Abstract

Tree cavities are a keystone resource for many wildlife species worldwide. In Andean temperate forests of South America, many species of birds, mammals and reptiles use cavities to achieve their life history requirements. However, information on cavity supply and drivers of cavity production in these forests remains largely undocumented. We examined the patterns of tree-cavity supply in successional native forests, exploring the potential drivers of cavity occurrence and relative abundances in Andean temperate ecosystems of southern Chile. In 10 forest stands, we established 369 vegetation plots and measured 7951 trees. For each tree, we recorded the species and measured the diameter at breast height (DBH), decay class and number of cavities. While tree density was much higher in secondary than in old-growth forest stands, the density of nonexcavated cavities was higher in old-growth than in secondary forests. Cavity occurrence and relative abundances (number of cavities per tree) were higher in large decaying and standing dead trees (i.e. habitat legacies) than in young healthy trees. Importantly, DBH and decay had a stronger influence on the supply of nonexcavated than excavated cavities. Our results highlight the importance of old-growth forest stands, tree decay processes and habitat legacies for securing a continuous supply of a keystone habitat resource for tree cavity-using wildlife in a global biodiversity hotspot of South America. in Spanish is available with online material.