19962015
  • Authors:
    • Austin,K. G.
    • Kasibhatla,P. S.
    • Urban,D. L.
    • Stolle,F.
    • Vincent,J.
  • Source: Web Of Knowledge
  • Volume: 10
  • Issue: 5
  • Year: 2015
  • Summary: Our society faces the pressing challenge of increasing agricultural production while minimizing negative consequences on ecosystems and the global climate. Indonesia, which has pledged to reduce greenhouse gas (GHG) emissions from deforestation while doubling production of several major agricultural commodities, exemplifies this challenge. Here we focus on palm oil, the world's most abundant vegetable oil and a commodity that has contributed significantly to Indonesia's economy. Most oil palm expansion in the country has occurred at the expense of forests, resulting in significant GHG emissions. We examine the extent to which land management policies can resolve the apparently conflicting goals of oil palm expansion and GHG mitigation in Kalimantan, a major oil palm growing region of Indonesia. Using a logistic regression model to predict the locations of new oil palm between 2010 and 2020 we evaluate the impacts of six alternative policy scenarios on future emissions. We estimate net emissions of 128.4-211.4 MtCO 2 yr -1 under business as usual expansion of oil palm plantations. The impact of diverting new plantations to low carbon stock land depends on the design of the policy. We estimate that emissions can be reduced by 9-10% by extending the current moratorium on new concessions in primary forests and peat lands, 35% by limiting expansion on all peat and forestlands, 46% by limiting expansion to areas with moderate carbon stocks, and 55-60% by limiting expansion to areas with low carbon stocks. Our results suggest that these policies would reduce oil palm profits only moderately but would vary greatly in terms of cost-effectiveness of emissions reductions. We conclude that a carefully designed and implemented oil palm expansion plan can contribute significantly towards Indonesia's national emissions mitigation goal, while allowing oil palm area to double.
  • Authors:
    • Guillaume,T.
    • Damris,M.
    • Kuzyakov,Y.
  • Source: Global Change Biology
  • Volume: 21
  • Issue: 9
  • Year: 2015
  • Summary: Indonesia lost more tropical forest than all of Brazil in 2012, mainly driven by the rubber, oil palm, and timber industries. Nonetheless, the effects of converting forest to oil palm and rubber plantations on soil organic carbon (SOC) stocks remain unclear. We analyzed SOC losses after lowland rainforest conversion to oil palm, intensive rubber, and extensive rubber plantations in Jambi Province on Sumatra Island. The focus was on two processes: (1) erosion and (2) decomposition of soil organic matter. Carbon contents in the Ah horizon under oil palm and rubber plantations were strongly reduced up to 70% and 62%, respectively. The decrease was lower under extensive rubber plantations (41%). On average, converting forest to plantations led to a loss of 10 Mg C ha -1 after about 15 years of conversion. The C content in the subsoil was similar under the forest and the plantations. We therefore assumed that a shift to higher delta 13C values in plantation subsoil corresponds to the losses from the upper soil layer by erosion. Erosion was estimated by comparing the delta 13C profiles in the soils under forest and under plantations. The estimated erosion was the strongest in oil palm (358 cm) and rubber (3310 cm) plantations. The 13C enrichment of SOC used as a proxy of its turnover indicates a decrease of SOC decomposition rate in the Ah horizon under oil palm plantations after forest conversion. Nonetheless, based on the lack of C input from litter, we expect further losses of SOC in oil palm plantations, which are a less sustainable land use compared to rubber plantations. We conclude that delta 13C depth profiles may be a powerful tool to disentangle soil erosion and SOC mineralization after the conversion of natural ecosystems conversion to intensive plantations when soils show gradual increase of delta 13C values with depth.
  • Authors:
    • Meriem, S.
    • Triadiati, T.
    • Leuschner, C.
    • Kotowska, M. M.
    • Hertel, D.
  • Source: Primary Research Article
  • Volume: 21
  • Issue: 10
  • Year: 2015
  • Summary: Natural forests in South-East Asia have been extensively converted into other land-use systems in the past decades and still show high deforestation rates. Historically, lowland forests have been converted into rubber forests, but more recently, the dominant conversion is into oil palm plantations. While it is expected that the large-scale conversion has strong effects on the carbon cycle, detailed studies quantifying carbon pools and total net primary production (NPP total) in above- and belowground tree biomass in land-use systems replacing rainforest (incl. oil palm plantations) are rare so far. We measured above- and belowground carbon pools in tree biomass together with NPP total in natural old-growth forests, 'jungle rubber' agroforests under natural tree cover, and rubber and oil palm monocultures in Sumatra. In total, 32 stands (eight plot replicates per land-use system) were studied in two different regions. Total tree biomass in the natural forest (mean: 384 Mg ha -1) was more than two times higher than in jungle rubber stands (147 Mg ha -1) and > four times higher than in monoculture rubber and oil palm plantations (78 and 50 Mg ha -1). NPP total was higher in the natural forest (24 Mg ha -1 yr -1) than in the rubber systems (20 and 15 Mg ha -1 yr -1), but was highest in the oil palm system (33 Mg ha -1 yr -1) due to very high fruit production (15-20 Mg ha -1 yr -1). NPP total was dominated in all systems by aboveground production, but belowground productivity was significantly higher in the natural forest and jungle rubber than in plantations. We conclude that conversion of natural lowland forest into different agricultural systems leads to a strong reduction not only in the biomass carbon pool (up to 166 Mg C ha -1) but also in carbon sequestration as carbon residence time (i.e. biomass-C:NPP-C) was 3-10 times higher in the natural forest than in rubber and oil palm plantations.
  • Authors:
    • Takahashi, H.
    • Limin, S. H.
    • Darung, U.
    • Hadi, A.
    • Arai, H.
    • Hatano, R.
    • Inubushi, K.
  • Source: SOIL SCIENCE AND PLANT NUTRITION
  • Volume: 60
  • Issue: 3
  • Year: 2014
  • Summary: Land use change in tropical peat soil is thought to cause intense greenhouse gas emissions by enhancing organic matter decomposition. Although microbes in peat soil play key roles in the emission of greenhouse gases, their characteristics remain unknown. This study was conducted to clarify the effect of land use change (drainage, forest fire and agricultural land use) on the control of gas emission factors with respect to the characteristics of microbes in tropical peat soils. Field observations were carried out in Central Kalimantan, Indonesia, from July 2009 to March 2011. Carbon dioxide (CO 2) and nitrous oxide (N 2O) fluxes in tropical peat soils were measured in an undrained natural forest, a drained forest, two burned forests and four croplands. A fumigation-extraction method was used to measure the soil microbial biomass to evaluate the relationships among the soluble organic carbon (SOC), microbial biomass carbon (MBC) and nitrogen (MBN) and the CO 2 and N 2O fluxes in peat soils. Regarding the relationships between weekly precipitation and N 2O emission, positive relationships were found in both the forest and cropland soils. However, the slope of the regression line was much higher in the croplands than in the forest soils. The CO 2 fluxes in the croplands but not in the forest soils were significantly correlated with both precipitation and N 2O fluxes. In contrast, the CO 2 fluxes in the forest but not in the croplands were significantly correlated with the MBC and the MBC/SOC ratio. The SOC did not show any relationship with the CO 2 fluxes but showed a positive relationship with the MBN and a negative linear relationship with the nitrate (NO 3-) concentration. In addition, the MBN showed a negative relationship with most of the probable numbers of ammonium oxidizers. These results indicate that the agricultural land use of tropical peat soils varied the factors controlling greenhouse gas emissions through microbial activities. Therefore, the microbial biomass may be a key factor in controlling CO 2 fluxes in forest soils but not in agricultural peat soils. However, precipitation may be a key factor in agricultural peat soils but not in forest soils.
  • Authors:
    • Smith, P.
    • Matthews, R.
    • Farmer, J.
    • Smith, J. U.
  • Source: Migration and Adaption Strategies for Global Change
  • Volume: 19
  • Issue: 6
  • Year: 2014
  • Summary: 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 (CO 2) 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 CO 2 emissions from tropical peat soils. The tool requires simple input values to determine the rate of subsidence, of which the oxidising proportion results in CO 2 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 CO 2 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.
  • Authors:
    • Osaki, M.
    • Limin, S.
    • Kusin, K.
    • Hirano, T.
  • Source: Global Change Biology
  • Volume: 20
  • Issue: 2
  • Year: 2014
  • Summary: In Southeast Asia, a huge amount of peat has accumulated under swamp forests over millennia. Fires have been widely used for land clearing after timber extraction, thus land conversion and land management with logging and drainage are strongly associated with fire activity. During recent El Nino years, tropical peatlands have been severely fire-affected and peatland fires enlarged. To investigate the impact of peat fires on the regional and global carbon balances, it is crucial to assess not only direct carbon emissions through peat combustion but also oxidative peat decomposition after fires. However, there is little information on the carbon dynamics of tropical peat damaged by fires. Therefore, we continuously measured soil CO 2 efflux [peat respiration (RP)] through oxidative peat decomposition using six automated chambers on a burnt peat area, from which about 0.7 m of the upper peat had been lost during two fires, in Central Kalimantan, Indonesia. The RP showed a clear seasonal variation with higher values in the dry season. The RP increased logarithmically as groundwater level (GWL) lowered. Temperature sensitivity or Q10 of RP decreased as GWL lowered, mainly because the vertical distribution of RP would shift downward with the expansion of an unsaturated soil zone. Although soil temperature at the burnt open area was higher than that in a near peat swamp forest, model simulation suggests that the effect of temperature rise on RP is small. Annual gap-filled RP was 38282 (the mean1 SD of six chambers) and 36274 gC m -2 yr -1 during 2004-2005 and during 2005-2006 years, respectively. Simulated RP showed a significant negative relationship with GWL on an annual basis, which suggests that every GWL lowering by 0.1 m causes additional RP of 89 gC m -2 yr -1. The RP accounted for 21-24% of ecosystem respiration on an annual basis.
  • Authors:
    • Husnain,H.
    • Wigena,I. G. P.
    • Dariah,A.
    • Marwanto,S.
    • Setyanto,P.
    • Agus,F.
  • Source: Mitigation and Adaption Strategies for Global Change
  • Volume: 19
  • Issue: 6
  • Year: 2014
  • Summary: With the increasing use of tropical peatland for agricultural development, documentation of the rate of carbon dioxide (CO 2) emissions is becoming important for national greenhouse gas inventories. The objective of this study was to evaluate soil-surface CO 2 fluxes from drained peat under different land-use systems in Riau and Jambi Provinces, Sumatra, Indonesia. Increase of CO 2 concentration was tracked in measurement chambers using an Infrared Gas Analyzer (IRGA, LI-COR 820 model). The results showed that CO 2 flux under oil palm ( Elaeis guineensis) plantations ranged from 3416 and 4525 Mg CO 2 ha -1 year -1 in two locations in Jambi province to 6625 Mg CO 2 ha -1 year -1 for a site in Riau. For adjacent plots within 3.2 km in the Kampar Peninsula, Riau, CO2 fluxes from an oil palm plantation, an Acacia plantation, a secondary forest and a rubber plantation were 6625, 5919, 6125, 5217 Mg ha -1 year -1, respectively, while on bare land sites it was between 5630 and 6724 Mg CO 2 ha -1 year -1, indicating no significant differences among the different land-use systems in the same landscape. Unexplained site variation seems to dominate over land use in influencing CO 2 flux. CO 2 fluxes varied with time of day ( p<0.001) with the noon flux as the highest, suggesting an overestimate of the mean flux values with the absence of night-time measurements. In general, CO 2 flux increased with the depth of water table, suggesting the importance of keeping the peat as wet as possible.
  • Authors:
    • Utomo,M.
  • Source: Sustainable Living with Environmental Risks
  • Volume: 9784431548041
  • Year: 2014
  • Summary: Global warming due to greenhouse gas emissions is currently receiving considerable attention worldwide. Agricultural systems contribute up to 20 % of this global warming. However, agriculture can reduce its own emissions while increasing carbon sequestration through use of recommended management practices, such as consernvation tillage (CT). The objective of this paper is to review the role of long-term CT in mitigating greenhouse gas emissions during corn production in rainfed tropical agro-ecosystems. The types of conservation tillage were no-tillage (NT) and minimum tillage (MT). In a long-term plot study, CO2 emission from CT throughout the corn season was consistently lower than that from intensive tillage (IT). The cumulative CO2 emissions of NT, MT, and IT in corn crops were 1.0, 1.5, and 2.0 Mg CO2-C ha-1season-1, respectively. Soil carbon storage at 0-20 cm depth after 23 years of NT cropping was 36.4 Mg C ha-1, or 43 % and 20 % higher than the soil carbon strorage of IT and MT, respectively. Thus, NT had sequestered some 4.4 Mg C ha-1of carbon amounting to carbon sequestration rate of 0.2 Mg C ha-1 year-1. IT, on the other hand, had depleted soil carbon by as much as 6.6 Mg C ha-1, yielding a carbon depletion rate of 0.3 Mg C ha-1 year-1. Assessment of the farmer's corn fields confirmed these findings. CO2 emission from CT corn farming was similar to that of rubber agroforest and lower than IT corn farming. Based on carbon balance analysis, it can be concluded that corn crops in tropical rainfed agro-ecosystems were not in fact net emitters, and that NT was a better net sinker than other tillage methods. © 2014 The Editor(s) (if applicable) and the Author(s). All rights reserved.
  • Authors:
    • Putri,E. A.
    • Koido,K.
    • Dowaki,K.
  • Source: Proceedings of the 9th International Conference on Life Cycle Assessment in the Agri-Food Sector
  • Year: 2014
  • Summary: Climate change is mainly linked to greenhouse gas (GHG) emissions in which the agricultural sector occupies 14% of total emissions. In this paper, the questionnaires were implemented to investigate the effects of green bean quality including eco-burden factor and price on consumer buying decision. Also, on the estimation of eco-burden, LCA methodology was considered, and the carbon footprint of green bean in the supply chain process in Indonesia was expressed. The results showed that the total emissions (CFP) of green bean were between 4.92 and 7.38 kg-CO 2eq/kg green bean by varying farmers, and they became larger than that of Japan case (1.11 kg-CO 2eq/kg green bean). In addition, through our questionnaires on basis of the quality and price of green bean, we confirmed that the factor of quality is more significant for consumer buying decision.
  • Authors:
    • Managanvi, K.
    • Erayya
    • Makanur, B
    • Jagdish, J.
  • Source: Environment and Ecology
  • Volume: 31
  • Issue: 2
  • Year: 2013
  • Summary: The evidence for climate change is now considered to be unequivocal, and trends in atmospheric carbon dioxide (CO 2), temperature and sealevel rise are tracking the upper limit of model scenarios elaborated in the Fourth Assessment (AR4) undertaken by the International Panel on Climate Change (IPCC). Agriculture directly contributes almost 14% of total Green House Gas (GHG) emissions and indirectly accounts for a further 7% incurred by the conversion of forests to agriculture (mostly conversion to rangeland in the Amazon), currently at the rate of 7.3 million ha/year. It focuses on specific aspects of agriculture and agricultural water management that contribute to greenhouse gas emissions and offer prospects for mitigation. In addition to the impacts of cycles of wetting and drying, the concentration of inorganic and organic fertilizer on land with some form of water management means that the practice of irrigation has scope to mitigate GHG emissions. Global atmospheric temperature is predicted to rise by approximately 4°C by 2080, consistent with a doubling of atmospheric CO 2 concentration. Increased atmospheric concentrations of CO 2 enhance photosynthetic efficiency and reduce rates of respiration, offsetting the loss of production potential due to temperature rise. Early hopes for substantial CO 2 mitigation of production losses due to global warming have been restrained. A second line of reasoning is that by the time CO 2 levels have doubled, temperatures will also have risen by 4°C, negating any benefit.