BRITISH FORESTRY PUTS PRICE ON FLOOD MITIGATION
TREES AND WOODLANDS DELIVER OVER £400M EACH YEAR IN FIGHT
AGAINST FLOODING, NEW STUDY FINDS
A LACK of forestation has long been acknowledged as a major factor in increased flooding risk. Now, new UK research has put a monetary value on how much forests are worth when it comes to protecting communities, and there are lessons that can be learned for Australia, too.
New research published in mid-January by Forest Research estimates Great Britain’s trees contribute over £400m annually in benefits. The flood regulation service of Great Britain’s trees, forests and woodlands as an annualised central estimate gave annual values of £843 million and £420 million compared to bare soil and grass, respectively. The valuation is based on the role trees, woodlands and forests play in intercepting rainfall, storing water and reducing the potentially devastating surface runoff that causes flooding.
Given the increased likelihood and frequency of extreme weather events as a result of climate change, the report highlights how woodland expansion can be a natural, cost-effective method of protecting homes and businesses.
British Forestry Minister Trudy Harrison said, “Communities across the country know all too well the potentially devastating impacts of flooding – from damage to homes and businesses and the disruption of critical infrastructure to the tragic loss of life.
“This report provides the best picture yet of the integral role that our trees, woodlands and forests play in protecting at-risk communities from flooding. With more severe weather events forecast in the future, there is even more incentive to accelerate our tree planting efforts.”
Forests help to reduce flooding in numerous ways. Firstly, evaporation from leaves and branches helps to reduce the amount of rainfall reaching the ground. This process, known as interception, is significantly greater for woodland compared to other land use types. Secondly, the soils within forests receive, store and delay water, helping to reduce rapid run-off and peak flows. Finally, the presence of trees, shrubs and large woody dams along rivers and on the floodplain creates a barrier effect that slows the passage of flood waters downstream, in addition to delivering biodiversity benefits.
As a result, tree planting can significantly affect the volume, pathway and timing of surface run-off, reducing the risk of downstream flooding. Responsible forestry management practices help to maintain and secure this key environmental service.