Life Sciences Commons^™

Regenerative Agriculture Effects On Invertebrate And Bird Communities And Insect-Provided Ecosystem Services, Alex Michels

Electronic Theses and Dissertations

Conventional agricultural practices can have unintended consequences on the environment and wildlife. Insects and birds are declining at rapid rates around the world, and the current conventional agricultural paradigm is a major driver through habitat loss and the intensification of production. Invertebrates in agroecosystems provide services to both farmers and the rest of society. Regenerative systems may promote the functioning of an agroecosystem by influencing invertebrate abundance, diversity, and ecosystem services and mitigate bird and insect declines through conservation practices that increase soil health, reduce disturbances, and increase biological diversity. Here I address knowledge gaps of the effects of regenerative …

Intellectual Property Rights In The Seed Industry: Barriers To Sustainable Agriculture, Elena A. Filatova

Electronic Theses and Dissertations

The dynamics of the dominant industrial agriculture system restrict the seed industry’s innovative landscape, leading to significant negative consequences including an exacerbation of environmental risks which threaten global food security. This thesis explores how exclusionary intellectual property rights (IPRs) in the context of the seed industry constrict innovation, evolutionary pathways, and opportunities for the implementation of sustainable agriculture methods. To overcome these barriers, the application of an open source framework to seed innovation, specifically through the platform of the Open Source Seed Initiative, is evaluated as a tool for enhancing innovative capacities in seed development while broadening the accessibility and …

Examining Biodiversity Metrics And The Utility Of Dna Barcoding In The Northern Great Plains, Sarah Herzog

Electronic Theses and Dissertations

Due to heavy threats to remaining global floral and faunal diversity, it is imperative we can identify species and quantify ecosystem health to find best practices for land management and conservation. The tallgrass prairies of the Northern Great Plains are one example of a heavily imperiled ecosystem. The tallgrass prairies have been reduced to less one percent of their historical extent and are facing continued loss. Genetic approaches and evolutionary theory offer insights for identifying species and assessing how biodiversity metrics may correlate with ecosystem processes. My two projects aim to address two facets imperative to conservation in the tallgrass …

Maximizing Ecosystem Services Provided To The New Oil Crop Brassica Carinata Through Landscape And Arthropod Diversity, Shane Stiles

Electronic Theses and Dissertations

Prairies, once spanning the Upper Midwest, have now largely been replaced by agriculture. The lack of resources available to pollinators in agricultural fields and the practices employed by farmers to maximize yield has led to a decline in insect and pollinator diversity. There is a need to better understand how ecosystem services provided by a diverse insect community scale to current farming practices as they relate to crop yield. We sought to explain how landscape heterogeneity relates to insect and pollinator diversity, as well as how insect diversity relates to crop yield across common farming practices. To evaluate how farming …

Delineating Metrics Of Diversity For A Snake Community In A Rare Ecosystem, Zachary John Marcou

Electronic Theses and Dissertations

Snakes are among the least understood vertebrate groups despite their considerable diversity. A diverse community of snakes in an ecosystem can indicate a complex habitat structure that is capable of supporting a robust assemblage of other biota. I used remote photography arrays (RPA) to quantify metrics of diversity for the snake community occurring in a ~7,000–ha tract of contiguous Longleaf Pine (Pinus palustris) Savanna within the Angelina National Forest (ANF; Angelina and Jasper Cos., TX), over the course of two consecutive snake activity seasons. I quantified the snake species richness, Shannon diversity, and Shannon equitability for the snake community in …

Biodiversity And Evolution In The Guiana Shield, South America, Andrew Michael Snyder

Electronic Theses and Dissertations

The neotropics are characterized as the most species rich region in the world. Unfortunately, the region's unparalleled biodiversity has not protected it from ongoing threats such as agriculture, mining, logging, oil extraction, and climate change. I studied the biodiversity and evolution of the herpetofauna of South America in order to investigate the influence of historical geological and climatological events in shaping extant neotropical diversity, particularly the Guiana shield. For my research, I set out to explore the processes involved in shaping the remarkable extant diversity using anuran amphibians as models. With my dissertation, I provide a comprehensive review of the …

Estimating Wildlife Biodiversity Of Pine Plantation Edges Of Contrasting Rotational Stages: A Case Study, Joshua Perry Harris

Electronic Theses and Dissertations

ESTIMATING WILDLIFE BIODIVERSITY OF PINE PLANTATION EDGES OF CONTRASTING ROTATIONAL STAGES: A CASE STUDY

By: Joshua Harris, Dr. Daniel Scognamillo, Dr. Gary Kronrad, and Dr. Jeremy Stovall

Abstract

Wildlife biodiversity was estimated amongst three loblolly pine (Pinus taeda) intra-plantation edge types of contrasting rotational phases in a two-year case study. Three structurally varied rotational phases that occur throughout plantation rotations combine to make three different edges: A= pre-thinned - post-thinned, B= pre-thinned - pre-clearcut, and C= post-thinned - pre-clearcut. For two summer seasons (May-August 2015-2016), invertebrates, birds, medium mammals, and small mammals were sampled in each edge type. …

Vegetation Community Changes In Two National Forests In The Pineywoods, East Texas, Trisha L. Williams

Electronic Theses and Dissertations

Despite extensive research into forest succession, little research has been directed to long-term studies. The fundamental properties of succession remain unclear and further research into terrestrial vegetation and an accounting of drivers in specific ecosystem types is required. This study addresses change in plant communities from five ecosystem types in two east Texas National Forests over a 20-year period. An analysis of 30 sample stands yields results due to various ecosystem drivers of vegetation change and uncovers plant community responses in multiple ecosystem types over this period. This research provided three key results: 1) that vegetation composition change occurs more …

Interactive Effects Of Cover Crops, Invertebrate Communities And Soil Health In Corn Production Systems, Claire Lacanne

Electronic Theses and Dissertations

The adoption of regenerative farming practices is gaining traction, but the costs and benefits are not often considered on a systems level. Encouraging biodiversity and soil health is the goal of many agricultural practices used in regenerative farming; regenerative systems employ practices which abide by the two main principles of increasing biodiversity and decreasing disturbance, with the goal of encouraging ecosystem functioning to minimize inputs and maximize the productivity of a farm. I examined the management of corn (Zea mays) fields across four states in the Upper Midwest region of the United States. Regenerative systems in this study …

Approaches To Arthropod Conservation : Landscape Genetics, Community Assessment, And Prediction Of Extinction Risk., Victoria Annette Prescott

Electronic Theses and Dissertations

Although urbanization is a leading cause of species extinction throughout the world, the impact of urban development on arthropods is little studied and, as a result, poorly understood. I used three distinct approaches to studying arthropod conservation in North America. First, I used landscape genetics techniques to study the impact of urbanization on gene flow among populations of Rabidosa rabida, the rabid wolf spider. While gene flow was not detrimentally reduced, urban development correlated with a reduction in migration rates among populations, and to my knowledge, this is the first study to document isolation by resistance in spiders. Next, …

Competitive Effects Of Increased Plant Species Richness And Increased Endemic Versus Native Generalist Species Dominance On The Invasive Grass Microstegium Vimineum During Oak Woodland Restoration, Sean Anthony Moyer

Electronic Theses and Dissertations

The hypothesis that species-rich assemblages are resistant to invasion by non-native species has generated considerable research and controversy. However, the relevance of such research to the conservation of biodiversity is questionable, given that local species richness often does not correlate with regional or global species richness, two metrics undoubtedly important to conservation. Furthermore, species of greater conservation interest (i.e. endemics) and widespread generalist species may compete differentially with non-native invasive species. To test whether plant species richness or species fidelity to a regionally rare habitat were more important in competitively suppressing an invasive species, I established a field competition experiment …

Biogeography And Conservation Of Tidal Marsh Bird Communities Across A Changing Landscape, Maureen D. Correll

Electronic Theses and Dissertations

Given the current mass extinction crisis and continued fragmentation of resources worldwide, the outlook is dire for global biodiversity. Rising global temperature, sea levels, and storm frequency all create environmental conditions that can drive change in species abundance and distribution across a landscape. Those species reliant upon a single type of habitat and resource for survival, termed “specialists”, are particularly vulnerable to change due to their inability to utilize a variety of resources well. As a result, specialism is now considered one of the dominant factors determining extinction of species. In this dissertation I explore the effects of disturbance on …

Species And Habitat Interactions Of The Gopher Tortoise: A Keystone Species?, Christopher Catano

Electronic Theses and Dissertations

Species-species and species-habitat interactions have been demonstrated to be important in influencing diversity across a variety of ecosystems. Despite generalities in the importance of these interactions, appropriate mechanisms to explain them are absent in many systems. In sandhill systems of the southeast U.S., gopher tortoises have been hypothesized to be a crucial species in the maintenance of diversity and function. However, the mechanisms and magnitude in which they influence their communities and habitats have rarely been empirically quantified. I examined how habitat structure influences tortoise abandonment of burrows and how tortoise densities influence nonvolant vertebrate community diversity. Tortoise burrow abandonment …

Predation On The Eastern Oyster Crassostrea Virginica On Intertidal Reefs Affected By Recreational Boating, Jennifer Stiner

Electronic Theses and Dissertations

Widely regarded as a keystone species and ecosystem engineer, the eastern oyster Crassostrea virginica plays a vital role in estuarine environments. Complex, three-dimensional oyster reefs act as havens for biodiversity and contribute to ecological processes. Recently, concern for this resource has arisen in Mosquito Lagoon, Florida, the southernmost limit along the Atlantic coast for undisturbed, intertidal reefs of C. virginica. Since the 1990s, intense recreational boating activity has caused atypical dead margins (mounds of disarticulated shells) to emerge on the seaward edges of oyster reefs located along major navigational channels. Once dead margins are formed, little is known about their …