QUADRAT

Trees are important people and nature. They provide shade on hot summer days, timber for commercial forestry, and provide a diverse range of other benefits, including carbon sequestration, flood control, shelter for people and livestock, and habitat for a plethora of fauna. However, the UK remains one of the least wooded countries in Europe with only 13% forest cover. Efforts to increase forest cover are ongoing, and researchers at the Geography Department in Aberdeen are studying how to make this happen.

Over the last 100 years, forest cover in Scotland has significantly increased from 5% at the end of the first World War to 18.5% at the moment (Scotland’s Forestry Strategy 2019-2029 (www.gov.scot)). The target is to achieve 21% forest cover by 2032, and for Scotland to be Net Zero by 2045. Afforestation and reforestation form Scotland’s multifaceted approach to increasing tree cover in the country for carbon sequestration, biodiversity, and to promote sustainable forestry practices. However, efforts to increase forest cover in Scotland have not gone unopposed.

There are those who feel tree planting will come at the expense of agricultural land and therefore leave the country food insecure. Others are worried about negative impacts of large monoculture conifer forest plantations on their local landscape, biodiversity and the ecosystem in general (see the case of BrewDog’s ‘dead forest’ in the Cairngorms National Park). So where is the land for more tree planting? Are there alternatives to the large tree planting schemes? The simple answer is yes! Integrating trees on farmland, also known as agroforestry, can significantly contribute to increasing tree coverage in Scotland and across the UK.

Agroforestry is simply defined as a land management approach that deliberately combines trees and agricultural activities (crops, livestock or a combination of both). About 70% of Scotland’s land is under agriculture, making it the largest use in the country. Only 10% of this agricultural land is suitable for crop production, the majority is for livestock grazing. With agroforestry, none of this land needs to be taken out of its original use. Agroforestry research has shown the multiple benefits of integrating trees into the farming systems. Increasing tree integration into Scotland’s farmland through agroforestry techniques would significantly contribute alongside the country’s other efforts to make its economy carbon neutral.

As a way to increase agroforestry in Scotland, the University of Aberdeen is collaborating with the James Hutton Institute and other stakeholders on a research project called FARM TREE. Funded by the UKRI Future of UK Treescape Programme, this interdisciplinary project seeks to generate more knowledge for increasing trees on farmland by:

1. exploring the socio-economic, cultural and policy incentives, barriers, and challenges of increasing agroforestry for different farm settings and landscapes,
2. undertaking environmental modelling to understand the different effects of tree planting designs and strategies for carbon sequestration, emissions, and water availability at different timescales and landscape settings, and
3. ultimately identifying optimal planting scenarios at farm and landscape levels through integration of the socio-economic and environmental conditions.

Existing literature and our interviews with 32 farmers, crofters and land managers indicate that lack of knowledge about trees on farmland is a prominent limiting factor for increasing agroforestry in Scotland. This includes knowledge of tree species selection, planting combinations, where on the farm to plant what type of trees, as well as challenges after planting. For example, diseases such as ash dieback may wipe out up to 80% of ash trees [see Ash Dieback (Hymenoscyphus fraxineu)], which may prompt a re-think of the intent to plant trees. What if you invest in tree planting and you lose it all to the unforeseen forces of nature? Is it worth the risk? And how about grant incentives? A number of funding schemes exist for farmers, crofters and land managers (see a list of funding options here ). How much of a hassle is the application process? Are the rules complex? What factors outweigh others in deciding to plant trees? Is this related to the level or availability of knowledge about trees?

We explore these pertinent questions and more to understand factors at play in the decision making to plant trees (or not) on farmland. So far, we have developed a web map tool called FarmTree Info Tool which provides case studies of existing agroforestry in Scotland to lower barriers and spark ideas for farmers, land managers and crofters contemplating tree planting. Anyone else who already has integrated trees on their farm or croft is invited to add their example to this tool at this survey link (add my farm survey) – This will allow us to bring together as many agroforestry case studies in Scotland as possible.

Dr Katrin Prager, co-investigator on FARM TREE said:

“Since we found that knowledge about how to integrate trees on farms is the biggest barrier, we wanted to provide an accessible way for farmers to find agroforestry examples so they can get inspired. Many of our example farms have a website and are happy to be contacted.”

While first initiatives (e.g. the Integrating Trees Network) organised by our partner organisations already exist, there is a need for more practical knowledge on establishing and managing trees on farms in Scottish conditions. Ultimately, we hope to establish a farmer network around trialling agroforestry in Scotland, similar to the Devon silvopasture network set up by Innovative Farmers in England.

Successful implementation of agroforestry requires a more nuanced understanding of the interplays among tree species combination, planting designs and other environmental factors that affect various aspects of tree growth and survival for optimal outcomes. To achieve this, a team of environmental modellers are working on different types of data from the James Hutton Institute’s Glensaugh Research farm to predict landscape-scale planting designs and scenarios that would give optimal outcomes for various farm settings. Using 34 years of agroforestry data from the James Hutton’s Glensaugh research farm, Farm Tree’s numerical modelling team has already developed and verified a water and carbon model that can estimate the environmental impacts of planting different tree species on pasture. The aim is to build on this model to estimate and predict specific tree planting designs and species impacts on soil water regulation, soil carbon storage, woody biomass production (timber volume) across time, and under multiple future climate scenarios (from best to worst cases). Speaking about the environmental modelling work, Dr Salim Goudarzi said:

“This puts us in a unique position to provide more insight into the potential benefits of agroforestry for land-owners/managers across Scotland who are contemplating planting trees on their farms. We are also in the process of generating predictions at the Scotland-scale which will be of great interest to policy-makers and practitioners in the region. Stay tuned for our Scotland-wide agroforestry impact maps, which will also be fed into our Agroforestry Suitability Mapping webtool) ”.

According to Dr Josie Geris, who is the principal investigator of the project, understanding how various socioeconomic and environmental factors interact at different scales can provide useful insights on what might work best for integrating trees on farmland. Dr Geris remarked:

“FARM TREE’s value lies in exploring factors that affect the environmental value of planting trees on farmlands, while also considering the socio-economic opportunities and barriers in realising this. Bringing these different aspects together is important for helping to improve farmer decision making and aid the development of better targeted and more flexible policies and grant schemes”

Moving forward, we anticipate integrating our findings into various useful outputs that we hope will support wider implementation of agroforestry across Scotland.

Author: Dr Albert Mvula (albert.mvula@abdn.ac.uk)

Notes for Editors