Determination of priority areas for amphibian conservation in Guerrero (Mexico), through systematic conservation planning tools

Conservation of more evolutionary unique amphibian communities in Türkiye: The role of protected areas

The alarming decline of amphibians, sometimes marked by sudden extinctions, underlines the urgent need for increased conservation efforts. Conservationists recognize that more action, particularly the setting of national targets, is needed to ensure the future persistence and recovery of species and habitats. Protecting habitats that harbor evolutionarily diverse species preserves divergent genetic information within ecosystems. Türkiye holds 36 amphibian species at the intersection of two continents, creating three biodiversity hotspots and phylogenetic transitional areas. In this study, we aimed to determine the hotspot regions and to evaluate the effectiveness of the protected areas in Türkiye in preserving amphibian populations. First, we estimated four community indexes (species richness and three evolutionary distinctiveness measures) for amphibian communities in Türkiye divided into 371 grid cells with a ca 50 × 50 km size. Then, the spatial extent of protected areas is evaluated from two perspectives: current (has a protection status) and candidate protected areas (Key Biodiversity Areas, not protected) coverage in those grid cells. Finally, these two approaches' effectiveness in protecting areas was assessed by modeling four diversity metrics using GLS models. Current protected areas protect about 6% of the total amphibian distribution in Türkiye, while Key Biodiversity Areas would cover 30% if declared protected areas. We estimated that the coastal areas of Türkiye are identified as hotspots based on the four measured amphibian community indexes. Our study also highlights that Key Biodiversity Areas (KBAs) can contribute to conserving high levels of amphibian richness and evolutionary distinctiveness of species across Türkiye. However, existing protected areas (PAs) networks were insufficient to protect amphibians.

Modelling the effects of climate and land-cover changes on the potential distribution and landscape connectivity of three earth snakes (Genus Conopsis, Günther 1858) in central Mexico

Anthropogenic land use and climate change are the greatest threats to biodiversity, especially for many globally endangered reptile species. Earth snakes (Conopsis spp.) are a poorly studied group endemic to Mexico. They have limited dispersal abilities and specialized niches, making them particularly vulnerable to anthropogenic threats. Species distribution models (SDMs) were used to assess how future climate and land-cover change scenarios might influence the distribution and habitat connectivity of three earth snakes: Conopsis biserialis (Taylor and Smith), C. lineata (Kennicott), and C. nasus (Günther). Two climate models, CNRM-CM5 (CN) and MPI-ESM-LR (MP) (Representative Concentration Pathway 85), were explored with ENMeval Maxent modelling. Important SDM environmental variables and environmental niche overlap between species were also examined. We found that C. biserialis and C. lineata were restricted by maximum temperatures whereas C. nasus was restricted by minimum ones and was more tolerant to arid vegetation. C. biserialis and C. lineata were primarily distributed in the valleys and mountains of the highlands of the TMBV, while C. nasus was mainly distributed in the Altiplano Sur (Zacatecano-Potosino). C. lineata had the smallest potential distribution and suffered the greatest contraction in the future whereas C. nasus was the least affected species in future scenarios. The Sierra de las Cruces and the Sierra Chichinautzin were identified as very important areas for connectivity. Our results suggest that C. lineata may be the most vulnerable of the three species to anthropogenic and climate changes whereas C. nasus seems to be less affected by global warming than the other species.

Potential Distribution and Connectivity for Two Plethodontid Salamanders: Conservation Areas and Landscape Corridors for Two Endemic Species of México and Guatemala

Habitat loss is one of the most important threats to biodiversity; it alters the habitat connectivity of species and is among the main causes of the global amphibian extinction crisis. Identifying the potential areas of distribution and connectivity of species is of the utmost importance so that informed decisions can be made for the conservation of vulnerable amphibian populations. In this study, we performed species distribution models and used circuit theory to model omnidirectional connectivity for two plethodontid salamanders of conservation concern distributed in the forests of Chiapas, Mexico, and Guatemala (Bolitoglossa franklini and Bolitoglossa lincolni). Potential distribution maps show an affinity for well-preserved montane forests for both species. Likewise, we found that the niches of the species are not similar. The connectivity models show that the main areas of connectivity are in the Meseta Central de Chiapas, Sierra Madre de Chiapas, and the Cordillera Volcánica Guatemalense, in this last range, important areas of connectivity were located, as well as least-cost paths and barriers to the movement of both species. We identified that important areas of climatic suitability and connectivity are not within the protected natural areas and may be threatened by the increasing influence of anthropogenic activities. The results of our study show the importance of preserving the regional forests to ensure the persistence of species with arboreal habits and high sensitivity to habitat transformation, as well as to recognize and prioritize potential areas for management and protection in both southern Mexico and Guatemala.