Julia Earl

Louisiana Tech University | Louisiana Tech · Department of Biological Sciences

Vegetation in and around freshwater ecosystems can affect aquatic organisms through production of secondary compounds, which are retained in leaves after senescence and are biologically active. Tannins can be toxic to tadpoles, but in previous studies the plant source of tannins and tannin concentration have been confounded in experimental designs....

Amphibian declines and extinction have been attributed to many causes, including disease such as chytridiomycosis. Other pathogens may also contribute to declines, with ranavirus as the most likely candidate given reoccurring die-offs observed in the wild. We were interested in whether it is possible for ranavirus to cause extinction of a local, cl...

Recently metamorphosed amphibians transport substantial biomass and nutrients from wetlands to terrestrial ecosystems. Previous estimates (except 1) were limited to either a subset of the community or a single year. Our goal was to examine temporal variability in biomass export of all amphibians within breeding ponds and the composition of that exp...

Phenology is a key driver of population and community dynamics. Phenological metrics (e.g., first date that an event occurred) often simplify information from the full phenological distribution, which may undermine efforts to determine the importance of life history events. Data regarding full phenological distributions are especially needed as man...

Animal sociality (i.e., conspecific attraction or avoidance) can influence how animals move (i.e., sinuous to straight) across landscapes. Active subsidies are animal-transported resources (e.g., nutrients, detritus, prey) or consumers (e.g., predators, parasites, pathogens) across ecosystem boundaries and can affect ecosystem function. Animal move...

Phenotypic plasticity in growth and development is commonly examined, but morphology can exhibit plasticity as well. Leg length plasticity is important, because it impacts mobility, which affects predator avoidance, prey capture, and seasonal movements. Differences in relative (i.e., body size adjusted) hind leg lengths > 5% in anurans affect jumpi...

Spatially distributed populations often rely on large‐scale processes for long‐term population stability. These processes are driven by individuals moving across the landscape through long‐distance dispersal movements. However, as landscapes are continually altered by anthropogenic development, increased fragmentation and avoidance behavior can aff...

Active subsidies are animal-transported consumption (e.g., predators, pathogens, parasites) and resources (e.g., prey, detritus, nutrients) moved between ecosystems. Animal movement behavior has the potential to mediate the extent and intensity of active subsidies and corresponding ecosystem responses. Animal movement behaviors could interact with...

Population projection models, such as matrix and integral projection models, are used increasingly to understand potential effects of anthropogenic stressors and inform conservation actions. However, vital rate and life history information needed to create robust population models is often missing or incomplete, making assumptions about parameters...

Ranaviruses began emerging in common frogs (Rana temporaria) in the United Kingdom in the late 1980s and early 1990s, causing severe disease and declines in the populations of these animals. Herein, we explored the transmission dynamics of the ranavirus(es) present in common frog populations, in the context of a simple susceptible-infected (SI) mod...

Ranaviruses began emerging in common frogs (Rana temporaria) in the United Kingdom in the late 1980s and early 1990s, causing severe disease and declines in the populations of these animals. Herein, we explored the transmission dynamics of the ranavirus(es) present in common frog populations, in the context of a simple susceptible-infected (SI) mod...

Many species that inhabit seasonally ponded wetlands also rely on surrounding upland habitats and nearby aquatic ecosystems for resources to support life stages and to maintain viable populations. Understanding biological connectivity among these habitats is critical to ensure that landscapes are protected at appropriate scales to conserve species...

Environmental variation favors the evolution of phenotypic plasticity. For many species, we understand the costs and benefits of different phenotypes, but we lack a broad understanding of how plastic traits evolve across large clades. Using identical experiments conducted across North America, we examined prey responses to predator cues. We quantif...

Many metrics exist for quantifying the relative value of habitats and pathways used by highly mobile species. Properly selecting and applying such metrics requires substantial background in mathematics and understanding the relevant management arena. To address this multidimensional challenge, we demonstrate and compare three measurements of habita...

Variation in movement across time and space fundamentally shapes the abundance and distribution of populations. Although a variety of approaches model structured population dynamics, they are limited to specific types of spatially structured populations and lack a unifying framework. Here, we propose a unified network-based framework sufficiently n...

Forestry practices affect various habitat characteristics that influence wildlife populations. Understanding the relative importance of the broad effects of forestry practices versus specific habitat variables for wildlife may help managers balance multiple forest management objectives and potentially adjust forestry practices to better conserve bi...

1.Connections between ecosystems via animals (active subsidies) support ecosystem services and contribute to numerous ecological effects. Thus, the ability to predict the spatial distribution of active subsidies would be useful for ecology and conservation. 2.Previous work modeling active subsidies focused on implicit space or static distributions,...

Understanding and conserving migratory species requires a method for characterizing the seasonal flow of animals among habitats. Source-sink theory describes the metapopulation dynamics of species by classifying habitats as population sources (i.e. net contributors) or sinks (i.e. net substractors). Migratory species may have non-breeding habitats...

In July 2014, the U.S. Fish and Wildlife Service and National Marine Fisheries Service announced a new policy interpretation for the Endangered Species Act. According to the Act, a species must be listed as threatened or endangered if it is determined to be threatened or endangered in a significant portion of its range. The 1973 law does not define...

To investigate effects of timber harvest on small mammals, we compared capture rates in experimental forestry arrays of uncut forest, partial cut forest, and clearcuts with high and low coarse downed wood in Missouri, USA. Past studies show that effects of timber harvest on small mammals depend on species and forest type. We used an information the...

There is growing evidence that pathogens play a role in population declines and species extinctions. For small populations, disease-induced extinction may be especially probable. We estimated the susceptibility of two amphibian species of conservation concern (the dusky gopher frog [Lithobates sevosus] and boreal toad [Anaxyrus boreas boreas]) to a...

Climate change is expected to affect temperature and precipitation means and extremes, which can affect population vital rates. With the added complexity of accounting for both means and extremes, it is important to understand whether one aspect is sufficient to predict a particular vital rate or if both are necessary. To compare the predictive abi...

AICc tables for the climate model set predicting variability in lesser prairie-chicken vital rates, where K is the number of parameters and N is the sample size (number of estimates). (DOCX)

List of reasons for excluding studies from quantitative synthesis. (DOCX)

PRISMA checklist showing compliance to standards for meta-analysis and quantitative reviews for the quantitative synthesis of lesser prairie-chicken vital rates. (DOC)

AICc tables for the limited model set predicting variability in lesser prairie-chicken vital rates, where K is the number of parameters and N is the sample size (number of estimates). (DOCX)

Data used in quantitative synthesis of lesser prairie-chicken vital rates. (CSV)

PRISMA flow chart showing steps of gathering studies and assessing whether they met inclusion criteria for the quantitative synthesis of lesser prairie-chicken vital rates. (DOCX)

Long-distance movements are important adaptive behaviors that contribute to population, community, and ecosystem connectivity. However, researchers have a poor understanding of the characteristics of long-distance movements for most species. Here, we examined long-distance movements for the lesser prairie-chicken (Tympanuchus pallidicinctus), a spe...

Reaching developmental milestones younger and at larger sizes is commonly claimed to reflect increased fitness. However, the amount of fitness gained from being larger and younger at a milestone may vary with several attributes, particularly evolutionary history, life history, and environmental characteristics. We used a meta-analysis to investigat...

Ranaviruses are pathogens that cause disease in ectothermic vertebrate species, and are responsible for die-off events in multiple taxa across the globe. Understanding the threat of ranavirus in wild and captive populations is a growing conservation and economic interest. Quantifying risk is a central premise to understanding the threat of a pathog...

Phenology often determines the outcome of interspecific interactions, where early-arriving species often dominate interactions over those arriving later. The effects of phenology on species interactions are especially pronounced in aquatic systems, but the evidence is largely derived from experimental studies. We examined whether differences in bre...

Background/Question/Methods Phenotypic plasticity is a ubiquitous phenomenon in nature. Over the past several decades, researchers have provided a tremendous number of insights regarding the ecology and evolution of plasticity of species across a wide range of taxa. However, we know relatively little about how these responses have evolved within...

Spatial subsidies are resources transferred from one ecosystem to another and which can greatly affect recipient systems. Increased subsidy quantity is known to increase these effects, but subsidy quality is likely also important. We examined the effects of leaf litter quality (varying in nutrient and tannin content) in pond mesocosms on gray treef...

In the case of contaminants that are commercially available and introduced by humans, understanding where and how often a product is used is critical in assessing its ecological impact. By contextualizing a product's ecotoxicological impact with details regarding its application, we can provide a more complete characterization of the product's envi...

Many populations are spatially structured with frequent extinction–colonization events. A clear understanding of these processes is necessary for making informed and effective management decisions. Due to the spatially and temporally dynamic nature of many systems, population connectivity and local extinction–colonization processes can be difficult...

Carryover effects occur when experiences early in life affect an individual's performance at a later stage. Many studies have shown carryover effects to be important for future performance. However, it is currently unclear whether variation in later environments could overwhelm factors from an earlier life stage. We were interested in whether simil...

In aquatic systems, light and subsidy input often co-vary along a canopy cover gradient. This creates systems where subsidies are more prevalent in areas with low primary productivity and less prevalent in areas with high primary productivity. We expect ecosystem processes and community structure to respond to these changes in resources. We examine...

Tree species composition can change as a result of succession, climate change, fire suppression, and invasive species. These changes clearly affect forests, but they can also affect aquatic ecosystems based on differences in the input quality of leaf litter, such as plant secondary compounds. These compounds vary in type and concentration depending...

Reciprocal subsidies occur when ecosystems are paired, both importing and exporting resources to each other. The input of subsidies increases reciprocal subsidy export, but it is unclear how this changes with other important factors, such as ambient resources. We provide a conceptual framework for reciprocal subsidies and empirical data testing thi...

1. Previous research shows that canopy-associated shifts from an algal to a detritus-based food web can affect anuran tadpoles negatively. This may not be true of salamander larvae, however, because they are predators. 2. To investigate the influence of canopy cover on the survival and growth of salamanders, and on the subsequent export of biomass...

Background/Question/Methods Spatial subsidies are resources that move from one ecosystem to another. In aquatic systems, canopy cover often determines both light availability (a major determinant of system productivity) and subsidy input in the form of senescing leaves and terrestrial invertebrates. This creates a system where subsidies are more...

Background/Question/Methods There is a pattern between declining amphibian populations and an increase in the use of commercial pesticides. Many studies have looked into the effects of these pesticides, but few have done so in the context of other, natural stressors faced by amphibians. We examine the impact of three commonly used mosquito insect...

Background/Question/Methods Metapopulation theory has commonly been used to address conservation questions, especially in view of increasing loss, alteration, and fragmentation of habitat due to land use change that can jeopardize the persistence of species. Crucial to metapopulation dynamics and species persistence is connectivity among habitat...

Background/Question/Methods Research has shown that metamorphosis is not a new beginning. Stressors in an individual's larval habitat affect their growth, development, and survival post-metamorphosis. However, it is unclear what the relative importance of larval and post-metamorphic stressors are to overall fitness. In order to address this questio...

Background/Question/Methods The presence of different tree species around pond habitats could affect the quality of these habitats for amphibians. Trees can alter water quality as well as light and nutrient availability through canopy cover and the input the leaf litter into the pond. These effects may depend on the composition and diversity of t...

Phosphate pollution is a widespread problem resulting from agricultural runoff and urban wastewater. Phosphates are known to cause eutrophication and algal blooms, but little is known about phosphate toxicity, particularly among amphibians. To investigate possible phosphate toxicity, Hyla chrysoscelis tadpoles were exposed to concentrations ranging...

Background/Question/Methods Forestry practices are implemented worldwide to manage tree populations and harvest resources. Forestry practices involve the thinning and/or intentional planting of trees which influence canopy cover and litter species. Leaf litter from different tree species play a role in pond ecosystems as a source of nutrients, refu...

Most toxicity tests investigate constant concentrations of a chemical. Concentrations of many compounds in the environment are dynamic, however, and individuals may be more sensitive to pulses of a chemical initiated at specific points during development. Realistic toxicity tests are important to accurately assess the toxicity of a compound. Bufo a...