Can trees outside woodlands in Britain be utilised to create our future woodlands?

With UK’s devolved governments pledging tens of millions of pounds for tree planting schemes, a PhD student at Bangor University is investigating how well unplanted trees growing outside woodlands are establishing, and how we might include these trees in overall plans to expand woodland.

“According to the latest government report, around three percent of trees are growing outside existing mapped woodlands,” explained Theresa Bodner, a third year PhD student Bangor University’s Sir William Roberts Centre for Sustainable Land Use.

“These include trees which have naturally colonised previously unwooded land. In a country where we only have around thirteen percent total woodland cover to begin with, that is 750,000 hectares of extra tree cover that can be used to achieve climate change targets. This is an obviously valuable resource and one we know very little about, as these trees are not included on formal maps and planting plans.”

Theresa is using a map detailing the location and attributes of more than 300 million trees, focussing on the Carneddau uplands: around 21,000 hectares in the north of Snowdonia National Park in Wales. This is a very complex landscape with lowlands, uplands, various types of land uses, different land ownerships, protected areas, several areas of common land, grazing rights, and different cultural and archaeological significance.

Theresa says:
“This is a perfect place to look at trees outside woodlands as not only a forestry topic, but also of a wider relationship with different land uses altogether. We can explore where We can explore where trees outside woodlands are located, on what type of land they grow on and their potential role in meeting our woodland targets.”

“I’m using the Bluesky National Tree Map data. Its invaluable in this research as it is the closest resource we have for understanding the natural colonisation of trees in Britain’s landscape.” 

Using QGIS geographic information system, Theresa and colleagues at the University’s School of Natural Sciences are comparing the National Tree Map data with other publicly available maps. Combined with interviews with stakeholders this will help them to understand where non-woodland trees are and how they relate to proposed woodland opportunities, such as the Glastir land management scheme in Wales.

Prior to her PhD, Theresa, from Gmünd, Austria, completed a Masters at the Universities of Padova and Bangor, and has a background in event planning.

Having spent an exchange period at Bangor University, she chose to return. She finds Bangor’s small size helps her to focus on her work and says:

“I chose Bangor because I believe this place could be one of THE institutions of cross-sector research, innovation and sustainability of the future - in an environment where I can walk the beach and climb a mountain on the same day, what else could you want – in the age of the internet who cares about spatial distance anymore, anyway!”

“Woodland expansion is an incredibly hot and relevant topic, and my PhD project proposal was worded very openly so I have a lot of flexibility to define what I want to do,” she added.

Dr Norman Dandy, Sir William Roberts Centre Director added:

“Theresa’s research is extremely timely as more attention is now being given to ways in which woodlands can be expanded through approaches that require only limited management intervention. Natural regeneration and colonisation, including by trees outside woodlands, is being taken increasingly seriously as a way of mitigating climate change. Theresa’s work and geographic information system analysis will form a foundation for further research at Bangor in this area.”

Publication date: 28 January 2021