Optimizing growth chamber conditions for maintaining Arctic lichen‐dominated biocrusts

Abstract

Optimizing growth chamber conditions for Arctic lichen biocrusts will create new opportunities to assess and prioritize reclamation techniques given the challenges associated with conducting arctic field work. Our study is the first to examine growth chamber conditions for optimizing survival and growth of Arctic lichen biocrusts, as measured by changes in lichen cover. We assessed effects of substrate crossed with substrate depth, substrate sterilization, lichen inoculation and community composition, and watering frequency in four concurrent experiments over 6 weeks on survival of arctic biocrusts collected from Diavik Diamond Mine Inc., Northwest Territories, Canada. Mixed species declined less than Flavocetraria cucullata, and substrate affected F. cucullata survival over time. Live lichen cover declined least with a 3-day watering frequency and substrate depth of 1 cm. Sterilization did not affect lichen survival, and no contamination was observed over 6 weeks. Our results highlight the challenges of maintaining and growing lichens under controlled conditions, as only a few treatments showed increases in cover. Our research shows that even short-term growth chamber experiments have potential to screen reclamation treatments prior to field assessments, permitting reclamation scientists to optimize limited time and resources while in the field.