It’s a new year, with new plans and resolutions, the time of year where we think about changes we can make to ensure this year is the best one yet. Holly and ivy, evergreen plants, are symbols of new life, said by some to offer protection from entities that may wish us harm going into this new year. In their natural woodland home, they play other more complex roles. You may have noticed, that they too have been impacted by some changes in Bovey Wood and Yarner Wood here at East Dartmoor National Nature Reserve…
In the temperate rainforest habitat of the oak woodlands in the south west, holly is a familiar sight growing amongst the trees and is an important part of the woodland ecosystem. The bark of older holly can support rare species of lichens, that like this smooth growing surface and for which the south west’s woodlands are particularly important. Berries produced by holly can last until February, and sustain woodland birds and small rodents through the cold winter months. Our temperate rainforest was probably once naturally oak-holly woodland, with grazing keeping the holly in check, as despite its spikiness, it is good forage for animals.
However, holly can have an adverse effect, where it grows uncontrolled. In the past holly was cleared from the woodland environment and more grazing occurred than in the present day. Where holly is not controlled, it can rapidly increase in woodlands, reducing light levels and inhibiting the growth of lichens, mosses, ferns and wild flowers on the forest floor and on tree trunks.
Ivy, another common site in our woodlands, creeps up tree trunks and slowly envelops them in their lush green foliage. It is hugely important for invertebrates which rely on its autumn nectar source, and for birds and bats which use the dense leafy growth as cover. Deer and livestock eat ivy which keeps it under control. In woods that aren’t grazed or browsed, ivy can quickly increase and come to dominate both tree trunks and the woodland floor. It will grow over and eventually eliminate lichens, mosses and liverworts.
Excessive growth of holly and ivy is an issue in these woodlands here at East Dartmoor. They threaten internationally important groups of lichens and inhibit their spread between parts of the woods where the habitat is in better condition. As part of the Building Resilience in South West Woodlands project, management work has been taking place here, that has been sensitively planned with the biodiversity of the whole woodland at the forefront. The need to create more light in the woods, has been balanced against the benefits these plants bring to woodland and other species that inhabit it.
In recent months, contractors have been opening up areas, creating a lighter woodland by removing some holly and thinning conifer trees. They have been linking up places, that are already rich in lichens and mosses, by removing dense patches of younger holly and have been hard at work clearing areas around older wood bank trees, that can harbour these important plants and other important species. In some areas you may see conifers that have been cut down, to allow more light to reach the old oak trees that are important for lichens as well as invertebrates, birds and bats. Trees cloaked heavily in ivy have been left untouched and larger specimens of holly have been preserved, while smaller holly and trees with new ivy growth and without ivy have been removed.
The reserve’s amazing volunteers have also been hard at work and have done a great job at removing small holly bushes to curb the spread of it through the woods. Pictured (below) are the volunteers hard at work during a festive Christmas themed holly removal work party.
It’s not just machinery and people that have contributed to this management. The local Dartmoor Horse Loggers have been removing felled trees from the woods, with their heavy horses doing the heavy lifting instead of machines. In some cases, horses are preferred as they can access areas such as steep slopes and wet environments better than machinery, and have less impact on the area. This is useful as these areas are important for lichens and mosses which can be disturbed by heavy machinery, and it is always fascinating to see a traditional skill being just as useful today.
It is hoped that this management will increase the woodlands’ biodiversity and a team of volunteers are carrying out regular monitoring to assess the impact of this management work.
If you would like to get involved, the Building Resilience in South West Woodlands project has been asking volunteers to go out into the south west’s woodlands and assess their health by carrying out a Rapid Woodland Assessment. This survey asks volunteers to look at a range of factors including tree species, and ages, and whether habitat features such as rivers, rock faces and boulders are present. It also asks them to look at whether there is dense holly and ivy growth in the woods, and how much of the woodland this growth covers, so we can learn more about this issue.
If you are interested in getting involved with the Rapid Woodland Assessment more information can be found here or for further information on the Building Resilience in South West Woodlands project follow this link.
Building Resilience in South West Woodlands is led by Plantlife in partnership with Natural England, Woodland Trust, Dartmoor National Park and other conservation organisations. It is funded by the National Lottery Heritage Fund.
Written by Emily Weeks, University Placement Student with Plantlife
You can read a previous blog written by Emily, ‘A light Introduction’, here