The conservation of biodiversity and the variation of species and ecosystems are fundamental for human survival, for livelihoods, physical health and overall well-being. Functioning ecosystems provide a number of critical ecosystem services, including the provision of food and water, and climate regulation.

Biodiversity is essential for maintaining ecosystem processes for the continued provision of such services and for ensuring ecosystem resilience to environmental perturbations. To avoid an extinction crisis and the associated impacts on humanity, the protection and restoration of nature must become a global priority.

KSI Sumatra High Conservation Value forest corridor in an Indonesian oil palm landscape © Calley Beamish

KSI Sumatra High Conservation Value forest corridor in an Indonesian oil palm landscape © Calley Beamish

Palm oil, biodiversity and environmental impacts

The potential environmental impacts associated with palm oil production are extensive.

  • Oil palm grows best in the aseasonal wet tropics, which tend to be naturally occupied by rainforests, and tropical rainforests contain some of the highest levels of terrestrial biodiversity on the planet. These highly diverse communities of species provide essential ecosystem services such as nutrient cycling, water purification and soil formation and stabilisation, food, fuel, building materials and weather and climate regulation at local and even global scales. Rainforests are highly complex habitats which means many of the species that live there have evolved to exploit specialised niches. There are high levels of endemism (species that occur nowhere else on the planet) and these include some of our most charismatic threatened species, such as the Sumatran rhinoceros and Bornean orangutan.
  • When rainforests are replaced by monoculture oil palm plantations the environment is changed dramatically, and becomes much more simplified. This means that they cannot support the same levels of biodiversity as forest. Research shows that plantations support just 47% of the biodiversity levels found in primary tropical forest and many of the highly specialised and rare species found in rainforest are replaced by widespread, generalist and open habitat species. Depending on the species studied, only around 15-30% of forest species continue to survive in plantations.
  • It is therefore essential that operations are managed in a way that safeguards the future of biodiversity.


Environmental management in palm oil production

Growers can manage and mitigate the environmental impacts resulting from their operations through a combination of risk assessment, the careful monitoring of their activities, and the development and implementation of comprehensive management plans and best management practices.

  • All management plans should incorporate a process of close monitoring and evaluation to assess their effectiveness and enable adaptive management.
  • Several standards and certification schemes exist to encourage and monitor the implementation of environmental risk management practices, such as those of the RSPO, ISCC and POIG (read more in our ‘Standards’ section).



The indiscriminate application of fertilisers and pesticides on oil palm plantations can contaminate waterways and soils, harming biodiversity, ecosystem services and local people.

  • Oil palm plantations grow in areas with high rainfall which means chemicals applied to plantations readily run off into rivers and infiltrate soils. Peatlands are even more vulnerable to chemicals infiltrating the spongy waterlogged soils.
  • The palm oil industry uses around 25 different pesticides, of which paraquat dichloride is one of the most commonly used. Paraquat is an indiscriminate herbicide which is highly toxic for plants and animals, as well as the plantation workers who apply it. Due to its adverse impacts, it is banned in several countries.
  • To minimise or eliminate the use of pesticides in their plantations and the impacts on the surrounding areas, companies can develop and implement integrated pest management plans (IMPs). These may include measures such as the use of predators to reduce rat populations and the planting of leguminous cover crops to discourage insect pests from breeding.
  • Oil palm plantations use large amounts of fertiliser to increase palm oil yields. If high levels of fertiliser enter waterways eutrophication can occur. This is where high nutrient levels cause rapid growth of algae which reduces oxygen availability threatening aquatic biodiversity. This has knock on effects for terrestrial biodiversity and human communities which use the rivers.
  • Plantations can minimise both fertiliser and pesticide runoff by 1) managing the amount of chemical application to reduce unnecessary excess 2) managing the timing and location of application so oil palms get maximum benefit, but minimal environmental impact (e.g. targeted pesticide application to control a localised pest outbreak instead of blanket spraying) 3) by creating barriers such as riparian buffers and groundcover, which slow down the flow of surface and ground water and filter chemical runoff before it reaches rivers.

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Water Contamination

The milling process requires large amounts of water and communities and ecosystems surrounding oil palm plantations can be badly affected by overuse and contamination of water resources.

  • The most environmentally damaging by-product of the milling process is palm oil mill effluent (POME), which has a high acidity, temperature, biological oxygen demand (BOD) and chemical oxygen demand (COD).
  • When discharged into waterways, POME contaminates drinking water and can be particularly harmful to aquatic ecosystems by creating highly acidic environments or causing eutrophication.
  • POME is typically discharged into open-air holding ponds for remediation, which releases the greenhouse gases carbon dioxide, methane, and hydrogen sulphide.
  • The development and implementation of comprehensive water management plans can address these negative impacts. These should incorporate measures to improve the efficiency of water consumption and the management of POME – for example, as done by Musim Mas.
Palm Oil Mill Effluent (POME), East New Britain, Papua New Guinea © Wakx

Palm Oil Mill Effluent (POME), East New Britain, Papua New Guinea © Wakx



Human-wildlife conflict and poaching

The replacement of key wildlife habitats with oil palm means many animals are forced onto plantations in search of food and in order to travel between increasingly fragmented patches of forest.

  • This inevitably brings them into more frequent contact with humans and increases the likelihood of human-wildlife conflict (HWC). Orangutans, tigers and elephants, for example, are often killed out of fear or because they are regarded as a pest and threat to oil palm production.
  • HWC can be avoided and reduced through increased understanding of the behaviour and movement of wildlife. Once it is understood which species are involved, measures can be taken to prevent HWC, including protecting sufficient habitat, providing alternative food sources, creating buffer zones between plantations and conservation areas, and constructing barriers. Translocation of wildlife should be considered as a last resort.
  • HWC can also further expose species to the illegal wildlife trade, as the infants of animals killed are sold on for a profit.
  • The illegal hunting and poaching of endangered wildlife in plantations is a common problem, particularly within set-aside areas of high conservation value (HCV).
  • The construction of roads and other infrastructure as part of the development of oil palm plantations exacerbates this problem as it opens up previously inaccessible areas of forest for poachers and hunters.
  • The regular monitoring of HCV areas can identify threat hotspots or areas particularly prone to poaching.
ZSL is working with palm oil companies to protect the critically endangered Sumatran tiger (Panthera tigris sumatrae)

ZSL is working with palm oil companies to protect the critically endangered Sumatran tiger (Panthera tigris sumatrae)

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Habitat loss and degradation, and conservation areas

The clearing of land for plantations through logging and burning removes, fragments and degrades key wildlife habitats, leading to a high loss of species, ecosystems and the services they provide.

  • This in turn exacerbates other issues, for example, by making ecosystems more susceptible to environmental damage through pollution, and by increasing access to valuable conservation areas the threat of encroachment and poaching.
  • Setting aside priority conservation areas, such as those with high conservation value (HCV) or of high carbon stock (HCS), is an essential strategy for reducing the impacts of planting on biodiversity.
  • The RSPO Principles and Criteria require that HCVs which may be affected by existing plantations (P&C 5.2) or by new developments (P&C 7.3), are identified, maintained and enhanced.
  • HCV areas include those containing rare or endemic species, endangered ecosystems, or areas containing important local food resources.
  • To identify potential impacts on biodiversity and delineate and protect HCV areas, growers must conduct a thorough HCV assessment before the acquisition or planting of any new oil palm plantations.
  • The monitoring of HCV areas is required to support adaptive management and ensure that HCVs are maintained and enhanced in the long term.
  • ZSL’s HCV Threat Monitoring Protocol, designed to standardise the monitoring of anthropogenic threats to High Conservation Value (HCV) areas within oil palm landscapes, includes advice on monitoring HCV threats, including details on setting up patrol teams and transects, data collection and reporting.
  • Fragmented forest patches deteriorate in quality over time due to ‘edge effects’ and smaller forest patches support lower levels of biodiversity. It is therefore important to consider the size and shape of set asides, as well as ensuring areas are protected by buffer zones.
  • It is important for growers to think at a landscape level when applying these approaches. Conservation corridors, or ‘stepping stones’ of suitable habitat, throughout a plantation can maintain landscape connectivity and significantly enhance conservation benefits.
  • Riparian reserves function as wildlife corridors and are also a key measure for protecting local water systems and the biodiversity associated with them – one study found that total species richness was 36% lower in streams without riparian reserves.
  • Another key measure to minimise and mitigate negative impacts of production is to carry out a thorough Social and Environmental Impact Assessment (SEIA). SEIAs evaluate how grower activities could affect local communities of wildlife and people, and what measures could be taken to reduce these impacts.
  • These assessments should be incorporated into company policies regarding the acquisition or development of any new land, along with a suite of other measures, such as processes for ensuring development takes place with the Free, Prior and Informed Consent (FPIC) of local stakeholders.

Useful resources