 Sir, Your interview (May 26) with the Bishop of Liverpool was timely as it coincided with the publication of new figures that show we have more tree cover than we thought ("Forest sale advisers may tell coalition to buy instead", May 26). This is good news but we should be in no doubt that for good economic, environmental and social reasons, we need much more.  Economically trees provide the green wonder product, capturing carbon in their timber, creating green fuel and providing thousands of jobs in a range of industries from tourism to manufacturing. Environmentally they have a huge role to play in mitigating the effects of climate change and providing first-class wildlife habitats.  But the Right Rev James Jones also picked up on the spiritual attachment people have with trees and forests. It's a theme that is close to my heart - we instinctively know that trees are good for us. Increasingly research backs up what our instincts tell us - that trees provide health, wellbeing and community dividends. Where industrial areas and work places include trees, employees are more productive and have a greater sense of job satisfaction.  This attachment with trees is something we work to understand better as we begin to realise the importance of this natural life support system to our own happiness. pam warhurst Chair, Forestry Commission