Research underpinning the conservation and restoration of Scotland’s montane woodlands.

“I am a plant ecologist and early career researcher undertaking a part-time PhD at the University of Stirling, while also working as Conservation Manager of Corrour Estate in the Scottish Highlands,” says Sarah Watts. “My research focuses on developing conservation management techniques to restore mountain woodland habitats to the Scottish uplands.”

Scotland’s montane woodland

“Mountain woodland is vitally important in Scotland for combatting climate breakdown and biodiversity loss. Having been degraded by centuries of overgrazing, burning and exploitation, these fragmented, remnant habitats are some of the rarest and most threatened in the country. Typically functioning as a mosaic or transitional habitat, they support a unique assemblage of specialist upland invertebrates and birds, enriching overall landscape diversity.

“Restoration of mountain woodland provides benefits for both wildlife and people through natural hazard protection, sheltering, structural variability, vegetation diversity and recreational opportunities. These nature-based solutions are critically needed to reduce risks from escalating climate change including soil erosion, flooding, warming temperatures and extreme weather.

“I am investigating the influence of abiotic and biotic environmental variables, habitat type and mycorrhizal associations on the survival, growth rates and natural regeneration of montane trees. This involves studying the results of pioneering tree-planting projects, as well as trialling new planting schemes under contrasting grazing management strategies. Concentrating particularly on downy willow (Salix lapponum) and dwarf birch (Betula nana), my research will facilitate the long-term recovery and resilience of altitudinal treeline habitats.

In it for the long-term

“A scientific approach is crucial to providing robust answers to key questions in ecology, but for me the real excitement and value comes in the applications. My greatest motivation for producing high quality research outputs is their impact on the delivery of practical, ‘on the ground’ action through my job as a conservation manager; aiding the decision-making processes and challenges that end-users such as myself face day to day. For example, I am currently undertaking an experimental growth trial of dwarf birch planted in contrasting upland vegetation types and red deer densities at three sites in Scotland (Corrour, Ben Lawers and Glen Finglas). Monitoring the growth and survival of these trees is informing our choice of restoration sites and the use of fences or sustainable landscape-scale grazing management. Open-access publication of research outputs is also key to ensuring that land managers and project implementers can utilise all that conservation science can offer.

“Mountain woodland restoration is a very long-term commitment. It takes a huge fieldwork effort to map populations, time to collect seed and cuttings, more time to grow saplings in a nursery and even more time and patience to wait for them to reach maturity on the hill. This process benefits from staff continuity and knowledge retention by highly motivated individuals who are willing to devote potentially decades of their career to achieving conservation objectives. But the outcome of such dedication is landscape-scale ecological restoration: a goal definitely worth striving for. The Mountain Woodland Action Group has played a key role in facilitating this occupational longevity. I have chaired the group since 2021, but there has been significant long-term membership continuity since its conception in 1996, with individuals who have delivered pioneering restoration projects continuing their involvement to support the next generation of environmental land managers such as myself. This is testament to the passion that mountain woodland restoration can invoke.

“In addition to studying montane trees, I’ve also monitored some of Scotland’s rarest plants on Ben Lawers National Nature Reserve (NNR), culminating in a long-term study of arctic-alpine flora under threat from climate change. One species, snow pearlwort (Sagina nivalis), has declined by 66% since the mid-1990s and, as a direct result of our work, has had its UK conservation status changed from ‘Vulnerable’ to ‘Endangered’. Such low-latitude arctic-alpine plant populations, already situated at maximum local elevations, are effectively on an ‘elevator to extinction’: there is no higher ground for them to retreat to as temperatures continue to rise. Our work demonstrates the need to focus on biodiversity loss in important groups such as small vascular plants, bryophytes, lichens, invertebrates and fungi, as well as the charismatic large mammals and birds.

Fieldwork and family

“As a child, my engagement with nature mostly went as far as enjoying watching documentaries narrated by David Attenborough. But I believe this demonstrates that science can be open to anyone – you don’t need to spend your whole life working towards it to be able take part and generate impact. In fact, arts and humanities disciplines offer valuable transferable skills including creativity, communication and persistence. My first career choice was actually in classical music performance, but when that didn’t work out as I hoped, I decided to try something completely different, and embarked on a degree in Ecological Sciences at the University of Edinburgh as a mature student.

A woman smiles from a mountain with a blue sky and wispy clouds behind and a young rowan sapling next to her — Sarah Watts

“The real hook came during local field courses on plant identification. It was overwhelmingly exciting to suddenly become aware of a spectrum of species occurring all around me with names waiting to be discovered, to appreciate the intricate physical structures of plants, their place within the local environment, and also their cultural influence on people. I am particularly drawn to plants because they provide the foundation for habitats on which other species depend: thriving vegetation is fundamental to ecosystem health and conserving organisms higher up the food chain.

“During my degree I was able to volunteer at my local NNR, and am fortunate that this happened to be Ben Lawers NNR, which is owned and managed by the National Trust for Scotland (NTS) and contains the best collection of rare mountain plants in the country! Here I could combine my burgeoning love of plants with my passion for mountaineering which had developed from enjoying hillwalking with my family as a teenager. Finding my own niche in this way gave me a closer physical connection to the Scottish Highlands and made me aware of the necessity for conservation management of our degraded and threatened ecosystems.

“After graduating, I was employed by NTS as a seasonal ecologist at Ben Lawers from 2013-2020 where I monitored the outcomes of pioneering habitat restoration projects, focusing on peatland and mountain woodland. The fact that I thoroughly enjoyed data analysis and applying scientific principles to my work motivated me to go on to develop a PhD proposal, and thus embark on my journey with the University of Stirling in the Faculty of Natural Sciences.

A woman stands behind shrubby vegetation with a measuring tape. There are mountains and a dam behind — Sarah amidst restored tall herb and montane willow scrub habitats on Ben Lawers

“Mountain fieldwork forms a huge component of my research, and takes me to many remote locations in the Scottish Highlands, often on very difficult ground far away from typical walking routes. Most montane woodland remnants exist on inaccessible cliff ledges and steep slopes out of reach of large herbivores. I enjoy the challenge of working in these incredible mountain landscapes and the opportunities to develop my skills as a mountaineer.

“Some of the hardest fieldwork I’ve done to date has been collecting soil samples from beneath relict montane willow shrubs across Scotland to document the co-occurring community of mycorrhizal fungi using eDNA metabarcoding. Safety is paramount when navigating complex terrain under the harsh Scottish weather, and the ability to collect intact samples and meaningful data becomes all the more rewarding. Perhaps the proudest achievement of my career is being able to combine being pregnant and raising my children while continuing with such physically demanding fieldwork.

Working together

“However, I don’t do it all myself. I engage with citizen scientists recording extreme high-altitude trees, via #HighMountainTrees on social media. This project has been excellent for public engagement and raising awareness of the threats faced by mountain woodland and the urgent need for restoration action. The records gathered have certainly pushed the limits of where we consider it possible for trees to grow – within just seven months we broke the British altitudinal records for 10 different tree species! For example, the highest known rowan tree in Britain is now from an incredible 1150 m on Sgurr nan Ceathreamhnan in West Affric. This may be a product of both increased recording effort, but also changes in grazing management at some locations facilitating natural tree regeneration.

“My work is made richer and more contextually relevant by collaborative knowledge exchange and outreach partnerships. I’m grateful to have met and worked with a range of inspiring people who have helped grow my confidence as a botanist and researcher throughout my career so far. I hope that interest in mountain woodland restoration continues to accelerate so that we can achieve significant progress and project connectivity on a national scale.

“Scotland is an exceptional place to work in conservation science due to its geographical situation and globally important assemblages of species – located at the edge of Europe it represents not only the north-western limit of many continental species’ distributions, but also the southernmost limit for many arctic-alpine plants. Scotland therefore contains important mountain outpost sites that are biodiversity hotspots of high cultural value and harbour populations of rare species with unique genetic adaptations.

“Because, or in spite of, habitat degradation and biodiversity loss caused by centuries of mismanagement, there is now an exciting opportunity for Scotland to become a global leader in biodiversity conservation through restoration ecology, and to fulfil our potential regarding natural capital. The challenge will be achieving this while responding to and mitigating the impacts of accelerating climate change.”

Sarah Watts is a PhD researcher at the University of Stirling working on the project “Improving outcomes in montane woodland restoration”. Her work is supported by the Woodland Trust, Corrour Estate, Scottish Forestry Trust, Macaulay Development Trust, Forest Research, National Trust for Scotland and Future Woodlands Scotland. She is also Chair of the Mountain Woodland Action Group. Find out more here.

This post is part of a series showcasing Scotland’s innovative, high-impact research supporting biodiversity conservation, in partnership with Scottish Government and NatureScot. Read the rest of the series here.

Botanics Stories

Scotland Conservation Science

Sarah Watts, Corrour Estate and University of Stirling

Scotland’s montane woodland

In it for the long-term

Fieldwork and family

Working together

Further reading