scholarly journals Conservation genetics of yellow-bellied toads (Bombina variegata): a matter of geographical scale and isolation

2020 ◽  
Author(s):  
Alena Marcella Hantzschmann ◽  
Ulrich Sinsch ◽  
Christa Göttlicher ◽  
Heike Pröhl
Keyword(s):  
Genetic Diversity ◽  
Habitat Fragmentation ◽  
Allelic Richness ◽  
Regional Scale ◽  
Local Scale ◽  
The South ◽  
Short Term ◽  
Genetic Structuring ◽  
Continental Scale ◽  
Bombina Variegata

AbstractAmphibian populations world-wide are threatened by declines and extinctions mainly due to habitat loss and fragmentation. Habitat fragmentation threatens the yellow-bellied toad Bombina variegata in the northern and western regions of its distribution where it is strictly protected. We studied the genetic structure and diversity of populations at three geographical scales using microsatellite loci to detect potential threats for population persistence. At the local scale, we sampled four neighbouring localities at 1–2.6 km distance to detect effects of short-term (decades) fragmentation on connectivity. At the regional scale, five additional localities in the mountains of the Westerwald (Rhineland-Palatinate, Germany) were studied at up to 50.1 km distance to analyse genetic diversity and population structure. At the continental scale, we included data from regions in the northern distribution with fragmented populations (Hesse and Lower Saxony, Germany) and more continuous populations in the South (Alsace, France; Geneva, Switzerland; Trentino, Italy) to evaluate variation of genetic diversity. At the local scale, short-term fragmentation caused significant genetic differentiation between breeding assemblages only 1.4 km apart from each other. At the regional scale, we found notable genetic distance among localities. At the continental scale, we identified Alsace, Trentino and Geneva in the South as regions with low genetic structuring and high allelic richness, and the northern remaining regions in Germany as deeply structured with reduced allelic richness. We suggest that reduced genetic diversity and habitat fragmentation in northern regions makes these populations particularly vulnerable to decline. In conclusion, informed conservation management of B. variegata should focus on measures maintaining or improving connectivity among neighbouring populations.

scholarly journals Insight into the Current Genetic Diversity and Population Structure of Domestic Reindeer (Rangifer tarandus) in Russia

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1309
Author(s):  
Veronika Kharzinova ◽  
Arsen Dotsev ◽  
Anastasiya Solovieva ◽  
Olga Sergeeva ◽  
Georgiy Bryzgalov ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Rangifer Tarandus ◽  
Allelic Richness ◽  
Environmental Changes ◽  
Principal Component ◽  
Genetic Structuring ◽  
Habitat Location ◽  
The Republic ◽  
Insight Into

To examine the genetic diversity and population structure of domestic reindeer, using the BovineHD BeadChip, we genotyped reindeer individuals belonging to the Nenets breed of the five main breeding regions, the Even breed of the Republic of Sakha, the Evenk breed of the Krasnoyarsk and Yakutia regions, and the Chukotka breed of the Chukotka region and its within-breed ecotype, namely, the Chukotka–Khargin, which is bred in Yakutia. The Chukotka reindeer was shown to have the lowest genetic diversity in terms of the allelic richness and heterozygosity indicators. The principal component analysis (PCA) results are consistent with the neighbor-net tree topology, dividing the reindeer into groups according to their habitat location and origin of the breed. Admixture analysis indicated a genetic structuring of two groups of Chukotka origin, the Even breed and most of the geographical groups of the Nenets breed, with the exception of the Murmansk reindeer, the gene pool of which was comprised of the Nenets and apparently the native Sami reindeer. The presence of a genetic component of the Nenets breed in some reindeer inhabiting the Krasnoyarsk region was detected. Our results provide a deeper insight into the current intra-breeding reindeer genetic diversity, which is an important requirement for future reindeer herding strategies and for animal adaptation to environmental changes.

scholarly journals Genetic Consequences of Forest Fragmentation in a Widespread Forest Bat (Natalus mexicanus, Chiroptera: Natalidae)

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 140
Author(s):  
Ricardo López-Wilchis ◽  
Aline Méndez-Rodríguez ◽  
Javier Juste ◽  
Alejandra Serrato-Díaz ◽  
Flor Rodríguez-Gómez ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Habitat Fragmentation ◽  
Natural Habitat ◽  
Mitochondrial Control Region ◽  
Genetic Structuring ◽  
Forest Connectivity ◽  
Contemporary Gene Flow ◽  
Multiple Species ◽  
Genetic Structure And Diversity

Recent historical and anthropogenic changes in the landscape causing habitat fragmentation can disrupt the connectivity of wild populations and pose a threat to the genetic diversity of multiple species. This study investigated the effect of habitat fragmentation on the structure and genetic diversity of the Mexican greater funnel-eared bat (Natalus mexicanus) throughout its distribution range in Mexico, whose natural habitat has decreased dramatically in recent years. Genetic structure and diversity were measured using the HVII hypervariable domain of the mitochondrial control region and ten nuclear microsatellite loci, to analyze historical and contemporary information, respectively. The mitochondrial and nuclear results pointed to a differential genetic structuring, derived mainly from philopatry in females. Our results also showed that genetic diversity was historically high and currently moderate; additionally, the contemporary gene flow between the groups observed was null. These findings confirm that the effects of habitat fragmentation have started to be expressed in populations and that forest loss is already building barriers to contemporary gene flow. The concern is that gene flow is a process essential to ensure that the genetic diversity of N. mexicanus populations (and probably of many other forest species) distributed in Mexico is preserved or increased in the long term by maintaining forest connectivity between locations.

scholarly journals Invasive species and postglacial colonization: their effects on the genetic diversity of a Patagonian fish

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182567 ◽  
Author(s):  
Iván Vera-Escalona ◽  
Evelyn Habit ◽  
Daniel E. Ruzzante
Keyword(s):  
Genetic Diversity ◽  
Native Species ◽  
Genetic Parameters ◽  
Allelic Richness ◽  
Short Term ◽  
Historical Processes ◽  
Rivers And Lakes ◽  
Present Distribution

The present distribution of Patagonian species is the result of a complex history involving Quaternary refugial populations, Holocene range expansions and demographic changes occurring during the Anthropocene. Invasive salmonids were introduced in Patagonia during the last century, occupying most rivers and lakes, preying on and competing with native species, including the fishGalaxias platei. Here, we usedG. plateias a case study to understand how long-term (i.e. population differentiation during the Holocene) and short-term historical processes (salmonid introductions) affect genetic diversity. Using a suite of microsatellite markers, we found that the number of alleles is negatively correlated with the presence of salmonids (short-term processes), withG. plateipopulations from lakes with salmonids exhibiting significantly lower genetic diversity than populations from lakes without salmonids. Simulations (100 years backwards) showed that this difference in genetic diversity can be explained by a 99% reduction in population size. Allelic richness and observed heterozygosities were also negatively correlated with the presence of salmonids, but also positively correlated with long-term processes linked to Quaternary glaciations. Our results show how different genetic parameters can help identify processes taking place at different scales and their importance in terms of conservation.

scholarly journals Biogeographical Patterns of Legume-Nodulating Burkholderia spp.: from African Fynbos to Continental Scales

2016 ◽  
Vol 82 (17) ◽  
pp. 5099-5115 ◽  
Author(s):  
Benny Lemaire ◽  
Samson B. M. Chimphango ◽  
Charles Stirton ◽  
Suhail Rafudeen ◽  
Olivier Honnay ◽  
...  
Keyword(s):  
South African ◽  
Spatial Scales ◽  
South American ◽  
The South ◽  
Genetic Structuring ◽  
Content Type ◽  
Nodulation Genes ◽  
Continental Scale ◽  
Specific Distribution ◽  
Distribution Ranges

ABSTRACTRhizobia of the genusBurkholderiahave large-scale distribution ranges and are usually associated with South African papilionoid and South American mimosoid legumes, yet little is known about their genetic structuring at either local or global geographic scales. To understand variation at different spatial scales, from individual legumes in the fynbos (South Africa) to a global context, we analyzed chromosomal (16S rRNA,recA) and symbiosis (nifH,nodA,nodC) gene sequences. We showed that the global diversity of nodulation genes is generally grouped according to the South African papilionoid or South American mimosoid subfamilies, whereas chromosomal sequence data were unrelated to biogeography. While nodulation genes are structured on a continental scale, a geographic or host-specific distribution pattern was not detected in the fynbos region. In host range experiments, symbiotic promiscuity ofBurkholderiatuberumSTM678TandB.phymatumSTM815Twas discovered in selected fynbos species. Finally, a greenhouse experiment was undertaken to assess the ability of mimosoid (Mimosapudica) and papilionoid (Dipogonlignosus,Indigoferafilifolia,Macroptiliumatropurpureum, andPodalyriacalyptrata) species to nodulate in South African (fynbos) and Malawian (savanna) soils. While theBurkholderia-philous fynbos legumes (D.lignosus,I.filifolia, andP.calyptrata) nodulated only in their native soils, the invasive neotropical speciesM.pudicadid not develop nodules in the African soils. The fynbos soil, notably rich inBurkholderia, seems to retain nodulation genes compatible with the local papilionoid legume flora but is incapable of nodulating mimosoid legumes that have their center of diversity in South America.IMPORTANCEThis study is the most comprehensive phylogenetic assessment of root-nodulatingBurkholderiaand investigated biogeographic and host-related patterns of the legume-rhizobial symbiosis in the South African fynbos biome, as well as at global scales, including native species from the South American Caatinga and Cerrado biomes. While a global investigation of the rhizobial diversity revealed distinct nodulation and nitrogen fixation genes among South African and South American legumes, regionally distributed species in the Cape region were unrelated to geographic and host factors.

scholarly journals Inferring the late Quaternary phylogeography of Pseudopanax crassifolius using microsatellite analysis

2021 ◽  
Author(s):  
◽  
Michael Gemmell
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
New Zealand ◽  
Late Quaternary ◽  
Leading Edge ◽  
The South ◽  
Genetic Structuring ◽  
The North ◽  
Chloroplast Haplotypes ◽  
Patterns And Processes

<p>Geologic processes have shaped the New Zealand archipelago throughout its existence. The last major geologic event was the Pleistocene glaciations beginning around 2.5 million years ago. This cold period left its mark in the phylogeography (the geographic distribution of genetic variation) of New Zealand’s globally significant biota. Studies into the phylogeography of New Zealand have largely focused on species with limited distributions through rarity or ecological preferences. This study focuses on the ubiquitous species Pseudopanax crassifolius (Sol. Ex A. Cunn) K. Koch, also known commonly as Horoeka or Lancewood. This species is widespread and almost continuously distributed throughout New Zealand giving a broad scale look at the patterns and processes that have influenced the formation of New Zealand’s natural history.  Seven microsatellite loci and two rps4 chloroplast haplotypes were utilised to study 247 Pseudopanax crassifolius and nine P. chathamicus individuals sampled from populations from around New Zealand. Pseudopanax crassifolius was found to have levels of genetic diversity and overall differentiation consistent with common widespread trees. The genetic structuring suggests P. crassifolius is not a single homogenous population across a southern cluster. The geographic structuring of genetic variation within these clusters is poor.   The genetic patterns and the spatial distribution of these patterns may reflect the response of Pseudopanax crassifolius to changing environmental conditions during the late Quaternary following the maximum extent of the last glacial maximum (LGM) period. During the maximally cold periods of the LGM, P. crassifolius is likely to have been eliminated or at least greatly reduced in the south and west coast of the South Island. In the remainder of the South Island and throughout the North Island it remained widespread. The heterogeneous pattern of genetic variation with little geographic correlation in the northern cluster may reflect either the extent of the historic distribution of the species or the effect of gene flow between populations acting to inhibit population structuring from establishing. The reduction in genetic diversity and the homogeneity of structure in the south indicate a pattern of leading edge re-colonisation into southern areas as conditions became more favourable following the LGM. The leading edge mode is supported by asymmetric introgression of rps4 haplotype seen between P. crassifolius and P. ferox along the east coast of the South Island.  This study also investigated levels of differentiation between Pseudopanax crassifolius and P. chathamicus. There is limited evidence of differentiation based on microsatellite markers. There is therefore no strong genetic evidence for either the support or rejection of the current species delimitation of the crassifolius group of Pseudopanax species. The two species are morphologically different and geographically isolated. This, alongside evidence from previous studies suggest that P. chathamicus is possibly an example of a group undergoing incipient allopatric speciation. A recent founder event is proposed with enough potential diversity carried in two individual fruit to account for the diversity seen in P. chathamicus.</p>

scholarly journals Inferring the late Quaternary phylogeography of Pseudopanax crassifolius using microsatellite analysis

2021 ◽  
Author(s):  
◽  
Michael Gemmell
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
New Zealand ◽  
Late Quaternary ◽  
Leading Edge ◽  
The South ◽  
Genetic Structuring ◽  
The North ◽  
Chloroplast Haplotypes ◽  
Patterns And Processes

<p>Geologic processes have shaped the New Zealand archipelago throughout its existence. The last major geologic event was the Pleistocene glaciations beginning around 2.5 million years ago. This cold period left its mark in the phylogeography (the geographic distribution of genetic variation) of New Zealand’s globally significant biota. Studies into the phylogeography of New Zealand have largely focused on species with limited distributions through rarity or ecological preferences. This study focuses on the ubiquitous species Pseudopanax crassifolius (Sol. Ex A. Cunn) K. Koch, also known commonly as Horoeka or Lancewood. This species is widespread and almost continuously distributed throughout New Zealand giving a broad scale look at the patterns and processes that have influenced the formation of New Zealand’s natural history.  Seven microsatellite loci and two rps4 chloroplast haplotypes were utilised to study 247 Pseudopanax crassifolius and nine P. chathamicus individuals sampled from populations from around New Zealand. Pseudopanax crassifolius was found to have levels of genetic diversity and overall differentiation consistent with common widespread trees. The genetic structuring suggests P. crassifolius is not a single homogenous population across a southern cluster. The geographic structuring of genetic variation within these clusters is poor.   The genetic patterns and the spatial distribution of these patterns may reflect the response of Pseudopanax crassifolius to changing environmental conditions during the late Quaternary following the maximum extent of the last glacial maximum (LGM) period. During the maximally cold periods of the LGM, P. crassifolius is likely to have been eliminated or at least greatly reduced in the south and west coast of the South Island. In the remainder of the South Island and throughout the North Island it remained widespread. The heterogeneous pattern of genetic variation with little geographic correlation in the northern cluster may reflect either the extent of the historic distribution of the species or the effect of gene flow between populations acting to inhibit population structuring from establishing. The reduction in genetic diversity and the homogeneity of structure in the south indicate a pattern of leading edge re-colonisation into southern areas as conditions became more favourable following the LGM. The leading edge mode is supported by asymmetric introgression of rps4 haplotype seen between P. crassifolius and P. ferox along the east coast of the South Island.  This study also investigated levels of differentiation between Pseudopanax crassifolius and P. chathamicus. There is limited evidence of differentiation based on microsatellite markers. There is therefore no strong genetic evidence for either the support or rejection of the current species delimitation of the crassifolius group of Pseudopanax species. The two species are morphologically different and geographically isolated. This, alongside evidence from previous studies suggest that P. chathamicus is possibly an example of a group undergoing incipient allopatric speciation. A recent founder event is proposed with enough potential diversity carried in two individual fruit to account for the diversity seen in P. chathamicus.</p>

Habitat fragmentation causes collapse of kelp recruitment

2020 ◽  
Vol 648 ◽  
pp. 111-123
Author(s):  
C Layton ◽  
MJ Cameron ◽  
M Tatsumi ◽  
V Shelamoff ◽  
JT Wright ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Patch Size ◽  
Life Stage ◽  
Extended Period ◽  
Anthropogenic Disturbances ◽  
Anthropogenic Sources ◽  
Kelp Forests ◽  
Natural Disturbances ◽  
Short Term ◽  
Turf Algae

Kelp forests in many regions are experiencing disturbance from anthropogenic sources such as ocean warming, pollution, and overgrazing. Unlike natural disturbances such as storms, anthropogenic disturbances often manifest as press perturbations that cause persistent alterations to the environment. One consequence is that some kelp forests are becoming increasingly sparse and fragmented. We manipulated patch size of the kelp Ecklonia radiata over 24 mo to simulate persistent habitat fragmentation and assessed how this influenced the demography of macro- and microscopic juvenile kelp within the patches. At the beginning of the experiment, patch formation resulted in short-term increases in E. radiata recruitment in patches <1 m2. However, recruitment collapsed in those same patches over the extended period, with no recruits observed after 15 mo. Experimental transplants of microscopic and macroscopic juvenile sporophytes into the patches failed to identify the life stage impacted by the reductions in patch size, indicating that the effects may be subtle and require extended periods to manifest, and/or that another life stage is responsible. Abiotic measurements within the patches indicated that kelp were less able to engineer the sub-canopy environment in smaller patches. In particular, reduced shading of the sub-canopy in smaller patches was associated with proliferation of sediments and turf algae, which potentially contributed to the collapse of recruitment. We demonstrate the consequences of short- and longer-term degradation of E. radiata habitats and conclude that habitat fragmentation can lead to severe disruptions to kelp demography.

scholarly journals Stand out from the Crowd: Small-Scale Genetic Structuring in the Endemic Sicilian Pond Turtle

Diversity ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 343
Author(s):  
Luca Vecchioni ◽  
Federico Marrone ◽  
Marco Arculeo ◽  
Uwe Fritz ◽  
Melita Vamberger
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Loci ◽  
Small Scale ◽  
Moderate Degree ◽  
Geographical Pattern ◽  
Genetic Structuring ◽  
Pond Turtle ◽  
Emys Trinacris ◽  
Polymorphic Microsatellite ◽  
Entire Distribution

The geographical pattern of genetic diversity was investigated in the endemic Sicilian pond turtle Emys trinacris across its entire distribution range, using 16 microsatellite loci. Overall, 245 specimens of E. trinacris were studied, showing high polymorphic microsatellite loci, with allele numbers ranging from 7 to 30. STRUCTURE and GENELAND analyses showed a noteworthy, geographically based structuring of the studied populations in five well-characterized clusters, supported by a moderate degree of genetic diversity (FST values between 0.075 and 0.160). Possible explanations for the genetic fragmentation observed are provided, where both natural and human-mediated habitat fragmentation of the Sicilian wetlands played a major role in this process. Finally, some conservation and management suggestions aimed at preventing the loss of genetic variability of the species are briefly reported, stressing the importance of considering the five detected clusters as independent Management Units.

scholarly journals Influence of the North Atlantic oscillation on the atmospheric levels of benzo[a]pyrene over Europe

2021 ◽  
Author(s):  
Pedro Jiménez-Guerrero ◽  
Nuno Ratola
Keyword(s):  
Spatial Pattern ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Transport Model ◽  
Regional Scale ◽  
The South ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

AbstractThe atmospheric concentration of persistent organic pollutants (and of polycyclic aromatic hydrocarbons, PAHs, in particular) is closely related to climate change and climatic fluctuations, which are likely to influence contaminant’s transport pathways and transfer processes. Predicting how climate variability alters PAHs concentrations in the atmosphere still poses an exceptional challenge. In this sense, the main objective of this contribution is to assess the relationship between the North Atlantic Oscillation (NAO) index and the mean concentration of benzo[a]pyrene (BaP, the most studied PAH congener) in a domain covering Europe, with an emphasis on the effect of regional-scale processes. A numerical simulation for a present climate period of 30 years was performed using a regional chemistry transport model with a 25 km spatial resolution (horizontal), higher than those commonly applied. The results show an important seasonal behaviour, with a remarkable spatial pattern of difference between the north and the south of the domain. In winter, higher BaP ground levels are found during the NAO+ phase for the Mediterranean basin, while the spatial pattern of this feature (higher BaP levels during NAO+ phases) moves northwards in summer. These results show deviations up to and sometimes over 100% in the BaP mean concentrations, but statistically significant signals (p<0.1) of lower changes (20–40% variations in the signal) are found for the north of the domain in winter and for the south in summer.

scholarly journals Genetic melting pot and importance of long-distance dispersal indicated in the Gladiolus imbricatus L. populations in the Polish Carpathians

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agnieszka Sutkowska ◽  
Józef Mitka ◽  
Tomasz Warzecha ◽  
Jakub Bunk ◽  
Julia Rutkowska ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Diversity Indices ◽  
Western Carpathians ◽  
Genetic Structuring ◽  
Long Distance ◽  
Plant Populations ◽  
Genetic Stock ◽  
Melting Pot ◽  
Mountain Ranges ◽  
Eastern Carpathians

AbstractThe genetic diversity in 11 populations of Gladiolus imbricatus in five mountain ranges, including the Tatra, Pieniny, Gorce, Beskid Niski (Western Carpathians) and Bieszczady Mts (Eastern Carpathians), was studied with inter-simple sequence repeat (ISSR) markers. The species is a perennial plant occurring in open and semi-open sites of anthropogenic origin (meadows and forest margins). We checked a hypothesis on the microrefugial character of the plant populations in the Pieniny Mts, a small calcareous Carpathian range of complicated relief that has never been glaciated. Plant populations in the Tatra and Pieniny Mts had the highest genetic diversity indices, pointing to their long-term persistence. The refugial vs. the non-refugial mountain ranges accounted for a relatively high value of total genetic variation [analysis of molecular variance (AMOVA), 14.12%, p = 0.003]. One of the Pieniny populations was of hybridogenous origin and shared genetic stock with the Tatra population, indicating there is a local genetic melting pot. A weak genetic structuring of populations among particular regions was found (AMOVA, 4.5%, p > 0.05). This could be an effect of the frequent short-distance and sporadic long-distance gene flow. The dispersal of diaspores between the remote populations in the Western Carpathians and Eastern Carpathians could be affected by the historical transportation of flocks of sheep from the Tatra to Bieszczady Mts.

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