分布特征在垂直方向上差异显著,土壤有机碳含量最大值出现在20～ 40 cm,土壤有机碳密度最大值出现在0～20cm;不同群落类型土壤有机碳含量存在明显差异,以东寨港红树林为例,海莲群落土壤有机碳含量最高,为20.89±6.75 g kg-1,人工无瓣海桑林最低,为12.71±3.62 gkg-1,进一步相关分析显示,土壤有机碳含量与群落植株胸径和基盖度呈显著正相关,与株高无关;在空间分布上,表现为东方四泌湾＞文昌清澜港＞儋州新英湾＞海口东寨港＞三亚湾.最后结合海南岛红树林面积,得出海南岛红树林土壤有机碳总储量为2.39×106t.
DISTRIBUTION OF SOIL ORGANIC CARBON IN MANGROVE WETLANDS OF HAINAN ISLAND AND ITS INFLUENCING FACTORS
Mangrove wetlands,typical of wetlands in subtropic and tropic area,are considered as a huge carbon pool along the coast.In this study,typical mangrove wetlands in the north,east,south and west coasts of the Hainan Island were selected for soil sampling.A total of 630 soil samples were collected from 126 sites,five soil samples each site from 5 soil layers,20 cm each,in 42 quadrats scattered in 14 mangrove communities.The samples were analyzed for soil organic carbon (SOC) contents with the potassium dichromate external heating method and SOC density was worked out based on soil bulk density.Through comparison between the sites in community structure,soil physical and chemical properties and natural conditions,exploration was done of regularities of the distribution of SOC in the mangrove wetlands and major factors affecting the SOC stock therein.Results show that the distribution of SOC content and density varied sharply with soil depth ; the peak of SOC content appeared in 20 ～ 40 cm,while that of SOC density did in 0 ～ 20 cm ;SOC content also varied with mangrove community; in the Dongzhai Harbor area,the Bruguiera sexangula community was the highest in SOC content (20.89 ± 6.75 g kg-1),while the artificial Sonneratia apetala community was the lowest (12.71 ± 3.62 g kg-1).Further correlation analysis shows that SOC content was positively related with DBH(diameter at breast height) of the mangrove trees and coverage of the community,but not with plant height.As to spatial distribution,a decreasing order of Simi Bay Dongfang ＞ Qinglan Harbor Wenchang ＞ Xinying Bay Danzhou ＞ Dongzhai Harbor Haikou ＞ Sanya Bay Sanya was observed.Finally,based on the area of the mangrove forests in Hainan Island,the mangrove forest soil in Hainan Island possesses a total stock of 2.39 × 106t organic carbon.
Soil organic carbon contentSoil organic carbon densityDistribution patternMangrove forestHainan Island
国家科技期刊平台
NSTL
万方数据
维普
