Biological soil crusts (‘biocrusts’) are communities of microorganisms that develop on soil surfaces and are a critically important functional component of dryland systems of the globe. Due to the functional importance of biocrust communities to the ecological functioning of dryland ecosystems there is keen interest in restoring these communities. The overarching research objective of this project was to facilitate the recovery of degraded arid and semi-arid Department of Defense (DoD) lands by restoring biocrust communities.
In this project, the research team: 1) established a biocrust nursery as an inoculum testing and supply center for biocrust restoration, 2) identified successful field application methods of biocrust inoculum in a series of field trials, 3) evaluated soil and plant responses to biocrust restoration in multi-factorial field experiments, and 4) shared knowledge of biocrust restoration success and challenges with DoD and federal land managers. In years 2013-2015 of the project, cultivation of inoculum was completed and delivered to field experiments in both the hot and cold desert sites. A broad range of experiments have continued over the past two years to optimize inoculum cultivation under greenhouse and laboratory controlled environments. The project team implemented multi-factorial field experiments at the two research sites, Utah Test Training Range (UTTR) and the Jornada Experimental Range (JER) in June and September of 2015. They monitored the biocrust response to three types of inoculum; field collected (FC), lab grown local biocrust (LB), and mixed isolates (MI) using two soil stabilization strategies (straw borders and polyacrylamide ‘DirtGlue’).
This research has yielded effective methods to grow biocrust inoculum both from small field collected samples and cultured isolates of early successional cyanobacteria, mosses, and lichens. The research team has shown that inoculation of soils with lab and greenhouse growth biocrusts enhance biocrust recovery. Barriers and challenges still exist in biocrust recovery with inoculation under field settings and this is likely due to resource limitation to biocrust growth and recovery and more specifically water availability. The research team did show that irrigation and shading likely alleviate resource constraints and ultra violet stress resulting in enhanced biocrust recovery over a short period of time.
The research team has developed novel approaches to developing biocrust inoculum for restoration of degraded dryland ecosystems. Biocrusts play a functional important role in dryland ecosystems influencing soil stability, nutrient availability, and hydrology. Thus, rehabilitation of these biotic communisms will benefit these ecosystems and the services they provide. A future challenge is scaling these approaches to larger landscape scale restoration approaches.