This is not true. The logical reasons behind the need for the regulation of forestry are derived from economic theory and provide a solid ground for forest policy. However, this is not something done only by economists. Each choice of policy results in a unique combination of marginal cost and marginal benefit solutions, i.e. implicit prices. There is no contradiction between economic theory and forest policy.
Economic theory is simply a tool that can be used to find the best policy.
Economics, as a science, cannot a priori recommend either market or interventionary solutions to a problem. What economic theory can do, however, is help the policy-maker to structure the problem, point out important factors, and reveal hidden preferences. When used with care, economic theory is a good servant to the makers of forest policy.