Taxonomy and conservation: A case study from Chamaedorea alternans

BACKGROUND AND AIMS: The establishment of justified recommendations in conservation biology requires robust taxonomic treatments for the group(s) being considered. Controversial or poorly developed taxonomies can have a negative impact on conservation assessments. One example of a taxonomically difficult and controversial species complex that is important in conservation involves two species of Mexican palms, Chamaedorea tepejilote and C. alternans. The goal of this study was to investigate whether C. alternans and C. tepejilote are genetically distinct within the Los Tuxtlas region of Veracruz. METHODS: Individuals corresponding to the morphology of C. alternans and C. tepejilote were collected from sympatric and allopatric regions within the Los Tuxtlas Biological Station. Eighty-eight samples were genotyped using amplified fragment length polymorphism (AFLP) markers. Cluster and ordination analyses were used to investigate patterns of differentiation. KEY RESULTS: UPGMA and PCO analyses of AFLP profiles recovered two divergent clusters corresponding to morphologically defined C. tepejilote and C. alternans. No intermediate genotypes were observed and five of the 45 loci were fixed for either the presence or absence between the species. The patterns of divergence observed do not identify a role for sympatric speciation. CONCLUSIONS: The observed patterns of differentiation support the recognition of C. alternans as distinct from C. tepejilote. A suite of vegetative and reproductive morphological features can be used to help distinguish these taxa in the field, but they can be difficult to differentiate from preserved material. Previous treatments of the variation found within the complex (C. alternans and C. tepejilote) as intraspecific variance is unjustified. Given that the Los Tuxtlas region has suffered from historical and ongoing deforestation and that Chamaedorea includes numerous endangered taxa, retaining conservation status for C. alternans serves to help safeguard individuals of the species as well as a region and larger taxonomic group all under considerable threat from human activities.