Abstract

Context: Understanding species–genetic diversity relationships is key to foster holistic conservation approaches aimed at preserving biodiversity across multiple dimensions. Despite the facts that genetic and species diversity are likely to be spatially structured and that species–genetic diversity correlations (SGDCs) reveal coincident spatial patterns between the two diversity levels, spatial autocorrelation has been largely overlooked. Objectives: We assessed the benefits of investigating species–genetic diversity relationships through a spatial framework using high Andean wetlands from Chile as a case study system. Methods: Genetic diversity was estimated using amplified fragment length polymorphism markers for five abundant species and species diversity was assessed as taxonomic richness for two communities (plants and benthic macroinvertebrates). We tested SGDCs using Moran Spectral Randomizations (MSR), and used a causal modelling procedure to elucidate relationships between species and genetic diversity and their coincident spatial structures. Results: While traditional correlation tests detected significant SGDCs in most cases (i.e. nine), only three species–genetic relationships reached significance or borderline significance with the MSR approach. In all these cases, genetic and species diversity displayed similar spatial autocorrelation patterns. The causal modelling analyses suggested direct effects of genetic diversity on plant richness for species involved in nutrient cycling. Conclusions: Our study provides new perspectives on species–genetic diversity relationships in high Andean wetlands. In addition, it demonstrates the usefulness of causal modelling approaches and the importance of incorporating spatial information to advance understanding of the processes driving both species and genetic diversity, as well as their interactions.