CrustCheck
: a conceptual framework for interpreting biocrust trait–function relationships in drylands
Nicky Parker, Susanne Schmidt, Lea Condon, Jaidyn Eastaughffe, Peter Coates, Wendy Williams Abstract
Introduction
Biocrusts are increasingly recognized for their contribution to soil stability, hydrology, nutrient cycling, and energy balance in drylands, yet practical field methods for assessing functional roles are limited. Existing approaches typically rely on cover estimates, taxonomic identification, or laboratory analyses, providing little insight into functional variation among biocrust types. To address this gap, we developed CrustCheck, a literature‐derived conceptual framework that synthesizes potential relationships between easily observable biocrust traits and key ecological functions. The framework provides a foundation for future empirical validation of these relationships.
Objectives
We aimed to: (1) identify visual characteristics of biocrusts potentially associated with key ecological functions, and (2) synthesize these relationships into a literature‐derived conceptual framework for comparative interpretation of potential biocrust contributions to landscape function.
Methods
We conducted a structured review of global literature on biocrusts' contribution to landscape function, drawing on multiple databases, targeted journals, and identifying relevant scientific publications from reference lists. We screened sources for information on relationships between visual traits and metrics of landscape function, synthesized relationships thematically, and used them to develop a multi‐trait, function‐oriented conceptual framework to inform further testing of these hypotheses in the field.
Results
Our review revealed that visual traits such as thickness/height, patchiness, cover, and surface roughness emerged as potential indicators of surface stability, hydrological function, and nutrient accumulation. Community composition was also frequently associated with these functions, while color reflected energy balance and carbon fixation potential.
Conclusions
Literature reveals that visual traits of biocrusts may serve as proxies for landscape function. CrustCheck is presented here as a conceptual synthesis framework intended to support interpretation of potential trait–function relationships rather than as a quantitatively validated predictive tool.