We are so used to increases in the price of oil and gas due to fluctuations in the demand and concerns about reserves, that wondering if the price of wood as a fuel is likely to increase; is a fair question.
Indeed the Scottish Timber Industry has warned that it could face a serious decline if the problem of more trees being felled than is planted is not addressed (http://www.bbc.co.uk/news/uk-scotland-11794511).
As the report pointed out however this is likely to take a few decades to become a noticeable problem. This then gives the likes of the Forestry Commission, and politicians, plenty of time to act to ensure the situation is reversed. Some companies like Egger, are involved in helping companies create and manage forestry. This in turn helps larger companies with their corporate social responsibility.
All this means that it is wood fuel is unlikely to mirror the volatility of mineral resources. After all one of the beauties of using wood in construction, door manufacturing and as a fuel for heating is that provide the forestry is managed in a sustainable way, it is a relatively easily replaced resource.