Alleviating Biocrust Blindness: An Easy Guide to Morphogroups of Biocrusts

Biological soil crusts (biocrusts) are increasingly recognized as important components of ecosystems. Biocrusts are instrumental in maintaining functions such as soil stability and reduced abundance of invasive annual grasses. Impacts of fire are likely to be less severe where invasive plants are reduced and biocrusts are abundant. These organisms can thrive under drought conditions and help intact ecosystems be more resilient to drought. However, expertise on these organisms remains limited.  Practitioners are often interested in the topic but might feel they would benefit from additional resources on how to identify these organisms. We have developed a single-page, front and back guide that enables anyone, regardless of previous experience, to recognize biocrusts in the field and categorize them into ecologically meaningful groups, with known functional roles. The guide has been tested both in the field and by examining biocrust samples in hand. Data associated with testing the guide was used to improve it. The resulting guide describes higher-level groups of algae, mosses, and lichens. Light algal crusts are described as their own group. Dark algal crusts are presented with gelatinous lichens due to similar ecologies and increased accuracy of identification when these groups are combined. The determination of algal crusts was accepted as correct, regardless of the light or dark designation, due to the quality of our samples. Mosses are split into short and tall. In addition to the gelatinous lichens / dark algal crust group, lichens were classified into five additional categories: crustose, cup, foliose, fruticose, and scale. This tool has been created from the ground up, driven largely by the accuracy with which non-experts can correctly classify presented groups. In addition to reporting on the accuracy of each group, we explain how sample type (resin, dried and in petri dishes, or enlarged photographs) played a role in the accuracy of identification. We describe the ecology and functional roles of the presented groups, giving further justification for their classification. We anticipate that adoption of the guide is likely to have far-reaching implications, such as an increase in the number of studies on biocrusts at the level of functional roles.