US-IALE 2018

AUTHORS: Ho Yi Wan*, Northern Arizona University; Samuel A. Cushman, U.S. Forest Service

ABSTRACT: Globally, human-induced environmental change is degrading habitats and driving biodiversity loss and species extinctions across nearly all taxonomic groups. Threatened and endangered species are particularly vulnerable to habitat loss and degradation. The 2015 IUCN red list identifies habitat loss and degradation as the main threat to 85% of all 79,837 species being assessed. Habitat loss and fragmentation increase spatial isolation of populations, reduce population size, and disrupt dispersal behavior and population connectivity. Protecting habitat that enhances broad-scale connectivity for landscape-level ecological processes such as dispersal and gene flow is a critical task for conserving rare species. Meanwhile, distribution and genetic data on rare species are often obscure because of small population size and low detection probability, and existing data are usually restricted to small or local region. As a result, identifying areas important for conservation over large landscapes can be challenging. In this study, we combined multi-scale optimization habitat selection model, resistance-based connectivity network (UNICOR), and landscape genetics simulation (CDPOP) into a single, spatially explicit framework for identifying broad-scale core habitats, long-distance species dispersal and gene flow patterns. We used the federally listed threatened Mexican spotted owl as an example to illustrate this framework. We identified potential suitable habitats and areas of high connectivity across a large portion of its range in Arizona, and tested how differences in species’ maximum dispersal distance affect prediction in connectivity corridor network and genetic diversity. Our analysis showed a strong positive relationship between landscape connectivity and genetic diversity, suggesting the importance of maintaining corridors and linkages between remnant habitats. We developed maps of suitable habitat, connectivity, and genetic diversity that inform broad-scale management and conservation planning. This framework provides a feasible and powerful solution for assessing effects of human and natural disturbances on species habitats and connectivity at the landscape level.