Assisted dispersal and retention of lichen‐dominated biocrust material for arctic restoration

Abstract

Arctic biocrust loss due to industrial activity can have long-lasting ecological impacts, highlighting the importance of restoring disturbed tundra environments. This research focused on biocrust establishment on substrates of by-product materials from diamond mining (crushed rock, lake sediment, processed kimberlite), inoculant dispersal (dry placement, slurry), habitat amelioration (erosion control blanket, tundra soil, woody debris), and containment (jute mat), over three field seasons at Diavik Diamond Mine, Inc., Northwest Territories. Three years after inoculation, lichens were detected on 100% of inoculated plots and 70% of uninoculated plots (likely blown in from inoculated plots). Uninoculated plots had significantly lower species richness and vegetation cover than inoculated plots. Biocrust retention was highest on plots with erosion control blanket, containment, woody debris, and crushed rock; larger scale application of these treatments should be assessed in future. Plots with processed kimberlite, no habitat amelioration or tundra soil, and no containment had the lowest cover, species richness, and individual species abundance in year 3. This research suggests that active restoration techniques using lichen biocrust inoculation and habitat amelioration is required for successful biocrust revegetation outcomes on substrates of mining by-products in the arctic.

Optimizing growth chamber conditions for maintaining Arctic lichen‐dominated biocrusts

“…The large decline of Flavocetraria cucullata on crushed rock relative to the smallest decline of unsieved mix on tundra soil indicates reclamation experiments must account for specific species' survival which may depend on substrate. Similarly, we documented species specific results for arctic lichen dominated biocrusts in our field study (Ficko et al 2022), while growth chamber studies of dryland biocrusts documented species‐specific responses, with increases in lichens with cyanobacterial partners and concomitant decreases in lichens with green algal photosynthetic partners (Bowker & Antoninka 2016). However, as biocrusts may decline initially in the growth chamber and then start to grow again (Antoninka et al 2015), future studies should assess arctic biocrust growth and survival over longer time periods.…”

“…Uplands are vegetated by dwarf-heath shrubs and lichen-dominated biocrust communities (fig. S1 in Ficko et al 2022), with a short growing season between late May and mid-August. Vegetation cover is 80 to 100% in mesic to wet areas, with lichens providing 25% or more ground cover in some areas (Kidd 1996;Naeth & Wilkinson 2008;Ecosystem Classification Group 2012)…”