Controlling water use of trees to alleviate subsidance risk

Horticulture LINK project 212 – Final report – May 2004

Controlling water use of trees to alleviate subsidence risk © BRE on behalf of the LINK Consortium for Horticulture LINK Project No. 212


Buildings and the environment in which we live are key elements of our quality of life. Whether trees grow within a private garden or in a roadside pavement, the general public by and large appreciates them. Justifiably, because trees contribute so much to our environment, as well as their visual contribution to our landscape. But trees and buildings in close proximity can lead to problems, whether restricting light or causing damage by root activity. The planting and management of trees close to buildings therefore needs to be planned and undertaken from a sound science base. In a similar way, the planning process (under the auspices of the Office of the Deputy Prime Minister) needs to take account of the potential for conflict to occur and employ innovative design and careful construction. All this will help to avoid such conflict occurring and ensure that trees are maintained and managed in a sustainable manner.

Tree pruning is perceived as a potentially effective control measure to conserve soil moisture that could prevent excessive removal of trees, but the hypothesis had never been tested on amenity trees in the urban environment. The aim of this project was to improve the understanding of how isolated amenity trees use water, and to determine whether reduction in canopy leaf area and root-restriction are sustainable ways to control growth and reduce water uptake from soil.