Drilling down hotspots of intraspecific diversity to bring them into on-ground conservation of threatened species

Abstract

Unprecedented rates of biodiversity loss rise the urgency for preserving species ability to cope with ongoing global changes. An approach in this direction is to target intra-specific hotspots of genetic diversity as conservation priorities. However, these hotspots are often identified by sampling at a spatial resolution too coarse to be useful in practical management of threatened species, hindering the long-appealed dialog between conservation stakeholders and conservation genetic researchers. Here, we investigated the spatial and temporal variation in species presence, genetic diversity, as well as potential risk factors, within a previously identified hotspot of genetic diversity for the endangered Apennine yellow bellied toad Bombina pachypus. Our results show that this hotspot is neither a geographically homogeneous nor a temporally stable unit. Over a time-window spanning 10-40 years since previous assessments, B. pachypus populations declined in large portions of its hotspot, and their genetic diversity levels decreased. Considering the demographic trend, genetic and epidemiological data, and models of current and future climatic suitability, populations at the extreme south of the hotspot area still qualify for urgent in-situ conservation actions, whereas northern populations would be better managed through a mix of in-situ and ex-situ actions. Our results emphasize that identifying hotspot of genetic diversity, albeit essential step, does not suffice to warrant on-ground conservation of threatened species. Hotspots should be analysed at finer geographic and temporal scales, to provide conservation stakeholders with key knowledge to best define conservation priorities, and to optimize resource allocation to alternative management practices.

Reconstructing hotspots of genetic diversity from glacial refugia and subsequent dispersal in Italian common toads (Bufo bufo)

“…However, the spatial distribution of genetic variation within the range of the southern lineage of B. bufo contrasts with that found in other species studied with enough sampling depth, typically comprising finer population structure and multiple population units arranged along the south-north axis 18,20,31,[34][35][36][37][38] . The south of the Italian peninsula has been recurrently identified as a hotspot of intraspecific genetic diversity 14,18,31 . Conversely, neither mtDNA nor microsatellites provided evidence for further population structure within the southern lineage of B. bufo, and, accordingly, the southernmost area of the peninsula is rather a 'cold spot' of genetic diversity for this species (Table 1).…”

“…A major research arena has involved the identification of hotspots of intraspecific genetic diversity, that is, geographic regions harbouring exceptionally high diversity 11 , 12 . These hotspots are increasingly recognised as key targets in conservation biology 11 , 13 , 14 , and their correct identification is an important step in designing effective strategies for the long-term persistence of populations in the face of global change 15 .…”

Shock or jump: deimatic behaviour is repeatable and polymorphic in a yellow-bellied toad

“…We collected adult males from close but distinct ponds to ensure similar environmental conditions and predators, and to avoid collecting related individuals. Also, we selected this population because it has not been affected by either recent and historical decline, and all the individuals can be considered belonging to a unique and panmittic population [29]. Details about the study species, sampling and housing procedures are provided as Supplementary material.…”

Drilling Down Hotspots of Intraspecific Diversity to Bring Them Into On-Ground Conservation of Threatened Species

“…This study was funded by the Italian Ministry of the Environment and Protection of Land and Sea, The Aspromonte National Park, The Italian Ministry of Education, University and Research (PRIN project 2012FRHYRA to DC). This article is published as a preprint in the biorXiv server (Zampiglia et al, 2018).…”