21 - Where to draw the line: integrating feasibility into connectivity planning

Summary

INTRODUCTION

The long-term persistence of populations in fragmented landscapes depends on connectivity among disjunct habitat patches. Retaining or restoring habitat corridors has become a dominant strategy for maintaining connectivity in fragmented landscapes (e.g., Bennett 1999; Groves 2003; this volume), especially when the surrounding matrix is hostile to dispersing wildlife. The biological merits of any particular corridor, however, will depend upon a variety of factors, including the ecology of the targets (species, communities, natural processes) it is intended to serve, as well as the specific attributes of the corridor itself, the habitat matrix in which it is embedded, and the core areas it is connecting. Often, the effects of corridors on target biota are unknown. In some cases, corridors may be ineffective or even counter-productive (e.g., Simberloff and Cox 1987; Hess 1994; Dobson et al. 1999; Crooks and Suarez Chapter 18). Biological advantages and disadvantages of corridors have been discussed elsewhere (e.g., Beier and Noss 1998; Groves 2003; Crooks and Sanjayan Chapter 1). Here, we focus on how feasibility considerations factor into the decision-making process of conservation practitioners deciding where best to invest resources in connectivity conservation.

In an ideal world, wildlife corridor planning would occur with detailed knowledge of biological resource needs, multiple options for corridor design, unlimited resources for implementation, and cooperative landowners. More often, virtually nothing is known about plant and animal movement needs within a landscape, human land uses have already greatly constrained corridor options, conservation funding is inadequate, and landowners and political entities are recalcitrant (Swenson and Franklin 2000).