Oil palm is one of the most valuable crops in the humid tropics, dominating the global vegetable fat market and also providing biofuel. The major global producers are Indonesia and Malaysia, where oil palm monocultures now cover over 11.5 million hectares of land, by replacing natural forests. This change has had seriously damaging effects on the biodiversity of flora and fauna, but also alters the emissions of the greenhouse gases (GHGs) nitrous oxide, methane and carbon dioxide, which in turn affects the global climate.

Scientists are currently investigating whether biodiversity can be improved by encouraging ground vegetation within and around the monocultures so as to minimise environmental damage and maximise co-benefits such as soil protection, pest control and conservation of biodiversity. Such practices include creating reserves and buffer strips of native vegetation and management of vegetation in the plantations themselves. The success of these management practices in delivering ecosystem services and the impact on GHG emissions are uncertain, and there is a real need for an evidence-base to guide improvements in the environmental sustainability of oil palm management.

A key proposed management strategy is to promote a more developed, more diverse understory within the plantation. As well as increasing biodiversity by creating a more complex habitat and links between forest remnants, the understory may sequester carbon in above-ground biomass and through maintenance of plant-soil interactions. This project specifically tests how different understory management practices affect GHG emissions in oil palm plantations. We expect that the understory may be one important aspect in determining GHG emissions because oil palms are routinely fertilised with nitrogen, of which a significant proportion can be lost to the atmosphere as the GHG nitrous oxide and leached to the rivers as nitrate and organic nitrogen compounds. A large understory biomass can potentially increase plant nitrogen uptake, so effectively could reduce nitrous oxide emissions and leaching.

We urgently need to quantify the greenhouse gas emissions in relation to a range of plantation management strategies so we can provide accurate environmental assessments and identify best agricultural practices. This project will collaborate with industry partners and disseminate findings to the Round Table of Sustainable Palm Oil (RSPO) and the Indonesian Sustainable Palm Oil (ISPO) board to feed in to the development of industry guidelines. The area of RSPO-certified plantations is rapidly growing, so identifying best agricultural practices will have a large impact.

The time scale for research relating to management options is critical for influencing decision making in the near-future; in Indonesia, most OP plantations were established in the late 1980s and early 1990s. Due to the 25 - 30 year life cycle of OP plantations, nearly half are due to be clear-cut for replanting in the near-future. Hence, it is vital to understand replanting and restoration options which simultaneously allow for high productivity as well as supporting biodiversity and minimising GHG emissions.

The proposed project, AP-GRO, will be a collaboration between the 'The Biodiversity and Ecosystem Function in Tropical Agriculture' (BEFTA) project team in Indonesia, consisting of the industry partner Sinar Mas Agro Resources Technology Corporation Research Institute (SMARTRI) and, in the UK, the University of Cambridge and the NERC Centre for Ecology and Hydrology (CEH). We will bring together CEH's long standing expertise in greenhouse gas research with the established BEFTA long-term experiment to investigate the impact of diversifying understory vegetation in oil palm plantations on GHG emissions in Sumatra, Indonesia.

Potential Impact:
The project will generate high quality research that will improve our understanding of the role of understory vegetation in improving prospects for biodiversity and reducing GHG emissions in oil palm (OP) plantations. It will contribute greatly to the pool of excellent studies published by UK academics, supporting our reputation as world-leaders in the field of global environmental change. To this end, the project is highly relevant to the NERC mission and delivers in relation to both its strategic 'biodiversity' and 'climate system' themes. We have identified the following specific non-academic stakeholder groups and describe in turn how we anticipate they will benefit and engage with AP-GRO outputs and the expected ongoing outputs from the collaboration beyond the duration of the project.

1) We envisage that the research will be of high value to OP and forestry industry groups, including OP companies, government agencies (e.g. Indonesian Palm Oil Association or GAPKI), multi-stakeholder groups (e.g. Roundtable on Sustainable palm Oil (RSPO) which provides the major certification standard for sustainable palm oil) and industry consumers (e.g. Unilever) who seek certified products. Through our project findings will plan to provide recommendations on how to maximise ecosystem function and biodiversity and minimise GHG emissions whilst maintaining profitability. This state-of-the-art knowledge will benefit organisations interested in sustainable OP production and will be disseminated via meetings where industry partners are in attendance (e.g. International Conference on Oil Palm and the Environment (ICOPE)), through publication on the BEFTA project webpage and an ecosystem services analysis report. By engaging these organisations in accessible knowledge exchange, we can ensure that our work will be of value in terms of 'real-world' implementation and impact.
2) The work will also be of great interest to consultancies (e.g. Daemeter Consulting Indonesia, People Nature Consulting Indonesia) who will be able to access the findings via the webpage and through peer-reviewed literature. Similarly, we envisage these findings to be of interest to non-governmental organisations: comprising of those working in forest-agricultural landscapes (e.g. Greenpeace, WWF).
3) Increasing sustainable OP agriculture is a key policy objective globally. For example the recently introduced 'Nutella Amendment' in France, has seen taxes on palm oil products increase by 300% due to environmental concerns. Developing best practice will therefore be of great interest to UK and EU policy-makers including the following departments:
(i) Department of Energy and Climate Change (DECC), which is the UK government department for international climate policy;
(ii) Department of Environment, Food and Rural Affairs (Defra), which is the producer of the UK Statement on Sustainable Palm Oil;
(iii) Department for International Development (DFID), funder of research into poverty alleviation through oil palm production;
(iv) European Commission, who make EU-wide decisions pertaining to palm oil production and consumption via instruments such as the Renewable Fuels Directive.
Our results will provide an informative evidence-base to support policy decision-making in this area, which is currently highly controversial, contradictory and dynamic (e.g. The recent decision by the EU to advocate palm oil produced according to RSPO guidelines as 'sustainable' indicates the real need for these guidelines to accurately, and with evidence, reflect best possible practice. Through publication of our results and linking with other established organisations (RSPO, SEnSOR programme) we will feed into evidence-based documentation to support decision-making).
4) The project will be of interest to the general public with interest in tropical environmental issues. Many are seeking ethically approved produce so there is a need for meaningful standards to be set.