Carbon Loss from Several Landuse Type on Tropical Peat Lands Drained

Peatland degradation indicated by stable isotope depth profiles and soil carbon loss

QUANTIFYING PEATLAND CARBON DYNAMICS USING MECHANISTICALLY-BASED BIOGEOCHEMISTRY MODELS

Peat land conversion to oil palm plantation affects carbon stocks and can change a net sink of atmospheric carbon (C) into a net source. The influence of location, type of peat, drainage practices and fertilization is insufficiently known. A study was conducted in West Aceh from May 2008 until October 2009  in oil palm plantations of various age.  Carbon stocks and  C loss were calculated from data of bulk density (BD), ash content, carbon content, and peat depth. A new method for C loss estimates using ash as internal tracer was developed and tested. Peat land characteristics after drainage and conversion to oil palm plantation were investigated by field observation and laboratory analysis of peat soil samples in the laboratory. Results showed that: 1) Distance from the drain influences the rates of: a) water table depth, b) subsidence, with rates of 1,1  to 9,2 cm/year and 22.67 – 57.23% influence of C loss, and c) soil carbon loss. 2) Ash content and bulk density of the peat are related, indicating the partial loss of soil C during compaction. 3) An “internal tracer” estimate of peat C loss yields estimates of CO2 flux up to 48 t CO2-eq ha-1 y-1 for young oil palm, highly correlated with measured rates of subsidence of the surface and water table depth. 4) Patterns of weight loss of surface litter, measured in litter bags, respond to inherent quality (C/N). Some data for oil palm on shallow peat suggest that a net sink for C can be maintained under such conditions.Key words: Carbon stock, carbon loss, carbon accumulation,  oil palm, tropical peat

Tropical peat swamp forests (TPSF) in Malaysia are infertile, ombrotrophic, acidic, and waterlogged forests of mixed tree composition. Knowledge about microbes in peat is still lacking, therefore ecological studies investigating microbial activity on leaf litter, in peat, and in tree roots in the North Selangor Peat Forest (NSPF) of Peninsular Malaysia were undertaken. Changes in peatland landuse were addressed including logging, drainage, fire, and conversion to agriculture. Microbial diversity and activity in a natural TPSF - Loagan Bunut in Sarawak, were determined. Questions asked included: Which factors most influence microbes as heterotrophs in tropical peat swamps - the environment, or the qualities of peat and leaf litter? What are the roles of tree roots and microbes during litter decomposition? Which anthropogenic manipulations most affect heterotrophic activities in peatlands, and what are the consequences? Finally, what is the microbial diversity and activity in peat of a natural TPSF? Does microbial diversity change with peat depth? Methods employed for these studies focused on leaf litter decay in the field complemented by peat core samples and the quantification of environmental factors, such as the watertable and its pH. In the lab, chemical and physical measurements of peat and leaves were complemented with microbial enzyme activity determinations, used as a proxy for microbial activity. DNA extractions of peat produced the metagenomes for microbial diversity using next generation sequencing. Leaf quality of 4 species local to NSPF (Macaranga tanarius, M. pruinosa, Shorea uliginosa, and Koompassia malaccensis) was investigated to elicit their contributions to peat, and to show how life strategies of trees influence nutrient cycling in peatlands. Leaves in litterbags were decomposed for 2 yrs. in NSPF to determine their contributions to nutrient cycling, and to carbon seqestration in peat. Anthropogenic effects on peatland microbial ecology focusing on heterotrophic activity were contrasted by comparing 2 forested and 2 deforested sites in which M. tanarius and S. uliginosa leaf litter was decomposed for 6 mo. to show that deforestation enhances leaf decomposition that increases nutrient cycling through infertile peatlands. Two metagenomes created from peat revealed that bacteria dominated microbial diversity in surface and 100cm deep peat. Microbial activity occurred in surface, 10 cm, and 45 cm deep peat. In 100 cm deep peat microbes were present, but dormant, due to high energetic requirements in deeper peat, and a buildup of tannic acids. The ecological importance for maintaining waterlogged low pH conditions in peatlands that house late successional tree communities to promote slowed nutrient cycling in infertile peat that allows for the accretion of carbon was demonstrated. Natural TPSF support diverse microbial communities that change when humans disrupt them, which threatens their existence.

Peat land has specific character, depends on depth of peat and peat decomposition rale.Earthworms has a role in decomposition,carbon cycle, nutrient redistribution, bioturbation and cycle of nutrient.The aim of the research was to identify the population and diversity of earthworms on peat soil in central Kalimantan and to get species of dominant earthworm in peat land.The research was carried out in several peat land use in Basarang and Kalampangan, Central Kalimantan within dry and rainy season.The collection of earthworms was by using hand sorting method. The result showed that population of earthworms on mulch was higher than the deep peat.Land use influenced population and diversity of earthworm. The population and diversity of earthworms were highest on pineapple (shallow peat soil).The dominant species earthworm in peat land was I'omoscolex corethurus.

Agricultural land extensification on peat land is one solution to fulfill national needed on food. Peat soil contains organic matter therefore it becomes one source of greenhouse gas emissions (GHG), i.e. Dioxide carbon (CO2), metahne (CH4), and NO2. Land use for agricultural activities will change the natural condition of peat soil. The changes could increase GHG emissions. One way to reduce GHG emissions and to increase rice production in peat soils is by adding of ameliorant. The aim of this study was to determine the effect of ameliorant on carbon balance at peat soil paddy rice. The experiment was conducted at research station of Agricultural Environmental Research Institute in 2008. Samples of peat soil as much as 8 tons was carried from South Kalimantan and placed into 12 microplots. The size of microplot was 1.5 x 1.5 x 0.8 m. Experimental design used randomized block design with four treatments: control, dolomite 2 t ha-1, rice straw 2 t ha-1 and animal manure 2 t ha-1 which was repeated three times. Rice variety was Batanghari and transplanted at age 21 days after seeding. Fluxes of CH4 were measured automatically using GC which equipped with FID (Flame Ionization Detector). Emissions of CO2 and N2O were measured manually using GC which equipped with ECD detector (electron capture detector) and TCD (thermal conductivity detector). The content of organic carbon in plants was determined by dichromate oxidation technique-titration. The lowest of net carbon/ carbon budget is animal manure treatment: 4,962.0 kg-C ha-1 followed by dolomite, without ameliorant, and rice straw: 5,270.2; 9,534.7; and 10,115.6 kg-C/ha respectively. The highest yield is rice straw, followed by dolomite, without ameliorant and manure: 4.98, 4.92, 4.69, and 4.54 t ha-1 respectively. Dolomite treatment has the highest ratio of yield GWP-1 : 933.58 kg of yield/ton of CO2-C followed by animal manure 913.30 kg of yield /ton of CO2-C, without ameliorant and rice straw: 492.13 and 491.59 kg of yield/ton of CO2-C respectively.

Land use change on Indonesian peatlands contributes to global anthropogenic greenhouse gas (GHG) emissions. Accessible predictive tools are required to estimate likely soil carbon (C) losses and carbon dioxide (CO2) emissions from peat soils under this land use change. Research and modelling efforts in tropical peatlands are limited, restricting the availability of data for complex soil model parameterisation and evaluation. The Tropical Peatland Plantation-Carbon Assessment Tool (TROPP-CAT) was developed to provide a user friendly tool to evaluate and predict soil C losses and CO2 emissions from tropical peat soils. The tool requires simple input values to determine the rate of subsidence, of which the oxidising proportion results in CO2 emissions. This paper describes the model structure and equations, and presents a number of evaluation and application runs. TROPP-CAT has been applied for both site specific and national level simulations, on existing oil palm and Acacia plantations, as well as on peat swamp forest sites to predict likely emissions from future land use change. Through an uncertainty and sensitivity analysis, literature reviews and comparison with other methods of estimating soil C losses, the paper identifies opportunities for future model development, bridging between different approaches to predicting CO2 emissions from tropical peatlands under land use change. TROPP-CAT can be accessed online from www.redd-alert.eu in both English and Bahasa Indonesia.

Tropical peat land is an important buffer for climate change as it absorbs atmospheric carbon and stores large carbon reserve. Inappropriate drainage and agricultural development on peat land results in GHG emissions such as CO2 and CH4which could shift the peat land ecosystem from carbon sink to carbon source. The objectives of this study were to: (i) quantify CO2 loss in a tropical soil under simulated water table fluctuation and (ii) determine the relationship between depth of water table and CO2 loss of a tropical soil cultivated with pineapples. Soil CO2 emission was captured using closed chamber method in field lysimeter and quantified using gas chromatography. It was carried out in July (dry month) and December 2015 (wet month). The peat soil water table fluctuation did not significantly affect emission of CO2 in pineapple cultivation. For lower water table, 147.5 t CO2 ha-1 yr-1 was emitted in the dry month whereas for higher water table, 19.6 t CO2 ha-1 yr-1. In the wet month, CO2emission of the lower water table was 23.7 t CO2 ha-1 yr-1whereasfor high water tables the emission was 25.6 t CO2 ha-1 yr-1. Soil CO2 emission for the lower water table was higher than that of the high water table whereas the opposite was true for the higher water table because of increase in soil temperature in the dry month. Regardless of season and depth of peat soil water table, this study will provide significant understanding of the effect of water table management on carbon loss in peat soils under pineapple cultivation.

Land- atmosphere exchange of elemental mercury : new insights using a novel relaxed eddy accumulation and enclosure techniques

Глубина прогорания торфа и потери углерода при лесном подземном пожаре

This research was conducted in October-December 2019 which took place at Peat Land of Kualu Nenas Village, Tambang Distric, Kampar Regency, Riau Province and in Soil Laboratory at Agriculture Faculty, Integrated Laboratory, Marine Chemistry Laboratory with Environmental Quality Laboratory at Fisheries and Marine Faculty of Universitas Riau. The objective of this research is to get a best dose of biofertilizer mixture from human and cow faeces to physical parameter of soil and water Patin fish culture media in peat ponds. The results of this research indicated that P4 (biofertilizer mixture of human biofertilizer 80% with cow biofertilizer 20%) is a best treatment (peat soil colour 10YR 3/1 brownish black, crude fiber of peat soil 5,43%, bulk density of peat soil 0,147 g/cm3, turbidity of peat water 74,14 NTU, total suspended solid of peat water 49,67 mg/L, absolute weight of Patin fish 17,3 g, absolute lenght of Patin fish 4,4 cm, and survival rate of Patin fish 86%). The porosity of Peat Soil, the best treatment is in P0 (control). The temperature of peat water that range from 26-29oC is still classified as optimal for aquatic organism.

A field model study was carried out in Klang area of Selengor Dharul Ehsan, Malaysia to observe the settlement of stabilized group peat columns. Peat soil exhibits very low bearing capacity and this soil is not suitable for constructing embankment, highway, building or any other load bearing engineering structure. Large areas of land all over the world are covered by problematic peat soils. The growing demand of space to accommodate new buildings and infrastructures has increased the utilization of soft ground such as peatland. Two sets of test group columns were constructed to stabilize tropical peat by in-situ soil-column with mixing auger and Prebored-premixed method using high setting PFA cement, calcium chloride and siliceous sand as binders. Static load test was performed to observe the settlement of group columns after 28 days of curing time. Computer modelling using PLAXIS software was conducted to compare the load vs. settlement data of group columns. From this study 13.5 mm settlement was observed for the group columns installed by hand mixing and 17.5 mm settlement was found for the mixing auger method. This is due to the fact that proper mixing plays an important role for the achievement of high load carrying capacity of stabilized column. Key words: Stabilization, binder, bearing capacity, field experiment, PFA cements, sand, mixing auger, prebored-premixed, static load test, computer modelling.

The continuously increasing population growth more than food agriculture growth on the existing land, has been encouraging to this research. The land use competition for agriculture and housing purposes have caused the land use change from forest to agriculture and housing. Within forested landscapes food production, commodity agriculture, biodiversity, resource extraction and other land uses are also competing for space. The forest land use change (deforestation) is one of the climate change causes. The impact of climate change among others is the uncertain climate, such as the long drought period, flood, and the extreme temperature that cause decreasing in agriculture production. Therefore, at present, many people use the marginal land, such as peat land for agriculture cultivation to increase the food agriculture production and to achieve the domestic and export demand. Indonesia has a huge peat land and the fourth biggest in the world after Rusia, Canada, and America. The focus of this study is comparing the life cycle assessment of three agriculture commodities: sago palm, oil palm, and paddy cultivated on peat land. The purpose of this research is to contribute a recommendation of the most sustainable commodity from the aspect carbon dioxide (CO 2 ) emission among three food agriculture commodities include oil palm and paddy that currently as excellent commodities, and sago palm, the neglected indigenous plant, which are cultivated on peat land. The method applied for this research to analyze the environmental aspect using life cycle assessment (LCA) started from seedling, plantation, harvesting, transportation, and production process. The analysis result reveals that sago palm is the most environmental friendly. The lowest CO 2 emission (ton/ha/year) is sago palm (214.75 ± 23.49 kg CO 2 eq), then paddy (322.03 ± 7.57 kg CO 2 eq) and the highest CO 2 emission (ton/ha/year) is oil palm (406.88 ± 97.09 kg CO 2 eq).

Monthly measurements of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes in peat soils were carried out and compared with groundwater level over a year at four sites (drained forest, upland cassava,upland and lowland paddy fields) located in Jambi province, Indonesia. Fluxes from swamp forest soils were also measured once per year as the native state of this investigated area. Land-use change from drained forest to lowland paddy field significantly decreased the CO2 (from 266 to 30 mg C m−2 h−1) and N2O fluxes (from 25.4 to 3.8 μg N m−2 h−1), but increased the CH4 flux (from 0.1 to 4.2 mg C m−2 h−1) in the soils. Change from drained forest to cassava field significantly increased N2O flux (from 25.4 to 62.2 μg N m−2 h−1), but had no significant influence on CO2 (from 266 to 200 mg C m−2 h−1) and CH4 fluxes (from 0.1 to 0.3 mg C m−2 h−1) in the soils. Averaged CO2 fluxes in the swamp forests (94 mg C m−2 h−1) were estimated to be one-third of that in the drained forest. Groundwater levels of drained forest and upland crop fields had been lowered by drainage ditches while swamp forest and lowland paddy field were flooded, although groundwater levels were also affected by precipitation. Groundwater levels were negatively related to CO2 flux but positively related to CH4 flux at all investigation sites. The peak of the N2O flux was observed at –20 cm of groundwater level. Lowering the groundwater level by 10 cm from the soil surface resulted in a 50 increase in CO2 emission (from 109.1 to 162.4 mg C m−2 h−1) and a 25% decrease in CH4 emission (from 0.440 to 0.325 mg C m−2 h−1) in this study. These results suggest that lowering of groundwater level by the drainage ditches in the peat lands contributes to global warming and devastation of fields. Swamp forest was probably the best land-use management in peat lands to suppress the carbon loss and greenhouse gas emission. Lowland paddy field was a better agricultural system in the peat lands in terms of C sequestration and greenhouse gas emission. Carbon loss from lowland paddy field was one-eighth of that of the other upland crop systems, although the Global Warming Potential was almost the same level as that of the other upland crop systems because of CH4 emission through rice plants.

Carbon loss from a deforested and drained tropical peatland over four years as assessed from peat stratigraphy