Connectivity of thermal refuges in a desert city: a thermal ecology of changing urban heatscapes

Keywords: landscape ecology, conservation, climate change, configuration
Abstract Type: Virtual Paper Abstract

Abstract

Habitat connectivity is a central tenet of landscape ecology and conservation planning and is key for population viability because it allows for ecological processes such as dispersal, movement, gene flow, migrations, and repopulation of areas. Connectivity also improves the chances that species will be able to adapt to changing climatic conditions, which reduces extinction risks and minimizes the effects of environmental variability on small populations. Connectivity has typically been conceptualized in terms of natural areas, habitat types, or specific land covers (e.g., forested areas), but as climate change continues to alter thermal environments, it is becoming imperative to understand how the direct effects of heat may be affecting connectivity or impeding species’ movement. This paper maps the change in the surface urban heat island (SUHI) effect over 35 years in Phoenix, USA to determine how the distribution of thermal refuges has changed over time and what those changes have meant for the functional connectivity of the landscape for species. We find that the conversion of agricultural lands to developed areas since the mid-1980s has significantly decreased the availability of thermal refuges over time, creating a fragmented landscape of cool patches that can provide refuge. The most important nodes for connectivity align with agricultural areas along the city fringes, which continue to be threatened by land cover conversion and decreasing water availability for crop irrigation.