Biology subjects

Ficetola, G. F.

Publications and source records attributed to Ficetola, G. F..

5 recordsLinked to original sources

bioRxiv2024

Keeping common species common: the role of future climate refugee in species conservation

Climate change is one of the most important challenges for biodiversity conservation. Species may respond to changing climates by moving, adapting, and/or adjusting. The move response is the easiest and quickest as it does not imply any evolutionary and/or physiological response. However, moving in space to track changing climate is not an option for species with restricted movement capacities (e.g., many amphibians) or species endemic to islands. Therefore, the impact of climate change on these species is potentially dramatic, even when they are currently widespread and least concern. Planning for the conservation of these species in a global change context requires a proactive approach, with the identification of climatic refugia, i.e., areas climatically suitable for a given species under both current climate and future scenarios. Here, we demonstrated our approach considering the Hyla sarda, an amphibian endemic of the islands of Sardinia and Corsica, currently widespread in its range, and Least Concern according to the IUCN Red List. We calibrated an SDM for the species focusing on Sardinia and projected it into the future, identifying all areas that can act as future climatic refugia. We also evaluated the coverage of the refugia by the existing protected areas. According to our results, Hyla sarda will experience a significant restriction of its distribution range due to projected climate changes, with small and highly fragmented climatic refugia mostly located outside of existing protected areas. Our findings highlight the importance of considering common species in global change studies. All our conservation strategies should be more proactive if we want to conserve common species before they become rare.

ecology↗

bioRxiv2024

Generation length of the world's amphibians and reptiles

Variation in life histories influences demographic processes from adaptive changes to population declines leading to extinction. Among life history traits, generation length offers a critical feature to forecast species demographic trajectories such as population declines (widely used by the IUCN Red List of Threatened Species) and adaptability to environmental change over time. Therefore, estimates of generation length are crucial to monitor demographic stability or future change in highly threatened organisms, particularly ectothermic tetrapods (amphibians and reptiles) - which rank among the most threatened groups - but for which uncertainty in future impacts remains high. Despite its importance, generation length for amphibians and reptiles is largely missing. Here, we aimed to fill-in this gap by modeling generation lengths for amphibians, squamates and testudines as a function of species size, climate, life history, and phylogeny using generalized additive models and phylogenetic generalized least squares. We obtained estimates of generation lengths for 4,543 (52%) amphibians, 8,464 (72%) squamates and 118 (32%) testudines. Our models performed well for most families, for example Bufonidae in amphibians, Lacertidae and Colubridae in squamates and Geoemydidae in testudines, while we found high uncertainty around the prediction of a few families, notably Chamaeleonidae. Species body size and mean temperature were the main predictors of generation length in all groups. Although our estimates are not meant to substitute robust and validated measurements from field studies or natural history museums, they can help reduce existing biases in conservation assessments until field data will be comprehensively available.

zoology↗

bioRxiv2024

Does hybridisation with an invasive species threaten Europe's most endangered reptile? Genomic assessment of Aeolian lizards on Vulcano island

Interspecific hybridisation can be consequential for rare and insular endemic species. The Critically Endangered Aeolian wall lizard, Podarcis raffonei, severely declined due to interactions with the invasive Italian wall lizard, Podarcis siculus. The largest population of P. raffonei survives on a narrow peninsula (Capo Grosso) that is mildly connected to the island of Vulcano, which has been entirely invaded by P. siculus. Recent observation of individuals with an intermediate phenotype raised concern over the risk that hybridisation might swamp this last stronghold. We genetically characterised lizards from Vulcano using genome-wide SNPs, considering individuals showing multiple phenotypes (native, invasive, and "intermediate"). Hybridisation rate was low ([~]3%), with just two F1 hybrids and two backcrosses. However, pure P. raffonei showed extremely low genetic diversity, a very small effective population size, and a low NE/NC ratio. Management strategies are urgently needed to control invasive species and maintain the genetic diversity of P. raffonei.

evolutionary biology↗

bioRxiv2023

In silico assessment of 18S rDNA metabarcoding markers for the characterization of nematode communities

Nematodes are keystone actors of soil, freshwater and marine ecosystems, but the complexity of morphological identification has limited broad-scale monitoring of their biodiversity. DNA metabarcoding is increasingly used to assess nematode biodiversity but requires universal primers with high taxonomic coverage and high taxonomic resolution. Several primers have been proposed for the metabarcoding of nematode diversity, many of which target the 18S rRNA gene. In-silico analyses have a great potential to assess key parameters of primers, including their taxonomic coverage, resolution and specificity. Based on a recently-available reference database, we tested in-silico the performance of fourteen commonly used and one newly optimized primer for nematode metabarcoding. Most primers showed very good coverage, as amplified most of sequences in the reference database, while four markers showed limited coverage. All primers showed good taxonomic resolution. Resolution was particularly good if the aim was the identification of higher-level taxa, such as genera or families. Overall, species-level resolution was higher for primers amplifying long fragments. None of the primers was highly specific for nematodes as, despite some variation, they all amplified a large number of other eukaryotes. Differences in performance across primers highlight the complexity of the choice of markers appropriate for the metabarcoding of nematodes, which depends on a trade-off between taxonomic resolution and the length of amplified fragments. Our in-silico analyses provide new insights for the identification of most appropriate primers, depending on the study goals and the origin of DNA samples. This represents an essential step to design and optimize metabarcoding studies assessing nematode diversity.

zoology↗

bioRxiv2023

An automated approach for systematic detection of Key Biodiversity Areas

The new Key Biodiversity Areas (KBA) standard is an important method for identifying regions of the planet hosting unique biodiversity. KBAs are identified through the implementation of threshold-based criteria that can be applied to any target species and region. Efficient methods to rapidly assess the existence of potential KBAs in different areas of the planet are still missing, although they are needed to accelerate the KBA identification process for large numbers of species globally. We developed a methodology to scan geographical regions and detect potential KBAs under multiple criteria. We tested the methodology on 59 species of reptiles and amphibians in Italy through the application of selected KBA criteria. Potential KBAs were identified for multiple species under most criteria, covering 1.4% to 12% of the study area, depending on analytical settings. Unit size used to identify KBAs played an important role in shaping the distribution of potential KBAs, also affecting the degree of overlap between areas triggered by different criteria. New potential KBAs identified in this study are only partially nested within current KBAs in Italy (previously identified for birds) and within the national protected areas.

ecology↗