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Understanding The Impacts Of Current And Future Environmental Variation On Central African Amphibian Biodiversity, Courtney A. Miller

University of New Orleans Theses and Dissertations

Global climate change is projected to impact multiple levels of biodiversity by imposing strong selection pressures on existing populations, triggering shifts in species distributions, and reorganizing entire communities. The Lower Guineo-Congolian region in central Africa, a reservoir for amphibian diversity, is predicted to be severely affected by future climate change through rising temperatures and greater variability in rainfall. Geospatial modelling can be used to assess how environmental variation shapes patterns of biological variation – from the genomic to the community level – and use these associations to predict patterns of biological change across space and time. The overall goal of …

Multiple Environmental Stressors Induce Complex Transcriptomic Responses Indicative Of Phenotypic Outcomes In Western Fence Lizard, Kurt A. Gust, Vijender Chaitankar, Preetam Ghosh, Mitchell S. Wilbanks, Xianfeng Chen, Natalie D. Barker, Don Pham, Leona D. Scanlan, Arun Rawat, Larry G. Talent, Michael J. Quinn Jr., Christopher D. Vulpe, Mohamed O. Elasri, Mark S. Johnson, Edward J. Perkins, Craig A. Mcfarland

Faculty Publications

Background

The health and resilience of species in natural environments is increasingly challenged by complex anthropogenic stressor combinations including climate change, habitat encroachment, and chemical contamination. To better understand impacts of these stressors we examined the individual- and combined-stressor impacts of malaria infection, food limitation, and 2,4,6-trinitrotoluene (TNT) exposures on gene expression in livers of Western fence lizards (WFL, Sceloporus occidentalis) using custom WFL transcriptome-based microarrays.

Results

Computational analysis including annotation enrichment and correlation analysis identified putative functional mechanisms linking transcript expression and toxicological phenotypes. TNT exposure increased transcript expression for genes involved in erythropoiesis, potentially in response to …

High-Frequency Temperature Variability Mirrors Fixed Differences In Thermal Limits Of The Massive Coral Porites Lobata, Daniel J. Barshis, Charles Birkeland, Robert J. Toonen, Ruth D. Gates, Jonathon H. Stillman

Biological Sciences Faculty Publications

Spatial heterogeneity in environmental characteristics can drive adaptive differentiation when contrasting environments exert divergent selection pressures. This environmental and genetic heterogeneity can substantially influence population and community resilience to disturbance events. Here, we investigated corals from the highly variable back-reef habitats of Ofu Island in American Samoa that thrive in thermal conditions known to elicit widespread bleaching and mortality elsewhere. To investigate the relative importance of acclimation versus site of origin in shaping previously observed differences in coral tolerance limits at Ofu Island, specimens of the common Indo-Pacific coral Porites lobata from locations with differing levels of thermal variability were …

Phenological Responses Of 215 Mothspecies To Interannual Climate Variation In The Pacific Northwest From 1895 Through 2013, Julie A. Maurer, Jon H. Shepard, Lars G. Crabo, Paul C. Hammond, Richard S. Zack, Merrill A. Peterson

Biology Faculty and Staff Publications

Climate change has caused shifts in the phenology and distributions of many species but comparing responses across species is challenged by inconsistencies in the methodology and taxonomic and temporal scope of individual studies. Natural history collections offer a rich source of data for examining phenological shifts for a large number of species. We paired specimen records from Pacific Northwest insect collections to climate data to analyze the responses of 215 moth species to interannual climate variation over a period of 119 years (1895–2013) during which average annual temperatures have increased in the region. We quantified the effects of late winter/early …

Coastal Wetland Dynamics Under Sea-Level Rise And Wetland Restoration In The Northern Gulf Of Mexico Using Bayesian Multilevel Models And A Web Tool, Tyler Hardy

Master's Theses

There is currently a lack of modeling framework to predict how relative sea-level rise (SLR), combined with restoration activities, affects landscapes of coastal wetlands with uncertainties accounted for at the entire northern Gulf of Mexico (NGOM). I developed such a modeling framework – Bayesian multi-level models to study the spatial pattern of wetland loss in the NGOM, driven by relative RSLR, vegetation productivity, tidal range, coastal slope, and wave height – all interacting with river-borne sediment availability, indicated by hydrological regimes. These interactions have not been comprehensively investigated before. I further modified this model to assess the efficacy of restoration …

Spatial Distribution And Stock-Recruitment Analysis Of The Atlantic Surfclam, Spisula Solidissima, In The Mid-Atlantic Bight And On Georges Bank, Jeremy Timbs

Master's Theses

Atlantic surfclams, Spisula solidissima, are long-lived bivalve molluscs with dispersive larval stages. Surfclam patchiness throughout the U.S. Exclusive Economic Zone (EEZ) has declined from the 1980’s to the present in all assessed regions (Delmarva, New Jersey, Long Island, Southern New England, and Georges Banks). Warming of Mid-Atlantic bottom waters is driving the surfclam stock into new habitat and extirpating the surfclams from nearshore areas. Based on a species distribution function model, the small surfclams appear to inhabit a greater area than the large market-size surfclams across the entire stock. The wider distribution of recent recruits relative to the fishable …

Quaternary Climate Instability Is Correlated With Patterns Of Population Genetic Variability In Bombus Huntii, Jonathan B. Koch, Rémy Vandame, Jorge Mérida-Rivas, Philippe Sagot, James Strange

All PIRU Publications

Climate oscillations have left a significant impact on the patterns of genetic diversity observed in numerous taxa. In this study, we examine the effect of Quaternary climate instability on population genetic variability of a bumble bee pollinator species, Bombus huntii in western North America. Pleistocene and contemporary B. huntii habitat suitability (HS) was estimated with an environmental niche model (ENM) by associating 1,035 locality records with 10 bioclimatic variables. To estimate genetic variability, we genotyped 380 individuals from 33 localities at 13 microsatellite loci. Bayesian inference was used to examine population structure with and without a priori specification of geographic …

Direct And Indirect Controls On Bee Community Composition, Caroline Marie Devan

Dissertations

Bees are important pollinators, critical for the continued survival of plants in both natural and agricultural ecosystems. Diverse bee communities have been shown to increase richness in plant communities and plant reproduction depends upon bee community richness. Yet there is growing concern that pollinators, especially bees, are declining globally. This dissertation focuses on evaluating the mechanisms responsible for bee community composition in order to promote bee conservation in natural systems and their restoration in human-dominated urban and agricultural landscapes.

Bee populations are impacted directly by three things: floral resources, nesting resources and risk, primarily from natural enemies. Bees are indirectly …

Linking Climate Change And Mortality In Piñon-Juniper Woodlands, From Leaf To Ecosystem, Amanda I. Liebrecht

Biology ETDs

As global climate changes, the Southwestern US is predicted to experience more frequent and intense drought events. Extreme droughts can drive decreases in both physiological and ecosystem function, and can result in widespread tree mortality. Piñon-juniper (PJ) woodlands are a prevalent ecosystem in the region, co-dominated by two tree species, piñon (Pinus edulis) and juniper (Juniperus monosperma). Drought-induced piñon mortality has occurred over the past few decades, coinciding with outbreaks of a piñon-specific bark beetle. Piñon and juniper have different hydraulic strategies (isohydry and anisohydry, respectively) that should affect the way each species responds to drought. …

Phenology Of A Southern Population Of Mountain Pine Beetle (Dendroctonus Ponderosae), Anne Elise Mcmanis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mountain pine beetle (Dendroctonus ponderosae, Hopkins) is a major disturbance agent in pine ecosystems of western North America. Adaptation to local climates has resulted in primarily univoltine (one generation per year) generation timing across a thermally diverse latitudinal gradient. We hypothesized that this pattern in total development time is shaped by selection for slower developmental rates, altered developmental thresholds, or oviposition rates in southern populations inhabiting warmer climates. To investigate traits responsible for latitudinal differences we measured lifestage-specific development of southern mountain pine beetle eggs, larvae and pupae across a range of temperatures. We also describe and model …

2018 3rd Place: The Growth And Characterization Of Psychromonas Aquimarina, A New Model Organism For Climate Change, Carrie Carpenter, Catherine Santai

Harrisburg University Research Symposium (2018 & 2019)

Climate change is currently affecting the Earth and will only increase with time1. A change to the environment means that wildlife will need to adapt. Adaptation occurs when an organism changes physiologically or otherwise to permit continued growth in the environment in which it resides. Scientists do not completely understand adaptation mechanisms. Psychromonas aquimarinais a novel bacterium, with little known. This bacteria will first be characterized and studied before conducting temperature studies. Psychromonas aquimarina is a psychrophile, a bacterium able to survive in colder regions where most bacteria would not. P. aquimarinais an ideal bacterium to study because climate change …

Landscape-Scale Effects Of Supra-Seasonal Drought On Semi-Aquatic Snake Assemblages, Philip N. Vogrinc, Andrew M. Durso, Christopher T. Winne, John D. Willson

Biology Faculty Publications

Climate change is predicted to alter the frequency and intensity of precipitation events, placing stress on freshwater aquatic ecosystems and their associated wildlife. Thus, understanding interspecific variation in drought sensitivity and the repeatability of those responses across heterogeneous landscapes is critical. Semi-aquatic snakes serve important roles within aquatic ecosystems and several species are threatened. Yet, little is known about the effects of drought on semi-aquatic snake populations or assemblages. We systematically trapped 20 isolated wetlands in South Carolina before (2006) and after (2013) a multi-year supra-seasonal drought to determine drought-induced shifts in occupancy and detection for five semi-aquatic snake species. …

Changes In Feeding Selectivity Of Freshwater Invertebrates Across A Natural Thermal Gradient, Timothy A C Gordon, Joana Neto-Cerejeira, Paula C. Furey, Eoin J. O’Gorman

Paula Furey

No abstract provided.

The Ecology And Economics Of Restoration: When, What, Where, And How To Restore Ecosystems, Jason R. Rohr, Emily S. Bernhardt, Marc W. Cadotte, William H. Clements

Integrative Biology Faculty and Staff Publications

Restoration ecology has provided a suite of tools for accelerating the recovery of ecosystems damaged by drivers of global change. We review both the ecological and economic concepts developed in restoration ecology, and offer guidance on when, what, where, and how to restore ecosystems. For when to restore, we highlight the value of pursuing restoration early to prevent ecosystems from crossing tipping points and evaluating whether unassisted natural recovery is more cost-effective than active restoration. For what to restore, we encourage developing a restoration plan with stakeholders that will restore structural, compositional, and functional endpoints, and whose goal is a …

The Role Of Climate In The Dynamics Of Annual Plants In A Chihuahuan Desert Ecosystem, Danielle Ignace, Nancy Huntly, Peter Chesson

Biological Sciences: Faculty Publications

Question: What is the role of temporal climate fluctuations in the dynamics of desert winter annual plants in the Portal Bajada, and in the sustained irruption of the non-native annual plant species, Erodium cicutarium?

Field site: Portal Bajada, San Simon Valley, Arizona, USA. Methods: We counted plants at flowering over a 21-year period on twelve permanent plots and related these numbers to weather data collected at an on-site weather station, supplemented by observations from the National Climate Data Center. Specific summary climate variables considered most relevant to annual plant biology were developed as candidate predictors of plant response variables.

Statistical …

Habitat Characteristics Provide Insights Of Carbon Storage In Seagrass Meadows, Inés Mazarrasa, Jimena Samper-Villarreal, Oscar Serrano, Paul S. Lavery, Catherine E. Lovelock, Núrià N. Marbà, Carlos M. Duarte, Jorge A. Cortés

Research outputs 2014 to 2021

Seagrass meadows provide multiple ecosystem services, yet they are among the most threatened ecosystems on earth. Because of their role as carbon sinks, protection and restoration of seagrass meadows contribute to climate change mitigation. Blue Carbon strategies aim to enhance CO2 sequestration and avoid greenhouse gasses emissions through the management of coastal vegetated ecosystems, including seagrass meadows. The implementation of Blue Carbon strategies requires a good understanding of the habitat characteristics that influence Corg sequestration. Here, we review the existing knowledge on Blue Carbon research in seagrass meadows to identify the key habitat characteristics that influence Corg sequestration in seagrass …