Why do we need to manage and protect Surrey’s heathlands?

Lowland heath was mostly created by human activity beginning in the Bronze Age which kept areas free from trees.  People cut plant materials for their own use and cleared land for farming and grazing animals.  Although not a natural habitat, lowland heath is an increasingly rare and important one which supports a range of specialist species, some of which cannot live anywhere else.

In recent decades, grazing of cattle has declined along with the exercise of other traditional commoners’ rights such as the collection of firewood, and this has led to increased scrub growth.  Housing developments and roads have also encroached onto former heathland areas.

Managing heathland for biodiversity

SWT and other organisations carry out work to promote biodiversity on remaining heathland sites, aiming to provide the necessary conditions for important species of plants, reptiles and invertebrates to thrive.  Without intervention, heathland would gradually turn into woodland.  Small trees and scrub plants are removed to create a more open habitat and encourage heathland plant species.  This work is often carried out during winter months by volunteers.

Reptiles are cold-blooded and need areas of bare ground, heated by the sun in summer, to bask and breed.  Removing trees prevents these areas from becoming too shaded.  Scrapes are sometimes created to make sure there is plenty of bare ground for snakes and lizards to use.

Cattle are used for conservation grazing, confined within designated areas by electric fencing.  They eat the more dominant grasses, such as Molinia caerulea, making space for other plant species to grow.  This can help rare flowering plants such as the marsh gentian, found on Chobham Common, to survive and potentially spread.  It also benefits butterflies and reptiles which need more open, unshaded areas of ground.

Managing heathland to reduce risk from wildfires

Wildfire is a threat to the survival of viable populations of rare and endangered species, so limiting its spread is a priority.  This also reduces risks to human life, health and property in adjacent residential areas.

Land use change is one factor which has increased the risk of wildfires.  Finer vegetation including shrubs and grasses, as well as leaves and twigs, influences the spread of fire.  Controlled burning has historically been used in some heathland areas to remove unwanted vegetation, but SWT does not use this method.  Evidence from research elsewhere in the world shows ‘prescribed burning’ does not have a reliable impact on the extent of future wildfires, with the creation of firebreaks a more effective strategy.  Prescribed burning, like wildfire, can change the composition of the plant community, favouring invasive species which are often more susceptible to fire.  For instance, Molinia caerulea has a very deep root system which enables it to recover after wildfire, often before any other plant species, increasing its invasive potential.  As it grows and spreads it produces lots of dry, flammable material, so it is thought to increase the likelihood of wildfires occurring in future.

You may see small fires which have been lit deliberately by staff members on heathland, together with staff or volunteers working in the vicinity.  These are never left unattended - if you see an unattended fire, report it immediately by calling 999.  These fires are used to dispose of woody material removed during conservation work.  Wood piles and ‘dead hedges’ are occasionally created in adjacent woodland, but burning is the most practical way to deal with larger quantities.  Precautions taken to prevent spread or reignition of these fires include creating a firebreak around the fire site, keeping water and fire beaters to hand, staff remaining with the fire until it is extinguished, checking for reignition of hotspots and marking the site with hazard tape if it is likely to be accessed by the public, as the ground may remain extremely hot for some time.

Fire suppression has been found to be the most important factor affecting the extent of wildfires in the South East of England.  Suppression of wildfires can be both active (once a fire has broken out) and pre-suppression (removing combustible materials including dry vegetation from high-risk locations).  Targeted vegetation removal also includes removal from areas close to buildings, and creation of firebreaks, although even firebreaks many metres wide may be ineffective against powerful fires during very windy conditions.  SWT removes vegetation from managed sites to maintain both firebreaks and access for emergency vehicles along heathland tracks.

Read Part 3 to find out about future wildfire management and what you can do to help.

By Elaine Brindley

Other blogs in this series

Wildfires: An Introduction

Wildfires: Future Wildlife Management