Eleanor Warren-Thomas: Blog re-look: Tropical peatland restoration

Shortlisted for the Southwood Prize 2022

In this blog re-look, Eleanor Warren-Thomas tells us about conducting research on the restoration of tropical peatlands, as well as the experiences of an early career ecologist.

You can find the original blog post discussing Eleanor’s research in English here and in Indonesian here!

The research process

Can you summarise your research and how it advances the wider field?

Drainage of peatlands to enable agriculture is a global phenomenon – it provides benefits by making more land available to cultivate, but also leads to land subsidence and carbon emissions as the peat decomposes on contact with air.

In Indonesia, peatland drainage alongside the use of fire to clear land led to hugely damaging peat fires and associated toxic haze, particularly in 2016. Indonesia set up a national agency and multiple laws and initiatives to start peat restoration, to retain water on peatlands and prevent fires. Few studies had assessed what this meant for people cultivating drained peatlands, or the impacts on biodiversity in cultivated peat landscapes.

Forest loss due to fire © Eleanor Warren-Thomas

Our research focussed on the effects of peatland drainage on the yields of smallholder oil palm crops and on-farm vegetation and bird diversity in Sumatra, Indonesia. We visited smallholder oil palm farms in Jambi province, Indonesia, that were next door to a remaining peat swamp forest (Sungai Buluh Protection Forest).

As we couldn’t do a before-after study of water table management, we found sites across the study landscape where water tables already differed. With the support of the farmers there, we collected data on oil palm yields, on-farm vegetation growing between the oil palms, bird diversity, and the level of the water table below the soil surface. We did the same thing in the neighbouring forest as a reference. Very few studies focus on smallholder oil palm rather than large-scale estates, and even fewer venture onto peatlands!

An overgrown oil palm on a smallholding © Eleanor Warren-Thomas

We showed that while farmers’ oil palm yields are very variable, they didn’t relate to water table depth. This suggests that water tables could be relatively close to the soil surface, minimising peat decomposition, while maintaining oil palm production. This is really important for the longer-term sustainability of peatland agriculture for farmers by slowing subsidence rates (ongoing peat decomposition and subsidence means the land will eventually fall below sea level and become permanently inundated). It would also slow down carbon release – but of course in the long term would not stop subsidence and carbon emissions completely. That would likely require full restoration of peat swamp forest systems.

We stress that much more data on the relationship between water table depths and oil palm yields is needed, and hope that larger plantations could collect and share data on this to understand patterns at bigger scales.

Water table depth on farms also had no effect on the amount of on-farm vegetation, which in turn had no effect on bird diversity. This was unexpected as other studies have shown that having additional weed or understorey plants in plantations can boost on-farm bird diversity. We found far fewer bird species on oil palm farms relative to the forest, as expected.

Ruby Cheeked Sunbird © Panji Gust Akbar @CrazyBirdGuy14

Our data showed the exceptional importance of peatland forests to sustain bird diversity. We found 10x the number of bird species of conservation concern, and a community of almost completely different species composition in the forest compared the oil palm farms. Large-bodied frugivorous birds living in the forest, such as trogons and hornbills, will be really important for seed dispersal of peat swamp plant species across the landscape – for example in areas where forest restoration might one day become feasible or desirable.

The Sungai Buluh forest is around 40km from any other peatland forest blocks, so we stress the importance of protecting this patch (for example by keeping water tables nearby high to avoid fire risk) and reconnecting this forest with other forest patches elsewhere in the landscape for long term maintenance of its amazing bird diversity!

What did you enjoy most about conducting this research?

Our team of researchers, students and farmers were a joy to work with! We had a lot of fun, particularly during the very messy job of measuring peat depth with augers, and installing water table measurement pipes (which I spent several days hand making from plastic tubing). Finding tiger footprints, hearing gibbons, and finding evidence of bears in the forest was also really thrilling.

Bridge leading to smallholdings © Eleanor Warren-Thomas

Have you continued this research and, if so, where are you currently at with it?

Prof Jane Hill (University of York, UK) and Prof Fahmuddin Agus (now at the Research Center for Horticultural and Estate Crops, National Research and Innovation Agency, Indonesia) established our research project, but unfortunately the timeline was only for two years (our work was possible through funding from the UK Newton Fund and the Indonesia Science Fund DIPI). But, in that time our team produced a number of other published studies that we hope contributes to knowledge and awareness of peatland management issues in Indonesia.

Team members from ZSL published two studies on remote-sensing methods for mapping vegetation types on peatlands, led by Merry Crowson (paper here), Mailys Lopes (paper here) and Nathalie Pettorelli. We also published work to understand perceptions of peat restoration and management, led by Caroline Ward and Lindsay Stringer, which included analysis of the multiple meanings of peat restoration among policymakers, academics and NGO representatives (paper here) and perceptions of peat restoration activities in Jambi among smallholder farmers (paper here).

A home in an oil palm smallholding © Eleanor Warren-Thomas

Finally, team members based in Indonesia are continuing to work on the science of peatland management and restoration. Fahmuddin Agus continues to work on greenhouse gas flux measurements from peatlands with ICRAF, while Bambang Hariyadi, based at Jambi University, continues to work in Jambi’s peat forests with his students, who recently produced videos on the importance of Indonesia’s peatlands and on forest vegetation survey methods!

About the author

How did you get into ecology?

Ecology definitely forms a core part of my work and interests and is where my education is rooted, but it is not the only discipline that I work within! I also use methods and tools from economics, land systems science and the social sciences in my research, and even better, get to work with real experts in each of these fields. I’m interested in socio-ecological systems, and understanding how people and nature interact and how they can thrive together. I would encourage all ecologists to work across disciplines if they can – it’s essential if we’re to help stem the loss of our biodiversity.

The author, Eleanor Warren-Thomas © Eleanor Warren-Thomas

My route to ecology was not completely direct. Despite an early fascination with and love for nature cultivated by my parents and being outside a lot, secondary school science didn’t really interest me. Luckily, where I grew up, post-16 education is at sixth form colleges and it’s possible to be flexible with subject choices. Alongside humanities subjects I started studying A-level Environmental Science which re-kindled my interest in the natural world and got me angry and worried about environmental degradation.

So, I switched courses to complete a Biology A-level, and then studied biological sciences at university where I picked all the modules relating to plants, animals and ecology. I managed to get funding from the Royal Geographic Society with two friends and an amazing supervisor to study frogs in the Peruvian Amazon for my dissertation.

I then did a masters in conservation science, which was really eye-opening as it expanded out from ecology into values, philosophy and policy. I did my MSc thesis on beetles and moths in northern China, again with amazing support from a supervisor, and access to funding from NERC who sponsored my place on the course (sadly these scholarships are no longer available) and fieldwork costs through my supervisor’s project.

Nepenthes in a peat swamp © Eleanor Warren-Thomas

I then spent a couple of years trying to find work in conservation with no luck, and instead did some semi-paid projects overseas, which were only possible with the help of my family who housed and supported me while I worked and saved up money to travel to the project sites. I kept an eye out for funded PhD projects that were at the interface of people and nature, and finally applied to a PhD at the University of East Anglia with Profs Paul Dolman and David Edwards, on the economics and biodiversity of forest loss in Cambodia.

I ended up focussing on plantations of natural rubber as an expanding monocultural crop. I was then lucky enough to be appointed to a two-year post-doc position at the University of York with Prof Jane Hill, where I conducted the work published in this paper.

I’m currently finishing up a NERC-IIASA Collaborative Fellowship at Bangor University, Wales, which is about understanding forest restoration and patterns of agricultural land expansion from an economic and land systems science perspective, and predicting biodiversity responses to land use changes in future. I will take up a lectureship here at Bangor in a few months’ time in the School of Natural Sciences, and am really looking forward to teaching on our conservation and forestry programs.

Now I am very desk-based, I try my best to get outside to watch birds, plug plant photos into my ID apps and enjoy the outdoors as much as possible in my free time!

Forest in a peat swamp © Eleanor Warren-Thomas

Do you have any advice for someone in your field?

I think things have changed a lot since I graduated, and many internships and research experience placements that are really important for finding long-term employment in ecology or conservation are now paid, as they absolutely should be. But, we often need to apply for extra funding to support projects, placements or other opportunities, and applying for funding is a skill in itself.

Take time to carefully read funder requirements (however large or small the grant), be sure to give funders all the information they need to award you their grant, and seek help from friends or colleagues to carefully check your applications before you send them off. Persist, and you’ll find the opportunities that are right for you!

Read the full article, “No evidence for trade-offs between bird diversity, yield and water table depth on oil palm smallholdings: Implications for tropical peatland landscape restoration in Journal of Applied Ecology

Find the other early career researchers and their articles that have been shortlisted for the 2022 Southwood Prize here!

2 thoughts on “Eleanor Warren-Thomas: Blog re-look: Tropical peatland restoration

  1. A very interesting read. I actually stumbled on here when researching closed ecological systems but I was not disappointed to learn more about your story.

    Best wishes,


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