Just as important as implementing connectivity in the landscape is the ability to measure whether or not the effort is successful. Given the complexities of measuring “success” and the wide variety of meanings that term can hold, determining if a project aimed at reconnecting habitats actually does what it’s intended can be difficult. New research by Watson et al. aims to clarify the challenges of measuring success in landscape-level connectivity restoration, and provides a detailed framework for managers and other decision-makers to use to plan connectivity efforts and quantify the effectiveness of their outcome.
The main message is that no single methodology for assessing success is adequate, because each occurs at a scale of monitoring that only explains part of the story. For example, some methods assess success by looking at individual movements, others by measuring changes in demographic or genetic rates, and others by measuring changes in species occurrence or richness. All levels of potential outcomes, from immediate, individual-based changes to long-term, large-scale changes need to be integrated to fully understand whether on-the-ground actions have translated into meaningful outcomes.
They point out two basic monitoring design principles that should be adhered to: 1. Monitoring should include control areas (i.e. areas where no management has occurred) so that it’s possible to determine whether changes in outcomes are related to changes in connectivity; and 2. the spatial and temporal scale of monitoring needs to align with project objectives (ex. don’t measure individual movement in one year if your goal is to increase species richness over a decade). Once this has been decided, there are numerous methods that can be applied to actually measure connectivity success.
They end with applying the framework to a real world example in the Australian Capital Territory (ACT), where 60,000 ha of remnant box-gum grassy woodlands are being connected along an urban to rural gradient. The framework was applied to to achieve two outcomes, mainly determining native plant and overall species richness and assessing the relative effectiveness of enhancing vs. creating connections.
The use of the framework allowed the ACT to concentrate its efforts on a few primary goals and to form partnerships to achieve other goals without spreading itself too thin and thus achieving no goals at all. By applying this new framework, this management problem and others have the potential to more effectively determine whether their efforts at connectivity are meaningful and making a difference for conservation priorities.
Watson, D. M., V. A. J. Doerr, S. C. Banks, D. A. Driscoll, R. van der Ree, E. D. Doerr, and P Sunnucks. 2017. Monitoring ecological consequences of efforts to restore landscape-scale connectivity. Biological Conservation 206: 201-209.