PS 34-221 - Novel approach to biocrust restoration using pelletized moss

Abstract: Drylands, approximately ~41% of the world’s terrestrial land, face significant loss of ecosystem services do to land use change. Restoring function and productivity to drylands is essential to preventing further anthropogenic degradation. Biocrusts, a living groundcover in drylands, can fix carbon and nitrogen, stabilize soil, provide habitat for microbial communities, and provide nutrients for surrounding plants. They also influence hydrology, sediment movement, and sometimes the composition and trajectory of plant communities. Still, there has been mixed success in restoration attempts and a knowledge gap persists. We chose Syntrichia ruralis, a common biocrust moss species occurring in communities across the northern hemisphere, to test a novel restoration method for moss application: pelletization. Pelletizing is a method already widely used in restoration with vascular plant seeds to increase the weight and size to improve handling, consistency, protection and stability in field trials. The objectives of this study are to determine whether pelletized biocrust will demonstrate higher establishment over time than non-pelletized ones and to determine which pellet shapes and compositions promote the highest biocrust establishment. We created eight combinations varying in recipe, size, and shape (n=10) to determine the most effective pellet for moss growth. Preliminary data measuring pellet breakdown and the number of active moss stems over time suggest that pellet size, shape, and recipe matter to some degree for moss establishment. Recipes that included pectin as a pest deterrent performed better than those without pectin across all shapes and sizes. Also, small flat pellets had the highest mean moss cover of all treatments. Flat pellets broke down faster than round pellets regardless of size, which could speed moss establishment. Although the experiment is ongoing, we see a trend over time that non-pelletized moss health is decreasing more rapidly than any other pelletized treatment. If we find that pelletizing works in small field trials like these, we can explore cost effective mechanized ways to distribute pellets with a purpose of scaling up, such as seed drilling or landscape-scale aircraft deployment. By rehabilitating biocrust organisms on the landscape in an efficient and scalable way, we can provide restoration managers with an important tool to improve degraded dryland systems.