Nature conserved in changing landscapes with and without spatial planning

We use a simple spatial model to illustrate an ecologically optimum sequence of landscape change, evaluate how much ecological difference it makes, and determine if there is a phase during which its use is most effective or important in protecting nature. Compared with a random pattern of vegetation removal, the spatial solution protects five times more area of high ecological value. Equally significant is the better spatial arrangement of vegetation. Using random change as an analogue for lack of planning, we compare different lengths of random change before spatial planning begins. The analysis suggests that spatial planning is most significant in nature conservation when 10-40% of the natural vegetation has been removed from a landscape. We conclude that the few simple patterns and principles presented, combined with a general survey of a landscape area, constitute an important solution to land planning and conservation, especially where detailed ecological data are Limited or lacking. (C) 1997 Elsevier Science B.V. All rights reserved.