Population ecology and conservation status of Parodia carambeiensis (Cactaceae)

Abstract

Parodia carambeiensis is a rupicolous, small-sized species, with globose cladode and showy flowers, and is the only endemic Cactaceae species in Paraná State (Brazil). Changes in natural landscapes and fragmentation isolate populations, increasing their vulnerability to local extinctions. Our aim was to verify the spatial distribution of P. carambeiensis, reviewing its conservation status and main threats in the distribution area. Expeditions were carried out in the Campos Gerais region to record the abundance, density and spatial distribution of P. carambeiensis populations. Local landscape and climatic variables as well as the joint effect of these with geographical distance, were analyzed. Our findings highlighted that population density differs among the studied sites and was driven by distinct levels of anthropic threats such as livestock, tourism, wildfires and their proximity to highways, along with the climatic variables evaluated (temperature range and precipitation). The models jointly explained 56% of the variation in the population density, which was mostly influence by climatic factors. Parodia carambeiensis is currently classified as (LC) least concern, however, our results provide strong evidence in favor of updating its status to (EN) endangered due to the elevated extinction risk of natural populations.