Oil Palm Expansion Research Articles

Greenhouse gas emissions from land use change due to oil palm expansion in Thailand for biodiesel production

Thailand depends heavily on importation of fossil oil to satisfy its energy demand. The transportation sector is an important contributor to energy demand; biofuels are therefore strongly promoted in Thailand, notably biodiesel from oil palm. According to the Renewable and Alternative Energy Development Plan (AEDP 2012–2021) a biodiesel target of 5.97 million litres per day is to be achieved by 2021. This research focuses on assessing the implication of this on oil palm plantation area requirement, regions most suitable for its expansion and related greenhouse gas (GHG) implications as well as feedstock security. The investigations revealed that about 91,200 ha of land would be required for oil palm expansion to achieve the biodiesel target while also meeting other requirements for palm oil including domestic consumption, export, stock and surplus. The Eastern and Southern regions were identified as the two most suitable for oil palm cultivation with respectively 29,772 ha and 61,427 ha of mainly grassland and abandoned land. Oil palm expansion in the East would lead to overall land use change related GHG savings amounting to 47,214 tonnes CO2-eq per year. Oil palm expansion in the South would also bring GHG savings, 2.5 times higher than for the East.

Additional supporting evidence for significant iLUC emissions of oilseed rape biodiesel production in the EU based on causal descriptive modeling approach

AbstractAgro‐economic modeling studies have shown that indirect land‐use change (iLUC) emissions of first‐generation biofuels can be significant, reducing or eliminating the climate change mitigating potential of these fuels. Recognizing this, proposed amendments to the European Union's Renewable Energy Directive (RED) would require reporting iLUC emissions of biofuels. The objective of this paper was to provide additional evidence of the iLUC emissions of oilseed rape (OSR) biodiesel using a noneconomic modeling approach called the causal descriptive (CD) model. The CD model originally developed by E4tech (A Causal Descriptive Approach to Modelling the GHG Emissions Associated with the Indirect Land Use Impacts of Biofuels, 2010, E4tech, London, UK) is one of the first noneconomic modeling approaches used for estimating indirect land‐use change (iLUC). Using the E4tech CD modeling framework, we refine assumptions for key parameters such as yields in marginal land, displacement of OSR oil by palm oil, land availability for OSR expansion in the EU, imports of OSR from Canada and Ukraine, and palm oil expansion on peatland and thereby estimate iLUC GHG emissions for a likely scenario (Central Scenario). We find GHG emissions of OSR biodiesel to be 57 g CO2 eq./MJ for the Central Scenario. To capture the possible range of iLUC GHG emissions, we calculate iLUC GHG emissions by changing assumptions for the Central Scenario and land‐use emission factors. We find that GHG emissions of OSR biodiesel may vary from 18 to 101 CO2 eq./MJ. The results provide additional evidence supporting the previous conclusions derived from agro‐economic modeling studies that iLUC emissions of food‐based biofuels can be expected to be significant compared to potential savings. Hence, to achieve meaningful GHG reductions from biofuel use and avoid policy failure, it is important that the EU should take concrete policy action to target support for biofuels toward those with the lowest expected iLUC emissions.

Assessment of Large Scale Land Cover Change Classifications and Drivers of Deforestation in Indonesia

Abstract. Indonesia possesses the third largest tropical forests coverage following Brazilian Amazon and Congo Basin regions. This country, however, suffered from the highest deforestation rate surpassing deforestation in the Brazilian Amazon in 2012. National capacity for forest change assessment and monitoring has been well-established in Indonesia and the availability of national forest inventory data could largely assist the country to report their forest carbon stocks and change over more than two decades. This work focuses for refining forest cover change mapping and deforestation estimate at national scale applying over 10,000 scenes of Landsat scenes, acquired in 1990, 1996, 2000, 2003, 2006, 2009, 2011 and 2012. Pre-processing of the data includes, geometric corrections and image mosaicking. The classification of mosaic Landsat data used multi-stage visual observation approaches, verified using ground observations and comparison with other published materials. There are 23 land cover classes identified from land cover data, presenting spatial information of forests, agriculture, plantations, non-vegetated lands and other land use categories. We estimated the magnitude of forest cover change and assessed drivers of forest cover change over time. Forest change trajectories analysis was also conducted to observe dynamics of forest cover across time. This study found that careful interpretations of satellite data can provide reliable information on forest cover and change. Deforestation trend in Indonesia was lower in 2000-2012 compared to 1990-2000 periods. We also found that over 50% of forests loss in 1990 remains unproductive in 2012. Major drivers of forest conversion in Indonesia range from shrubs/open land, subsistence agriculture, oil palm expansion, plantation forest and mining. The results were compared with other available datasets and we obtained that the MOF data yields reliable estimate of deforestation.

Oil palm expansion without enclosure: smallholders and environmental narratives

Recent debates on land grabbing and biofuels tend to link oil palm expansion to rural dispossession, environmental degradation and rural resistance. In this paper, we examine to what extent ‘enclosure’, a central concept in two critiques – ‘environmentalism of the poor’ and ‘green grabbing’ – is intrinsically linked to oil palm expansion. We argue that where enclosure is absent, poor peasants may seek greater market integration over resistance to modernisation processes. We analyse how and why peasants engage in oil palm cultivation and how their involvement undermines green efforts to curb its expansion in Chiapas, Mexico. Our analysis suggests that an exclusive focus on enclosure as the main driving force behind contestation and agrarian social relationships is unable to explain agrarian dynamics and the multiple uses to which environmental narratives are put.

Legal Dispossession: State Strategies and Selectivities in the Expansion of Indonesian Palm Oil and Agrofuel Production

ABSTRACTThis article examines the role of the state in the appropriation and control of land in Indonesian palm oil and agrofuel production. Drawing on political ecology and critical state and hegemony theory, it focuses particularly on the legal state strategies that support the hegemonic project of agro‐industrial and export‐oriented palm oil and agrofuel production. The article analyses the structural, strategic and spatial selectivities — the mechanisms of marginalization and privilege — that accompany the strategies the state employs. Three important strategies are discussed, namely the codification of land ownership, the concentration of land possession and the valorization of natural resources in the context of de‐ and recentralization. The article concludes that these legal state strategies represent an important means to organize and protect a large‐scale palm oil project as they succeed in universalizing dominant interests whilst at the same time (partially) integrating subaltern interests.

Oil palm boom and land-use dynamics in Indonesia: The role of policies and socioeconomic factors

We investigate land-use dynamics in Jambi, Sumatra, one of the hotspots of Indonesia's recent oil palm boom. Data from a structured village survey are used to analyze the role of socioeconomic and policy factors. Oil palm is partly grown on large plantations, but smallholders are also involved to a significant extent. We find that, in spite of considerable oil palm expansion, rubber remains the dominant crop. Most of the oil palm growth takes place on previous fallow and rubber land. Oil palm has not been a major driver of deforestation. Much of the forest in Jambi was cleared more than 20 years ago, and rubber was an established cash crop long before the oil palm boom started. However, oil palm growth occurs in locations with ongoing logging activities, so indirect effects on deforestation are possible. The Indonesian government's transmigration program of the 1980s and 1990s was instrumental for the start and spread of oil palm in Jambi. Some autochthonous villages have adopted oil palm. But oil palm adoption in autochthonous villages started later and happens at a slower pace than in the villages of the transmigrants from Java.

Impacts of oil palm expansion in Colombia: What do socioeconomic indicators show?

The impact of energy crops and biofuel production on development, social welfare and conservation of ecosystems and ecological services has constituted a heated debate. At the center of these controversies is the development of agro-industrial plantations, particularly oil palm. To contribute to a better informed debate, we use existing data to analyze the socioeconomic impacts of the expansion of oil palm plantations in Colombia, the major producer of Latin America. We used the official database of socioeconomic indicators of municipalities for the period 1993–2009, and apply several descriptive and multivariate analyses. The results of the study confirm several issues found in the international literature: oil palm municipalities present lower levels of unmet basic needs and bigger fiscal incomes in comparison to municipalities where this crop is not cultivated. However, in Colombia depending on the region and time period, violence and land tenure concentration are higher in oil palm municipalities, which may help to explain the persistence of inequity and poverty in some areas.

Advancing palm genomics by developing a high-density battery of molecular markers for Elaeis oleifera for future downstream applications

Background Although (Elaeis guineensis) is planted on only 5% of the total world vegetable oil acreage, it accounts for more than 30% of vegetable oil produced worldwide [1]. In Brazil, the Federal Government launched a plan to boost Oil Palm production as a way to meet the biofuels market increasing demand for vegetable oil. Nevertheless, the Oil Palm expansion areas in Brazil coincide with the area of occurrence of bud rot [2], a major disease that is decimating plantations already established in the area. In a way to circumvent such problem, breeders are now using E. oleifera germplasm in Oil Palm breeding programs, generating inter-specific hybrids not only resistant to bud rot, but with higher unsaturated fatty acid content, lower height [3]. E. oleifera, however, lack the genomic resources currently available for Oil Palm [1], hampering many possible studies that could potentially help breeding. Based on the foregoing, we started a project to develop a large set of molecular markers for the species based on the DArTSeq platform [4].

Land cover change interacts with drought severity to change fire regimes in Western Amazonia.

Fire is becoming a pervasive driver of environmental change in Amazonia and is expected to intensify, given projected reductions in precipitation and forest cover. Understanding of the influence of post-deforestation land cover change on fires in Amazonia is limited, even though fires in cleared lands constitute a threat for ecosystems, agriculture, and human health. We used MODIS satellite data to map burned areas annually between 2001 and 2010. We then combined these maps with land cover and climate information to understand the influence of land cover change in cleared lands and dry-season severity on fire occurrence and spread in a focus area in the Peruvian Amazon. Fire occurrence, quantified as the probability of burning of individual 232-m spatial resolution MODIS pixels, was modeled as a function of the area of land cover types within each pixel, drought severity, and distance to roads. Fire spread, quantified as the number of pixels burned in 3 × 3 pixel windows around each focal burned pixel, was modeled as a function of land cover configuration and area, dry-season severity, and distance to roads. We found that vegetation regrowth and oil palm expansion are significantly correlated with fire occurrence, but that the magnitude and sign of the correlation depend on drought severity, successional stage of regrowing vegetation, and oil palm age. Burning probability increased with the area of nondegraded pastures, fallow, and young oil palm and decreased with larger extents of degraded pastures, secondary forests, and adult oil palm plantations. Drought severity had the strongest influence on fire occurrence, overriding the effectiveness of secondary forests, but not of adult plantations, to reduce fire occurrence in severely dry years. Overall, irregular and scattered land cover patches reduced fire spread but irregular and dispersed fallows and secondary forests increased fire spread during dry years. Results underscore the importance of land cover management for reducing fire proliferation in this landscape. Incentives for promoting natural regeneration and perennial crops in cleared lands might help to reduce fire risk if those areas are protected against burning in early stages of development and during severely dry years.

A GIS-based model to analyze the spatial and temporal development of oil palm land use in Kuala Langat district, Malaysia

In Malaysia, areas under oil palm plantations have increased dramatically since the early twentieth century and have resulted in multiple conversions of land change. This paper presents a spatial and temporal model for simulation of oil palm expansion in the Kuala Langat district, Malaysia. The model is an integration of cellular automata (CA), multi-criteria evaluation (MCE), and Markov chain (MC) analysis while MCE provides transition rules of CA iterations and MC analysis assigns a transition probability to each single pixel at the time steps. Evaluation criteria consist of constraints and nine suitability factors indicating environmental and socio-economic issues of oil palm development. In the first simulation, changes of six land-cover classes were projected to the year 2008 based on transitions between 1997 and 2002. Two measures of quantity disagreement and allocation disagreement were adopted to validate model outcome. The simulation of land-cover change of the year 2020 was done based on the transition observed between 1997 and 2002 regarding the satisfactory agreement of the projection and the reference data at the first simulation. The results, based on five landscape metrics, indicated continuous spatial patterns of oil palm plantations but more fragmented spatial patterns of other land classes by the year 2020.

Rooted in Violence: Civil War, International Trade and the Expansion of Palm Oil in Colombia

Internal armed conflict severely inhibits economic growth according to a prominent set of civil war literature. Similarly, emerging scholarship finds that civil war inhibits processes of economic globalisation which are argued to produce economic growth. A case in point is international trade, which is reportedly stymied by intra-state war. In contrast, this article employs a critical theoretical framework which acknowledges the often violent tendencies of globalised capitalism. By analysing Colombia's palm oil industry, this article argues that civil war violence can facilitate international trade. In the case study which is presented, violence perpetrated by Colombia's public armed forces and right-wing paramilitaries has enabled the palm oil sector to enter and compete in the globalised economy. This includes processes of forced displacement, which have acquired land for palm oil cultivation, and violence directed at civil groups deemed inimical to the interests of the palm oil sector. By employing a micro-level approach, this article attempts to isolate violent trends related to palm oil cultivation in Meta, the largest African palm-growing region in Colombia. An attempt is therefore made to give an empirically informed account of how violence in Colombia's civil war is facilitating palm oil exports.

Will Oil Palm’s Homecoming Spell Doom for Africa’s Great Apes?

Expansion of oil palm plantations has led to extensive wildlife habitat conversion in Southeast Asia [1]. This expansion is driven by a global demand for palm oil for products ranging from foods to detergents [2], and more recently for biofuels [3]. The negative impacts of oil palm development on biodiversity [1, 4, 5], and on orangutans (Pongo spp.) in particular, have been well documented [6, 7] and publicized [8, 9]. Although the oil palm is of African origin, Africa's production historically lags behind that of Southeast Asia. Recently, significant investments have been made that will likely drive the expansion of Africa's oil palm industry [10]. There is concern that this will lead to biodiversity losses similar to those in Southeast Asia. Here, we analyze the potential impact of oil palm development on Africa's great apes. Current great ape distribution in Africa substantially overlaps with current oil palm concessions (by 58.7%) and areas suitable for oil palm production (by 42.3%). More importantly, 39.9% of the distribution of great ape species on unprotected lands overlaps with suitable oil palm areas. There is an urgent need to develop guidelines for the expansion of oil palm in Africa to minimize the negative effects on apes and other wildlife. There is also a need for research to support land use decisions to reconcile economic development, great ape conservation, and avoiding carbon emissions.

Mapping palm oil expansion using SAR to study the impact on the CO2 cycle

With Malaysia being the second largest palm oil producer in the world and the fact that palm oil ranks first in vegetable oil production on the world market the palm oil industry became an important factor in the country. Along with the expansion of palm oil across the nation causing deforestation of natural rain forest and conversion of peat land into plantation land there are several factors causing a tremendous increase in carbon dioxide (CO2) emissions. Main causes of CO2 emission apart from deforestation and peat-land conversion are the fires to create plantation land plus the fires burning waste products of the plantations itself. This paper describes a project that aims at the development of a remote sensing monitoring system to allow a continuous observation of oil palm plantation activities and expansion in order to be able to quantify CO2 emissions. The research concentrates on developing a spaceborne synthetic aperture radar information extraction system for palm oil plantations in the Tropics. This will lead to objective figures that can be used internationally to create a policy implementation plan to sustainably reduce CO2 emission in the future.

Modelling environmental and socio‐economic trade‐offs associated with land‐sparing and land‐sharing approaches to oil palm expansion

Summary The effectiveness of land‐sharing and land‐sparing approaches has been widely debated. Yet, few studies quantify the environmental and socio‐economic outcomes of these approaches within a real‐world landscape. Indonesia's plans to increase its palm oil production present an opportunity to investigate the potential environmental and socio‐economic implications of the land‐sharing and sparing approaches. We developed a computer model to simulate the expansion of oil palm agriculture in Sumatra, Indonesia, under four different scenarios distinguishable by the dominance of scheme smallholders or industrial estates: business‐as‐usual, BAU (25 : 75, scheme smallholders:industrial estates); high‐yielding industry dominated, ESTATE (10 : 90); low‐yielding smallholder dominated, SMALLHOLDER (40 : 60), high‐yielding smallholder dominated, HYBRID (40 : 60; but with improved smallholder yields). Our results reveal several trade‐offs associated with varying the proportion of scheme smallholders and productivity of oil palm plantations. The ESTATE scenario (reflecting land‐sparing) resulted in lowest environmental costs in terms of forest conversion, greenhouse gas emissions, biodiversity losses and nitrogen fertilizer usage. Additionally, infrastructural development and tax revenues were highest under the land‐sparing approach, though fewer jobs were created. The SMALLHOLDER scenario (indicating land‐sharing) resulted in highest environmental costs in terms of forest conversion, carbon dioxide emissions and biodiversity losses but involved more households in oil palm agriculture and thus created more employment opportunities. The HYBRID scenario ranked second best in terms of both minimizing forest loss and job creation. However, the drawbacks of this approach included high nitrogen fertilizer consumption, lower infrastructural development and lower tax revenues. Synthesis and applications. From an environmental perspective, it is far more important to implement spatial restrictions on oil palm expansion over forests since increasing the productivity of smallholdings and industrial estates among the four scenarios examined show minimal differences to biodiversity loss and greenhouse gas emissions. The hybrid approach shows that increasing the proportion of scheme smallholders need not come at a great environmental cost for achieving Indonesia's palm oil production target. From a policy perspective, this hybrid approach requires a change in legislation to increase the minimum land area an industrial estate owner must allocate to scheme smallholders (40%), as well as increased support to improve productivity in oil palm smallholdings.

Status and prospects of oil palm in the Brazilian Amazon

Oil palm is a widely cultivated palm tree, whose oil is ranked first in supply and export among all vegetable oils in the world. Despite being a minor producer and major importer of palm oil, Embrapa, Brazil's leading agricultural research agency, has identified deforested land with soil and climate suitable for oil palm cultivation whose combined area is twice that currently being employed throughout the world, most of which located in the Brazilian Amazon. This region, characterized by low socioeconomic indicators, as well as precarious access to energy, has recently become the focus of Brazilian Government policies whose aim is to ensure that the observed expansion of oil palm occurs in an orderly manner, within the precepts of the region's environmental and economic zoning, currently in deployment. With a doubling of its cultivated area between 2004 and 2010 and an even faster projected growth in 2015, the rapid expansion of oil palm in the Brazilian Amazon presents great potential to influence the development of the region. This article provides an updated picture of the palm oil sector in Brazil, its prospects, opportunities and challenges, with a particular focus on the Amazon region and the rising use of palm oil as biodiesel.

Effects of monoculture and polyculture practices in oil palm smallholdings on tropical farmland birds

Industrial oil palm expansion has led to dramatic landscape changes that have negatively affected forest biodiversity in the tropics. In contrast to large-scale plantations, oil palm smallholdings may support greater levels of biodiversity through the implementation of multi-cropping system or polyculture. We examined bird species richness, together with community structure, conservation status, and feeding guild of existing smallholdings in Peninsular Malaysia. Based on point transect sampling, we sampled birds in 100 smallholdings that practiced either monoculture or polyculture farming. Our results revealed that bird species richness was significantly greater in monoculture smallholdings than in polyculture smallholdings, but the opposite was true for bird abundance. Non-forest birds constituted the major species of bird communities in oil palm smallholdings. However, we found that the abundances of insectivores and frugivores were greater in polyculture smallholdings than in monoculture smallholdings. In the monoculture models, predictor variables explained 11.31–19.98% of the variation in bird species richness. When polyculture was being practiced, bird species richness increased significantly with the height of ground vegetation cover, distance to major roads, and distance to rice fields. In the polyculture models, predictor variables accounted for 11.71–24.85% of the variation in bird species richness. We also found that bird species richness increased significantly with height of ground vegetation, but it decreased with ground vegetation cover and distance to rivers. The evidence from this study suggests that monoculture and polyculture farming were able to maintain farmland biodiversity in smallholdings, at least for birds, but differed in richness, population, and feeding guild.

Proximate and underlying causes of forest cover change in Peninsular Malaysia

This study examined the process and causes of forest cover change in Peninsular Malaysia from 1970 to 2010. Time series data on forest cover, land use, timber production, and socio-economic variables of Peninsular Malaysia were analyzed by regression modeling using Akaike Information Criterion (AIC). Peninsular Malaysia experienced extensive deforestation during the 1970s and early 1980s, but since then deforestation has slowed down substantially. Regression results highlighted that poverty alleviation was the principal underlying factor leading to change in forest area. Neither population growth nor economic growth was a major factor affecting forest cover. Oil palm expansion was identified as the main proximate cause of deforestation. Regression results also indicate that oil palm expansion greatly contributed to poverty reduction. Our empirical evidence suggests that in Peninsular Malaysia, agricultural development to reduce poverty, in particular oil palm development, initially led to deforestation. However, substantial decrease in poverty caused decrease in deforestation over the long term. Based on the results of this study, we propose poverty alleviation as a strategy to reduce deforestation. Our findings demonstrate the need to analyze factors that reduce deforestation and to develop effective REDD programs.

Isoprene emissions over Asia 1979–2012: impact of climate and land-use changes

Abstract. Due to the scarcity of observational constraints and the rapidly changing environment in East and Southeast Asia, isoprene emissions predicted by models are expected to bear substantial uncertainties. The aim of this study is to improve upon the existing bottom-up estimates, and to investigate the temporal evolution of the fluxes in Asia over 1979–2012. To this purpose, we calculate the hourly emissions at 0.5°×0.5° resolution using the MEGAN–MOHYCAN model driven by ECMWF ERA-Interim climatology. In order to remedy for known biases identified in previous studies, and to improve the simulation of interannual variability and trends in emissions, this study incorporates (i) changes in land use, including the rapid expansion of oil palms, (ii) meteorological variability according to ERA-Interim, (iii) long-term changes in solar radiation (dimming/brightening) constrained by surface network radiation measurements, and (iv) recent experimental evidence that South Asian tropical forests are much weaker isoprene emitters than previously assumed, and on the other hand, that oil palms have a strong isoprene emission capacity. These effects lead to a significant lowering (factor of 2) in the total isoprene fluxes over the studied domain, and to emission reductions reaching a factor of 3.5 in Southeast Asia. The bottom-up annual isoprene emissions for 2005 are estimated at 7.0, 4.8, 8.3, and 2.9 Tg in China, India, Indonesia and Malaysia, respectively. The isoprene flux anomaly over the whole domain and studied period is found to be strongly correlated with the Oceanic Niño Index (r = 0.73), with positive (negative) anomalies related to El Niño (La Niña) years. Changes in temperature and solar radiation are the major drivers of the interannual variability and trends in the emissions, except over semi-arid areas such as northwestern China, Pakistan and Kazakhstan, where soil moisture is by far the main cause of interannual emission changes. In our base simulation, annual positive flux trends of 0.2% and 0.52% throughout the entire period are found in Asia and China, respectively, related to a positive trend in temperature and solar radiation. The impact of oil palm expansion in Indonesia and Malaysia is to enhance the trends over that region, e.g., from 1.17% to 1.5% in 1979–2005 in Malaysia. A negative emission trend is derived in India (−0.4%), owing to the negative trend in solar radiation data associated with the strong dimming effect likely due to increasing aerosol loadings. The bottom-up emissions are compared to field campaign measurements in Borneo and South China and further evaluated against top-down isoprene emission estimates constrained by GOME-2/MetOp-A formaldehyde columns through 2007–2012. The satellite-based estimates appear to support our assumptions, and confirm the lower emission rate in tropical forests of Indonesia and Malaysia. Additional flux measurements are clearly needed to characterize the spatial variability of emission factors better. Finally, a decreasing trend in the inferred top-down Chinese emissions since 2007 is in line with recorded cooling in China after that year, thus suggesting that the satellite HCHO columns are able to capture climate-induced changes in emissions.

The oil palm boom: socio-economic implications for Q’eqchi’ households in the Polochic valley, Guatemala

Oil palm (Elaeis guineensis) has become one of the most rapidly expanding crops in the world. Many countries have promoted its cultivation as part of a broader rural development strategy aimed at generating paid work and producing both export commodities and biofuels. However, oil palm expansion has often occurred at the expense of ecosystems and subsistence agriculture, and on lands riddled with tenure conflicts. In this article, we analyse the implications of the combined effect of labouring in oil palm plantations and land access on households, and we discuss how these implications affect human well-being in two indigenous communities of the Polochic valley, Guatemala. Combining participant observation, semi-structured interviews, and land-time budget analysis at household level, we reveal how oil palm cultivation increases incomes for plantation workers’ households, but decreases the productivity of maize cultivation, reduces the time that household members have available for other activities and, particularly, reduces women’s resting time. In contrast, households that focus more intensively on maize cultivation show higher degrees of food security and women can allocate more time to social activities. However, our results also show that maize consumption per capita has not decreased in households working in oil palm plantations since such crop is considered sacred by the Q’eqchi’ and plays a central role in their diet and culture. In conclusion, we argue that while working for an oil palm cultivation can increase specific elements of the basic material conditions for a good life, other aspects such as food security, health, freedom of choice, and social relationships can become deteriorated.

Do riparian reserves support dung beetle biodiversity and ecosystem services in oil palm-dominated tropical landscapes?

Agricultural expansion and intensification are major threats to global biodiversity, ecological functions, and ecosystem services. The rapid expansion of oil palm in forested tropical landscapes is of particular concern given their high biodiversity. Identifying management approaches that maintain native species and associated ecological processes within oil palm plantations is therefore a priority. Riparian reserves are strips of forest retained alongside rivers in cultivated areas, primarily for their positive hydrological impact. However, they can also support a range of forest-dependent species or ecosystem services. We surveyed communities of dung beetles and measured dung removal activity in an oil palm-dominated landscape in Sabah, Malaysian Borneo. The species richness, diversity, and functional group richness of dung beetles in riparian reserves were significantly higher than in oil palm, but lower than in adjacent logged forests. The community composition of the riparian reserves was more similar to logged forest than oil palm. Despite the pronounced differences in biodiversity, we did not find significant differences in dung removal rates among land uses. We also found no evidence that riparian reserves enhance dung removal rates within surrounding oil palm. These results contrast previous studies showing positive relationships between dung beetle species richness and dung removal in tropical forests. We found weak but significant positive relationships between riparian reserve width and dung beetle diversity, and between reserve vegetation complexity and dung beetle abundance, suggesting that these features may increase the conservation value of riparian reserves. Synthesis and applications: The similarity between riparian reserves and logged forest demonstrates that retaining riparian reserves increases biodiversity within oil palm landscapes. However, the lack of correlation between dung beetle community characteristics and dung removal highlights the need for further research into spatial variation in biodiversity–ecosystem function relationships and how the results of such studies are affected by methodological choices.