Evaluating the role of biodiversity enhancement interventions in supporting bat conservation in a temperate forest

1. Forest structural complexity is a key driver of biodiversity in temperate ecosystems and strongly influences insectivorous bats by shaping foraging opportunities and the availability of suitable roosting structures. However, traditional forest management has often simplified stand structure, reducing both habitat heterogeneity and key habitat resources. In this context, this study investigates how different Biodiversity Enhancement Interventions (BEIs) affect bat activity across functional guilds in managed temperate forests. 2. We evaluated the short-term effects of three BEIs—(i) habitat trees creation through pre-senescence and artificial microhabitat formation, (ii) selective thinning with deadwood retention and (iii) canopy gap creation—0–2 years after implementation on bat guild acoustic activity in a temperate forest in northern Italy. Bat activity was quantified using passive acoustic monitoring and analysed across open, edge and narrow-space guilds using generalized linear mixed models (GLMMs) with a negative binomial distribution. 3. Bat guild acoustic activity responded to BEIs, with gap creation producing the strongest response across all guilds. Activity in gap areas was approximately 13× higher for edge-space foragers, 8× higher for open-space foragers and 2× higher for narrow-space foragers compared to control stands. Edge-space foragers responded positively to all interventions, whereas open and narrow-space foragers showed limited or non-significant responses to habitat trees creation and selective thinning. These results indicate that BEIs differentially affect bat guilds and that while effects of gap creation are immediately positive, responses to habitat trees creation and selective thinning may take more time. 4. Synthesis and applications. Our findings highlight that combining small-scale canopy interventions with the retention of habitat trees and deadwood can improve habitat conditions for bats. Canopy gap creation represents an effective shortterm intervention to increase bat activity, whereas habitat trees and selective thinning with deadwood retention are likely to provide longer-term benefits by maintaining key structural resources. Integrating complementary enhancement interventions within retention forestry strategies can therefore support the conservation of diverse bat communities in temperate forests.