Variation in vegetation and ecosystem carbon stock due to the conversion of disturbed forest to oil palm plantation in Peruvian Amazonia

Peruvian national and regional plans promoting oil palm have prompted a rapid expansion of the crop in the Amazonian region. This expansion has taken place primarily at the expense of forest, both undisturbed and disturbed. Assessments of carbon emissions from forest-to-oil palm conversion have essentially been confined to Southeast Asia, and research on Peruvian Amazonian forests has mainly targeted undisturbed sites. This study characterizes the vegetation structure and composition of disturbed forests and smallholder oil palm plantations and evaluates the change in ecosystem (that is, phytomass and soil) carbon stocks associated with forest-to-oil palm conversion. Inventories were conducted in four degraded forest sites neighboring six oil palm plantation sites in Ucayali. Time-averaged carbon stocks over the 30-year oil palm rotation were computed from models developed upon the sampled chronosequence (1 to 28 years old). Disturbed forests harbored species typical of primary forests, pioneer species and gaps opportunistic species. Their tree basal area (18.7 ± 1.4 m2 ha-1) and above-ground C stock (71.3 ± 4.2 Mg C ha-1) were, respectively, 50 and 60% of the values of undisturbed forests from the literature. The growth curve for oil palm above-ground biomass was consistently below models developed for plantations in Indonesia. Thirty-year time-averaged ecosystem C stock (Mg C ha-1) in oil palm plantations (78.2 ± 2.0) represented 55% of the stock in disturbed forest (140.9 ± 5.8), resulting in a 62.7 ± 6.1 loss from such conversion. These results reinforce recommendations to redirect oil palm expansion toward low-carbon degraded lands, sparing disturbed and undisturbed forests.

Spatio-Temporal Variability of Peat CH4 and N2O Fluxes and Their Contribution to Peat GHG Budgets in Indonesian Forests and Oil Palm Plantations

Land-use change in tropical peatlands substantially impacts peat emissions of methane (CH4) and nitrous oxide (N2O) in addition to emissions of carbon dioxide (CO2). However, assessments of full peat greenhouse gas (GHG) budgets are scarce and CH4 and N2O contributions remain highly uncertain. The objective of our research was to assess changes in peat GHG flux and budget associated with peat swamp forest disturbance and conversion to oil palm plantation and to evaluate drivers of variation in trace gas fluxes. Over a period of one and a half year, we monitored monthly CH4 and N2O fluxes together with environmental variables in three undrained peat swamp forests and three oil palm plantations on peat in Central Kalimantan. The forests included two primary forests and one 30-year-old secondary forest. We calculated the peat GHG budget in both ecosystems using soil respiration and litterfall rates measured concurrently with CH4 and N2O fluxes, site-specific soil respiration partitioning ratios, and literature-based values of root inputs and dissolved organic carbon export. Peat CH4 fluxes (kg CH4 ha−1 year−1) were insignificant in oil palm (0.3 ± 0.4) while emissions in forest were high (14.0 ± 2.8), and larger in wet than in dry months. N2O emissions (kg N2O ha−1 year−1) were highly variable spatially and temporally and similar across land-uses (5.0 ± 3.9 and 5.2 ± 3.7 in oil palm and forest). Temporal variation of CH4 was controlled by water table level and soil water-filled pore space in forest and oil palm, respectively. Monthly fluctuations of N2O were linked to water table level in forest. The peat GHG budget (Mg CO2 equivalent ha−1 year−1) in oil palm (31.7 ± 8.6) was nearly eight times the budget in forest (4.0 ± 4.8) owing mainly to decreased peat C inputs and increased peat C outputs. The GHG budget was also ten times higher in the secondary forest (10.2 ± 4.5) than in the primary forests (0.9 ± 3.9) on the account of a larger peat C budget and N2O emission rate. In oil palm 96% of emissions were released as CO2 whereas in forest CH4 and N2O together contributed 65% to the budget. Our study highlights the disastrous atmospheric impact associated with forest degradation and conversion to oil palm in tropical peatlands and stresses the need to investigate GHG fluxes in disturbed undrained lands.

High-resolution global map of smallholder and industrial closed-canopy oil palm plantations

Oil seed crops, especially oil palm, are among the most rapidly expanding agricultural land uses, and their expansion is known to cause significant environmental damage. Accordingly, these crops often feature in public and policy debates which are hampered or biased by a lack of accurate information on environmental impacts. In particular, the lack of accurate global crop maps remains a concern. Recent advances in deep-learning and remotely sensed data access make it possible to address this gap. We present a map of closed-canopy oil palm (Elaeis guineensis) plantations by typology (industrial versus smallholder plantations) at the global scale and with unprecedented detail (10 m resolution) for the year 2019. The DeepLabv3+ model, a convolutional neural network (CNN) for semantic segmentation, was trained to classify Sentinel-1 and Sentinel-2 images onto an oil palm land cover map. The characteristic backscatter response of closed-canopy oil palm stands in Sentinel-1 and the ability of CNN to learn spatial patterns, such as the harvest road networks, allowed the distinction between industrial and smallholder plantations globally (overall accuracy =98.52±0.20 %), outperforming the accuracy of existing regional oil palm datasets that used conventional machine-learning algorithms. The user’s accuracy, reflecting commission error, in industrial and smallholders was 88.22 ± 2.73 % and 76.56 ± 4.53 %, and the producer’s accuracy, reflecting omission error, was 75.78 ± 3.55 % and 86.92 ± 5.12 %, respectively. The global oil palm layer reveals that closed-canopy oil palm plantations are found in 49 countries, covering a mapped area of 19.60 Mha; the area estimate was 21.00 ± 0.42 Mha (72.7 % industrial and 27.3 % smallholder plantations). Southeast Asia ranks as the main producing region with an oil palm area estimate of 18.69 ± 0.33 Mha or 89 % of global closed-canopy plantations. Our analysis confirms significant regional variation in the ratio of industrial versus smallholder growers, but it also confirms that, from a typical land development perspective, large areas of legally defined smallholder oil palm resemble industrial-scale plantings. Since our study identified only closed-canopy oil palm stands, our area estimate was lower than the harvested area reported by the Food and Agriculture Organization (FAO), particularly in West Africa, due to the omission of young and sparse oil palm stands, oil palm in nonhomogeneous settings, and semi-wild oil palm plantations. An accurate global map of planted oil palm can help to shape the ongoing debate about the environmental impacts of oil seed crop expansion, especially if other crops can be mapped to the same level of accuracy. As our model can be regularly rerun as new images become available, it can be used to monitor the expansion of the crop in monocultural settings. The global oil palm layer for the second half of 2019 at a spatial resolution of 10 m can be found at https://doi.org/10.5281/zenodo.4473715 (Descals et al., 2021).

Carbon Stocks from Peat Swamp Forest and Oil Palm Plantation in Central Kalimantan, Indonesia

Conserving high carbon density tropical peat forests is one of the most cost-efficient strategies for climate change mitigation at national and global levels. Over past decades, large areas of tropical peat forests have been converted to oil palm plantation in Indonesia resulting in significant carbon emissions into the atmosphere. Here, we quantified the ecosystem carbon stocks in a total of six sites: two primary peat swamp forest sites, one secondary peat swamp forest site, and three young oil palm plantation sites in Tanjung Puting, Central Kalimantan, Indonesia. We further determined potential carbon emissions from vegetation change due to peat swamp forest conversion to oil palm plantation. The mean total ecosystem carbon stock of primary and secondary peat swamp forests were 1770 ± 123 Mg C/ha and 533 ± 49 Mg C/ha, respectively. In contrast, the mean carbon stock of oil palm plantations was 759 ± 87 Mg C/ha or 42% of peat swamp forests. The ratio of the aboveground to belowground C stock was highest in secondary forest with an estimated value of 0.48, followed by primary forest at 0.19 and oil palm plantation at 0.04. Using a stock difference approach, we estimated potential carbon emissions from vegetation change resulting from the conversion of primary peat swamp forest to oil palm plantation of 640 ± 114 Mg CO2/ha. Finally, while restoring peatlands is important, avoiding peat conversion is imperative for Indonesia’s climate change mitigation effort.

The challenge of reconciling conservation and development in the tropics: Lessons from Brazil’s oil palm governance model

Due to its controversies, oil palm cultivation has been targeted by regulatory innovations. Among these, transnational efforts—such as the Roundtable on Sustainable Palm Oil (RSPO) and corporate commitments to zero deforestation have been highly influential but often tend to overvalue environmental over socio-economic outcomes. This article discusses to what extent domestic governance models of palm oil producing countries can be better equipped to reconcile domestic demands such as economic development and poverty alleviation, and transnational concerns about forest conservation. We do so by looking into the Brazilian case, where the government intended to drive oil palm expansion in the Amazon through a program launched in 2010 that simultaneously only allowed expansion into already deforested areas and offered companies incentives to engage smallholder farmers in their supply chains. Our findings, drawn from primary research activities and existing literature, indicate that Brazil has managed to avoid deforestation typically associated with oil palm expansion elsewhere. Oil palm establishment involved the conversion of 0.8% and 1.3% of primary forests for corporate and smallholder plantations, respectively. However, the Brazilian government did not manage to optimally enhance smallholder participation in the sector, as significant differences in performance were observed between farmers, ranging from very successful (17%) to highly unsuccessful (12%); and failed to achieve sectoral development and competitiveness targets. While some failings can be attributed to external factors such as context, broader domestic governance frameworks and alignments, and private supply chain initiatives, the program itself did not manage to reconcile social, environmental and economic objectives into a single coherent sectoral governance model. Yet, this case study suggests that domestic governance strategies can enable commodity production in a way that is more coherent with national priorities, at the same time as preventing deforestation and minimizing social risks more effectively.

Slowing deforestation in Indonesia follows declining oil palm expansion and lower oil prices

Much concern about tropical deforestation focuses on oil palm plantations, but their impacts remain poorly quantified. Using satellites, we estimated annual expansion of large-scale (industrial) and smallholder oil palm plantations and their overlap with forest loss from 2001 to 2019 in Indonesia, the world’s largest palm oil producer. Over nineteen years, the area under oil palm doubled, reaching 16.24 million hectares (Mha) in 2019 (64% industrial; 36% smallholder), more than official estimates of 14.72 Mha. This expansion was responsible for nearly one-third (2.85 Mha) of Indonesia’s loss of old-growth forests (9.79 Mha). Industrial plantations were associated with three times as much forest conversion as smallholder plantings (2.13 Mha vs 0.72 Mha). New plantations peaked in 2009 and 2012 and declined thereafter. Deforestation peaked in 2016 and fell below pre-2004 levels in 2017-2019. Expansion of industrial plantations and forest loss were correlated with palm oil prices. A price decline of 1% was associated with a 1.08% decrease in new industrial plantations and with a 0.68% decrease of forest loss. This slow-down provides an opportunity for the Indonesian government to focus on details of sustainable oil palm management. If prices rise, effective regulations will remain key to minimising deforestation.

Evaluation Report. Oil Palm Portfolio. An Outcome Evaluation of FTA’s Research Portfolio on Oil Palm

This report assesses the project design, implementation, and outcome realization of FTA’s research portfolio on oil palm in Indonesia. Four projects from the portfolio were selected for in-depth assessment: Supporting Local Regulations for Sustainable Oil Palm in East Kalimantan (EK), Governing Oil Palm Landscapes for Sustainability (GOLS), Oil Palm Adaptive Landscapes (OPAL), and Engendering RSPO Standards (ERS). The report documents and empirically tests whether and how intended portfolio outcomes were realized, with specific attention to the characteristics of projects’ design and implementation that contributed to changes in policy and practice within Indonesia’s oil palm sector.

Agroforestry as Policy Option for Forest-Zone Oil Palm Production in Indonesia

With 15–20% of Indonesian oil palms located, without a legal basis and permits, within the forest zone (‘Kawasan hutan’), international concerns regarding deforestation affect the totality of Indonesian palm oil export. ‘Forest zone oil palm’ (FZ-OP) is a substantive issue that requires analysis and policy change. While spatial details of FZ-OP remain contested, we review literature on (1) the legal basis of the forest zone and its conversion, (2) social stratification in oil palm production (large-scale, plasma and independent growers), and (3) environmental consequences of forest conversion to FZ-OP, before discussing policy options in a range of social and ecological contexts. Policy options range from full regularization (as FZ-OP stands could meet international forest definitions), to conditional acceptance of diversified smallholder plantings in ‘agroforestry concessions’, to gradually phasing out FZ-OP and eviction/destruction. A nuanced and differentiated approach to FZ-OP is needed, as certification of legality along supply chains is vulnerable to illegal levies and corruption. Corporate actors trading internationally can avoid use of uncertified raw materials, effectively shifting blame and depressing farmgate prices for domestic-market palm oil, but this will not return forest conditions or stop further forest conversion. We discuss an agenda for follow-up policy research.

How does replacing natural forests with rubber and oil palm plantations affect soil respiration and methane fluxes?

Replacement of forest by agricultural systems is a major factor accelerating the emissions of greenhouse gases; however, related field studies in the tropics are very scarce. To evaluate the impact of forest transition to plantations on soil methane (CH4) and respiration (CO2) fluxes, we conducted measurements in an undisturbed forest, a disturbed forest, young and old rubber plantations, and an oil palm plantation on mineral soil in Jambi, Sumatra, Indonesia. Methane fluxes and their controlling variables were monitored monthly over fourteen months; soil respiration was measured less frequently. All of the plantations were managed by smallholders and had never been fertilized. To assess the effect of common management practices in oil palm plantations, we added urea at a rate of 33.3 kg N/ha and thereafter monitored intensively soil CH4 fluxes. The soil acted as a sink for CH4 (kg CH4‐C·ha−1·yr−1) in the undisturbed forest (−1.4 ± 1.0) and young rubber plantation (−1.7 ± 0.7). This was not the case in the other land‐use systems which had fluxes similar to fluxes in the undisturbed forest, with 0.4 ± 0.9, −0.2 ± 0.3, and 0.2 ± 0.7 kg·ha−1·yr−1 in the disturbed forest, old rubber plantation, and oil palm plantation, respectively. In the oil palm plantation, there was no inhibitory effect of nitrogenous fertilizer on methanotrophy. Annual soil respiration (Mg CO2‐C·ha−1·yr−1) was higher in the oil palm plantation (17.1 ± 1.9) than in the undisturbed forest (13.9 ± 1.2) while other land‐use systems respired at a similar level to the undisturbed forest (13.1 ± 1.4, 15.9 ± 1.7, and 14.1 ± 1.0 in the disturbed forest, young, and old rubber plantations, respectively). Substrate (litterfall and soil) availability and quality exerted a strong control over annual fluxes of both gases along the land‐use gradient. Temporal variation in CH4 was extremely high and in respiration fluxes was moderate, but was not specifically linked to seasonal variation. Further comprehensive and long‐term research is critically needed to determine more thoroughly the direction and magnitude of changes in soil trace gas emissions as affected by forest‐to‐plantation conversion in the tropics.

Non-state certification of smallholders for sustainable palm oil in Sumatra, Indonesia

Rapid expansion of oil palm plantations is one of the leading causes of Indonesia’s continued deforestation over the past decades. To reverse this trend against the wave of increasing global demand for palm oil, non-state certification programs, such as the Roundtable on Sustainable Palm Oil (RSPO), have been promoted to ensure sustainable palm oil production. However, limited empirical studies exist for understanding how RSPO is perceived and practiced by various stakeholders along the palm oil supply chain, especially at the source by small-scale farmers. We surveyed 181 certified independent smallholders in two sites in Jambi, Sumatra to understand: (1) the challenges and benefits of participating in RSPO; (2) the willingness of independent smallholders to continue their participation; and 3) the factors affecting their willingness. We found that most of the challenges of RSPO certification are not well understood by smallholders, except the need for organizational support. In both sites, extensive external support from a local NGO was the key factor that facilitated RSPO certification. Most of the respondents recognize both non-financial (e.g. knowledge, market access, and social recognition) and financial benefits (e.g. sales from RSPO credits) of certification. Although overall, direct financial benefits may be small, they can be a motivator for farmers to continue with certification and for others to consider joining the group when disbursed equitably in non-monetary and communal form, such as in shared food. In contrast, indirect and long-term benefits were not enough to motivate smallholders to maintain RSPO certification. This study provides important insights about the characteristics of the leaders (governing members) and factors affecting RSPO participation from actual experiences of certified smallholders. The information can be used to target early adopters to initiate the RSPO process in farmers’ groups and to develop appropriate facilitation strategies at different stages of certification development for independent smallholders.

Resilient Landscapes is powered by CIFOR-ICRAF. Our mission is to connect private and public actors in co-beneficial landscapes; provide evidence-based business cases for nature-based solutions and green economy investments; leverage and de-risk performance-driven investments with combined financial, social and environmental returns.

2025 All rights reserved    Privacy notice