Synthesis: Thresholds in conservation and management

This paper is a brief overview of some of the key issues which have emerged from the preceding set of papers on ecological thresholds. These include: • Whether threshold relationships are common and widespread. • The potential for large variations in the use and application of the threshold concept to lead to adverse conservation outcomes, particularly when overly simplistic levels of vegetation cover are specified by policy makers and land managers. • The inherent multi-variate nature of landscape processes and responses of individual species and assemblages that creates variability in datasets. This may lead to a limited ability to make accurate predictions from threshold relationships, even when those relationships are highly statistically significant. We believe that although the threshold concept is an appealing one and there is some empirical evidence to support it in some landscapes, it is not free of problems and a concerted research effort on the topic is needed. This is particularly important if it is to have value for robustly underpinning applied landscape management practices without unintentionally having negative impacts on rates of species loss or the loss of particular species.