Assessing the impact of mining exploration infrastructure on ground-dwelling arthropod communities using DNA metabarcoding and habitat characteristics.

Abstract For most mining projects, regular monitoring of environmental impacts is typically measured solely for the main operation footprint and not the supporting network of exploration infrastructure. Such infrastructure includes exploration tracks, roads and drill pads, where localised areas are cleared of native vegetation, and the surrounding habitat is undisturbed. Here we use DNA metabarcoding to study the impacts of mining exploration infrastructure on the ground-dwelling arthropod communities found on Banded Ironstone Formations (BIFs) in the Midwest region of Western Australia. Further, we examine whether two indicator species groups, Formicidae and Collembola, reflect the patterns in overall arthropod communities. The study was conducted at three mine sites, each with three infrastructure types: maintained tracks, unmaintained tracks, and drill pads. We collected ground-dwelling arthropods and recorded habitat characteristics (e.g. total vegetation cover, bare ground cover) along transects extending 100 m away from the disturbance into remnant vegetation. We found that all three infrastructure types impacted the habitat characteristics similarly, with physical changes in habitat extending into the remnant vegetation. However, among all three groups of arthropods (overall arthropods, Formicidae and Collembola), we observed a clear distinction between each exploration infrastructure type at the three sites, indicating a disturbance effect extending more than 100 m into remnant vegetation. We found that Formicidae communities reflected the changes in overall arthropod communities better than Collembola. Our results demonstrate the utility of DNA metabarcoding for documenting fine-scale impacts on arthropod communities and highlight the need to consider different types of disturbances associated with mining activity.