COS 297-3 - Diversity metric selection and their applications for spatial conservation planning

Abstract: On-the-ground conservation efforts require managers to consider various and sometimes conflicting conservation goals. For instance, areas important for conserving threatened and endangered species may have little to no spatial overlap with areas important for high climate change resilience (e.g., high functional redundancy). Following a systematic conservation planning (SCP) approach can help managers address some of these conflicting goals, but using standard SCP tools like prioritization can complicate conservation efforts further if conflicting diversity metrics identify different high-priority areas with little spatial overlap. Given these concerns, we compare multiple community-level diversity metrics to determine which are appropriate for specific conservation planning goals, including overall species richness, richness of species with decreasing population trends, threatened and endangered (T&E) species richness, Rao's quadratic entropy, and functional redundancy and compared their spatial overlap. To compare each diversity metric, we first examined spatial correlations before prioritization, then disagreement in spatial patterns after using linear integer programming-based prioritization. We finally determined which metrics were most appropriate for contemporary conservation questions and examined where metrics had high spatial agreement. As expected, our diversity metrics had low correlation values (median = 0.31, range = 0.11 to 0.71) and identified different high-priority conservation areas. Thus, we recommended specific research questions and management objectives that are best served by each metric or combination of metrics. Despite low correlations for many metrics, we did find areas where all or most of our prioritization output agreed, suggesting that aggregates of several metrics could support multiple-objective conservation planning, particularly in the East where there are far fewer protected areas. We also provide detailed methods, code, and a set of US-wide conservation maps that can be used to support management efforts in tandem with further regional analyses. Overall, we reiterate how important it is that researchers and managers select metrics that best reflect their conservation goals.