A Case for Using Plethodontid Salamanders for Monitoring Biodiversity and Ecosystem Integrity of North American Forests
TL;DR: The median coefficient of variation indicated that variation in counts of individuals among studies was much lower in plethodontids than in lepidoptera, passerine birds, small mammals, or other amphibians, which means plehodontid salamanders provide an important statistical advantage over other species for monitoring long-term forest health.
Abstract: Terrestrial salamanders of the family Plethodontidae have unique attributes that make them excellent indicators of biodiversity and ecosystem integrity in forested habitats. Their longevity, small territory size, site fidelity, sensitivity to natural and anthropogenic perturbations, tendency to occur in high densities, and low sampling costs mean that counts of plethodontid salamanders provide numerous advantages over counts of other North American forest organisms for indicating environmental change. Furthermore, they are tightly linked physiologically to microclimatic and successional processes that influence the distribution and abundance of numerous other hydrophilic but difficult-to-study forest-dwelling plants and animals. Ecosystem processes such as moisture cycling, food-web dynamics, and succession, with their related structural and microclimatic variability, all affect forest biodiversity and have been shown to affect salamander populations as well. We determined the variability associated with sampling for plethodontid salamanders by estimating the coefficient of variation (CV ) from available time-series data. The median coefficient of variation indicated that variation in counts of individuals among studies was much lower in plethodontids (27%) than in lepidoptera (93%), passerine birds (57%), small mammals (69%), or other amphibians (37–46%), which means plethodontid salamanders provide an important statistical advantage over other species for monitoring long-term forest health.
Resumen: Las salamandras terrestres de la familia Plethodontidae tienen atributos unicos que las hacen excelentes indicadores de la biodiversidad y la integridad del ecosistema en habitats forestales. Su longevidad, sus territorios de tamano pequeno, su fidelidad de sitio, su sensibilidad a las perturbaciones naturales y antropogenicas, su tendencia a ocurrir en densidades altas y los bajos costos de muestreo indican que los conteos de salamandras plethodontidas proveen numerosas ventajas sobre otros organismos de los bosques de Norteamerica para representar cambios ambientales. Ademas, estas salamandras estan estrechamente ligadas fisiologicamente a procesos microclimaticos y sucesionales que influencian las distribuciones y abundancias de otras especies de plantas y animales hidrofilicas que habitan los bosques, pero que son dificiles de estudiar. Los procesos de los ecosistemas tales como el ciclo de humedad, las dinamicas de la red alimenticia y la sucesion, con su variabilidad estructural y microclimatica inherente, afectan la biodiversidad forestal y ha sido demostrado que afectan tambien a las poblaciones de salamandras. Determinamos la variabilidad asociada con el muestreo de salamandras plethodontidas mediante la estimacion del coeficiente de variacion (CV ) a partir de datos accesibles de series de tiempo. La mediana del CV indico que la variacion en los conteos de individuos entre estudios fue mucho menor en plethodontidos (27%) que en lepidopteros (93%), aves paserinas (57%), mamiferos pequenos (69%) y otros anfibios (37–46%), lo cual significa que las salamandras plethodontidas proveen una importante ventaja estadistica sobre las otras especies para el monitoreo a largo plazo de la salud del bosque.
Citations
More filters
TL;DR: Evidence is found that the most global model considered provides a poor fit to the data, hence an overdispersion factor is estimated to adjust model selection procedures and inflate standard errors.
Abstract: Few species are likely to be so evident that they will always be detected at a site when present. Recently a model has been developed that enables estimation of the proportion of area occupied, when the target species is not detected with certainty. Here we apply this modeling approach to data collected on terrestrial salamanders in the Plethodon glutinosus complex in the Great Smoky Mountains National Park, USA, and wish to address the question “how accurately does the fitted model represent the data?” The goodness-of-fit of the model needs to be assessed in order to make accurate inferences. This article presents a method where a simple Pearson chi-square statistic is calculated and a parametric bootstrap procedure is used to determine whether the observed statistic is unusually large. We found evidence that the most global model considered provides a poor fit to the data, hence estimated an overdispersion factor to adjust model selection procedures and inflate standard errors. Two hypothetical datasets with known assumption violations are also analyzed, illustrating that the method may be used to guide researchers to making appropriate inferences. The results of a simulation study are presented to provide a broader view of the methods properties.
715 citations
Cites background from "A Case for Using Plethodontid Salam..."
..., longevity, sensitivity to environmental perturbation) which are believed to make them good indicators of forest biodiversity and integrity (Welsh and Droege 2001)....
[...]
...…salamanders have gained increasing attention in conservation and management arenas because they possess unique attributes (e.g., longevity, sensitivity to environmental perturbation) which are believed to make them good indicators of forest biodiversity and integrity (Welsh and Droege 2001)....
[...]
TL;DR: In this article, the authors analyzed intraand interspecific patterns of mitochondrial variation in two distantly related groups of amphibians, mantellid frogs and salamanders, to determine the promise of DNA barcoding with cytochrome oxidase subunit I (cox1) sequences in this taxon.
Abstract: Amphibians globally are in decline, yet there is still a tremendous amount of unrecognized diversity, calling for an acceleration of taxonomic exploration. This process will be greatly facilitated by a DNA barcoding system; however, the mitochondrial population structure of many amphibian species presents numerous challenges to such a standardized, single locus, approach. Here we analyse intraand interspecific patterns of mitochondrial variation in two distantly related groups of amphibians, mantellid frogs and salamanders, to determine the promise of DNA barcoding with cytochrome oxidase subunit I (cox1) sequences in this taxon. High intraspecific cox1 divergences of 7‐14% were observed (18% in one case) within the whole set of amphibian sequences analysed. These high values are not caused by particularly high substitution rates of this gene but by generally deep mitochondrial divergences within and among amphibian species. Despite these high divergences, cox1 sequences were able to correctly identify species including disparate geographic variants. The main problems with cox1 barcoding of amphibians are (i) the high variability of priming sites that hinder the application of universal primers to all species and (ii) the observed distinct overlap of intraspecific and interspecific divergence values, which implies difficulties in the definition of threshold values to identify candidate species. Common discordances between geographical signatures of mitochondrial and nuclear markers in amphibians indicate that a single-locus approach can be problematic when high accuracy of DNA barcoding is required. We suggest that a number of mitochondrial and nuclear genes may be used as DNA barcoding markers to complement cox1.
493 citations
TL;DR: Salamanders are cryptic and, though largely unrecognized as such, extremely abundant vertebrates in a variety of primarily forest and grassland environments, where they regulate food webs and contribute to ecosystem resilience-resistance (= stability).
Abstract: ▪ Abstract Salamanders are cryptic and, though largely unrecognized as such, extremely abundant vertebrates in a variety of primarily forest and grassland environments, where they regulate food webs and contribute to ecosystem resilience-resistance (= stability) in several ways: (a) As mid-level vertebrate predators, they provide direct and indirect biotic control of species diversity and ecosystem processes along grazer and detritus pathways; (b) via their migrations, they connect energy and matter between aquatic and terrestrial landscapes; (c) through association with underground burrow systems, they contribute to soil dynamics; and (d) they supply high-quality and slowly available stores of energy and nutrients for tertiary consumers throughout ecological succession. Salamanders also can provide an important service to humans through their use as cost-effective and readily quantifiable metrics of ecosystem health and integrity. The diverse ecological roles of salamanders in natural areas underscore th...
391 citations
TL;DR: In this paper, the authors applied a new method to estimate proportion of area occupied using detection/nondetection data from a terrestrial salamander system in Great Smoky Mountains National Park.
Abstract: Recent, worldwide amphibian declines have highlighted a need for more extensive and rigorous monitoring programs to document species occurrence and detect population change. Abundance estimation methods, such as mark–recapture, are often expensive and impractical for large-scale or long-term amphibian monitoring. We apply a new method to estimate proportion of area occupied using detection/nondetection data from a terrestrial salamander system in Great Smoky Mountains National Park. Estimated species-specific detection probabilities were all <1 and varied among seven species and four sampling methods. Time (i.e., sampling occasion) and four large-scale habitat characteristics (previous disturbance history, vegetation type, elevation, and stream presence) were important covariates in estimates of both proportion of area occupied and detection probability. All sampling methods were consistent in their ability to identify important covariates for each salamander species. We believe proportion of area occupie...
375 citations
Cites background from "A Case for Using Plethodontid Salam..."
...Among amphibians, plethodontid salamanders have been promoted as indicators of overall biodiversity and forest ecosystem integrity (Welsh and Droege 2001)....
[...]
TL;DR: Among the populations examined, census declines outnumbered increases yet the average magnitudes for both declines and increases were not demonstrably different, substantiating findings of amphibian decline and giving no support for the idea that amphibian population sizes are dictated by regimes featuring relatively rare years of high recruitment offset by intervening years of gradual decline.
272 citations
Cites background or methods from "A Case for Using Plethodontid Salam..."
...For each time series, I also calculated a coefficient of variation (CV), which is the standard deviation of population size divided by the mean, as used by Marsh and Trenham (2001) and Welsh and Droege (2001)....
[...]
...Terrestrial, direct-developing salamanders, though, may be extremely sedentary and territorial (Mathis, 1989; Thurow, 1976; Welsh and Droege, 2001)....
[...]
References
More filters
01 Jan 1999
TL;DR: In this paper, the authors focus on the biogeograpbic consequences of the creation of habitat islands of different sizes and have provided little of practical value to managers in the field of landscape management.
Abstract: . Abstract Research on fragmented ecosystems has focused mostly on the biogeograpbic consequences of the creation of habitat “islands” of different sizes and has provided little of practical value to managers. However, ecosystem fragmentation causes large changes in the physical environment as well as biogeograpbic changes. Fragmentation generally results in a landscape that consists of remnant areas of native vegetation surrounded by a matrix of agricultural or other developed land. As a result fluxes of radiation, momentum (La, wind), water, and nutrients across the landscape are altered significantly. These in turn can have important influences on biota within remnant areas, especially at or near the edge between the remnant and the surrounding matrix. The isolation of remnant areas by clearing also has important consequences for the biota. These consequences vary with the time since isolation distance from other remnants, and degree of connectivity with other remnants. The influences of physical and biogeographic changes are modified by the size, shape, and position in the landscape of individual remnant, with larger remnants being less adversely affected by the fragmentation process. The Dynamics of remnant areas are predominantly driven by factors arising in the surrounding landscape. Management of, and research on, fragmented ecosystems should be directed at understanding and controlling these external influences as much as at the biota of the remnants themselves. There is a strong need to develop an integrated approach to landscape management that places conservation reserves in the context of the overall landscape
3,869 citations
"A Case for Using Plethodontid Salam..." refers background in this paper
...Most species have distributions that lay between these extremes, so special consideration needs to be given to issues of fragmentation and land management for this group (Saunders et al. 1991; Fahrig & Merriam 1994)....
[...]
TL;DR: In this article, the authors focus on the biogeograpbic consequences of the creation of habitat islands of different sizes and have provided little of practical value to managers in the field of landscape management.
Abstract: . Abstract Research on fragmented ecosystems has focused mostly on the biogeograpbic consequences of the creation of habitat “islands” of different sizes and has provided little of practical value to managers. However, ecosystem fragmentation causes large changes in the physical environment as well as biogeograpbic changes. Fragmentation generally results in a landscape that consists of remnant areas of native vegetation surrounded by a matrix of agricultural or other developed land. As a result fluxes of radiation, momentum (La, wind), water, and nutrients across the landscape are altered significantly. These in turn can have important influences on biota within remnant areas, especially at or near the edge between the remnant and the surrounding matrix. The isolation of remnant areas by clearing also has important consequences for the biota. These consequences vary with the time since isolation distance from other remnants, and degree of connectivity with other remnants. The influences of physical and biogeographic changes are modified by the size, shape, and position in the landscape of individual remnant, with larger remnants being less adversely affected by the fragmentation process. The Dynamics of remnant areas are predominantly driven by factors arising in the surrounding landscape. Management of, and research on, fragmented ecosystems should be directed at understanding and controlling these external influences as much as at the biota of the remnants themselves. There is a strong need to develop an integrated approach to landscape management that places conservation reserves in the context of the overall landscape
3,715 citations
1,729 citations
TL;DR: This list of scientists and lecturers from the United States and Canada who have contributed to the scientific literature over the past 25 years has been compiled.
Abstract: Mary E. Power is a professor in the Department of Integrative Biology, University of California, Berkeley, CA 94720. David Tilman is a professor in the Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55108. James A. Estes is a wildlife biologist in the National Biological Service, Institute of Marine Science, University of California, Santa Cruz, CA 95064. Bruce A. Menge is a professor in the Department of Zoology, Oregon State University, Corvallis, OR 97331. William J. Bond is a professor doctor in the Department of Botany, University of Cape Town, Rondebosch 7700 South Africa. L. Scott Mills is an assistant professor in the Wildlife Biology Program, School of Forestry, University of Montana, Missoula, MT 59812. Gretchen Daily is Bing Interdisciplinary Research Scientist, Department of Biological Science, Stanford University, Stanford, CA 94305. Juan Carlos Castilla is a full professor and marine biology head in Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de Chile, Casilla 114-D, Santiago, Chile. Jane Lubchenco is a distinguished professor in the Department of Zoology, Oregon State University, Corvallis, OR 97331. Robert T. Paine is a professor in the Department of Zoology, NJ-15, University of Washington, Seattle, WA 98195. ? 1996 American Institute of Biological Sciences. A keystone species is
1,724 citations
"A Case for Using Plethodontid Salam..." refers background in this paper
...Of particular interest are species, such as keystone species, whose life histories are tightly intertwined with other small life forms and fine-scale forest ecosystem processes (Power et al. 1996; Simberloff 1998)....
[...]
TL;DR: Assessment of water resource quality by sampling biological communities in the field (ambient biological monitoring) is a promising approach that requires expanded use of ecological expertise and the Index of Biotic Integrity provides a broadly based, multiparameter tool for the assessment of biotic integrity in running waters.
Abstract: Water of sufficient quality and quantity is critical to all life. Increasing human population and growth of technology require human society to devote more and more attention to protection of adequate supplies of water. Although perception of biological degradation stimulated current state and federal legislation on the quality of water resources, that biological focus was lost in the search for easily measured physical and chemical surrogates. The "fishable and swimmable" goal of the Water Pollution Control Act of 1972 (PL 92-500) and its charge to "restore and maintain" biotic integrity illustrate that law's biological underpinning. Further, the need for operational definitions of terms like "biological integrity" and "unreasonable degradation" and for ecologically sound tools to measure divergence from societal goals have increased interest in biological monitoring. Assessment of water resource quality by sampling biological communities in the field (ambient biological monitoring) is a promising approach that requires expanded use of ecological expertise. One such approach, the Index of Biotic Integrity (IBI), provides a broadly based, multiparameter tool for the assessment of biotic integrity in running waters. IBI based on fish community attributes has now been applied widely in North America. The success of IBI has stimulated the development of similar approaches using other aquatic taxa. Expanded use of ecological expertise in ambient biological monitoring is essential to the protection of water resources. Ecologists have the expertise to contribute significantly to those programs.
1,494 citations
"A Case for Using Plethodontid Salam..." refers background in this paper
...…the naturally occurring sets of these species and their respective physical habitats are present and self-replicating within an area, then the components and processes that constitute a functioning ecosystem are present and the biological integrity (Karr 1991) of that ecosystem is being maintained....
[...]