We address the problem of optimal use of renewable resources under a variety of assumptions both about the nature of the economy in which these resources are embedded and about the objective of that economy. In this second respect, we are particularly interested in investigating the consequences of a definition of sustainability as a form of intertemporal optimality recently introduced by Chichilnisky [7], and comparing these consequences with those arising from earlier definitions of intertemporal optimality. In terms of the structure of the economy considered, we review the problem initially in the context of a model where a renewable resource is the only good in the economy, and then subsequently we extend the analysis to include the accumulation of capital and the existence of a productive sector to which the resource is an input