What is a temperate rainforest?

Temperate rainforests occur in mid-latitude, temperate zones, in places which receive heavy rainfall due to an ‘oceanic’ climate – where it is both very wet and sufficiently mild.

There are not very many places on the planet where temperate rainforest can flourish. It has to be wet, with about 1,400mm of rain a year. But it also has to be mild enough for plants to grow in mid-air.

Temperate rainforests are very damp woodlands, so damp that plants grow on other plants.

These are fragile ecosystems growing in small patches across the world: America’s Pacific Northwest, Chile’s southern tip, parts of Japan, Korea and New Zealand. But they truly thrive on the wet Atlantic fringe of the British Isles.

Historically, temperate rainforests covered a much larger area of Britain. They were initially cleared in the Bronze Age and the medieval period. Some have been lost more recently due to forestry policies and overgrazing.

Where are British rainforests?

At one time rainforest covered a fifth of Britain’s land stretching through Cornwall, Devon, Wales, the Lake District and up the west coast of Scotland. Today only isolated scraps survive, covering about 0.5% of Britain, but including our own beautiful Rocky Valley.

The map shows both Britain’s rainforest zone and fragments. The rainforest zone is where the climate is sufficiently rainy and mild for temperate rainforest to thrive. This region extends to around 20% of Britain.

Britain’s rainforest fragments are where it is believed that Britain’s surviving fragments of temperate rainforest are located and where there is an opportunity for it to expand. The best way to bring back the lost rainforests is to better protect what we have left, and then allow these rainforests fragments to expand and regenerate naturally.

Our temperate rainforests, like their tropical cousins, harbour a huge wealth of flora and fauna. A 2018 report by the Joint Nature Conservation Committee said the UK has an “international responsibility” to protect its rainforests as vital habitats.

How to spot them in the UK

In the Tropics a rainforest is somewhere wet enough for the trees to have other plants growing on them. You can look for similar clues for rainforests in cooler climates.

Epiphytes, plants that grow on other plants, are the key indicator. The key is abundance. Anywhere wet enough to host a mass of lichens, mosses and fungi is a likely candidate.

Here are a few indicators of a temperate rainforest.

• Beefsteak fungus (Fistulina hepatica): resembles a slab of raw meat and complete with dripping blood. It thrives on oaks in both dry woodlands and rainforests.
• Octopus suckers (Collema fasciculare): a type of jelly lichen found in the rainforests of western Scotland.
• Hazel gloves fungus (Hypocreopsis rhododendri): found only on decaying branches of rare hazelwoods on the Atlantic coast.
• Lobaria virens: a green, shiny lichen marked by orange disks, thrives in the dampest parts of the Lake District, Wales, Scotland and the West Country.

The Department for Environment, Food, and Rural Affairs recently announced its £30 million Big Nature Impact Fund to back efforts to “support and expand England’s temperate rainforests.” However, The Lost Rainforests of Britain are still waiting for more details on the specifics of the funding and how much will be allocated for rainforest restoration and protection.

The government has previously said that much of the country’s temperate rainforest is protected and that it is committed to its safekeeping.