Threat patterns for endemic plants of Argentina reveal disparity of vulnerability and protection among spatially associated species groups

Abstract

Given the accelerated rate of environmental degradation and climate change, there is an urgent need to protect biodiversity, especially endemic species with restricted ranges. However, which areas should be prioritized for protection remains a critical issue. A common approach to prioritizing conservation is to rank areas using species-level metrics. Nevertheless, biodiversity and threat patterns can become complex when the amounts of data increase. Here, we analyzed the distribution of 1570 Argentinean endemic plants using clustering of spatially associated species to disentangle distribution and threat patterns. We explored vulnerability levels in each cluster using mean values of species-level metrics of vulnerability, relating values obtained to the regions and environments they occupy. For each cluster we also identified its hotspots and evaluated the effectiveness of the current protected area network for their conservation. Results yielded nine main clusters, mostly differentiated by their geographic distribution and by the ecoregions they occupy. Metrics revealed disparity in vulnerability levels among clusters, with the highest values recorded for clusters related to the Central Puna in northwestern Argentina, to the Espinal, Humid Pampas, and Low Monte in the east of the country, and to the Patagonian steppe in the south. Likewise, coverage by protected areas was low for most hotspots, with the lowest values recorded for the Patagonian cluster. In particular, for hotspot of this cluster, located along the Patagonian steppe in southern Chubut and northeastern Santa Cruz provinces, analyses showed that it has both high levels of vulnerability and low levels of protection, giving it the highest conservation priority of the entire pool analyzed. Our findings identify gaps in the current protected area network and highlight key areas in need of conservation policies and strategies, both in situ and ex situ, to protect the endemic plants of Argentina.