Biodiversity Commons^™

Distribution And Soil Characteristics Associated With The Neches River Rose-Mallow (Hibiscus Dasycalyx), Morgan E. Langlinais

Electronic Theses and Dissertations

The Neches River rose-mallow, Hibiscus dasycalyx, is a rare herbaceous perennial endemic to East Texas. The threatened, obligate wetland species is currently at risk of being lost in the wild due to habitat loss, encroachment of nonnative and native plant species, and hybridization with two other Hibiscus congeners, Hibiscus laevis and Hibiscus moscheutos. Known locations of each of the three Hibiscus species were used to measure select soil characteristics and habitat variables associated with each of the rose-mallows. H. dasycalyx was concluded to be associated with more fertile soils and slightly more canopy coverage than H. laevis and …

Detection, Occupancy, Abundance, And Mercury Accumulation Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Texas, David Rosenbaum

Electronic Theses and Dissertations

Land use practices and physical alterations of ecosystems result in habitat loss and fragmentation, while chemical alterations, such as pollutant input, reduce habitat quality and health of exposed organisms. Here, I investigated the effects of watershed- and local-scale environmental variables on the occupancy, abundance, and mercury accumulation of a threatened aquatic species (Macrochelys temminckii, i.e., alligator snapping turtle) within the southwestern periphery of its distribution. Hierarchical modeling suggested the distribution of the species is more affected by watershed-scale land-cover than local habitat, and provided a baseline estimate of average species abundance across its range in eastern Texas. Abundance …

Fish Community Assembly At Multiple Spatial Scales In East Texas Streams, Jake R. Swanson

Electronic Theses and Dissertations

Stream communities are structured by environmental processes that vary in strength across different spatiotemporal scales. Therefore, revealing how stream fish communities are influenced by environmental gradients may clarify how communities respond to disturbance associated with anthropogenic change. I investigated the relative role environmental variables play in the processes that structure the taxonomic and functional diversity of stream fish communities, as well as historical trends in occurrence and local habitat associated with a species of greatest conservation need within east Texas. The results of this study indicate that stream sites with more habitat complexity and stability support a more taxonomically and …

Food-Web And Functional Trait Community Structure Of Predator Assemblages In Pine Forests Under Different Management Regimes, Connor Adams

Electronic Theses and Dissertations

Anthropogenic activities can alter natural disturbance regimes in ecosystems, and thereby affect the structure and function of biological diversity. As many of the world’s ecosystems are degraded beyond natural recovery, well-defined restoration goals are necessary to maintain the ecological processes that provide valuable ecosystem services. Utilizing taxonomic, functional, and food-web approaches, I investigated the impacts of forest management practices in structuring predator communities in two pine forest systems of eastern Texas. The results of this study indicate that the increased frequency of forest management practices such as prescribed fires and thinning operations encourages predator diversity while increasing functional and trophic …

The Bees Of Two Sites In The Big Thicket National Preserve, Texas, With A Consideration Of The Effects Of A Rare Flooding Event, Archie Ray Sauls Jr.

Electronic Theses and Dissertations

Native bees are an important part of terrestrial ecosystems due to their coevolution with flowering plants. This study catalogued the bee fauna of two sandyland sites in the Big Thicket National Preserve and assessed whether a community was impacted by a historic hurricane-induced flooding event. It was hypothesized that a change in diversity metrics would be evident following the flood. Datasets were analyzed for differences in species richness, abundance, evenness, and Shannon’s diversity. Similarities between datasets were also assessed using the multivariate tests analysis of similarity (ANOSIM) and similarity of percentages (SIMPER). At two sites over two years of sampling …

An Economic Analysis Of Using Retired Vessels To Create Artificial Reefs In Costa Rica, Josué González

Electronic Theses and Dissertations

ABSTRACT

The Republic of Costa Rica is a Central American country with only 0.03% of the world’s landmass, but 5% of the world’s biodiversity, making it a leading ecotourism destination. Ecotourism is one of the main sources of revenue for the country, but the degradation of coastal reefs has resulted in a significant loss of financial income for developing areas. As a result, many of these areas are searching for methods to revert the degradation of coral reefs.

Artificial reefs play an important ecological role in marine ecosystems due to their complexity and size. They help in the development of …

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. …

Breeding Season Avian Community Composition And Prey Availability In Eucalyptus And Slash Pine Plantations Of Southwestern Louisiana, Elizabeth J. Messick

Electronic Theses and Dissertations

The increased demand for wood products related to industries such as bioenergy and paper has resulted in a need for a consistent supply of raw materials. Eucalyptus (Eucalyptus spp.) plantations have the potential to boost wood production for pulpwood and biomass feedstocks. Species characteristics such as rapid, indeterminate growth, coppice regrowth, resistance to disease and insects, and tolerance of a range of environmental conditions make these species successful short-rotation woody crops (SRWCs). Camden white gum (Eucalyptus benthamii), a more cold tolerant species, has made management of eucalyptus plantations viable in southern portions of the United States such …

Relationships Between Herbaceous Diversity And Biomass In Two Habitats In Arid Mediterranean Rangeland, Mohammad N. Alhamad, Brian P. Oswald, Mohammad M. Bataineh, Mohammad A. Alrababah, Mohammad M. Gharaibeh

Faculty Publications

Plant diversity patterns vary across the landscape. This study was conducted to answer the question: What is the pattern of species diversity (α and β) along an abstract productivity/cover gradient at two topographical positions (Wadi (a depression with overland flow) and hilltop) of a Mediterranean herbaceous plant community in Jordan? Results indicated that the less productive hilltop localities exhibited higher species richness than the more productive Wadi localities. Species richness exhibited a unimodal relationship with aboveground biomass within Wadis whereas a positive linear relationship was revealed for hilltops. Within Wadis, abundant species did not show a significant relationship with productivity …

Selection For Salt Tolerance In Tidal Freshwater Swamp Species: Advances Using Bald Cypress As A Model For Restoration (Chapter 14), David Creech

Faculty Publications

No abstract provided.

Shorebird Breeding Biology In Wetlands Of The Playa Lakes, Texas, Usa, Warren C. Conway, Loren M. Smith

Faculty Publications

Wetlands in the Playa Lakes Region of Texas are important habitats for North American wintering waterfowl and migrant shorebirds. However, shorebird breeding biology has been overlooked in characterizing the region’s ecological importance. In 1998 and 1999, American Avocet (Recurvirostra americana), Black-necked Stilt ( Himantopus mexicanus ), Killdeer (Charadrius vociferous), and Snowy Plover (C. alexandrinus) breeding ecology were studied in playas, saline lakes, and riparian wetlands in the Playa Lakes Region of Texas. Chronology of nest initiation, clutch sizes, and hatching success for 298 Snowy Plover, 111 American Avocet, 43 Killdeer, and 26 Blacknecked Stilt …

Avian Use Of Chinese Tallow Seeds In Coastal Texas (Abstract), Warren C. Conway

Faculty Publications

The Chinese tallow tree (Sapium sebiferum) (Euphorbiaceae) was introduced into coastal Texas in the late 1800s and forms monotypic woodlands once naturalized. However, few studies have examined avian use of tallow seeds during fall migration in coastal Texas. We documented use of Chinese tallow seeds and compared foraging frequency on Chinese tallow seeds among permanent, summer, and winter residents and migrants. We also tested the hypothesis that Chinese tallow seed germination was enhanced by foraging activities of yellow-rumped warblers (Dendroica coronata), the most common species observed foraging on tallow seeds. During fall migration 1995 and 1996, …

Life In A Pine Cone, David L. Kulhavy

Faculty Publications

This exercise focuses on a little-known microhabitat -- the pine cone. A pine cone's primary function is, of course, reproduction ... housing the seeds of the next generation of conifer trees. However, pine cones are also the basis of a food web that provides both resources and living space for a wide variety of small arthropod species. The procedure outlined below is designed to examine this microhabitat and compare its community diversity among different species of conifers and habitats.

The exercise is based on a 1985 paper, Life in a Pine Cone, by David L. Kulhavy, Robert S. Baldridge and …