How to Rewild

Coniferous Woodland

Habitat Management Plan

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Coniferous Woodland
Habitat Guide

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Most coniferous woodland in the UK is a plantation, with the rare exception of Caledonian pine forest, which is found only in scattered areas of the Scottish Highlands (with a few isolated patches in England, at least as far south as Shropshire).

Scots Pine is our only large native conifer, as Yew is classed as a broadleaf, and Juniper tends to be a shrub. However, Scots Pine is typically found in dense rows as part of a plantation woodland.

Conifer plantation is a crop of trees – like an arable crop, there is low biodiversity compared to native habitat. Plantations may support some fungi and a few specialist birds and mammals, but they also supply an important resource – timber and pulp products. Timber is a low carbon construction material, and sourcing it locally is much more efficient than shipping it from abroad due to the weight. So conifer plantations are likely to play an essential role in a future, low-carbon British landscape, despite their poor biodiversity value.

Sub Habitats

Caledonian pine forest, typically found in the Scottish uplands, where Scots Pine-dominated woodland is accompanied by a unique plant community (more info on the UKHab website).

Scots Pine-dominated woodland which has been artificially planted and may not include certain characteristic ground flora.

Coniferous woodland dominated by non-native trees.

Value

We have very few Native Pine Woodlands left in the UK, and what remains is under pressure from overtourism. These woodlands are home to enigmatic species like the Capercaillie, Red Squirrel and Pine Marten, all of which are also under threat. This habitat used to be much more widespread, but human activity and a changing climate have caused it to retreat to isolated locations which are unsuitable for other land use.

You may have heard that conifer plantations are valuable for biodiversity – there is dubious literature produced by the industry which attempts to support this claim. However, any ecologist walking through a typical plantation can see and hear that biodiversity is highly degraded in these habitats. While there are a large number of fungi which thrive on the dark, dank forest floor, there is little else below canopy level. In the canopy, specialist birds from the boreal forests of Northern Europe, like Siskin, Crested Tit and Firecrest have flown over to take advantage of these non-native trees. Some forests are the last outpost of Red Squirrels and Pine Marten, but these animals have healthier populations in Native Pine Woodlands.

While conifer plantation might then appear to be bad for the environment, it, like any other crop we grow, is an important part of our modern life. Without these woodlands, the current progressive shift away from concrete and steel towards more eco-friendly timber construction would not be possible. Conifers have a very high yield class – they grow quickly – putting on biomass more rapidly than most native trees, which also helps these plantations to lock down carbon. While rewilders tend to push for the removal of plantations, we believe that a more holistic view of a shared productive landscape with lasting environmental benefits is likely to include areas of productive coniferous woodland.

Coniferous woodland
Most coniferous woodland in the UK is not Scots Pine, but plantations dominated by non-native species, such as this one in Wales.

Protect

Old growth forests (conifer wildwoods) are very different from conifer plantations. In these ancient woodlands, there is a mix of tree heights, with young and old conifers growing alongside deadwood, broadleaved trees and low scrub. In contrast, same-age plantation trees are packed so closely together that light cannot reach the forest floor, so moss is typically the only ground cover. The trees are all planted at the same time, so there is not usually much variation in height across the canopy.

Studies have shown that the lack of understory vegetation has a significant impact on species diversity. So selectively felling trees to improve light penetration, and allowing the natural regeneration of undergrowth (even of conifers and other non-native species) can improve the biodiversity of conifer plantations. This selective felling can take place within the context of Continuous Cover Forestry – a practice which is becoming increasingly widespread in Britain. Alternatively, the fallen deadwood can be left to rot down, encouraging fungal growth and boosting local biodiversity.

In a Native Pine Woodland, trees are spaced unevenly, and the short lifespan of Scots Pine means that there is typically deadwood lying around. Protecting this woodland requires removing non-native trees and shrubs like Rhododendron, and reducing unnatural levels of woodland disturbance from people and deer. People can often be rerouted away from sensitive areas by creating and maintaining good quality public footpaths, while deer may be managed at sustainable levels with culling and/or deer fencing to allow regrowth of saplings.

Conifer woodland recruitment
Clearfelling of conifer woodland will often result in rapid regeneration of conifers across the ground, and these fast-growing trees can outcompete other vegetation.

Restore

If you would prefer to swap out a non-native conifer plantation for a higher-biodiversity ecosystem, the process is not as simple as clear felling the trees. This would cause a sudden change in the local environment which could be very damaging to animal, plant and microbiological life. The resulting bare earth ecosystem would also be highly susceptible to erosion, creating nutrient pollution in nearby watercourses while losing valuable topsoil. Instead, it may be better to slowly transition from one habitat to another, taking out small sections at a time, while leaving some isolated trees in place.

These standing trees, especially in Acid Grassland or Dwarf Shrub Heath habitats, can be valuable bird and bat refuges and perches. They create structural diversity within the newly-felled habitat beneath, and change the local ecosystem, with effects on shade, wind and the water table. Expect the felled area to begin regenerating rapidly, with many new conifer saplings appearing – these will need to be cut back regularly with a brushcutter and/or cut by volunteers (Christmas is an ideal opportunity for this activity!) until they no longer appear. But most conifers can be killed off by cutting at the base, unlike most broadleaf trees. Eventually, when large native trees begin to appear, the standing remnants of the plantation can be cut and removed.

What happens to the habitat below as it develops depends on the history of the land on which the conifers were planted. The needles from these trees will have acidified the topsoil, so the resulting habitat is likely to be Acid Grassland (including Bracken), or Dwarf Shrub Heath. But if a broadleaved woodland had been growing onsite beforehand, it may naturally regenerate despite the poor conditions. Allowing this natural regeneration is a better strategy than tree planting, because it preserves the existing species and genetic diversity of the local habitat. However, if a broadleaved woodland is the goal and no regeneration is occuring, then tree planting should reflect the native diversity of trees in the area. To maximise biodiversity, recreate the non-linear, irregular spacing of a wild woodland, rather than spacing evenly and planting in rows.

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