Restoration management of quarries is one of the major tasks in global restoration ecology due to the magnitude of impacts link with extraction activities and the potential conservation value of these post-industrial sites. However, identifying a target to reach can be challenging as ecological issues can be numerous and post-exploitation state can differ from the original due to ecosystems removal or topography alterations caused by exploitation. Here, we assess the restoration potential of gravel-sand pits for Bats, a targeted group for conservation, using data from 21 gravel-sand pits monitored by the ROSELIERE scheme and we selected external data from 76 sites of the French Bat Monitoring. We analysed the relative attractiveness of 17 habitats and 5 gravel-sand pit operating statuses (before quarrying, during quarrying, rehabilitation post-quarrying younger than 5 years, rehabilitation post-quarrying between 5 and 10 years and, finally, rehabilitation post-quarrying older than 10 years). We paid close attention to comparison between gravel-sand pits states and aquatic habitats, because the restoration process in the gravel-sand pits studied often leads to bodies of water and these habitats are among the most favorable for numerous bats species. In addition, we focus our comparisons on arable land because new gravel-sand pit settlements are usually planned on such agricultural land and furthermore because it represents the major land-use pressure for bats. We found that bat activity in gravel-sand pit displays a range comparable to what is observed in numerous habitats, though it does appear both slightly lower than in bodies of water and greater than arable land. Bat activity appears increasing during the gravel-sand pit life's cycle. However, only quarries which had been rehabilitated for more than 10 years exhibited significantly greater bat activity than observed in the four other gravel-sand pit states. Our results, highlight the length of time required to detect obvious changes in the attractiveness of site being rehabilitated and the magnitude of the gap between the current state and the target (i.e. aquatic habitat). Such results should be take into account when sizing offsetting measures of quarries.

Despite the impacts of extraction activities, quarries have great potential for conservation of biodiversity, and their restoration can be considered a major task in restoration ecology. A particularly important issue is to quantify the roles of the following various factors that may influence biodiversity and restoration success: (a) local variables, (b) landscape variables and (c) ecological management. Following a multi-model inference, we identify which variables were the most useful predictors of bat activity in gravel-sand pits. We used data from 21 French gravel-sand pits provided by the biodiversity-monitoring scheme, ROSELIERE. Our results suggest that within these restored gravel-sand pits, landscape variables appear to be better predictors of the attractiveness of restored gravel-sand pits for the foraging activity of bats than local variables. Species or community indexes appeared to be more sensitive to landscape variables measured at a large scale (i.e., 1,000 m). Among local variables, the time elapsed after operation was a better predictor of bat foraging activity than the description of the habitat itself. The effect was more obvious within a site with an elapsed time since operation greater than 10 years. Our findings suggest that to increase the attractiveness of gravel-sand pits for bat foraging activities, planning policies should consider not only the intrinsic characteristics of a project (i.e., local variables) but also the surrounding environment (i.e., landscape variables).