We believe there is potential to encourage the development of wood pasture and the growth of more trees generally on Dartmoor, particularly along indented valleys and gullies. (Independent Review of Protected Site Management on Dartmoor 2023)
With this short statement trees secured a small toehold in the Fursdon Review recommendations alongside more weighty references to the trade-offs between upland heath, blanket bog and acid grassland.
With predicted weather patterns including more frequent violent rainstorms and longer, hotter droughts valley woodland and hillside wood pasture will help to preserve aquatic life by cooling watercourses, mitigate downstream flooding and provide much-needed shade and shelter for livestock. The benefits of trees to biodiversity and carbon capture are already well-known. Dartmoor National Park estimates that only around 12.5% of the Moor is wooded with a third of that being non-native conifer plantations. The authority’s Your Dartmoor Partnership Plan for 2021-26 pledges 500 hectares of “new valley native broadleaf woodland” by 2026.
Arguably the “best” new tree growth is achieved by natural colonisation of open ground from existing woodland because it brings its diverse plant communities (including fungi, mosses and lichens) with it.
Perhaps the most successful example of that happening on Dartmoor in the last 50 years is in the Erme valley north of Harford Bridge. This is unimproved private enclosed land which has had the same tenant since the 1970s. His farm is planned so that the fodder needs of the sheep and suckler cows are met by the improved in-bye land and a few fields rented from a neighbour. This means that for decades grazing of the three unimproved fields along the west bank of the Erme has been extremely light, with sheep excluded during the winter months. The land is a steep valley side with a flat plateau above so that livestock has favoured the easier, higher ground. There is ancient woodland to the south providing an ample seed source for oak, rowan, hawthorn, birch and willow. The spectacular result is shown in my photograph with closed-canopy woodland in the southern field (left) shading to wood pasture further north. And the contrast with the sheep-grazed common of Stall Moor couldn’t be more stark.
There are also some striking examples of recent natural colonisation on Dartmoor’s commons, notably The Becka Brook valley on Haytor Down and the Venford Brook valley on Holne Moor. However, with the process of renewing Stewardship agreements on the commons at its present delicate stage, I haven’t been able to learn details of current and recent grazing regimes in these areas. Commoners’ associations were understandably reluctant to give me facts and figures. It will be interesting to see whether the 2-year extensions to Higher Level Stewardship agreements and, eventually, the work of the Dartmoor Land Use Management Group have a visible impact on tree cover in the coming years.
It’s worth nevertheless comparing three Dartmoor commons with broadly similar “natural” characteristics, especially the presence of extensive nearby woodland seed sources. I’m indebted to the Foundation for Common Land for the revealing citizen science survey, Healthy Trees for Tomorrow, carried out in 2022 on the commons of Walkhampton, Holne and Harford & Ugborough (HUG). All trees were recorded but my interest here is in naturally-regenerated saplings – the trees of the future – where the contrast was marked: three saplings per hectare for Holne, 0.14 for Walkhampton, and just 0.05 for HUG. Are there any differences other than the grazing regimes that could cause this disparity?
If a nature-rich Dartmoor needs significantly more woodland than at present – alongside healthy blanket bog and revived upland heath as well as grassland – what needs to change? The simple answer would be the wholesale fencing of target areas of the commons for a period of years to exclude livestock. However, the law only allows that with the permission of the Secretary of State for the Environment which would only be given if the landowner, all the affected commoners and other stakeholders were in favour – something of a long shot, to say the least. An alternative, being pioneered extensively on Exmoor and now here on Harford and Holne Moors, is so-called “applied nucleation”. This involves the planting of small fenced copses of trees and scattered individual trees in stockproof “cactus guards”. Grown from locally-collected seeds, these are an investment in the future, providing more widespread seed sources for a time when the push for nature recovery and hill-farming practice are more closely aligned and more general woodland colonisation becomes acceptable. Co-operation between landowners, commoners and conservation bodies such as, notably, Moor Trees is already on the increase on Dartmoor which has no fewer than three Landscape Recovery projects in preparation. We could be on the threshold of significant change.
Tim Ferry
Image: 50 years of natural colonisation in the Erme valley