Using Drone Imagery to Reveal How Fire, Vegetation Cover and Landform Shape Thermal Mosaics in Desert Landscapes

Extreme heat is an increasing risk for dryland fauna, making it important to understand how landscape features influence thermal conditions. This study used drone-based thermal mapping to measure fine-scale temperature variation across two Australian dryland sites during summer. It examined how landform, fire history, vegetation cover, and grazing affected surface temperatures. Temperatures varied widely, from 6 to 36 °C in the morning to 24–80 °C in the afternoon. Vegetation coverage did not significantly affect surface temperatures. Landform strongly influenced temperature patterns: sand dunes were cooler than swales in the morning but hotter in the afternoon. Dunes also showed more fragmented and patchy thermal environments, likely due to uneven vegetation, steeper slopes, and soil properties. These conditions may offer greater opportunities for animals to regulate body temperature behaviourally. Fire significantly altered thermal landscapes. Recently burned areas were hotter and had more fragmented thermal patches, creating harsher conditions for diurnal species. In contrast, grazing exclusion had minimal effect, though areas without introduced herbivores showed more stable temperatures. Overall, fire and landform shape thermal mosaics by influencing both temperature levels and spatial patterns. Maintaining diverse thermal environments is likely critical for supporting thermoregulation and species survival under increasing heat extremes.