by N A Hipps, C J Atkinson and H Griffiths (02-Jun-2006)
Trees close to buildings, roads and other built facilities can increase the risk of subsidence when the roots take water from shrinkable clay soils beneath foundations.
A series of experiments was conducted by East Malling Research and Cambridge University over five years to assess if soil drying by trees could be controlled by branch pruning. Two standard pruning techniques were used to reduce the crown size of mature trees. An alternative approach for newly planted trees was also investigated, using a geotextile membrane to limit the growth of the tree roots.
This BRE information paper summarises the findings of the project. Comments and recommendations are made about the effectiveness of the three techniques, and the implications for managing trees in shrinkage susceptible soils. 8 pages.
Pruning trees to reduce water use
Restricting growth to reduce water use
Determining tree growth and water use
Summary of results
Summary of scientific advances
Tree management implications