Forest Sciences Commons^™

Fact Or Fiction: Random Mating In Field Populations Of Western Corn Rootworm (Diabrotica Virgifera Virgifera Leconte) Emerging On Bt And Refuge Corn Plants, Steven Joel Smith

Open Access Theses

The western corn rootworm, or WCR, (Diabrotica virgifera virgifera LeConte) is the most significant pest of field corn (Zea mays) in the United States, and has recently expanded its range into Europe. Since 2004, hybrid corn containing Bt toxins targeting the corn rootworm complex have been heavily adopted and are now the primary control measure for this pest in North American corn production. ^ The evolution of resistance is an ongoing concern, and to ensure Bt products will retain their usefulness, insect resistance management (IRM) tactics using various refuge structures have been adopted. One of the key …

Assessing Grazing Impacts On A Tropical Dry Forest System In Madagascar Through Vegetation, Satellite Image, Lemur Occupancy, And Acoustic Analysis, Lyndsay Lee Rankin

Theses, Dissertations and Capstones

The ability to assess the quality or ecological value of a landscape is a useful tool in effective conservation and natural resource management. Ecosystem biodiversity and functionality are reduced when human activities cause habitat alteration and/or fragmentation. Compromised habitats are unlikely to support naturally occurring communities or healthy ecosystem functions. Conservation scientists have historically concentrated their efforts on large, intact habitats with little human disturbance; the conservation value of small and/or disturbed areas has been comparatively overlooked. One limitation may be a lack of tools to identify disturbed areas with conservation value. Techniques that allow researchers to assess the habitat …

Fate Of Eucalyptus Marginata Seed From Canopy-Store To Emergence In The Northern Jarrah Forests Of Western Australia: Research To Help Improve Regeneration Following Shelterwood Treatment, Jeffrey Cargill

Theses: Doctorates and Masters

The establishment of seedling regeneration is a key process in and indicator of ecologically sustainable forest management. The availability of seed and the creation of a suitable seedbed are recognised as important factors limiting seedling recruitment. A silvicultural method commonly used across northern and eastern jarrah forest blocks is shelterwood cutting. The primary objective of treating jarrah forest to shelterwood is to promote seedling regeneration in areas lacking sufficient advanced growth. Despite the widespread and progressive implementation of the shelterwood method, its application in jarrah forest has shown varying degrees of success.

This thesis sought to investigate and better understand …

Drought Sensitivity Of Slash Pine And Longleaf Pine Deduced By Tree Ring Analysis, Conor Madison

Honors Theses and Capstones

Annual tree rings give us the opportunity to investigate the adaptation of trees to climate and environmental changes over a long period of time. In particular, the physical characteristics of each ring (width and earlywood and late wood differentiation) can be used to reconstruct past environment conditions. Physiological responses of trees will be evaluated for two conifers species, i.e. Longleaf pine and Slash pine, giving the opportunity to compare the two species and understand how each species (Longleaf pine and Slash pine) adapt their water use to thrive in such extreme environments. Growth data will then be related to the …

The Effects Of Herbicide On The Endangered Herb Baptisia Arachnifera And Preliminary Nutrient Survey Of Leaf Tissue And Soil, Ruth Ann C. Steinbrecher

Electronic Theses and Dissertations

Baptisia arachnifera (Hairy Rattleweed) is an endangered herbaceous legume that only occurs in Wayne and Brantley Counties of Georgia, United States. Many of the remaining populations exist in areas now managed for timber. This study investigated the effects of Imazapyr, an herbicide commonly used in timber management, on health and vitality of B. arachnifera under both field and greenhouse conditions. This study also analyzed leaf and soil samples from six populations of B. arachnifera to determine the nutrient content of the leaves. A recensus of a B. arachnifera population was also conducted in a site without commercial timber management. In …

Long-Term Changes In Four Plant Communities Along An Elevational Gradient In The Front Range Of Colorado, Gregory J. Sproull

Electronic Theses and Dissertations

We surveyed four plant communities along an elevational gradient in the Front Range of the Colorado Rocky Mountains for long-term overstory and understory changes. Our results were compared to those found in 1981 and 1996. We evaluated changes in succession, elevational species migration and range expansion, community diversity, and composition. We related temporal floristic shifts to prior literature on disturbance history at each site. Over time, all communities changed significantly, though in different manners. This analysis shows that plant communities are changing in dynamic and idiosyncratic ways that correspond to individualistic distribution shifts. Moreover, we exhibit the necessity of comprehensively …

Comparison Of Oak And Sugar Maple Distribution And Regeneration In Central Illinois Upland Oak Forests, Peter J. Frey

Masters Theses

Although white oak (Quercus alba) dominated much of the mid-west and eastern US hardwood forests prior to European settlement, changes in disturbance frequencies and habitat fragmentation, coupled with other biotic pressures, are allowing sugar maple (Acer saccharum Marshall) to displace oak in the upland forest understory. Since our understanding of how disturbance mechanisms influence oak regeneration is not fully clear, there is lack of consensus on how to employ management practices. We collected seedling microhabitat data from 5 upland oak forest sites in central Illinois, each differing in age class and/or silvicultural treatment to determine: 1) Whether …