The number of oil palm publications relative to those on agriculture has fluctuated considerably over time but has shown a net increase. In contrast, the number of publications relative to oil palm production has shown a net decrease (). Despite being a major source of vegetable oil worldwide, oil palm has attracted relatively little research interest compared to other oil crops. Palm oil and soyabean contribute over 60% to the world's vegetable oil production but have less than 10% of the research interest (). Over the last 35 years, the major focus of oil palm research has been its uses in food and the resultant health issues (22.19% of total, 678 publications). In the last ten years there has been a marked increase in the number of publications on i) byproducts from the oil palm industry, ii) chemistry, engineering and biotechnology, and iii) the production of biofuel. The number of publications on biodiversity (0.75% of total, 23 publications) and other environmental issues (2.06% of total, 63 publications) has been extremely low ().
Relative number of publications on oil palm between 1970 and 2005.
Figure 3 Oil yield from top eight crops in 2005  in relation to total number of publications on each crop.
Figure 4 Changes in the focus of research on oil palm between 1970 and 2006 .
Publications concentrating on biodiversity and species conservation have tended to focus on large animals 
and birds 
where a severe negative impact on biodiversity has been noted 
. Although these larger animals are important flagships for the state of the tropical environment, they are not good indicators of oil palm plantation biodiversity. The vast majority of species worldwide are insects, which carry out the lion's share of the ecosystem function 
. We found only five publications that relate to the impact of conversion of forest to oil palm plantations on invertebrate biodiversity 
Understanding the impacts of oil palm expansion on invertebrates and other taxa is vital given the projected increase in oil palm area. Not only will such information allow us to make informed judgments as to the genuine status of biodiversity in oil palm plantations, but it will also allow us to begin to quantify how well these managed ecosystems are functioning. By understanding how different taxa and guilds are affected by oil palm expansion we can begin to see how management can be manipulated to enhance beneficial ecosystem functions with minimum detrimental effects on productivity. Agricultural theory highlights the use of integrated pest management in plantation and agricultural systems 
. Such management draws the link between components of the biotic environment and beneficial functioning in the managed landscape, and therefore may increase the yield or profit from an area whilst minimizing cost to biodiversity. In oil palm, much research has focused on the uses of focal species for pollination (e.g. the pollinating weevil Elaeidobius kamerunicus
) or parasitization of herbivores 
. We suggest that the focus now needs to be on the function of biological diversity in the plantation. Can practices to increase biodiversity be integrated with traditional management to produce a net benefit for plantation managers and the environment alike? Management for the benefit of a wider range of species increases the stability of ecosystem functions 
. This is likely to lead to greater sustainability in the future as ecosystem function is less tied to the fortunes of individual species.
Management to enhance biodiversity may not be as costly in terms of yield or profit as it may first appear, as management techniques may provide other benefits. For example, maintenance of forest fragments in the plantation landscape is likely to increase biodiversity, but is also likely to reduce erosion and flooding if maintained around river margins. Flooding can be a major cause of mortality in oil palms and incur huge costs. Recent publications have also pointed out that oil palm estates are effectively self-sufficient villages 
. Therefore maintaining biodiversity in a plantation context is also potentially important from recreational and educational points of view, as oil palm has already become the countryside for a large number of people in the tropics. Without an awareness of biodiversity, future generations are less likely to value and protect it 
Despite the lack of research on the subject, several groups have formed in the last few years aiming to promote and investigate the potential of sustainable palm oil cultivation 
. The most influential of these is the Roundtable on Sustainable Palm Oil (RSPO), which has made considerable progress in promoting sustainable plantation management 
. It is now up to ecologists to provide information on the biodiversity status of oil palm plantations and to investigate practices that may benefit biodiversity, the environment, the community and the industry alike.