Ecological Monitoring and Assessment Network's proposed core monitoring variables: an early warning of environmental change.

This article reports on the evaluation of existing ecological monitoring variables from a variety of sources to select a suite of core variables suitable for monitoring at the Ecological Monitoring and Assessment Network (EMAN) sites located across Canada. The purpose of EMAN is to promote the acquisition of relevant and consistent data that can be used to report on national trends and provide an early warning of ecosystem change. Existing monitoring variables were evaluated in two steps. In the first step, three primary criteria were used to pre-screen preliminary variables. In the second step, a more detailed evaluation considered twenty criteria based on data quality, applicability, data collection methods, data analysis and interpretation, existing data and programs, and cost effectiveness to select a draft set of core monitoring variables (CMV). An ecological framework was developed to organize the CMV in a manner that permitted a gap analysis to confirm the CMV assessed a wide range of relevant environment components. The suite of CMV were then tested to determine their effectiveness in detecting ecosystem change caused by stressors with ecosystem responses that have been well documented in the literature. This project is part of a process lead by Environment Canada to select CMV to detect and track ecosystem change at EMAN sites. It is anticipated that the proposed CMV will undergo future discussion and development leading to the final selection of a suite of CMV for use at EMAN sites.