The riparian zone

Scotland’s forests and woods are covered by a huge network of burns, lochs and rivers, not to mention thousands of hectares of wetlands.

These are really important areas. They are rich in biodiversity and also provide our drinking water, our defence against flooding and contributions to local economies through recreation.

But just as important is the narrow strip of trees and vegetation on the banks of these watercourses. It’s called the riparian zone.

birch-alder-riparian-woodland-Aberdeenshire

Why is riparian woodland important?

Native woodland on the riparian zone is a vital part of the water ecosystem. It helps regulate the temperature of the water by providing shade, while falling leaves and insects feed the hungry animals below.

Even when they die, these trees contribute to the environment – rotting wood provides good habitat for invertebrates that ultimately provide food for fish and other aquatic life. Large branches and whole trees that fall into the water provide shelter for animals and help change the water flow, creating a variety of habitats on the river bed.

Some of our most iconic species rely on healthy riparian and aquatic habitats:

Osprey (copyright: Pete Cairns/2020Vision)

The loss of a vital habitat

Until the 1980’s, we saw the riparian zone on Scotland’s National Forest Estate as just another place to plant trees. We planted conifers right up to the water’s edge.

The resulting deep shade and acidification upset the delicate chemistry of the water. Soil from forestry operations and road building blocked streams and rivers. Pollution from machinery became a problem too. As a result, life drained from the water.

Restoring the riparian zone

Fortunately, modern woodland management is now addressing these problems, and Scotland’s precious riparian resource is now recognised for its contribution to species richness and diversity.

During our land management planning, we now identify all the watercourses that need conservation action.

In the northern Highlands, for example, we plan to restore almost 5,000 hectares of riparian woodland. This will give every watercourse the breathing space it needs by establishing permanent buffers of native woodland and scrub up to 100 metres wide.

In recent years, we’ve spent millions of pounds on this valuable work, combining it with other conservation measures, including the control of invasive non-native species such as rhododendron and mink.