How to Rewild

Temperate Rainforest

Habitat Management Plan

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Temperate Rainforest
Habitat Guide

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Scattered across the British Isles, you can find fragments of an ancient temperate rainforest, which have only recently been mapped.

How to Identify a Temperate Rainforest

Ecologists tend to have spirited arguments about how to classify a temperate rainforest, and there are certainly a number of different factors that you can consider (we’ve listed some below). 

But for ease of use, we like Guy Shrubsole’s single indicator – polypody ferns growing on the branches of trees. If you see these, then there’s a good chance that you have a temperate rainforest habitat on your hands.

Polypody ferns have fingerlike leaves, rather than the fractal leaves you see on ferns like Bracken. But seeing any ‘plants growing on plants’ is a good sign of a rainforest, unless it’s a climber with roots in the ground, like Ivy, Old Man’s Beard or Honeysuckle.

If you’re still not sure, there’s a handy map available from the Lost Rainforests of Britain project.

Fern growth
Polypody ferns can grow out of walls and stones in many different places, but a rainforest has them growing from tree branches

How Does a Rainforest Form?

Of course, the obvious factor required for a rainforest is rain, and it’s typically thought that between 1400 and 2000mm of annual precipitation is necessary for a temperate rainforest to form. But it’s not just the rainfall, but when it happens, and where that is key.

In hidden glens and gorges, lower levels of rainfall may still create rainforest conditions, as lower sunlight and wind can lead to trapped humidity, creating suitable conditions. Moss will begin to grow on exposed surfaces, including tree branches, and this rots over time, forming a soil in the canopy.

With soil on branches, other plants take root up there, especially ferns, and the airborne vegetation increases humidity further by trapping rainfall, blocking wind, and slowly transpiring water vapour back into the air.

What Can Damage a Rainforest?

The two worst things for rainforest habitat are clearfelling and sheep. Clearfelling (removing all timber in one go) creates exposed areas that could take over a century to recover to their previous state. Timber production is still possible here, but with the use of selective logging and underwood coppicing.

Sheep prevent rainforest from continuing to regenerate over time, so the forest will slowly peter out, with new growth ceasing. The impact may not be obvious for decades, but as sheep are non-native grazers, they are not suitable for this habitat, and their impact can be devastating in the medium to long term. 

Even a few sheep finding their way into the forest every so often can create a significant impact, as they browse off new saplings. So if you have sheep nearby, be sure to check fences regularly, and install a new one if necessary.

Another factor that’s worth considering is climate – there will be increasing drought pressure on temperate rainforests in the future. This has the potential to shift the rainforest climatic zone northwards. A healthy forest, with a lot of diversity and no clear-felling will be able to hold out longer.

How Can I Restore a Rainforest?

A rainforest may have become degraded in a number of ways over time…

Low levels of management may have led to a high canopy woodland with little deadwood or ground flora. Under a license, you can strategically fell trees at points across the woodland, leaving half of the wood to rot down (and taking half for timber/firewood). This will allow light to reach the forest floor, increasing biodiversity.

No coppicing or livestock will lead to uniform underwood structure, with low levels of structural diversity and disturbance. Introduce cattle for one or two days per year, and/or begin coppicing the underwood in an uneven pattern to create more diverse vegetation. This will create more biodiversity at ground level.

Sheep grazing can kill a rainforest over time (see above), leading to the expression ‘sheepwrecked’. They should be excluded from the woodland at all times by good quality fencing. Farmers recommend erecting standalone post and line fences, rather than afixing wire to trees, to prevent sheep passing through.

Species such as Sycamore and conifers can outcompete native rainforest trees and shade out their saplings. Where possible, over time, the non-native trees should slowly be removed from the land, using their wood for timber or firewood, allowing recolonisation by natural regeneration of native tree saplings, rather than tree planting.

What is the Economic Value of the Habitat?

Temperate rainforest has high potential for woodland carbon credits, and the habitat, while not providing much in the way of high value timber, can supply firewood and coppiced products. 

This habitat has very high potential for ecotourism, and public trails could attract visitors who may also visit your shop or website. Don’t miss out on the opportunity to market your services and products to visitors, with tasteful promotion of related products on interpretation boards and signs.

Look at Cabilla Cornwall for a good example of marketing a temperate rainforest tourism destination.

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