Carbon mineralization dynamics of tropical peats in relation to peat characteristics

Abstract

Saidy AR, Mariana ZT, Adji FA, Nusantara RW, Fitria I, Syahrinudin. 2018. Carbon mineralization dynamics of tropicalpeats in relation to peat characteristics. Biodiversitas 19: 1413-1421. Understanding the dynamics of carbon mineralization of peats inthe tropical areas is of essential significance in controlling carbon dioxide (CO2) gas emission rates. An incubation study of tropicalpeats sampled from 3 different sites of the Barito Basin on the Borneo Island, Indonesia (uncultivated, used for paddy cultivation for  5years and 5-10 years) was carried out to investigate a relationship between CO2 production and peat characteristics. Results of studyrevealed that land use change from uncultivated peats to paddy fields resulted in significant changes in the chemical structure of peatorganic carbon. Carbohydrate contents of the peat decreased significantly as a consequence of the conversion of natural peats to paddyfields. However, the paddy peats contained higher lignin than uncultivated peats. Changes in the chemical structure of the tropical peatsresulted in changes in carbon mineralization. Carbon mineralization of uncultivated peats ranged from 29255310 mg CO2-C kg-1 peat,while carbon mineralization of 10652678 mg CO2-C kg-1 C peat was observed for paddy peats. Moreover, carbon mineralization dataobtained from the experiment fitted properly to a two-pool C mineralization model. The developed carbon mineralization model showedthat slowly and rapidly decomposable pools have a close relation with rubbed fiber and carbohydrate content data. Thus, results of thisstudy suggested that carbon mineralization of peats could be estimated appropriately using rubbed fiber and carbohydrate content data.

Reduction in carbon dioxide and methane production of tropical peatlands due to coal fly-ash application

“…This indicates that the change in carbon mineralization in peat that produces CO2 and CH4 with the addition of coal fly-ash is not related to changes in peat pH. The results of the study are in agreement with previous studies reported that pH of peat does not correlated with carbon mineralization of peatlands [10,21].…”

“…As a result of the rapidly increasing population, part of the tropical peatlands in Indonesia has been reclaimed for agricultural cultivation [9,10]. The use of tropical peatlands as agricultural land has resulted in increased emissions of green house gases (GHG) of reclaimed tropical peatlands.…”

Diversity in characteristics of tropical peatlands varying in land uses leads to differences in methane and carbon dioxide emissions

“…The lowest carbohydrate content in burned peatland produced the lowest CO2 emission, while high CO2 emission was produced from a high content of carbohydrates on shrubspeatland (Figure 4.A). Several previous studies have also shown that peatlands with low carbohydrate content exhibit low CO2 emission, while high CO2 emission is generally observed in peatlands with high carbohydrate content (Grover and Baldock 2013;Saidy et al 2018).…”

“…The decrease in carbohydrates and increase in lignin contents with changes in land use from uncultivated peatlands to cultivated peatlands are in agreement with the concept of changes in the chemical structure of organic C contained in peatlands with agricultural activities. Several agricultural activities in peatlands, such as drainage, fertilizing and liming, enhance the decomposition process of organic C contained in the peats, which in turn causes a decrease in organic C with structures that are easily decomposed, such as carbohydrates and results in the accumulation of organic C that is resistant to biodegradation such as lignin (Saidy et al 2018;Saidy et al 2020).…”

“…Peatlands with high lignin content have a low rate of CO2 emission (Könönen et al 2016). Saidy et al (2018) developed a model of greenhouse gas emissions of tropical peatlands and used peat lignin content as a parameter to predict the amounts of CO2 produced in tropical peatlands, in which increasing peat lignin content suppresses the rate of CO2 emissions. Results of these studies indicate that lignin content controls the rate of CO2 emissions of tropical peatlands.…”