摘要：There is likely to be a divergence in the interests of farmers and their neighbours or the community in the management of land and hence a greater rate of exploitation of soil qualities than that desired by the community. This is particularly true under current institutional arrangements with respect to nonpoint forms of land degradation, such as soil acidification, where the property rights of the community are weak. Hence it is important to understand the nature and extent of off-site impacts so as to form a basis either for potential collective action or for some form of intervention by government. One of the objectives of this paper is to draw out the analogies between offsite effects of a spatial nature with those of a dynamic or temporal nature with a view to providing useful insights to biological and economic research into the spatial off-site effects of alternative land management strategies. To make the discussion less abstract the management of soil acidity will be used as an example throughout the paper. To date it would seem that most biological and economic research into this issue has focussed on the temporal dimension.
