<p> Cold-water corals increase habitat heterogeneity and enhance biodiversity in deep waters worldwide. Despite the recognition of their importance in the deep sea, limited data exist on the ecology and evolution of deep-water corals. The overarching goal of this dissertation research was to integrate molecular, morphological, and ecological data to understand the degree to which populations are connected, species are distributed, and communities are assembled in the deep (250&ndash;2500 m) Gulf of Mexico (GoM). Specifically, several hypotheses were tested regarding the roles of environmental variables, particularly depth, influencing population and community structure. Combining phylogenetic and population genetic approaches with ecological data enabled species delimitations of many taxa while demonstrating that deep-water populations and communities diverge over short bathymetric distances. It appears that population isolation, congeneric species replacement and changes in community composition occur rapidly with depth, and these changes are likely due to a combination of both dispersal limitation and adaptive divergence with depth. Local self-recruitment may also be strong within any one site. Furthermore, results suggest that evolutionary history and neutral dynamics play a critical role in octocoral community assembly in the deep sea. This dissertation not only contributes a substantial amount of evolutionary and ecological information on a poorly studied group of foundation species in the deep sea, this research has broader implications for aiding in efforts to protect these long-lived, foundation species from anthropogenic disturbances.</p>

<p> This dissertation introduces the idea of alchemical permaculture: a new field that integrates ecopsychology, permaculture, and Jung's interpretation of alchemy&mdash;three areas of study and practice concerned with the transformative relationship(s) between planet Earth and its humans. An interdisciplinary approach to the research suggests that permaculture can become ecopsychological praxis if it is situated within the mythopoeic context of Jung's interpretation of alchemy. In addition to creating a very practical application of ecopsychology the conception of alchemy is dreamt onward, finding contemporary ecopsychological expression through permaculture landscape design. </p><p> Through comparative theoretical interpretation and narrative illustration the author emphasizes the interdisciplinary significance these three primary subjects have to offer each other and the present moment. Literature for comparison includes writings from a variety of ecopsychologists and historians of alchemy, scholars of Goethean science and Jungian psychology, and contemporary voices in the field of permaculture. Integrating these disciplines offers multiple perspectives to the science of ecology, provides a unique philosophical praxis to caring for the Earth, and highlights every act of land stewardship as an equal opportunity for both ecological and psycho-spiritual transformation. </p><p> Alchemical permaculture addresses the question "How can we dream the alchemical project forward, encouraging humanity as a whole to improve its ecological, psychological, and spiritual relationship with nature?" Alchemical permaculture integrates the practical designs, ethics, and values of permaculture with human psychology and spirituality. Alchemical permaculture illustrates what may be considered a branch of ecotherapy, or a kind of ecopsychological praxis, taking place in a broadened vessel of transformation that includes nature as well as psyche, helping to illuminate the mirroring relationships between inner and outer landscapes, between land and steward.</p>

<p> Increased agriculture and urbanization in southwestern Illinois have severely fragmented the forests of the region. Habitat fragmentation may cause lower species richness, population declines, or extirpation due to phenomena such as edge effects, inbreeding depression, and stochasticity. The effects of habitat fragmentation on suburban wildlife are poorly understood, especially for small mammals such as the Southern Flying Squirrel (<i>Glaucomys volans</i>). Flying squirrels are arboreal rodents whose presence in a forest is indicative of habitat quality, as this species prefers mature and relatively open forest stands. Flying squirrels can be found in the forested areas of the Southern Illinois University Edwardsville (SIUE) campus. Demographic features of this population and habitat use among forest patches were unknown. Artificial nest boxes were utilized to perform a mark-recapture study of the flying squirrel population as well as examine habitat use. Objectives were to obtain demographic information, and to create a predictive habitat model relating habitat characteristics to presence or absence of nest box materials using logistic regression. Study sites consisted of 145 randomized plots in three forest patches located within the SIUE campus, which were monitored November 2013 through October 2014. A model was generated for combined activity (nesting or feeding materials were present) at plots, which contained forest age, dominance of hard mast at a plot, tree density, topographic position, richness of the shrub layer, and the 90th percentile diameter at breast height. Habitat models were also generated for specified response variables of feeding material presence and nesting material presence. The top model for predicting feeding material presence in a nest box contained dominance of hard mast on a plot, richness of the shrub layer, and basal area of logs. The top model for predicting nesting material presence in a nest box contained the shrub layer stem count, roughness of the nest box tree bark, proximity to edge, cavity count, and the average hard mast dominance in the area surrounding the plot. Models tended to include characteristics regarding hard mast dominance and refugia, suggesting nest box use was influenced by avoidance of predation and food resource availability.</p>

<p> While the processes that led to the formation of modern plant communities are often cryptic, biogeographic patterns of extant species can provide clues to their origin. The Midriff Islands, an archipelago in the Gulf of California at the center of the Sonoran Desert, provide an opportunity to investigate the origins of the desert. This research uses three case studies at three different time scales to better understand the factors responsible for modern biodiversity. </p><p> Chapter 1 revisits the theory of island biogeography and incorporates the long history of humans on the Midriff Islands to determine factors controlling plant species richness. Area, habitat diversity, island type, and seabird dynamics explain 98% of the variability in species richness across this archipelago. Interestingly, human presence is not predictive, suggesting an island system with ancient human interactions that functions in a pre-Anthropocene state. </p><p> Chapter 2 investigates Holocene extinctions. In 1975, bighorn sheep (<i> Ovis canadensis</i>) were introduced as a novel element to Isla Tibur&oacute;n as a conservation measure. Fossil dung found on Isla Tibur&oacute;n was 14C-dated to 1476-1632 years before present and identified as <i>Ovis canadensis </i> by morphological and ancient DNA analysis. Bighorn sheep went locally extinct on the island sometime in the last ~1500 years prior to their "unintentional rewilding." This discovery questions the definition of a non-native species and extends an ecological and conservation baseline. </p><p> Disjunct long-lived plant taxa on Isla Tibur&oacute;n suggests climate and vegetation change on the Midriff Islands in the Pleistocene. Chapter 3 is a phylogeographic study of the desert edge species <i>Canotia holacantha </i> (Celastraceae) that tests whether <i>Canotia</i> on Isla Tibur&oacute;n is a Pleistocene relict or a recent dispersal event. Results suggest long isolation and divergence of <i>Canotia</i> on Tibur&oacute;n but recent arrival in the core of its modern day distribution in Arizona. In contradiction to an expected temperate origin, <i>Canotia</i> seems to have tracked the northward shift of the desert's edge at the end of the last Ice Age from glacial refugia in Sonora or Chihuahua. </p><p> Collectively, this research helps illuminate the history of the desert and establishes baselines to support management decisions of the world's best-preserved archipelago.</p>

<p> Suisun Marsh is a 470 km² wetland situated between the Sacramento-San Joaquin Delta and San Pablo Bay in the San Francisco Estuary. Today, about 80 percent of the marsh plain is privately owned by duck hunting clubs and managed in accordance with conservation agreements. A complex network of sloughs weaves through the Marsh, providing habitat for numerous aquatic species. Together the waterways and marsh plain support a stunning array of species, provide exurban open space, and are increasingly called upon to meet regional conservation objectives. The Marsh is vulnerable to sea level rise impacts, pollution, and other human impacts, so understanding how it functions so it can be successfully managed to meet the lofty objectives set out for it will be critically important in the decades ahead. This study reviews landscape-scale historical ecology of Suisun Marsh and examines recent variation in fish populations from a geographical perspective.</p><p> Chapter 1 presents the geomorphic and physical history of the landscape, explaining processes driving wetland development and contributing to unique functional subregions within the Marsh. Chapter 2 examines human- and animal-landscape interactions. Ecologically significant shifts in human and animal populations during the Spanish and Mexican eras, followed by agricultural development in the late 1800s and duck club management starting around 1900, have kept the Marsh landscape continually changing. The rate and magnitude of landscape change has intensified since European contact in 1769 and even more since the Gold Rush of 1849. Chapter 3 explores landscape-scale variation in species distribution and abundance based on a long-term study of Suisun Marsh fishes and invertebrates and presents these data in novel animations. Animated maps are used to explore shifting populations of fishes and invertebrates from 1980 to 2013, demonstrating the value of long-term biogeographical datasets in understanding biological communities at the landscape scale.</p><p> Understanding both the deep and recent history of the Marsh provides insights and inspiration, informs management approaches, points to potential restoration and rehabilitation targets, and affects attitudes about appropriate human interactions with this dynamic biological system and landscape.</p>

<p> The Sunken Forest, located on Fire Island National Seashore, is a critically imperiled habitat and is one of only two known old-growth maritime holly forests in the world. Analysis of a dataset that dates back to nearly half a century has helped to identify major drivers influencing changes within the forest. These major drivers include; white-tailed deer herbivory, erosion, sea level rise, increased storm events, and canopy-gap dynamics. As of 2013, the Sunken Forest canopy is still analogues of 1967, but over the last 35 years vegetation recruitment within the forest has become limited due to white-tailed deer (<i>Odocoileus virginianus</i>) herbivory. The bayside of the Sunken Forest has also been eroding. Erosion with added pressure from sea-level rise is causing mortality of trees/understory vegetation, limiting seedling and herb recruitment, and shifting vegetation toward the bayside and low elevation areas within the interior of the forest.</p>

<p> Buffelgrass (<i>Pennisetum ciliare</i>) is a perennial bunchgrass native to Africa that has invaded ecologically intact areas of the Sonoran Desert in southern Arizona. It threatens many native plant species by means of competitive exclusion as well as increased fire frequency and intensity. Since the 1990s, efforts have been underway in southern Arizona to control buffelgrass using manual removal. A problem with this method is that the resulting bare, disturbed soil provides a favorable environment for buffelgrass seed germination. This study examined whether thatch composed of uprooted buffelgrass parent plants spread over disturbed areas reduces the density of progeny seedlings. A secondary goal was to determine whether light attenuation and/or autoallelopathy were major factors involved in the effect of thatch on buffelgrass seedling density. The effect of light attenuation on seedling density was tested in containers in the field and in the greenhouse. The propensity of thatch to produce autoallelopathic chemicals was tested in the greenhouse. Field plots with thatch had 1.9 buffelgrass seedlings/m² which was significantly fewer (<i>p</i> = 0.03) than the 2.9 seedlings/m² in plots without thatch. These results suggest that the placement of thatch over areas disturbed during manual treatment of dense stands of buffelgrass will increase the efficiency of follow-up control of buffelgrass progeny seedlings in these areas. Results of the field container study suggest that light attenuation does not play a significant role (<i>p</i> = 0.39) in the reduction of seedling density by thatch, whereas those of the greenhouse shade treatment study indicated that light attenuation is a significant factor (<i>p</i> = 0.004). However, because percent germination was very low in the field container study, those results may be of little value compared to the greenhouse shade treatment study results which indicate that light attenuation is a mechanism by which thatch reduces buffelgrass seedling emergence. Chemicals leached from decomposed buffelgrass thatch did not have a significant effect (<i>p</i> = 0.09) on buffelgrass seedling density. Only the combination of thatch and leached chemicals significantly reduced (<i>p</i> = 0.014) seedling density. Thatch may also increase the activity of other factors that could reduce seedling density such as pathogens, and predators of seeds and seedlings.</p>

Typically, drought occurs once every three years across the Canadian Prairies. Most research addressing such droughts has concentrated on the large scale conditions associated with this form of extreme weather whereas little research has been conducted on its smaller scale characteristics. The present research begins to address the latter issue. / Several datasets (surface observations, drought indices, and re-analysis products) were used to identify and analyze the 11 most severe droughts occurring over the Prairies since 1953. Warm season hourly surface observations (temperature, moisture, clouds, and precipitation) from 10 observational sites were then compared for extreme drought, drought, non-drought, and extreme wet conditions. When compared to non-drought or extreme wet conditions, drought and extreme drought conditions are associated with warmer temperatures and drier conditions and there is little change in the amount of total cloud cover but cloud bases are higher. As well, the maximum temperature and highest cloud base both occur 1-2 h later in the afternoon during drought and extreme drought conditions as compared to non-drought and extreme wet conditions. Such factors act to extend the drought conditions. For example, the higher cloud bases during drought and extreme drought conditions lead to greater evaporation of falling precipitation and this prevents significant precipitation from occurring thereby reinforcing the dry conditions.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7071. Adviser: Patrick J. Weatherhead. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008. / Source: Dissertation Abstracts International, Volume: 69-11, Section: B, page: 6531. Adviser: George O. Batzli. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.