Going mad in Totnes

Via J.F. Beck, The Guardian reports on emergency planning in Totnes. When the millennium strikes, they'll be prepared:

Transition Totnes has introduced its own currency with notes that can only be spent in local shops. Its businesses are being audited by an accountant who provides a wake-up call by identifying parts of their operations that become unprofitable as oil prices rise. The town is planting nut trees which can provide emergency food and timber for construction while also acting as carbon sinks.

Nut trees? Do they really need the trees?