Browsing by Author "Bacigalupe, Leonardo D."

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Amphibian phylogenetic diversity in the face of future climate change: not so good news for the chilean biodiversity hotspot
    (2022) Rodriguez, Leonardo J.; Barbosa, Olga A.; Soto-Azat, Claudio; Alvarado-Rybak, Mario; Correa, Claudio; Mendez, Marco A.; Moreno-Gomez, Felipe N.; Rabanal, Felipe E.; Vidal, Marcela A.; Velasquez, Nelson A.; Bacigalupe, Leonardo D.
    Climate change is projected to be the most extensive human-induced disturbance to occur on natural ecosystems, inducing changes in different biodiversity features including the evolutionary history of a region through the decline and loss of its phylogenetic diversity. Amphibians, given their ectothermic life cycle and critical conservation status, would potentially be exposed to extinction processes under conditions of climate change, with the corresponding loss of evolutionary history in regions of high biodiversity. This research addresses the effects of climate change on the evolutionary history of amphibians in the Chilean Biodiversity Hotspot, by estimating the PD (Phylogenetic diversity) and PE (Phylogenetic endemism) of 27 species. Using different RCP (RCP 4.5 and 8.5) and time frames (years 2050 and 2070), we create species distribution models (SDM) to evaluate the species range dynamics and the phylodiversity in the Hotspot. Also, given that Protected Areas (PA) are the main global strategy to ensure the conservation of species and their features, we evaluate the capacity of PA to conserve the evolutionary history in the Hotspot. Our results show a set of modeled species that will become extinct, or will experiment changes in their distributional ranges, inducing a clear decline of amphibian evolutionary history for the next 30 to 50 years, and a worrying low capacity of the PA to contain current and future PD and PE. Given the critical amphibian scenario, our results highlight the need for further research to improve the decision-making process in the hotspot area addressing the potential amphibian extinction risk, the lack of protection by the PA system, and the loss of evolutionary history as a key aspect of biodiversity.
  • Thumbnail Image
    Item
    Bioclimatic and anthropogenic variables shape the occurrence of Batrachochytrium dendrobatidis over a large latitudinal gradient
    (NATURE PORTFOLIO, 2021) Alvarado Rybak, Mario; Lepe Lopez, Manuel; Penafiel Ricaurte, Alexandra; Valenzuela Sanchez, Andres; Valdivia, Catalina; Mardones, Fernando O.; Bacigalupe, Leonardo D.; Puschendorf, Robert; Cunningham, Andrew A.; Azat, Claudio
    Amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused the greatest known loss of biodiversity due to an infectious disease. We used Bd infection data from quantitative real-time PCR (qPCR) assays of amphibian skin swabs collected across Chile during 2008-2018 to model Bd occurrence with the aim to determine bioclimatic and anthropogenic variables associated with Bd infection. Also, we used Bd presence/absence records to identify geographical Bd high-risk areas and compare Bd prevalence and infection loads between amphibian families, ecoregions, and host ecology. Data comprised 4155 Bd-specific qPCR assays from 162 locations across a latitudinal gradient of 3700 km (18 degrees to 51 degrees S). Results showed a significant clustering of Bd associated with urban centres and anthropogenically highly disturbed ecosystems in central-south Chile. Both Bd prevalence and Bd infection loads were higher in aquatic than terrestrial amphibian species. Our model indicated positive associations of Bd prevalence with altitude, temperature, precipitation and human-modified landscapes. Also, we found that macroscale drivers, such as land use change and climate, shape the occurrence of Bd at the landscape level. Our study provides with new evidence that can improve the effectiveness of strategies to mitigate biodiversity loss due to amphibian chytridiomycosis.
  • No Thumbnail Available
    Item
    Intra and interspecific variation in thermal performance and critical limits in anurans from southern Chile
    (2024) Vidal, Marcela A.; Rezende, Enrico L.; Bacigalupe, Leonardo D.
    The relationship between temperature and performance can be illustrated through a thermal performance curve (TPC), which has proven useful in describing various aspects of ectotherms' thermal ecology and evolution. The parameters of the TPC can vary geographically due to large-scale variations in environmental conditions. However, only some studies have attempted to quantify how thermal performance varies over relatively small spatial scales, even in the same location or consistently among individuals within a species. Here, we quantified individual and species variation in thermal sensitivity of locomotor performance in five amphibia Eupsophus species found in the temperate rainforests of southern Chile and compared their estimates against co-occurring species that exhibit a substantially more extensive distributional range. We measured critical thermal limits and jumping performance under five different temperatures. Our results suggest that thermal responses are relatively conserved along the phylogeny, as the locomotor performance and thermal windows for activity remained narrow in Eupsophus species when compared against results observed for Batrachyla taeniata and Rhinella spinulosa. Additionally, we found significant individual differences in locomotor performance within most species, with individual consistency in performance observed across varied temperatures. Further analyses explored the influence of body size on locomotor performance and critical thermal limits within and between species. Our results suggest a trade-off scenario between thermal tolerance breadth and locomotor performance, where species exhibiting broader thermal ranges might have compromised performance. Interestingly, these traits seem partly mediated by body size variations, raising questions about potential ecological implications.