Identifying typical and early warning species by the combination of functional-based diagnostic species and dark diversity

Abstract The European Union Habitats Directive requires the identification of typical species that reflect structure and functions habitat types, as well early changes in condition, but no common methods are available for their selection. Diagnostic with high fidelity to a specific group plots identified by traditional methods, value is still debated. We designed protocol plant based on recently proposed method detect diagnostic combining abundances functional traits. tested set alpine subtypes, comparing traits or Grime’s CSR strategies (competitive, stress-tolerant, ruderal) those presence/absence abundance only, then we calculated each dark diversity probability—i.e. probability being absent from type suitable ecological conditions. Functional-based allowed recognize larger sets exclusive species, adding dominant linked subtypes (i.e. centroid). Dark was equally distributed between non-diagnostic functional-based methods. Species higher among associated centroid can be considered warning indicators here enables ranking measurable variables (functional association, probability) applied standardized tool types dominated plants.