Measurement of carbon accumulating rate in a tropical peat swamp

为了评价热带泥炭沼泽林的有效积累速率，测定了泥炭沼泽森林生态系统的二氧化碳排放速率。此外，还发展了一种简便的方法来估算泥炭沼泽林的碳积累速率。在泰国南部的一片原生泥炭沼泽森林中，测量了泥炭和凋落物分解以及树木呼吸产生的二氧化碳(CO2)排放量。将得到的树叶、树枝、树干、泥炭土壤、凋落物和积水水面的排放速率进行综合，估算出森林生态系统的总二氧化碳排放量。以单位表面积计算，枝条的呼吸速率在地上部分中最大。然而，树叶的单位地表面积增长率最大。按碳量计算，该生态系统的年二氧化碳排放量为8.84tC ha；-1。茎、枝、叶、根、凋落物和泥炭的分值分别为6%、6%、28%、28%、18%和14%。这说明地下排放对评价泥炭沼泽林的碳平衡起着相当重要的作用。提出了一种简便易行的碳积累速率估算方法。采用泥炭探针法现场测量堆积密度分布。分别用NC分析仪和碳同位素测定了现场采集的泥炭的碳含量和累积年限。利用这些剖面，得到了碳累积速率的剖面，在最近的森林砍伐之前，它大约是1tC/ha/年。

In order to evaluate the available accumulation rate in a tropical peat swamp forest, emission rate of carbon dioxide from the peat swamp forest ecosystem was measured. Also, simple and convenient method was developed to estimate carbon accumulation rate in a peat swamp forest.1. Carbon dioxide (CO_2) emission by peat and litter decomposition and by tree respiration were measured in a primary peat swamp forest of southern Thailand. The obtained emission rates from foliage, branch, stem, peat soil, litter and ponding water surface were integrated to estimate the total CO_2 emission from the forest ecosystem. On the basis of unit surface area, the branch had the greatest respiration rate among the aboveground components. However, the foliage had the greatest rate per unit ground surface area. Annual CO_2 emission from the ecosystem was estimated to 8.84 tC ha^<-1> yr^<-1> on the carbon weight basis. The breakdown of the value to each component was 6, 6, 28, 28, 18 and 14 % for stems, branches, foliage, roots, litter and peat, respectively. This indicates that emission from underground plays quite important role to assess the carbon balance of the peat swamp forest.2. Simple and convenient method to estimate carbon accumulation rate was developed. Profile of bulk density was measured in situ by Peat Probe method. Profiles of carbon content and accumulated year for sampled peat at the site were determined by NC analyzer and by Carbon isotopes, respectively. By using these profiles, profile of carbon accumulation rate was derived, which was about 1 tC/ha/year before the recent deforestation.