Life Sciences Commons^™

The Effects Of Commercial Harvest On The Density And Demography Of Aquatic Turtles In Arkansas, Andrhea Darleen Massey

Graduate Theses and Dissertations

The United States is home to the second highest concentration of turtle species in the world, after Asia. As of 2018, there are 57 turtle species recognized within the US, 40% of which are listed as threatened or endangered, with the primary threats to population persistence identified as over-consumption and/or habitat loss. Within the US, the Mississippi Alluvial Valley (MAV) region represents the second highest turtle species richness, after the Mobile River Basin. The MAV region of Arkansas is one of the least regulated in terms of commercial aquatic turtle harvest and has undergone large-scale habitat conversion from bottomland hardwood …

Habitat Assessment Of Ozark Glades Using Selected Epigeal Predatory Arthropods, Austin Key Jones

Graduate Theses and Dissertations

Epigeal predatory arthropods were collected with pitfall-style traps in nine sandstone glades of varying ecological stages, and management histories, in the Ozarks of Northern Arkansas over three years. These sites were categorized into three Site Types; Intact, high quality glades; Degraded, forest-encroached glades, and Restored glades which had received woody vegetation removal and burning. Collections of ground spiders (Gnaphosidae), predatory ground beetles (Carabidae), and the sole species of scorpion present in the Ozarks, Centruroides vittatus, were reported on as well as the applicability of arthropod collection methods for glade habitat assessment. Habitat characteristics were recorded for each site and analyzed …

Body Mass And Body Condition Variation Of Mallards (Anas Platyrhynchos) Within And Among Winters Within The Lower Mississippi Alluvial Valley, John Thompson Veon

Graduate Theses and Dissertations

Most North American waterfowl overwinter in southern North America before migrating back to breeding grounds in the northern US and Canada. These species face the challenge of needing to maintain or increase their body mass during an environmentally difficult winter period. Successful body mass maintenance during the winter period has major ramifications not only for their winter survival but for their fitness across the entire year. Recent research in Europe and the western United States suggests that the body mass of mallards (Anas platyrhynchos) has increased from the late 1960s to early 2000s. However, the factors responsible for increases in …

Host-Parasite Interactions Within Food Webs, Adam Zvanut Hasik

Graduate Theses and Dissertations

Parasitism is one of the most common life history strategies employed in nature, yet the effects of parasites are often thought to be minimal, and the vast majority of studies fail to consider parasites and their effects on host organisms. This is likely a problem, as the magnitude of parasite-mediated effects on their hosts can be quite large. Additionally, the effects of parasites are known to extend beyond the host to affect other species interactions. I used a series of approaches to gain a more integral understanding of host-parasite interactions by studying (1) the effects of parasites on biotic interactions …

Establishment Of Pollinator Habitat Within A Livestock Pasture Ecosystem, Roshani Sharma Acharya

Graduate Theses and Dissertations

Pollinators are important for fertilization, setting fruits, and seed development of more than 78% of the flowering plants that provide food for human beings and other species. Use of pollinators to maximize crop production is a proven agricultural practice; however, it has been less explored in livestock forage production systems. This study investigated pollinator abundance and diversity in pastures using different sampling methods and determined the impact of different pasture management practices on insect pollinators in a livestock pasture ecosystem. In Chapter 2, utility of four different colors of pan trap (blue, green, yellow, and purple) for sampling bees in …

Influence Of Local- And Landscape-Scale Factors On Avian Assemblage In Fragmented Tallgrass Prairie Landscape, Pooja Panwar

Graduate Theses and Dissertations

Agricultural expansion and increasing urbanization are driving rapid landscape modification in the Tallgrass prairies ecosystem and are affecting biodiversity at multiple spatial scales. Thus, the conservation of fragmented grassland and steeply declining grassland avifauna is dependent on the relationship between local- and landscape-scale factors and avian assemblage. We also need to understand how these factors, operating at different spatial scales, drive the occupancy of different guilds in the assemblage. We conducted repeated point count surveys during the breeding season of 2019 at 66 grassland sites across Arkansas and Missouri, USA. We developed a multi-species occupancy model to estimate species richness, …

Climate-Driven Impacts On Himalayan Aquatic Biodiversity: A Case Study Involving Snowtrout (Cyprinidae: Schizothorax), Riri Wiyanti Retnaningtyas

Graduate Theses and Dissertations

Monitoring biodiversity, to include its relative dispersal and contraction, has become a conservation task of great importance, particularly given the catastrophic and ongoing loss of habitat due to climate change. However, the timing, direction, and magnitude of these rates vary across taxa and ecosystems. Predicting specific impacts of climate change can thus be difficult and this, in turn, hampers management action. Metrics are needed to not only quantify contemporary requirements of species, but also predict potential distributions that fluctuate in lockstep with climate.

Montane ecosystems in the Himalayas are highly impacted by climate change, yet remain largely understudied due to …

Population Connectivity Of The Eastern Collared Lizard Crotaphytus Collaris In Arkansas, Whitney Allison Murchison-Kastner

Graduate Theses and Dissertations

Habitat reduction and fragmentation can isolate populations and decrease genetic diversity, making them susceptible to local extirpation. Additionally, geographic barriers can further impede dispersal among populations thus reducing gene flow. Field studies suggest these factors may be responsible for the decline in Eastern Collared Lizard (Crotaphytus collaris) populations in Arkansas. To address the impacts of habitat loss and fragmentation on the Eastern Collared Lizard (C. collaris) in Arkansas, I used DNA fragment analysis to examine genetic diversity, population structure and connectivity among C. collaris populations. I do so herein by employing microsatellite data from 138 adults across 11 loci to …

Role Of Reptile-Invertebrate Interactions In Enigmatic Reptile Declines, Meredith Swartwout

Graduate Theses and Dissertations

Reptile populations are declining world-wide and the mechanisms behind many of these declines remain enigmatic. Food web interactions (i.e., reduced prey availability or increased predation) have been implicated behind some reptile declines. However, relatively little is known about predation on lizard and snake eggs, despite egg survival being important for population dynamics of some species. Ants are important predators of squamate reptile eggs in tropical and temperate systems. In Costa Rica, long-term declines in terrestrial anole lizards were linked with reduced leaf litter depth, a factor that could influence egg vulnerability to ant predation. Fire ants (genus Solenopsis) are aggressive …

Spore Dispersal Of Slime Molds And Higher Fungi Via Animal Vectors, Courtney Trimble

Graduate Theses and Dissertations

Myxomycetes and dictyostelids are Amoebozoans that are cosmopolitan inhabitants of a variety of habitats, particularly forest environments. Both groups reproduce using spores which are primarily dispersed via wind in myxomycetes but this characteristic poses a problem for dictyostelids. The spores of dictyostelids are incased in a mucilaginous matrix that makes wind ineffective except in exceptional cases. It has been suggested that animals such as birds may play an important yet understudied role in the dispersal of these organisms. This study investigated how animals could potentially serve as vectors for spore dispersal of dictyostelids and myxomycetes with some limited data obtained …

Of Biodiversity, Boundaries, And Distribution: The Myxomycetes Of The Philippines And Beyond, Sittie Aisha Bustamante Macabago

Graduate Theses and Dissertations

This dissertation contains a compilation of independently performed studies primarily focusing on the myxomycetes (plasmodial slime molds) from the Philippines and integrating local and worldwide data to demonstrate regional and global trends. The major themes include the following: (I) a review of the diverse group of spore-producing amoeboid protists, including the myxomycetes; (II-IV) diversity assessments in three different groups of islands in the Philippine archipelago; (V) mapping the myxomycetes found in the Philippines for databasing and analyzing the geocoded data; (VI) a study on regional boundaries, including the Philippines, using myxomycete species composition; and, (VII) creating a global species distribution …