Geographical and ecological distribution analysis of Dalbergia calderonii Standl. (Fabaceae): implications for the conservation of this critically endangered rosewood

Abstract

Dalbergia is economically essential for its high-quality rosewood wood in fine furniture. Thus, there is a high demand for wood, which has led to illegal logging. Dalbergia calderonii Standl. is associated with tropical deciduous forests, where there is a high rate of deforestation, leading to the decline of the species' natural populations. The knowledge of its potential areas of presence and associated environments can contribute to species conservation. Here, we modeled the potential distribution of D. calderonii and identified areas with remnants. We found that the potential distribution model for D. calderonii predicts two geographically separate areas, one in southern Mexico and the other in northern Central America; thus, we also modeled them as two independent populations and compared their ecological niches. We transferred all models into the Last Interglacial, the Last Glacial Maximum, and the mid-Holocene climatic scenarios to understand the species' recent biogeographic history. We found that 65% of the species' potential distribution comprises sites with sparse vegetation and bare soil; besides, we found no significant differences between the niches of the Mexican and Central American populations. The transferences to the past scenarios showed that the potential history of the species distribution had been characterized by dynamics of expansions and contractions describing commonly geographical isolations but also including stages of continuum distributions. We suggest that future conservation strategies prioritize both populations independently, based on their disjunct distribution.