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![Complex life cycle [132] of the Mole Salamander, Ambystoma talpoideum. Black arrows indicate metamorphic pathway; red arrows indicate paedomorphic pathway. Except during breeding periods, metamorphosed adults occur in the terrestrial habitat; all other life stages are aquatic.](publication/262384939/figure/fig1/AS:202999508017152@1425410262191/Complex-life-cycle-132-of-the-Mole-Salamander-Ambystoma-talpoideum-Black-arrows.png)
Complex life cycle [132] of the Mole Salamander, Ambystoma talpoideum. Black arrows indicate metamorphic pathway; red arrows indicate paedomorphic pathway. Except during breeding periods, metamorphosed adults occur in the terrestrial habitat; all other life stages are aquatic.
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![Complex life cycle [132] of the Mole Salamander, Ambystoma talpoideum....](publication/262384939/figure/fig1/AS:202999508017152@1425410262191/Complex-life-cycle-132-of-the-Mole-Salamander-Ambystoma-talpoideum-Black-arrows_Q320.jpg)
The Class Amphibia is one of the most severely impacted taxa in an on-going global biodiversity crisis. Because amphibian reproduction is tightly associated with the presence of water, climatic changes that affect water availability pose a particularly menacing threat to both aquatic and terrestrial-breeding amphibians. We explore the impacts that...
Contexts in source publication
Context 1
... Mole Salamander is typically associated with fishless, seasonal wetlands, although this species has been found naturally-occurring with fish elsewhere on the Atlantic Coastal Plain of the U.S. [126]. Individuals of this species can be facultatively paedomorphic (i.e., become sexually mature in the aquatic environment while retaining larval features; Figure 1) in fish-free ponds with long hydroperiods [126]. Alternatively, aquatic larvae are capable of metamorphosing in 45 months in landscapes with temporary ponds that dry annually [26,106], resulting in populations that consist of predominantly metamorphosed, terrestrial adults (Figure 1). ...Context 2
... of this species can be facultatively paedomorphic (i.e., become sexually mature in the aquatic environment while retaining larval features; Figure 1) in fish-free ponds with long hydroperiods [126]. Alternatively, aquatic larvae are capable of metamorphosing in 45 months in landscapes with temporary ponds that dry annually [26,106], resulting in populations that consist of predominantly metamorphosed, terrestrial adults (Figure 1). Paedomorphic adults (Figure 1) predominate in permanent and semi-permanent ponds, where they can persist 1415 months [127]. ...Context 3
... aquatic larvae are capable of metamorphosing in 45 months in landscapes with temporary ponds that dry annually [26,106], resulting in populations that consist of predominantly metamorphosed, terrestrial adults (Figure 1). Paedomorphic adults (Figure 1) predominate in permanent and semi-permanent ponds, where they can persist 1415 months [127]. Pond drying influences the expression of these alternative life history strategies, although its propensity to do so varies among populations [128]. ...Citations
... Temperature is regarded as a critical factor affecting amphibian abundance and distributions, and it influences a series of physiological processes, including metamorphosis time, growth rates and energy metabolism (Blaustein et al., 2010;Lowe et al., 2021;Mcwhinnie et al., 2021;Whittaker et al., 2007). Given the dependence of amphibians on water for their reproductive processes, lack of rainfall has been associated with reduced calling activity in anurans, failed reproduction and shrinking body size (Pincheira-Donoso et al., 2019;Semlitsch, 1987;Sheridan & Bickford, 2011;Walls et al., 2013). Overall, climate change plays a broad role in amphibian behaviour, morphology and physiology, with temperature primarily influencing phenological changes and precipitation mainly affecting population dynamics (Daszak et al., 2005;Ficetola & Maiorano, 2016). ...
Aim
Genetic diversity driven by natural selection contributes to population divergence in amphibians, thus facilitating local adaptation to climate change. Understanding the mechanisms of genetic adaptation is one of the important issues in evolutionary biology. This study set out to reveal drivers responsible for intraspecific divergence in Fejervarya multistriata and further investigate the potential involvement of selected genes in responding to climate challenges.
Location
China.
Method
To identify adaptive traits associated with climate change, we conducted genome RAD‐seq of 300 F. multistriata individuals from 15 locations across a bio‐geographical range with gradual climatic variation in China.
Results
The results indicate a substantial genetic diversity among populations of F. multistriata and highlight specific genes and pathways that likely contribute to intraspecific divergence. The demographic history of F. multistriata can be traced back to the last interglacial period, during which elevated temperatures may have led to a significant decline in effective population size. The analysis of genome‐climate association identified five candidate genes (BMP2K, NRAP, ZW10, MYH1 and PLB1) potentially involved in local climate adaptation.
Main Conclusions
Our findings have shed light on the genetic mechanisms of local adaptation to climate change in F. multistriata, thereby aiding in determining the possible fate of populations under future climate change.
... The variation of precipitation patterns (e.g. drought) can result in the drying aquatic sites and has been linked to declines in anuran calling activity, reproductive failure, immune-system damage, facilitated disease outbreaks and local extinctions, especially to amphibians that breed in temporary and intermittent streams (Pounds et al., 1999;Ryan et al., 2014;Walls et al., 2013). ...
Aim
We propose a combined approach to explore the model transferability and the effect of climate change on habitat suitability.
Location
Southwest United States.
Taxon
Amphibians; Anura; Bufonidae; Anaxyrus microscaphus.
Methods
To assess the impacts of climate change on A. microscaphus , we obtained 3162 records from the Arizona Game and Fish Department. We classified occurrence records data into six historical groups (from 1960 to 2018) and a contemporary group (from 2019 to 2022). We investigated the ability of historical data to generate accurate predictions of the species' contemporary distribution. We used species distribution modelling to compute habitat suitability values and identified spatial clusters of high suitability values (using hotspot analyses).
Results
We show that historical occurrences successfully predicted the contemporary distribution of A. microscaphus . We demonstrate that the geographical distribution of contemporary hotspots is strongly related to precipitation of the wettest quarter. This research provides evidence that climate change will likely affect the distribution of hotspots and the habitat suitability of A. microscaphus . Losses of 37%–48% contraction are expected at the margins of the range both in the north and south of the geographic limits.
Main Conclusions
We show that recent past data can be used to predict contemporary species distribution accurately. We highlight that habitat suitability values of A. microscaphus are strongly related to climate, topography and distance to streams. This study provides clear evidence of the negative impacts of climate change on habitat suitability in the Southwest United States drylands. Our approach has applied utility to managers to target survey areas, monitor habitat changes, plan for conservation mitigation measures, conserve stream flows across the species' range and inform recovery if needed. Thus, managers could use previously collected data to predict contemporary species distribution when their occurrence accurately characterizes the species' ecological niche.
... Climate change is driving notable shifts in the timing of amphibian migration patterns and breeding activity. Warmer autumn or spring temperatures, for example, have been shown to result in later or earlier breeding migrations and breeding activity (e.g., vocalization, egg deposition, etc.) in a variety of frog, toad, and salamander species (Todd et al. 2011;Walpole et al. 2012;Benard 2014;Green 2017;Homan 2019;Kirk et al. 2019), though not all species or populations follow this trend (Blaustein et al. 2001;Walls et al. 2013;Homan 2019). Even changes in environmental variables outside of the breeding season can still impact amphibian breeding. ...
... Increase in summer temperature could directly affect juvenile dispersal through increased heat stress or threat of desiccation or indirectly through impacts on changes to natal pond hydroperiod (Rowe and Dunson 1995;Brooks 2009;Lesbarrères et al. 2014;Messerman et al. 2022). Drought can also result in severe declines in juvenile recruitment in a given year (Semlitsch et al. 1996;Mullin and Klueh 2009;Van Drunen et al. 2021) and predicted increases in temperature combined with reduced summer precipitation could pose a serious threat to the persistence of populations (Walls et al. 2013;Lesbarrères et al. 2014). Warming temperatures and increased precipitation later in the year may extend the length of time salamanders have to reach overwintering habitat but this could come with energetic costs. ...
Understanding the environmental drivers of species’ dispersal and migration patterns is needed to accurately predict climate change impacts on populations. For pond-breeding amphibians, adult movements associated with the breeding period are well studied but major gaps exist in our knowledge of the drivers of adult and juvenile non-breeding movements. Here, we assess environmental drivers of adult and juvenile Ambystoma maculatum (Shaw, 1802), Ambystoma jeffersonianum (Green, 1827) and their unisexual dependants (Ambystoma laterale – jeffersonianum (Uzzell, 1964)) summer and fall non-breeding movements using data from pitfall trapping and radio telemetry tracking. We used generalized linear models to assess the influence of precipitation, minimum temperature, day-of-year, and days since last precipitation on salamander movements. Juvenile summer dispersal movements were related to days since last precipitation in Jefferson Salamander complex individuals and 24-hr precipitation in Spotted Salamanders. Adult and juvenile fall movements were driven by minimum temperature, 24-hr precipitation, and days since last precipitation, and the effect of these environmental factors varied slightly between species and between Jefferson bisexual and unisexuals. Our work indicates changes in both temperature and precipitation will likely impact non-breeding dispersal and migration in these species and, overall, improves our understanding of ecological patterns throughout their entire life cycle.
... This site was found to be relatively dry, and researchers could not find a stream on this site, and only a few puddles were found along the trails. This condition likely contributes to the scarcity of herpetofauna diversity in the area, especially amphibians, as water availability can influence their reproduction and survival (Walls et al., 2013). In terms of diversity scores, the highest score was detected in O'Kranhak community forest, and this area has more flowing streams and puddles than other sites. ...
Many community forests are located in the area surrounding the Prey Lang Wildlife Sanctuary, which is currently managed by the local communities. Among those, eight community forests in Kampong Thom province have been included in the pilot project of Tumring REDD +. While these areas are likely to support a high diversity of wildlife, a limited amount of wildlife research and monitoring has been conducted for them, especially herpetofauna studies. To support Tumring REDD +-related work, research was conducted to collect information of herpetofauna species in the targeted eight community forests. Opportunistic searches for amphibians and reptiles and pitfall traps, were applied to collect data. Captured species were photographed and released back unharmed. A total of 36 herpetofauna species (16 amphibian and 20 reptile species) were recorded across all survey sites. Most of the recorded species from this survey are listed as of the Least Concern by the IUCN Red List. The most detected amphibian species were Microhyla fissipes and Eutropis macularia reptile species. In terms of diversity scores, the O'Kranhak community forest was identified as the site with the highest diversity for herpetofauna species, and this area was observed to contain more flowing streams and puddles than other studied sites. This good habitat condition supports more species and organisms' ability to keep active even in the dry season. The lowest diversity score was at Prey Ang Taen Forest. This area was observed to be more degraded and isolated from other forest fragments. Illegal logging and wildlife hunting were observed as the main threats to these community forests. Our findings provide a species list of the herpetofauna in these studied community forests useful for supporting the development of long-term biodiversity monitoring and conservation. We recommend conducting further study and restoration of these community forests, preservation of swamps and streams, and tackling illegal logging and wildlife hunting in these areas.
... Species adapted to ephemeral ponds generally exhibit high developmental plasticity in response to drying, allowing them to adjust the moment at which they can leave the aquatic environment (Denver et al., 1998;Merilä et al., 2000;Newman, 1992;Richter-Boix et al., 2011). However, increased evapotranspiration and droughts could induce faster drying of ephemeral ponds, further constraining growth and development in amphibians (Brooks, 2009;Walls et al., 2013). For example, pond drying could lead to smaller body mass at metamorphosis, through developmental acceleration (Richter-Boix et al., 2011), which may ultimately impair fitness in the terrestrial environment (Altwegg & Reyer, 2003;Berven, 1990;Smith, 1987). ...
Pesticides and climate change are both thought to contribute to the global amphibian decline, yet their combined effects are still poorly understood. Metolachlor is a widespread herbicide applied across North America, but little is known about its effects on amphibians. Here, we used a replicated mesocosm experimental design with different levels of drying (i.e., no drying, medium and rapid drying) and metolachlor concentrations (0, 0.8, 8 and 80 µg/L) to assess their respective and combined effects on wood frog (Lithobates sylvaticus) larvae throughout metamorphosis. Metolachlor had no significant effect on survival and development of tadpoles. However, metolachlor significantly interacted with drying levels to reduce growth of tadpoles, which was mainly due to a difference detected among metolachlor concentrations under the rapid drying treatment. Drying also directly reduced growth and body mass at metamorphosis. Our results suggest that environmental stressors, such as drying, should be considered in toxicological experiments to provide relevant exposure conditions to pesticides for ephemeral pond species in the context of global climate change.
... The frequency and severity of droughts will also continue to increase in many regions. Changes in precipitation can have substantial impacts on organismal fitness (Bonebrake & Mastrandrea, 2010;Walls et al., 2013). These impacts include changes to population size (Williams & Middleton, 2008) or offspring growth due to differences in food availability (Groenewoud & Clutton-Brock, 2021) and changes in reproductive phenology driven by water availability (Walls et al., 2013). ...
... Changes in precipitation can have substantial impacts on organismal fitness (Bonebrake & Mastrandrea, 2010;Walls et al., 2013). These impacts include changes to population size (Williams & Middleton, 2008) or offspring growth due to differences in food availability (Groenewoud & Clutton-Brock, 2021) and changes in reproductive phenology driven by water availability (Walls et al., 2013). Similarly, changes in rainfall could affect gut microbial community composition by altering the distribution of microbes in the environment outside the host or by affecting variables like host water intake, diet availability or diet preference (Baniel et al., 2021;Hartmann et al., 2017;Naidoo et al., 2022;Vásquez-Dean et al., 2020). ...
Climate change has rapidly altered many ecosystems, with detrimental effects for biodiversity across the globe. In recent years, it has become increasingly apparent that the microorganisms that live in and on animals can substantially affect host health and physiology, and the structure and function of these microbial communities can be highly sensitive to environmental variables. To date, most studies have focused on the effects of increasing mean temperature on gut microbiota, yet other aspects of climate are also shifting, including temperature variation, seasonal dynamics, precipitation and the frequency of severe weather events. This array of environmental pressures might interact in complex and non-intuitive ways to impact gut microbiota and consequently alter animal fitness. Therefore, understanding the impacts of climate change on animals requires a consideration of multiple types of environmental stressors and their interactive effects on gut microbiota. Here, we present an overview of some of the major findings in research on climatic effects on microbial communities in the animal gut. Although ample evidence has now accumulated that shifts in mean temperature can have important effects on gut microbiota and their hosts, much less work has been conducted on the effects of other climatic variables and their interactions. We provide recommendations for additional research needed to mechanistically link climate change with shifts in animal gut microbiota and host fitness.
... One of the most threatened groups in these ecosystems are amphibians, with at least 40% of their species experiencing worldwide population declines (Bishop et al., 2012;Colomer et al., 2014). Amphibians depend on water quality and availability for their survival and reproduction, which makes them highly sensitive to threats like climate change, metal pollution, stream regulation, and water-associated diseases, among others (Bednarek, 2001;Lessard and Hayes, 2003;Wake, 2007;Walls et al., 2013;Dovick et al., 2020). ...
The Pyrenean Brook Newt, Calotriton asper, is a key component of the ecosystem in Pyrenean headwater streams. We here describe the effects of metal pollution and damming on a newly discovered population of C. asper by assessing differences in population density and body size of subpopulations above and below the dam, using available environmental data to discern their causes. We found a decrease in population density and body size in the upstream subpopulation due to metal pollution. Water diversion by the dam reduced the metal pollution impact downstream. Water flow reduction and warming due to damming are threats to this C. asper population, and the issue is particularly pressing in the Pyrenees due to the expected reduced water availability caused by climate change. We also tested for chytridiomycosis in this population but did not find any infected individuals despite their proximity to an infected population.
... Prior work suggests that marbled salamanders disproportionately affect communities and ecosystems (Urban, 2007(Urban, , 2013Urban & Richardson, 2015), but we do not know what mechanisms determine their occupancy patterns and if they are sensitive to climate change. We focus on the effects of climate on recruitment and overwinter survival, which previous evidence suggests are the most sensitive demographic variables for this species (Gamble et al., 2009;Herstoff & Urban, 2014;Stenhouse, 1987;Walls et al., 2013). ...
... (2) high autumn precipitation and pond filling prior to breeding, requiring adults to lay eggs above normal water levels where inundation cannot reach them and precipitate successful hatching (Gamble et al., 2007;Walls et al., 2013); (3) low survival when ponds freeze solid (Herstoff & Urban, 2014); and (4) winterkill via hypoxia (winterkill hereafter) (Table 1). We define winterkill via hypoxia as a mortality event caused when ice seals pond water from atmospheric oxygen, and decomposition consumes most oxygen, suffocating aquatic life (Greenbank, 1945). ...
Ameliorating the impacts of climate change on communities requires understanding the mechanisms of change and applying them to predict future responses. One way to prioritize efforts is to identify biotic multipliers, which are species that are sensitive to climate change and disproportionately alter communities. We first evaluate the mechanisms underlying the occupancy dynamics of marbled salamanders, a key predator in temporary ponds in the eastern United States We use long‐term data to evaluate four mechanistic hypotheses proposed to explain occupancy patterns, including autumn flooding, overwintering predation, freezing, and winterkill from oxygen depletion. Results suggest that winterkill and fall flooding best explain marbled salamander occupancy patterns. A field introduction experiment supports the importance of winterkill via hypoxia rather than freezing in determining overwinter survival and rejects dispersal limitation as a mechanism preventing establishment. We build climate‐based correlative models that describe salamander occupancy across ponds and years at two latitudinally divergent sites, a southern and middle site, with and without field‐collected habitat characteristics. Correlative models with climate and habitat variation described occupancy patterns better than climate‐only models for each site, but poorly predicted occupancy patterns at the site not used for model development. We next built hybrid mechanistic metapopulation occupancy models that incorporated flooding and winterkill mechanisms. Although hybrid models did not describe observed site‐specific occupancy dynamics better than correlative models, they better predicted the other site's dynamics, revealing a performance trade‐off between model types. Under future climate scenarios, models predict an increased occupancy of marbled salamanders, especially at the middle site, and expansion at a northern site beyond the northern range boundary. Evidence for the climate sensitivity of marbled salamanders combined with their disproportionate ecological impacts suggests that they might act as biotic multipliers of climate change in temporary ponds. More generally, we predict that top aquatic vertebrate predators will expand into temperate‐boreal lakes as climate change reduces winterkill worldwide. Predaceous species with life histories sensitive to winter temperatures provide good candidates for identifying additional biotic multipliers. Building models that include biological mechanisms for key species such as biotic multipliers could better predict broad changes in communities and design effective conservation actions.
... As such, even modest changes in hydroperiod may have important ecological consequences. For instance, increased extinction risk has been demonstrated for a range of species following changes in the regional distribution of wetland habitats with variable hydroperiods (Pinceel et al., 2018;Tuytens et al., 2014;Walls et al., 2013). ...
etlands are among the most threatened ecosystems worldwide due to climate change and land-use conversion.
Regional biodiversity of temporary wetlands is dependent on the existence of habitat complexes with variable
hydroperiods. Because temperature and rainfall regimes are predicted to shift globally, together with land-use
patterns, different scenarios of wetland loss are expected in the future. To understand how wetland biodiver-
sity might change in the future, it is important to evaluate how the loss of particular hydroperiods will affect
overall diversity in a region. Using invertebrate datasets from five wetland complexes distributed across South
and North America, we calculated beta diversity metrics for each region. Then we contrasted those metrics to
simulations of sequential deletions of subsets (30%) of the long-, moderate- and short-hydroperiod wetlands to
assess which wetland class would most affect invertebrate beta diversity in each region. Deletions of the short-
hydroperiod wetlands led to the most significant decline in beta diversity. However, deletion effects of different
wetland classes varied across study regions, with a negative correlation existing between deletions of the long-
and short-hydroperiod wetlands on invertebrate beta diversity. Our simulations indicate that loss of short-
hydroperiod wetlands will have the most significant effects on invertebrate beta diversity, but loss of long-
hydroperiod wetlands will also be important. Thus, wetlands from both hydroperiod extremes should be
considered when assessing potential biodiversity declines associated with habitat loss.
... In the case of mammals, 60% of threatened species are located in hotspots [18], with the highest percentage of declining species concentrated in the Neotropics [19]. For the Neotropics and its diversity, climate change and change use of land are some of the greatest threats [16,20,21], as it influences the occurrence of infectious diseases in various types of the environment [22], as well as the distribution patterns of hosts, and their pathogens and vectors [23][24][25]. ...
Arthropod-borne viruses (arboviruses) are a diverse group of ribonucleic acid (RNA) viruses , with the exception of African swine fever virus, that are transmitted by hematophagous ar-thropods to a vertebrate host. They are the important cause of many diseases due to their ability to spread in different environments and their diversity of vectors. Currently, there is no information on the geographical distribution of the diseases because the routes of transmission and the mammals (wild or domestic) that act as potential hosts are poorly documented or unknown. We conducted a systematic review from 1967 to 2021 to identify the diversity of arboviruses, the areas, and taxonomic groups that have been monitored, the prevalence of positive records, and the associated risk factors. We identified forty-three arboviruses in nine mammalian orders distributed in eleven countries. In Brazil, the order primates harbor the highest number of arbovirus records. The three most recorded arboviruses were Venezuelan equine encephalitis, Saint Louis encephalitis and West Nile virus. Serum is the most used sample to obtain arbovirus records. Deforestation is identified as the main risk factor for arbovirus transmission between different species and environments (an odds ratio of 1.46 with a 95% confidence interval: 1.34-1.59). The results show an increase in the sampling effort over the years in the neotropical region. Despite the importance of arboviruses for public health, little is known about the interaction of arboviruses, their hosts, and vectors, as some countries and mammalian orders have not yet been monitored. Long-term and constant monitoring allows focusing research on the analysis of the interrelationships and characteristics of each component animal, human, and their environment to understand the dynamics of the diseases and guide epidemiological surveillance and vector control programs. The biodiversity of the Neotropics should be considered to support epidemiological monitoring strategies.
