A concentration on environmental income is not by itself sufficient if this income stream is not sustainable. Nations thus need to take care that the strategies they promote in their PRSPs for exploiting natural resources are viable over the long term. PRSPs frequently include expansions of the agriculture, forestry, or fisheries sectors, but rarely look at the implications of these activities for the future health of the resource. For example, of the 20 PRSPs reviewed, several targeted transformation of subsistence agriculture as a key means of reducing rural poverty. In many cases, however, plans for agricultural intensification, modernization, and commercialization did not explicitly address how this transformation could be achieved in ways that would ensure long-term sustainability of agricultural income and protection of the agricultural resource base. Likewise, few PRSPs described detailed plans to generate additional income and employment from forests and fisheries that were explicitly based on improved, sustainable management of these natural resources.
PRSPs might do a better job of incorporating the concepts of sustainability if they were more closely linked to existing environmental planning processes such as a national strategy for sustainability, or a national plan to meet the terms of the Convention on Biological Diversity. For instance, Nicaragua
