Restoration management of fly ash deposits crucially influence their conservation potential for terrestrial arthropods

Fly ash deposits are a relatively common component of many industrial landscapes. Recently, these post-industrial sites were shown to host highly endangered communities of bees & wasps of vanishing continental drift sands. Nevertheless, nothing is known about this conservation potential for other arthropods, nor how it has been influenced by the practice of restoration. We sampled communities of bees wasps, moths, spiders, hoverflies, and ants colonizing several spontaneously developed and technically reclaimed plots in two fly ash deposits in northern Czech Republic, Central Europe. In addition to species richness, we also concentrated on the potential for colonization by species included in national red-lists and/or specialized to the highly threatened environments of continental drift sand dunes. In total, we recorded 585 species of the studied arthropods, including six considered as nationally extinct, 17 critically endangered, and 84 other red-listed species. From those numbers, 34 species were highly specialized for drift sands. bees & wasps and spiders comprised the overwhelming majority of the threatened species, and all the specialists. The overwhelming majority of the most threatened species colonized the non-reclaimed habitats and generally avoided afforested plots. Some of the endangered bees & wasps occurred also in the artificial grasslands, probably feeding on nectar. Summarizing, the studied fly ash deposits harbor arthropod communities of high conservation interest, importance of the spontaneously developed habitats differ among individual arthropod groups. However, this conservation potential is suppressed by artificial afforestation. Following the occurrence patterns of the most threatened species we suggest applying a mosaic-like combination of non-reclaimed habitats with reclaimed grasslands as a potentially effective solution combining both biodiversity conservation and environmental protection. The expected ensuing controversy of this approach should be one of the most essential challenges of current restoration ecology research and practice. (C) 2014 Elsevier B.V. All rights reserved.