Australasian Science: Australia's authority on science since 1938

How Oil Palm Can Become More Ecologically Friendly

Of the five species of primates recorded, three were detected only in the forest, and rarely. Credit L.E. Pardo-JCU

Of the five species of primates recorded, three were detected only in the forest, and rarely. Credit L.E. Pardo-JCU

By Lain E. Pardo & Mason J. Campbell

Oil palm is not a suitable habitat for most terrestrial mammals, but there are ways to improve it and promote the conservation value of these landscapes.

We all use palm oil in our daily life. In fact, approximately half of the packaged products in supermarkets contain palm oil, and it is an important product for biofuel production.

South-East Asia produces at least 80% of the world’s palm oil. However, more than half of the area given over to this crop has occurred at the expense of native forest, including a loss of approximately three million hectares of forest in Indonesia alone.

This situation has triggered conservation alarms as the cultivation of this fruit rapidly expands across Latin America and Africa to match the demand for products derived from oil palm. However, research into the conservation impacts of oil palm outside of South-East Asia is lagging. Are these regions condemned to a similar fate?

We evaluated the effect of oil palm on the diversity and abundance of mammals across several sites in the Llanos region of Colombia – the largest oil palm-producing nation in the Americas. We used an unprecedented amount of camera traps to remotely detect and monitor the animals in oil palm plantations and nearby riparian forests.

Our findings, published in PLoS One (https://goo.gl/kVWRKK), identified oil palm as an unsuitable habitat for most terrestrial mammals. In fact, the number of species inside oil palm plantations was 47% lower, on average, than in riparian forest. In total, we detected 24 terrestrial species and two primates with camera traps, 19 inside oil palm, 24 in the riparian forest, and 17 species shared between both ecosystems. Some of these species included capybaras, ocelots, agouties and armadillos.

In addition, three more primate species ­– the night monkey, the titi monkey and the howler monkey – were recorded by direct observations, but only in the forests and only rarely. The night monkey and titi monkey are considered vulnerable by the Colombian national assessment of threatened species.

While the number of individuals we detected per site varied considerably, most species were found at low numbers in oil palm. In fact, seven species were absent from oil palm and found only in the forest. These included the paca, tayra and agouti. The exception to this finding was medium-sized carnivores, which were more abundant in oil palm, including jaguarundis and foxes. Interestingly, giant anteaters and deer were relatively common in both ecosystems.

We also found that the number and abundance of species increased when plantations retained undergrowth vegetation and excluded cattle inside the lots. Clearly these factors are linked, as cattle reduce undergrowth in plantations through grazing and soil compaction. Furthermore, restricting cattle movement along riparian forest favours forest regeneration. Undergrowth vegetation has a positive effect on local diversity as it provides more habitats for species such as arthropods, lizards, birds and snakes, which in turn attract mammals that consume them.

South-East Asia Versus Colombia

In general, the oil palm plantations in the Llanos region of Colombia have had a lower impact on wildlife than in South-East Asia. This regional difference is likely due to the fact that most land developed for oil palm in Colombia was previously pasture, not forest (unlike South-East Asia), so less biodiversity existed prior to its conversion.

Moreover, hunting pressures are likely to have reduced the forest-dwelling mammals in the study area. As such, mammalian species richness differences between forests and oil palm plantations in Colombia, and the Llanos region in particular, are not as large as those in previously forested parts of South-East Asia.

This assertion is supported by the fact that we didn’t detect disturbance-sensitive species in our study, such as the giant armadillo, danta or jaguar. In fact, in the forests we detected only ~43% of the total medium- and large-sized mammal species that we expected to see in these areas. Therefore, the decrease in present-day species in the study area cannot solely be attributed to oil palm expansion.

Conservation Implications of Our Study

While oil palm plantations were not suitable habitat for most mammals, they can be managed to increase their capacity to support diversity. Based on our findings, we recommend retaining native riparian forest as the most critical conservation management action for oil palm landscapes, regardless of its structure or age. These forests strips serve as the last and only refuge for many wildlife species, and the only elements that allow connectivity across the landscape. In addition, oil palm growers could promote undergrowth vegetation and avoid the presence of cattle inside plantations to increase local biodiversity.

Another conclusion from our study is that, although species richness is the most important metric when evaluating bio­diversity and human impacts, we recommend caution when using this metric in isolation. We found that current biodiversity in oil palm-dominated landscapes in the Llanos region is low, but more worrying is that species abundance is very low. Almost half of the species detected in oil palm were recorded on less than three occasions during approximately 12 months of surveys, and about 30% of species were rare in the riparian forest. Unfortunately, there is no baseline data to compare these numbers, but clearly rareness of species in oil palm landscapes is more evident than what we would expect in a more conserved landscape. Consequently, this rareness in species abundance increases the likelihood of local extinctions.

Certification Schemes May Need to Adapt

Certification schemes for sustainable agriculture, such as the Roundtable on Sustainable Palm Oil (https://www.rspo.org), usually focus on identifying well-conserved areas or endangered species within production landscapes. But what happens when these features are absent, like in our study area? Would this suggest that this area is of “low conservation value”? We think this should be reconsidered.

While biodiversity is lower in oil palm landscapes, the species residing in them all have ecological roles that are important. These species also provide a genetic pool across the landscape, increasing the diversity of species and allowing interconnectivity of populations in more pristine regions. In other words, agro-industrial landscapes are not uninhabited or defaunated; they play a crucial role in the retention of many iconic mammal species, particularly wide-ranging ones.

As we showed, the apparently empty and degraded forest found in oil palm landscapes is the most important feature maintaining local biodiversity of mammals. Even large and charismatic species such as the puma can traverse oil palm landscapes when a just a little native vegetation is present. We therefore suggest that certification schemes should recognise the potential conservation role of productive landscapes and also focus on protecting common and unthreatened species.

Focusing on endangered and charismatic species may not help to raise awareness about them in productive landscapes, as “common” species might be taken for granted as they don’t appear to be at risk. However, we confirmed through interviews that people in the area usually ignore the biodiversity surrounding their lands, but they become excited once we show them the pictures of the species we detected. What may be common for a biologist might be rare and interesting for locals.

This is one of the beauties of camera trapping. It allows us to see what is hidden from us, which helps to raise the interest of local people and increase their “buy-in” to conservation aims. On the other hand it is worth keeping in mind that apparently “common” species can also decrease at some point. Therefore, a monitoring scheme for the whole community is important.

All living species have important roles in nature. Maximising local diversity – even for species that aren’t currently threatened – plays an important role in maintaining regional diversity.

In this sense, our results highlight the potential contribution, and responsibility, of privately owned lands toward the conservation of regional biodiversity. This is especially important in the context of the Llanos region considering its lack of legislated protected areas.

The Future of Oil Palm in Colombia

Colombia is a very complex country with outstanding natural capital, but also increasing challenges. Recently, for example, the country ended a long-lasting armed conflict that generated new “post-conflict” scenarios that will challenge the economy and well-being of people.

Oil palm origins have been associated with social issues in some areas in Colombia. However, depending on the region, this sector could play an important role in the post-conflict era. It is therefore vital to engage with relevant stakeholders to balance socioeconomic and environmental goals.

If oil palm development continues to replace pastures and other crops in Colombia, and company managers are open to include the management suggestions of our findings and those to come from future research, Colombia could become a leader in sustainable oil palm. There has been an increase in awareness and commitments from farmers in this regard, especially to meet sustainability certification standards, which encourage producers to improve harvesting practices through the provision of economic benefits.

Therefore Colombia has great potential to produce palm oil in a more sustainable way for fauna by learning from the past mistakes of countries such as Malaysia and Indonesia, and developing management strategies developed from sound scientific studies.


Lain Pardo recently completed his PhD, which was supervised by Mason Campbell at James Cook University’s Centre for Tropical Environmental and Sustainability Science.