Vulnerability and fragility risk indices for non-renewable resources.

Protected areas are tasked with mitigating impacts to a wide range of invaluable resources. These resources are often subject to a variety of potential natural and anthropogenic impacts that require monitoring efforts and management actions to minimize the degradation of these resources. However, due to insufficient funding and staff, managers often have to prioritize efforts, leaving some resources at higher risk to impact. Attempts to address this issue have resulted in numerous qualitative and semi-quantitative frameworks for prioritization based on resource vulnerability. Here, we add to those methods by modifying an internationally standardized vulnerability framework, quantify both resource vulnerability, susceptibility to human disturbance, and fragility, susceptibility to natural disturbance. This modified framework quantifies impacts through a six-step process: identifying the resource and management objectives, identifying exposure and sensitivity indicators, define scoring criteria for each indicator, collect and compile data, calculate indices, and prioritize sites for mitigations. We applied this methodology to two resource types in Grand Canyon National Park (GRCA): caves and fossil sites. Three hundred sixty-five cave sites and 127 fossil sites in GRCA were used for this analysis. The majority of cave and fossil sites scored moderate to low vulnerability (0-6 out of 10 points) and moderate to low fragility for fossils. The percentage of sites that fell in the high-priority range was 5.5% for fossils and 21.9% for caves. These results are consistent with the known state of these resources and the results present a tool for managers to utilize to prioritize monitoring and management needs.