Biology Commons^™

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 …

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

Biology 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-yeaer 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. …

Understanding Community And Ecophysiology Of Plant Species On The Colorado Plateau, Hannah Elizabeth Yokum

Theses and Dissertations

The intensification of aridity due to anthropogenic climate change is likely to have a large impact on the growth and survival of plant species in the southwestern U.S. where species are already vulnerable to high temperatures and limited precipitation. Global climate change impacts plants through a rising temperature effect, CO2 effect, and land management. In order to forecast the impacts of global climate change, it is necessary to know the current conditions and create a baseline for future comparisons and to understand the factors and players that will affect what happens in the future. The objective of Chapter 1 is …

Adaptive Variation In Tiger Salamander Populations, Meghan Parsley

Masters Theses & Specialist Projects

Amphibians face an unknown future in a time of rapid environmental change due to global climate perturbations. Since amphibians are perceived to be indicators of ecosystem health, understanding the causes of their declines can improve our perception of threats to other species. Molecular techniques have allowed us to explore how environmental change affects genetic variation and to predict evolutionary adaptive potential of amphibian populations. The identification of populations with the greatest potential to respond to changing environmental variables may be an important conservation strategy to aid in future management efforts. I utilized targeted exon capture sequencing to identify adaptive variation …

Parasite Biodiversity Faces Extinction And Redistribution In A Changing Climate, Colin J. Carlson, Kevin R. Burgio, Eric R. Dougherty, Anna J. Phillips, Veronica M. Bueno, Christopher F. Clements, Giovanni Castaldo, Tad Dallas, Carrie A. Cizauskas, Graeme S. Cumming, Jorge Doña, Nyeema C. Harris, Roger Jovani, Sergey Mironov, Oliver C. Muellerklein, Heather C. Proctor, Wayne M. Getz

Faculty Publications

Climate change is a well-documented driver of both wildlife extinction and disease emergence, but the negative impacts of climate change on parasite diversity are undocumented. We compiled the most comprehensive spatially explicit data set available for parasites, projected range shifts in a changing climate, and estimated extinction rates for eight major parasite clades. On the basis of 53,133 occurrences capturing the geographic ranges of 457 parasite species, conservative model projections suggest that 5 to 10% of these species are committed to extinction by 2070 from climate-driven habitat loss alone. We find no evidence that parasites with zoonotic potential have a …

Spatial And Temporal Variation In Mangrove Distribution (1950-2014) In Tampa, Florida Usa, Carolyn Cheatham Rhodes

USF Tampa Graduate Theses and Dissertations

I carried out an observational study of historic high resolution aerial imagery spanning six decades (1950-2014) to identify recent and historic spatial extent of mangrove forests, within the municipal boundaries of the City of Tampa, Florida USA. My objectives were to map mangrove distribution and spatial extent and any change or patterns of change discernable. I observed variable patterns of change and rates of expansion varied between sites spatially as well as within sites between time intervals. I found notable changes in mangrove extent in the Tampa from historic and modern aerial imagery for the ~64-year period between 1950 and …

Modelling Climate Suitability For Ephedra Viridis In Space And Time, Anne Thomas, Richard Gill

Journal of Undergraduate Research

Climate change is expected to decrease soil moisture in the sensitive, water-limited ecosystems of America’s southwestern deserts, leading to shifts in plant distributions and altering ecosystem function. Studies have already documented the loss of desert grasses and the expansion of desert shrubs on the Colorado Plateau near Canyonlands National Park.i The objective of this work is to identify the climatic and biophysical factors influencing the distribution of an evergreen shrub, Ephedra viridis, and its expansion in plot-scale studies over the past 30 years.ii A gymnosperm and member of the plant division Gnetophyta, this shrub is unique because of its …

Using Maximum Entropy Species Distribution Modeling For Long-Term Conservation Planning Of Three Federally Listed Bats In North America, Mitchell L. Meyer

Master's Theses or Doctor of Nursing Practice

We are currently in a sixth mass extinction event in which the extinction rate is higher than it has ever been. This mass extinction event is caused by human influence on the environment. Biodiversity is worth conserving because of its many uses to humans. Bats are a diverse group of mammals that humans rely on for pest control services. The gray bat, northern long-eared bat, and Indiana bat are on the Threatened and Endangered Species List and are in need of conservation. I built species distribution models using occurrence records, climate data, and Maximum entropy (MaxEnt) modeling technique. I predicted …

Growth Of Orbicella Faveolata In La Parguera, Puerto Rico, Darren B. Marshall

HCNSO Student Theses and Dissertations

Reef-building corals are subject to high amounts of stress, including pollution and rising sea surface temperatures due to climate change. These factors can affect the ability of corals to produce their calcium carbonate skeletons. Evaluation of the effects of climate change may be facilitated by evaluation of records of coral skeletal growth over a long period of time. The aim of this study was to evaluate skeletal growth of the coral Orbicella faveolata in La Parguera, Puerto Rico over a 32-year period. For this, 14 Orbicella faveolata core samples were collected from corals at two reefs (1.2 km apart) in …

The Alpine Vascular Plants Of Baxter State Park, Maine, Usa, Abigail J. Urban, Glen H. Mittelhauser, Matthew Dickinson, N. Rajakaruna

Biological Sciences

We conducted 12 days of field surveys on five mountains over 1100 m in elevation (Katahdin, North Brother, South Brother, Mount Coe, and The Owl) in Baxter State Park (BSP), Maine during the summers of 2013–14. In addition, we examined historic manuscripts, unpublished data, and herbarium records for plant records from the five mountains. Katahdin, the largest and tallest of the five mountains, has a rich history of botanical exploration and we documented 1559 herbarium vouchers that were collected from the mountain, primarily before the mid-1900s. Combining all data sources, we documented 38 families, 87 genera, and 131 taxa of …

Hydraulic Mechanisms Of Fungal-Induced Dieback In A Keystone Chaparral Species During Unprecedented Drought In California, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Frank E. Ewers, Stephen D. Davis

Seaver College Research And Scholarly Achievement Symposium

Between 2012-2016, southern California experienced unprecedented drought that caused dieback in Malosma laurina, a keystone species of chaparral shrub communities. Dieback was especially severe in coastal exposures of the Santa Monica Mountains, leading to whole plant mortality exceeding 50% at some sites. We hypothesized that the endophytic fungus causing the dieback, Botryosphaeria dothidea, was successful in invading the xylem tissue of M. laurina because of protracted water stress, carbon starvation, or a combination of the two. We tested these possibilities in a controlled pot experiment by comparing three treatments, each inoculated with the fungus: (1) irrigated controls (2) …

Climate Warming Can Accelerate Carbon Fluxes Without Changing Soil Carbon Stocks, Susan E. Ziegler, Ronald Benner, Sharon A. Billings, Kate A. Edwards, Michael Philben, Xinbiao Zhu, Jerome Laganière

Faculty Publications

Climate warming enhances multiple ecosystem C fluxes, but the net impact of changing C fluxes on soil organic carbon (SOC) stocks over decadal to centennial time scales remains unclear. We investigated the effects of climate on C fluxes and soil C stocks using space-for-time substitution along a boreal forest climate gradient encompassing spatially replicated sites at each of three latitudes. All regions had similar SOC concentrations and stocks (5.6 to 6.7 kg C m−2). The three lowest latitude forests exhibited the highest productivity across the transect, with tree biomass:age ratios and litterfall rates 300 and 125% higher than those in …

Differential Response Of Barrier Island Dune Grasses To Species Interactions And Burial, April Harris, Julie C. Zinnert, Donald R. Young

Biology Publications

Barrier islands are at the forefront of storms and sea-level rise. High disturbance regimes and sediment mobility make these systems sensitive and dynamic. Island foredunes are protective structures against storm-induced overwash that are integrally tied to dune grasses via biogeomorphic feedbacks. Shifts in dune grass dominance could influence dune morphology and susceptibility to overwash, altering island stability. In a glasshouse study, two dune grasses, Ammophila breviligulata and Uniola paniculata, were planted together and subjected to a 20 cm burial to quantify morphological and physiological responses. Burial had positive effects on both plants as indicated by increased electron transport rate and …

A Comparison Of Benthic Macroinvertebrate Assemblages Between Perennial And Intermittent Headwater Streams Of The Mattole River In Northern California, Usa, Mason S. London

Cal Poly Humboldt theses and projects

Intermittent streams are common throughout the world and comprise 60% or more of total river lengths in the conterminous United States. Despite their prevalence, intermittent streams are understudied, particularly first-order headwater streams, which are vital for maintaining the function, health and biotic diversity of river networks. In June 2016, I sampled five intermittent and five perennial headwater streams in the Mattole River watershed in northwestern coastal California, USA, to compare benthic macroinvertebrate (BMI) assemblages between intermittent and perennial streams. BMI samples were collected using a 500µm mesh D-net at eight randomly located riffles along a 150-m reach, and then composited, …

Large But Uneven Reduction In Fish Size Across Species In Relation To Changing Sea Temperatures, Itai Van Rijn, Yehezkel Buba, John Delong, Moshe Kiflawi, Jonathan Belmaker

School of Biological Sciences: Faculty Publications

Ectotherms often attain smaller body sizes when they develop at higher temperatures. This phenomenon, known as the temperature size rule, has important consequences for global fisheries, whereby ocean warming is predicted to result in smaller fish and reduced biomass. However, the generality of this phenomenon and the mechanisms that drive it in natural populations remain unresolved. In this study we document the maximal size of 74 fish species along a steep temperature gradient in the Mediterranean Sea and find strong support for the temperature size rule. Importantly, we additionally find that size reduction in active fish species is dramatically larger …

Efectos Del Cambio Climático En La Interacción Planta-Hormiga: Una Mini Revisión Sobre La Tolerancia Térmica, Florencio Luna Castellanos, Mariana Cuautle, Teresa Patricia Feria-Arroyo, Citlalli Castillo Guevara

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Sin duda alguna el clima está cambiando debido al aumento de la concentración de gases de efecto invernadero en la atmósfera provocado por la acción humana. Dichos cambios van a tener un efecto importante en algunas actividades humanas tales como la agricultura y también pueden afectar enormemente la distribución geográfica de los organismos vivos y por tanto sus interacciones. Las hormigas y las plantas tienen una larga historia evolutiva de interacción. La actividad de las hormigas y su relación con las plantas en los últimos años ha tenido un número creciente de estudios que están poniendo de relieve su papel …

Fluctuating Temperatures Alter Environmental Pathogen Transmission In A Daphnia–Pathogen System, Tad Dallas, John M. Drake

Faculty Publications

Environmental conditions are rarely constant, but instead vary spatially and temporally. This variation influences ecological interactions and epidemiological dynamics, yet most experimental studies examine interactions under constant conditions. We examined the effects of variability in temperature on the host–pathogen relationship between an aquatic zooplankton host (Daphnia laevis) and an environmentally transmitted fungal pathogen (Metschnikowia bicuspidata). We manipulated temperature variability by exposing all populations to mean temperatures of 20°C for the length of the experiments, but introducing periods of 1, 2, and 4 hr each day where the populations were exposed to 28°C followed by periods of …

Winter Warming Effects On Overwinter Survival, Energy Use, And Spring Emergence Of Cerotoma Trifurcata (Coleoptera: Chrysomelidae), Emily A. Berzitis, Heather A. Hager, Brent J Sinclair, Rebecca H. Hallett, Jonathan A. Newman

Biology Publications

1. Bean leaf beetle Cerotoma trifurcata (Förster) (Coleoptera: Chrysomelidae) is a pest of soybean in the U.S.A. and is becoming a concern in Canada. The projected increase in winter temperatures under climate change could affect overwinter survival, timing of spring emergence and, ultimately, the severity of this pest.
2. We assessed the potential effects of warmer winters in field experiments performed in three consecutive years. Three warming levels were applied: (i) heated approximately 4 °C above ambient; (ii) unheated with snow cover left intact; and (iii) unheated with snow cover removed. Survival and date of emergence were assessed in all years, and …

Variable Effects Of Snow Conditions Across Boreal Mesocarnivore Species, C. B. Pozzanghera, K. J. Sivy, M. S. Lindberg, L. R. Prugh

Biology Faculty Publications and Presentations

Mesocarnivores are increasingly recognized as key drivers of community dynamics, but the effects of bottom-up and abiotic factors on mesocarnivore populations remain poorly understood. We evaluated the effects of snow conditions, prey abundance, and habitat type on the distribution of five sympatric mesocarnivore species in interior Alaska using repeated snow track surveys and occupancy modelling. Snow depth and snow compaction were the best predictors of mesocarnivore occupancy, with differential effects across species. Coyotes (Canis latrans (Say, 1823)) and red foxes (Vulpes vulpes L., 1758) occurred in areas of shallow, compact snow, Canada lynx (Lynx canadensis (Kerr, 1792)) …

Coarse Root Biomass And Architecture: Applications Of Ground Penetrating Radar, John Claude Bain

Biological Sciences Theses & Dissertations

The effectiveness of ground penetrating radar (GPR) to identify and quantify coarse roots was tested in a mixed-oak forest in Southeastern Virginia using experimental pits and locally excavated root segments. GPR was found to be highly dependent on low soil moisture levels as it is unable to differentiate root structures if they possess similar moisture content as their surrounding soil. Likewise, GPR was unable to identify simulated dead roots. This does not alter the effectiveness of GPR to measure living coarse root biomass, but does present the potential for underestimation of carbon storage in coarse root structures, as a dead …

Rapid Museum, Gary Barwin

The Goose

Poetry by Gary Barwin

Altitudinal Gradients Do Not Predict Plant-Symbiont Responses To Experimental Warming, Melanie R. Kazenel

Biology ETDs

Fungal symbionts, ubiquitous inhabitants of above- and belowground plant tissues, can play important roles in increasing plant tolerance to abiotic and biotic stress. Disruption of plant-fungal interactions may therefore have important consequences for plant responses to climate change. Both altitudinal gradients and warming experiments can be useful tools for understanding responses of symbioses to climate shifts, but the degree to which altitudinal patterns will predict species responses to warming has received little attention for plant-symbiont interactions. This study combined surveys along replicated altitudinal gradients with a long-term warming experiment at the Rocky Mountain Biological Laboratory (RMBL) in Colorado, USA to …

The Effects Of Large Herbivores On Soil Organic Matter Quality In Terrestrial Ecosystems, Adrian Alvarez

Renée Crown University Honors Thesis Projects - All

Understanding the factors that control the natural fluxes of carbon into and out of terrestrial ecosystems is of paramount importance to forecast and adapt to climate change. Soil respiration – the release of carbon dioxide from roots and soil micro-organisms– is considered to be the largest terrestrial source of carbon dioxide. Microbial respiration, the least understood component of soil respiration, is to a great extent determined by soil organic matter quality, reflecting the relative fractions of labile and recalcitrant soil carbon. The goal of this research was to examine how herbivory affects soil organic matter quality across a wide range …

Damsels In Distress: A Study Of The Effect Of Temperature On Damselfly Competitive Interactions, Madison Pitts

Biological Sciences Undergraduate Honors Theses

Temperature has a fundamental role in shaping numerous physiological aspects of organisms, such as growth rate, that determine an organism's performance. Due to global climate change, temperature is projected to keep increasing. As temperature increases, so does an organism’s growth rate. Also, as competition increases organisms’ growth rate decreases. While studies have examined these factors individually, no experiments have assessed the combined impact of temperature and competition on organism’s growth rates. The experiment we conducted manipulated temperature and density in order to project what will happen as a result of rising temperatures.

Translating Ecology, Physiology, Biochemistry And Population Genetics Research To Meet The Challenge Of Tick And Tick-Borne Diseases In North America, Maria Dolores Esteve-Gassent, Ivan Castro-Arellano, Teresa Patricia Feria-Arroyo, Ramiro Patino, Andrew Y. Li, Raul F. Medina, Adalberto A. Pérez De León, Roger Iván Rodríguez-Vivas

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several …

Consensus On Consensus: A Synthesis Of Consensus Estimates On Human-Caused Global Warming, John Cook, Naomi Oreskes, Peter T. Doran, William R L Anderegg, Bart Verheggen, Ed W. Maibach, J Stuart Carlton, Stephan Lewandowsky, Andrew G. Skuce, Sarah A. Green, Dana Nuccitelli, Peter Jacobs, Mark Richardson, Bärbel Winkler, Rob Painting, Ken Rice

Department of Chemistry Publications

The consensus that humans are causing recent global warming is shared by 90%–100% of publishing climate scientists according to six independent studies by co-authors of this paper. Those results are consistent with the 97% consensus reported by Cook et al(Environ. Res. Lett. 8 024024) based on 11 944 abstracts of research papers, of which 4014 took a position on the cause of recent global warming. A survey of authors of those papers (N = 2412 papers) also supported a 97% consensus. Tol (2016 Environ. Res. Lett.11 048001) comes to a different conclusion using …

Detection And Attribution Of Long-Term Vegetation Changes In Northern Alaska, Robert Barrett

Masters Theses

Climate change is impacting terrestrial ecosystems world-wide and the Arctic is particularly vulnerable as it is warming faster and with greater magnitude than other regions. Understanding the responses of arctic plants species to abiotic factors is crucial to predicting the impact climate change will have on the Arctic because plants play critical roles in carbon exchange, energy balance, and trophic interactions. Using data from long-term research sites in Barrow and Atqasuk, Alaska, the purpose of this thesis was to investigate how arctic plants respond to 17-19 years of experimental warming, establish the relative strengths of various abiotic factors in predicting …

Damsels In Distress: A Preliminary Assessment Of Pomacentridae Extinction Risk, Allison Roberts

Undergraduate Research Symposium

The family Pomacentridae is among the most diverse of the perciformes, boasting 400 different species of damselfish. These fish are found in coral reefs of varying depths around the world, most of which risk great damage due to climate change. In addition, many species are key components of the ornamental aquarium trade. Considering these threats, the importance of examining the state of Pomacentridae is paramount in examining the health of our oceans. Using IUCN Red List methods, preliminary data suggests some species of damselfish are at elevated risk of extinction.

Insights From Wildfire Science: A Resource For Fire Policy Discussions, Tania Schoennagel, Penny Morgan, Jennifer Balch, Philip Dennison, Brian Harvey, Richard L. Hutto, Meg Krawchuk, Max A. Moritz, Ray Rasker, Cathy Whitlock

Biological Sciences Faculty Publications

Record blazes swept across parts of the US in 2015, burning more than 10 million acres. The four biggest fire seasons since 1960 have all occurred in the last 10 years, leading to fears of a ‘new normal’ for wildfire. Fire fighters and forest managers are overwhelmed, and it is clear that the policy and management approaches of the past will not suffice under this new era of western wildfires. In recent decades, state and federal policymakers, tribes, and others are confronting longer fire seasons (Jolly et al. 2015), more large fires (Dennison et al. 2014), a tripling of homes …

A Genetically Distinct Hybrid Zone Occurs For Two Globally Invasive Mosquito Fish Species With Striking Phenotypic Resemblance, Rebecca J. Wilk, Lisa Horth

Biological Sciences Faculty Publications

Hybrid zones allow for the investigation of incipient speciation and related evolutionary processes of selection, gene flow, and migration. Interspecific dynamics, like competition, can impact the size, shape, and directional movement of species in hybrid zones. Hybrid zones contribute to a paradox for the biological species concept because interbreeding between species occurs while parental forms remain distinct. A long‐standing zone of intergradation or introgression exists for eastern and western mosquito fish (Gambusia holbrooki and G. affinis) around Mobile Bay, AL. The region has been studied episodically, over decades, making it perfect for addressing temporal dynamics and for providing …