Salamander Abundance Research Articles

Exploratory Survey of Salamanders in Pennsylvanian Forests with Dense Understories of Berberis thunbergii (Japanese Barberry), an Invasive Shrub

We conducted a limited survey to analyze the potential effects of thick understory patches of Berberis thunbergii (Japanese Barberry), an invasive shrub, on forest-dwelling salamanders. Our observational survey of 4 riparian streams was aimed at addressing the hypothesis that Japanese Barberry would negatively affect salamander populations due to detrimental impacts on soil properties and native vegetation. We placed cover boards along the riparian zones of 2 streams that were heavily invaded and 2 that were sporadically invaded by Japanese Barberry in a western Pennsylvanian suburban deciduous forest. The following year, we surveyed each coverboard on 3 occasions to quantify amphibian abundance and diversity. We identified specimens to species whenever possible and quantified Japanese Barberry invasion intensity by estimating aboveground biomass. Results suggest salamander abundance was unaffected by the presence of Japanese Barberry. Species composition differed between invaded and uninvaded habitat, with more Desmognathus spp. salamanders dominating uninvaded sites, though data limitations prevented rigorous comparisons of community-scale differences. Our limited data are unable to determine if Japanese Barberry invasions are associated with indirect effects on salamander populations. However, the lack of any measurable effect on salamander abundance suggests that Japanese Barberry does not induce a strong direct effect on these species.

Influence of prescribed fire and forest structure on woodland salamander abundance in the central Appalachians, USA

Prescribed fire is used in the central Appalachians to promote and maintain mixed-oak and pine forests, create open forest conditions, improve habitat for wildlife, and to reduce the risk of impact of higher intensity wildfires on human development. Few studies have investigated responses of terrestrial salamander populations to habitat management using fire, and estimated responses have been neutral, negative, and positive depending on geography, species, and fire-severity. We examined woodland salamander (genus Plethodon) population responses to habitat management using prescribed fire on Shenandoah Mountain in the George Washington National Forest in West Virginia and Virginia, USA. We focused on responses of the Cow Knob Salamander (P. punctatus), a talus specialist and species of high conservation concern, but also examined responses of the Eastern Red-Backed Salamander (P. cinereus), a widespread habitat generalist. Three burn units were subjected to two low-severity burns and one unit was burned five times with ca. 40% tree mortality. Using a combination of nighttime visual encounter surveys and coverboard surveys, we compared terrestrial salamander abundance and body condition in unburned and burned areas. We also measured habitat characteristics at sampling sites to determine if prescribed burn histories were correlated with habitat conditions important to woodland salamanders. Mean abundance for P. punctatus was lower at sites that were burned, but there was not a strong burn effect for P. cinereus. Abundance of both species was positively correlated with canopy cover. Mean and median body condition index (BCI) score was higher for P. punctatus and lower for P. cinereus on the West Virginia side of Shenandoah Mountain, and lower in burned areas for both species. However, the most parsimonious BCI models did not contain the burn predictor. Management using prescribed fire altered microhabitat conditions that are important for woodland salamanders, such as canopy cover, leaf litter depth, and vegetation groundcover. Our study suggests that woodland salamanders in the central Appalachians can persist in forests managed using prescribed fire, but also indicates that prescribed fire can result in reduced habitat quality for some woodland salamander species.

Two salamander species respond differently to timber harvests in a managed New England forest.

BackgroundManaging forests for timber while protecting wildlife habitat is of increasing concern. Amphibians may be particularly sensitive to forest management practices due to their unique biology; however, it is not clear how different species respond to timber harvest practices—particularly over longer time scales.MethodsHere we report on the differential responses of two salamander species—the eastern red-backed salamander (Plethodon cinereus Green) and the eastern newt (Notophthalmus viridescens Rafinesque)—to forest harvesting, by examining communities across a 25-year chronosequence of regenerating shelterwood harvests.ResultsPopulations of both species were lowest immediately after harvest, but increased at substantially different rates. Red-backed salamander populations were highest in 20–25 year-old shelterwoods—significantly higher than in mature, unharvested, control (100–120 year old) stands. Eastern newt populations, however, were greatest in unharvested control stands and still had not recovered to population levels found in mature stands in the 25 years since harvest. Red-backed salamander abundances were strongly tied to stand age as well as abundance of decayed coarse woody debris, suggesting that timber harvests influence some wildlife species by affecting a suite of interacting habitat variables that change over time. In contrast, newt abundances were not directly related to stand age but were more related to downed wood and vegetation characteristics. Our results highlight markedly variable responses by two common salamander species to forest harvesting—species with markedly different life histories and reproductive patterns—and that time since harvest may be useful in predicting abundance.

Drought impacts to trout and salamanders in cool, forested headwater ecosystems in the western Cascade Mountains, OR

Climate change projections for the western United States suggest that many regions will experience increasing frequency and severity of droughts. In summer 2015, the Pacific Northwest experienced a drought with early onset of stream low flows, reduced summer discharge, and elevated temperatures. We evaluated population responses of two dominant stream predators—coastal cutthroat trout (Oncorhynchus clarkii clarkii) and coastal giant salamander (Dicamptodon tenebrosus)—across nine Cascade Mountain streams. Drought conditions impacted both trout and salamanders, but their responses differed. Adult trout abundance and biomass were significantly lower in 2015 relative to 2014, a year with discharge and temperature closer to historical norms. Juvenile trout abundance did not differ between years but juveniles were significantly larger in 2015. Salamander abundance and biomass were not significantly different between years but body condition was lower in all nine streams in 2015. Differences in temperature among streams did not explain trout or salamander responses. Habitat was important for trout responses with trout abundance and biomass experiencing smaller declines in systems with more deep pool area. Despite notable short-term drought impacts to trout and salamanders in 2015, populations recovered to pre-drought conditions within two years in all but the smallest stream.

Effects of land use legacies and habitat fragmentation on salamander abundance

Landscape modification is an important driver of biodiversity declines, yet we lack insight into how ongoing landscape change and legacies of historical land use together shape biodiversity. We examined how a history of agricultural land use and current forest fragmentation influence the abundance of red-backed salamanders (Plethodon cinereus). We hypothesized that historical agriculture and fragmentation cause changes in habitat quality and landscape structure that limit abundance. We measured salamander abundance at 95 forested sites in New York, USA, and we determined whether sites were agricultural fields within the last five decades. We used a structural equation model to estimate relationships between historical agriculture and salamander abundance mediated by changes in forest vegetation, microclimate, and landscape structure. Historical agriculture affected salamander abundance by altering forest vegetation at a local scale and forest cover at a landscape scale. Abundance was lowest at post-agricultural sites with low woody vegetation, leaf litter depth, and canopy cover. Post-agricultural sites had limited forest cover in the surrounding landscape historically, and salamander abundance was positively related to historical forest cover, suggesting that connectivity to source populations affects colonization of regenerating forests. Abundance was also negatively related to current forest fragmentation. Historical land use can have legacy effects on animal abundance on par with effects of ongoing landscape change. We showed that associations between animal abundance and historical land use can be driven by altered site conditions and surrounding habitat area, indicating that restoration efforts should consider local site conditions and landscape context.

Mountaintop removal mining alters stream salamander population dynamics

AbstractAimPopulation dynamics are often tightly linked to the condition of the landscape. Focusing on a landscape impacted by mountaintop removal coal mining (MTR), we ask the following questions: (1) How does MTR influence vital rates including occupancy, colonization and persistence probabilities, and conditional abundance of stream salamander species and life stages? (2) Do species and life stages respond similar to MTR mining or is there significant variation among species and life stages?LocationFreshwater and terrestrial habitats in Central Appalachia (South‐eastern Kentucky, USA).MethodsWe conducted salamander counts for three consecutive years in 23 headwater stream reaches in forested or previously mined landscapes. We used a hierarchical, N‐mixture model with dynamic occupancy to calculate species‐ and life stage‐specific occupancy, colonization and persistence rates, and abundance given occupancy. We examined the coefficients of the hierarchical priors to determine population variation among species and life stages.ResultsOver 3 years, reference sites had greater salamander abundances and were occupied at a much higher rate than streams impacted by MTR. At sites impacted by MTR mining, most salamander species and life stages exhibited reduced initial occupancy, colonization rates, persistence rates and conditional abundance relative to reference stream reaches. Furthermore, the rates in MTR sites showed low variance, reinforcing that species and life stages were responding similar to MTR.Main conclusionsSalamander populations in landscapes modified by MTR mining exhibited significantly reduced vital rates compared to reference sites. Yet, similarity in responses across species suggests that management or restoration may benefit the entire salamander assemblage. For example, reforestation could reduce landscape resistance, repair altered hydrologic regimes and allow for higher rates of colonization and persistence in streams impacted by MTR.

Risk of survival, establishment and spread of Batrachochytriumsalamandrivorans (Bsal) in the EU.

Batrachochytrium salamandrivorans (Bsal) is an emerging fungal pathogen of salamanders. Despite limited surveillance, Bsal was detected in kept salamanders populations in Belgium, Germany, Spain, the Netherlands and the United Kingdom, and in wild populations in some regions of Belgium, Germany and the Netherlands. According to niche modelling, at least part of the distribution range of every salamander species in Europe overlaps with the climate conditions predicted to be suitable for Bsal. Passive surveillance is considered the most suitable approach for detection of Bsal emergence in wild populations. Demonstration of Bsal absence is considered feasible only in closed populations of kept susceptible species. In the wild, Bsal can spread by both active (e.g. salamanders, anurans) and passive (e.g. birds, water) carriers; it is most likely maintained/spread in infected areas by contacts of salamanders or by interactions with anurans, whereas human activities most likely cause Bsal entry into new areas and populations. In kept amphibians, Bsal contamination via live silent carriers (wild birds and anurans) is considered extremely unlikely. The risk‐mitigation measures that were considered the most feasible and effective: (i) for ensuring safer international or intra‐EU trade of live salamanders, are: ban or restrictions on salamander imports, hygiene procedures and good practice manuals; (ii) for protecting kept salamanders from Bsal, are: identification and treatment of positive collections; (iii) for on‐site protection of wild salamanders, are: preventing translocation of wild amphibians and release/return to the wild of kept/temporarily housed wild salamanders, and setting up contact points/emergency teams for passive surveillance. Combining several risk‐mitigation measures improve the overall effectiveness. It is recommended to: introduce a harmonised protocol for Bsal detection throughout the EU; improve data acquisition on salamander abundance and distribution; enhance passive surveillance activities; increase public and professionals’ awareness; condition any movement of captive salamanders on Bsal known health status.

Comparison of Relative Abundance and Microhabitat of Desmognathus organi (Northern Pygmy Salamander) and Desmognathus wrighti (Southern Pygmy Salamander) in North Carolina

There are currently no quantitative studies describing the habitat of Desmognathus organi (Northern Pygmy Salamander) and D. wrighti (Southern Pygmy Salamander). We investigated the relative abundance and microhabitat selection of Northern Pygmy Salamander and Southern Pygmy Salamander in 3 forest types of different elevations across the mountains of North Carolina during the summer of 2015. We conducted 2-h time-constrained searches at 4 sites in Picea rubens (Red Spruce) —Abies fraseri (Fraser Fir) forests, northern hardwood forests, and mountain cove forests for each species. We quantified microhabitat characteristics at each pygmy salamander location and at a corresponding random location 2–30 m away. We captured a total of 98 pygmy salamanders (D. organi = 41, D. wrighti = 57): 52 in spruce—fir forests, 26 in northern hardwood forests, and 20 in cove forests, and recorded 655 other salamanders representing 15 species. Relative abundance of pygmy salamanders was greater in spruce—fir forests than in cove forests, but was not significantly different between spruce—fir and northern hardwood forests. Microhabitat did not differ between Northern Pygmy Salamander and Southern Pygmy Salamander for any of the variables examined, except for soil moisture, which was greater at Northern Pygmy Salamander locations and may have been a spurious result. We observed pygmy salamanders almost exclusively beneath wood cover-objects, and size of cover objects did not differ from the size available in the surrounding environments. Total area of small-sized down woody debris (DWD) and total area of large-sized DWD were the only variables associated with the presence of pygmy salamanders, suggesting that pygmy salamanders avoid predation and interspecific competition by selecting sites that minimize encounters with larger salamanders.

Behavioral interactions between terrestrial salamanders and spiders: competition or intraguild predation?

Several studies suggest that small terrestrial salamanders are important regulators of leaf litter arthropod communities, and likely contribute to ecosystem processes such as decomposition and nutrient cycling. Despite the recognition that salamanders have the potential to strongly affect ecosystem function through both direct and indirect pathways, little is known regarding the nature of interactions between small vertebrates and the large, predatory arthropods with which they share both microhabitat and prey. Our study was designed to explore interactions between Eastern Red-backed Salamanders, Plethodon cinereus, and spiders in the genus Wadotes in an eastern North American temperate forest ecosystem. We were particularly interested in teasing apart behaviors such as territoriality and intraguild predation in an attempt to determine specifically which interaction is most likely responsible for the observed negative relationship between salamander and spider abundance at our field site. Field data indicate that P. cinereus and large syntopic spiders exhibit negative spatial associations in the microhabitat beneath cover objects, a possible indication of interspecific territoriality. In our laboratory experiments, resident salamanders displayed agonistic postures similarly toward both intruding conspecifics and spiders, suggesting that salamanders may perceive large intruding spiders as competitors. Finally, we observed no injuries to individual P. cinereus or adult spiders even though occasional chases and bites by both were recorded during the behavioral trials. We found no evidence that adults or juveniles of P. cinereus were envenomated by adult Wadotes spp., and there were no instances of intraguild predation in this study. Multiple lines of evidence from this study, and others, suggest that the primary interaction between individuals of P. cinereus and large spiders is competitive in nature rather than predatory. We suggest that the cost associated with intraguild predation on salamanders with noxious skin secretions may preclude them from being preyed upon by spiders.

In-stream habitat predicts salamander occupancy and abundance better than landscape-scale factors within exurban watersheds in a global diversity hotspot

The southern Appalachian Mountains have experienced rapid human population growth rates since the 1980s. Land used practices are shifting from rural to residential. The majority of development has been low density, and is often near biologically diverse areas such as National Forests and National Parks. The long-term effects of urbanization in the southeastern Appalachian Mountains are not clearly understood and even less is known with respect to stream salamander response to urbanization. In order to determine the temporal influence of exurban housing on southern Appalachian streams we sampled 27 first- and second-order streams in watersheds containing exurban developments ranging in age from 4 to 44 years, along with eight forested streams, over the course of two summers. We sought to determine if the relative age of an exurban development related to occupancy and abundance of southern Appalachian stream salamanders. Age of exurban development and other watershed scale variables were not top predictors of salamander assemblages, while local site variables such as salinity and undercut banks predicted the abundance of several species of salamander. Our results suggest local habitat improvements can be used to better conserve salamanders and stream ecosystems in an increasingly urbanized region.

Investigation of environmental disturbances on habitat associated with Plethodon nettingi, Cheat Mountain Salamander.

Habitat fragmentation and disturbances due to anthropogenic activities are some of the most pressing problems in modern conservation biology. Fragmentation is often due to construction of barriers through habitats. Barriers include land development, roads, pipeline and powerline rights-of-way or through destructive energy resource collection such as timber harvest and mining. We investigated the effects of three fragmentation types on environmental conditions and abundance of plethodontid salamanders in temperate upland forest of West Virginia, USA. The study area targeted habitat supporting Plethodon nettingi, Cheat Mountain Salamander, to help determine potential impacts to this federally protected species. The study used five 50m transects of artificial coverboard arrays beginning at the edge of the disturbance and extending into the forest. Arrays were placed every 10m and salamanders and environmental data were collected at each coverboard array. The results of the study showed a positive linear relationship between distance from the habitat edge and abundance of salamander species. In addition, habitat disturbance influenced environmental conditions such as soil moisture and temperature and air temperature. This work was supported by the United States Fish and Wildlife Service.

EFFECT OF RECREATIONAL TRAIL TRAFFIC LEVEL ON EASTERN RED-BACKED SALAMANDER (PLETHODON CINEREUS) RELATIVE ABUNDANCE

The effects of roads and trails on terrestrial salamanders, primarily plethodontids, can be important. The abundance of terrestrial salamanders often increases with distance from roads. Less is known about the effects of recreational or hiking trails on terrestrial salamanders than is known about the effects of roads. We explored how low and high traffic trails in a suburban biological reserve affect the relative abundance of Eastern Red-backed Salamanders (Plethodon cinereus). We found more salamanders under cover objects next to low traffic trails compared to either high traffic trails or wooded areas without trails. At wooded sites, we found only striped morphs whereas at high traffic sites we found only unstriped morphs. Low traffic sites included a range of color morph frequencies. The proportion of females found in each site did not differ, nor did the mean size of the salamanders. Our results suggest that the impact of recreational walking trails needs to be examined more closely to see how and why the distributions of P. cinereus, and potentially other woodland salamanders, are affected and what trail characteristics are important in driving the apparent effects. Such information will contribute to the design and maintenance of walking trails in natural areas that minimize effects on terrestrial salamanders, and likely other organisms.

Antipredator behavior of the Barton Springs salamander (Eurycea sosorum) in response to aquatic invertebrates: potential consequences of habitat restoration

The Barton Springs Salamander, Eurycea sosorum, is a fully aquatic salamander found in Barton Springs in Texas, USA, and has benefited from habitat restoration efforts. While important to improve overall habitat quality for this imperiled species, current management and restoration practices may also inadvertently increase the abundance of non-target organisms such as predatory invertebrates. Fish represent major predators of this species, but little is known about the role of invertebrates as potential predators. It is important to understand the role of these aquatic invertebrates as predators of E. sosorum, especially if habitat restoration also increases predator abundance. Using adult, predator-naive salamanders, we examined the antipredator response of E. sosorum to chemical cues from the following treatments: crayfish, dragonfly larvae, snails, and water. Salamanders decreased activity (antipredator behavior) only in response to the crayfish treatment. The responses to dragonfly larvae, snails, and water did not differ, suggesting that dragonfly larvae are not perceived as predators by these salamanders. Our study provides preliminary evidence suggesting that habitat restoration has unexpectedly increased crayfish abundance, which in turn may negatively affect E. sosorum, and that future management strategies should consider crayfish removal if salamander abundances decline with increasing crayfish abundance.

Linkages between Land Use, Invasive Fishes, and Prairie Pothole Wetland Condition

In the North American Prairie Pothole Region (PPR), agricultural and developed land uses may affect wetland condition by influencing contaminant inputs and invasions by fishes. To improve understanding of human impacts on wetlands, we quantified relationships between land use, physical attributes (herbicides, chloride, turbidity, wetland size), and biological attributes (tiger salamander [Ambystoma tigrinum] abundance; fish, plant, and invertebrate assemblages) of 45 permanently-ponded Iowa wetlands. Wetland area and water-column chloride concentration increased as cropped and developed land-covers increased in the watershed. However, we did not find strong relationships between land-cover type and biological attributes, with the exception of plant cover, which declined as water-column herbicide concentration increased. Fish abundance was an especially important determinant of wetland condition. As fish abundance increased, turbidity increased, and plant cover declined. Tiger salamander abundance and macroinvertebrate taxon richness also declined as fish abundance increased. Our findings suggest that in Iowa PPR wetlands, chloride concentration is an indicator of land-use intensity, and plant abundance can be predicted to some extent by herbicide concentrations. However, wetlands with low macroinvertebrate diversity, plant abundance, and salamander abundance tend to be those with high fish abundance.

English

Large-scale coal mining practices, particularly surface coal extraction and associated valley fills as well as residential wastewater discharge, are of ecological concern for aquatic systems in central Appalachia. Identifying and quantifying alterations to ecosystems along a gradient of spatial scales is a necessary first-step to aid in mitigation of negative consequences to aquatic biota. In central Appalachian headwater streams, apart from fish, salamanders are the most abundant vertebrate predator that provide a significant intermediate trophic role linking aquatic and terrestrial food webs. Stream salamander species are considered to be sensitive to aquatic stressors and environmental alterations, as past research has shown linkages among microhabitat parameters, large-scale land use such as urbanization and logging, and salamander abundances. However, there is little information examining these relationships between environmental conditions and salamander occupancy in the coalfields of central Appalachia. In the summer of 2013, 70 sites (sampled two to three times each) in the southwest Virginia coalfields were visited to collect salamanders and quantify stream and riparian microhabitat parameters. Using an information-theoretic framework, effects of microhabitat and large-scale land use on stream salamander occupancy were compared. The findings indicate that Desmognathus spp. occupancy rates are more correlated to microhabitat parameters such as canopy cover than to large-scale land uses. However, Eurycea spp. occupancy rates had a strong association with large-scale land uses, particularly recent mining and forest cover within the watershed. These findings suggest that protection of riparian habitats is an important consideration for maintaining aquatic systems in central Appalachia. If this is not possible, restoration riparian areas should follow guidelines using quick-growing tree species that are native to Appalachian riparian areas. These types of trees would rapidly establish a canopy cover, stabilize the soil, and impede invasive plant species which would, in turn, provide high-quality refuges for stream salamanders. Key words: Canopy cover, coal mining, Desmognathus, Eurycea, headwater streams, surface mining.

Evaluating the impacts of small impoundments on stream salamanders

Abstract Large dams have been repeatedly implicated in declines of riverine species, but the impacts of small dams are largely understudied. The placement of small dams (< 5 m high) on headwater streams, their density, and lack of regulation suggests that these dams may also have significant adverse impacts on headwater biota. The objective of this study was to determine whether small impoundments affect downstream salamander abundance and water quality. Salamanders were identified and counted from 10 paired catchments draining either a small impoundment (< 0.8 ha) or a free‐flowing stream. A binomial mixture model was used to estimate abundance after accounting for incomplete detection. Estimated abundance of larval Desmognathus conanti, Eurycea wilderae, and Pseudotriton ruber was 3.9, 19.6, and 9.8 times greater downstream of small impoundments than in unaltered streams. Iron concentrations and pH had positive effects on salamander abundance while conductivity was negatively associated with salamander abundance. Increases in abundance may be due to increased hydrologic stability below dams, different geomorphology, and altered water quality. Despite their small size, small impoundments can have localized, downstream effects on water chemistry and species abundance and may create high quality habitat for some stream species in a heterogeneous landscape. Copyright © 2016 John Wiley & Sons, Ltd.

Invasive Asian Earthworms Negatively Impact Keystone Terrestrial Salamanders.

Asian pheretimoid earthworms (e.g. Amynthas and Metaphire spp.) are invading North American forests and consuming the vital detrital layer that forest floor biota [including the keystone species Plethodon cinereus (Eastern Red-backed Salamander)], rely on for protection, food, and habitat. Plethodon cinereus population declines have been associated with leaf litter loss following the invasion of several exotic earthworm species, but there have been few studies on the specific interactions between pheretimoid earthworms and P. cinereus. Since some species of large and active pheretimoids spatially overlap with salamanders beneath natural cover objects and in detritus, they may distinctively compound the negative consequences of earthworm-mediated resource degradation by physically disturbing important salamander activities (foraging, mating, and egg brooding). We predicted that earthworms would exclude salamanders from high quality microhabitat, reduce foraging efficiency, and negatively affect salamander fitness. In laboratory trials, salamanders used lower quality microhabitat and consumed fewer flies in the presence of earthworms. In a natural field experiment, conducted on salamander populations from “non-invaded” and “pheretimoid invaded” sites in Ohio, salamanders and earthworms shared cover objects ~60% less than expected. Earthworm abundance was negatively associated with juvenile and male salamander abundance, but had no relationship with female salamander abundance. There was no effect of pheretimoid invasion on salamander body condition. Juvenile and non-resident male salamanders do not hold stable territories centered beneath cover objects such as rocks or logs, which results in reduced access to prey, greater risk of desiccation, and dispersal pressure. Habitat degradation and physical exclusion of salamanders from cover objects may hinder juvenile and male salamander performance, ultimately reducing recruitment and salamander abundance following Asian earthworm invasion.

Responses of Eastern Red-backed Salamander (Plethodon cinereus) abundance 1 year after application of wood ash in a northern hardwood forest

Wood ash may be an effective soil amendment in North America to restore acidified and low-nutrient forest soils, but little research exists beyond its effects on soil and plants. Eastern Red-backed Salamander (Plethodon cinereus (Green, 1818)) abundance was assessed in a northern hardwood forest 1 year following an ash-addition field trial. Plots were established with fly ash and bottom ash treatments of 0, 1, 4, and 8 Mg·ha−1 (n = 4), and cover boards were positioned both with and without ash beneath. One year following ash additions, salamander abundance had increased under boards with fly ash beneath, and bottom ash had no effect. Soil pH and electrical conductivity increased under cover boards with ash beneath them and for uncovered soil, and the effects were strongest under cover boards with ash beneath. The effects of ash were generally stronger at higher dosages, and fly ash was stronger than bottom ash. The moisture holding capacity of fly ash was 60% higher than the soil and was 63% lower than the soil for bottom ash, but they had little effect on moisture of the forest floor. These results suggest that ash altered salamander abundance via soil pH and moisture and would not inhibit salamander movement over the forest floor.

Effects of mountaintop removal mining and valley filling on the occupancy and abundance of stream salamanders

Summary Human‐induced land‐use changes are among the primary causes of ecosystem degradation and biodiversity loss. Across central Appalachia (USA), mountaintop removal mining and valley filling (MTR/VF) is the prevailing form of land‐use change and represents a stressor to stream ecosystems. Salamanders are the dominant vertebrate in Appalachian headwater streams. Thus, we addressed the question: Is salamander occupancy and conditional abundance reduced in streams impacted by MTR/VF? We conducted repeated counts of adult and larval salamanders within 10‐m reaches in 11 valley‐filled streams and 12 reference streams in south‐eastern Kentucky. Relationships between occupancy, conditional abundance, and site type (MTR/VF vs. reference) were modelled using the hurdle model (Ecology, 94, 2013 and 1472), where occupancy is modelled separately from abundance while accounting for differences in per‐individual detection probabilities among groups. We found mean occupancy probabilities were >0·85 for all groups in reference reaches, whereas mean occupancy probabilities were relatively lower in MTR/VF reaches (ranging from 0·23 to 0·66). Posterior means of the difference in occupancy between site types were negative across all groups, although MTR/VF stream reaches were at least 95% less likely to be occupied by spring salamander Gyrinophilus porphyriticus, adult southern two‐lined salamander Eurycea cirrigera and larval dusky salamanders Desmognathus compared to reference reaches. Posterior means of the difference in conditional abundance between MTR/VF and reference stream reaches were negative across all groups; 95% credible interval for difference in conditional abundance covered zero for only one species (red salamander Pseudotriton ruber). After adjusting for goodness‐of‐fit, point estimates of differences in occupancy and conditional abundance still remained below zero for most species. Additionally, MTR/VF reaches had higher ion concentrations, total organic carbon and specific conductance compared to reference reaches. Synthesis and applications. Our study concludes that mountaintop removal mining and valley filling (MTR/VF) reduces salamander occupancy and conditional abundance. Although the potential mechanisms responsible for reduction are numerous, our findings suggest a change in the current regulatory framework is needed to offset the impacts of MTR/VF on stream ecosystems and biota. Reclamation techniques that enhance conditions for vegetative succession within catchments may improve habitat on reclaimed surface mines.

Effective Use of Trails for Assessing Terrestrial Salamander Abundance and Detection: A Case Study at Great Smoky Mountains National Park

ABSTRACT: The conservation and management of wildlife species is contingent on estimating distribution and abundance. Sampling of wildlife requires repeated visits to accurately determine species occurrence and to quantify abundance across temporal and spatial scales. The use of trails to sample wildlife populations is increasing and offers opportunities to potentially sample more frequently, with increased ease of access, and less disturbance to habitats, which can be important in sensitive natural areas. We examined capture data of terrestrial salamanders within Great Smoky Mountains National Park to determine if detection and abundance estimates from trail and non-trail transects were significantly different. Across two, 3-week periods during June and July 2012, we sampled 195 transects (70 along trails and 125 within non-trail habitat) on multiple occasions. We found that most microhabitat variables associated with salamander detection and abundance did not differ between trail and non-trail transects...