Habitat Suitability for Small Mammals in Mediterranean Landscapes: How and Why Shrubs Matter

Fires are usually seen as a threat for biodiversity conservation in the Mediterranean, but natural afforestation after abandonment of traditional land uses is leading to the disappearance of open spaces that benefit many species of conservation interest. Fires create open habitats in which small mammals can live under more favourable conditions, such as lower predation, interspecific competition, and higher food availability. We analysed the role of changes in shrub cover and shrub preference by small mammals along the Mediterranean post-fire succession. We used data (period 2008-2018) from 17 plots woodlands and post-fire shrublands present in the study area (Barcelona's Natural Parks, Catalonia, NE Spain), and vegetation structure was assessed by LiDAR technology for modelling ground-dwelling small mammal preferences. The diversity, abundance, and stability of Mediterranean small mammal communities negatively responded to vegetation structural complexity, which resulted from the combined effects of land abandonment and recovery after wildfires. We suggest that biotic factors such as vegetation profiles (providing food and shelter) and their interaction with predators and competitors could be responsible for the observed patterns. Considering the keystone role of small mammals in the sustainability of Mediterranean forest, our results could be useful for management under the current global change conditions.

Automated summary

Natural afforestation after abandonment of traditional land uses is causing the disappearance of open spaces beneficial for many conservation species in the Mediterranean. However, fires, which are considered a threat, create open habitats where small mammals can thrive. Our analysis reveals that the diversity, abundance, and stability of Mediterranean small mammal communities are negatively influenced by vegetation structural complexity, resulting from land abandonment and recovery after wildfires. Biotic factors such as vegetation profiles and interactions with predators and competitors may explain these patterns.