No description available.

Thesis (M. Phil.)--University of Hong Kong, 1995. / Includes bibliographical references (leaf 191-199).

No description available.

Revised

No description available.

This research presents the findings of a pollinator diversity study that took place at three study sites. Although variation in pollinator diversity occurred between the three sites, fewer pollinators than expected were recorded from the La Joya Tract (revegetated site). Numerous genera and species were recorded from the Havana Tract (native site) as well as the Valley Nature Center (urban garden). In contrast, the La Joya Tract had a comparatively depauperate pollinator fauna. The numbers of pollinator genera and species recorded from the three study sites were decreased in comparison to the total number of genera and species recorded from Hidalgo County. Hidalgo County has 35 known genera and 75 species of bees documented to date. About 40% of the genera and 23% of the species recorded from Hidalgo County were recorded from the Havana Tract in this study, while a mere 8.5% of the genera and 4% of the species were reported from the La Joya Tract and 34% of the genera and 16% of the species were reported from the Valley Nature Center. Although the vascular plant species identified from these study sites were diverse, the floral rewards they provided yielded an insight as to what was going on in terms of pollinator diversity. Plants may yield nectar or pollen floral rewards or both in some cases to pollinators. The current study provides evidence that revegetation of land with plants that primarily provide nectar rewards will result in fewer observed bee taxa than from land revegetated with plants that provide a mix of nectar and pollen floral rewards.

Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on January 6, 2010. Major professor: V.L. Holland, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Biological Sciences." " 2009." Includes bibliographical references (p. 79-88).

Electrical generating stations in arid regions produce saline water from their cooling systems. Coal fired plants generate fly ash which is recovered by smokestack scrubbers. This ash typically is disposed in large evaporation ponds, which leave vast ash beds and volumes of saline leachate. Restoration of vegetation and wildlife habitat on ash ponds and other impacted areas is complicated by a lack of high quality water for irrigation. I used saline water generated by plant operations to irrigate species of halophytes. These salt tolerant plants were used to revegetate ash ponds and other degraded sites at two generating stations. Once vegetation was established, it provided habitat for wildlife, forage for domestic ruminants, ornamental landscaping, controlled fugitive dust and reduced wastewater disposal costs. At the Four Corners Plant in New Mexico, 16 accessions of Atnplex canescens were tested in a common garden experiment irrigated with saline water recovered from a drainage system collecting leachate from the plant's ash ponds. Accessions from latitudes similar to Northern New Mexico grew faster and had a higher percentage of survival than accessions from more southern or northern locations. Accessions best adapted to an area would be preferable for revegetation projects. I also studied several species of halophytes (Atnplex canescens, A. lentiformis, Prosopis velutina and Paspalum distichum) planted at the Ocotillo Plant in Tempe, Arizona and irrigated with saline water from the cooling system. The vegetation had high survival and growth rates after transplanting. Ground cover increased from 5% to 60%. Surveys of wildlife were conducted pre and post-transplantion. Birds, rabbits and lizards were significantly more numerous in experimental planted areas than in untreated control plots. Rodent populations were not significantly different between treatments. Halophytes can be used to revegetate areas adjacent to electrical power plants and irrigated with saline waters that are normally discharged. Devoting saline water to revegetation irrigation is a cost effective method of disposal compared to evaporation ponds. Plantings attracted several forms of wildlife. Birds, rabbits and lizards specifically used the plants for food, cover and nesting. I developed an economic analysis which compares costs and benefits of restoration projects using halophytes irrigated with saline wastewater.

Sod-seeding techniques offer graziers a convenient way to introduce superior grass cultivars into underproductive permanent pastures. Production loss and erosion are minimized. In conjunction with improved grazing management and fertilization, renovation can significantly improve yield and quality of pastures. Existent vegetation must be suppressed prior to introducing new cultivars. This study was conducted on two non-irrigated pastures near Corvallis, Oregon, one dominated by annual grass species and the other by perennial grasses and clover. A split-plot design with four replications on each site was used to compare three seeding methods and either (a) two herbicides following close mowing or (b) close mowing alone. The seeding methods were drilling with an Aerway Seedmatic chisel-type drill, drilling with a Tye double disc drill, or broadcasting seed followed by harrowing. Glyphosate and paraquat were the herbicides used for vegetation suppression. Effect of fertilization was compared to no fertilization. Sod-seeded perennial ryegrass had minimal establishment at the site dominated by annual grass species. An inadequate amount of time was allowed for germination of annual grass seeds before herbicides were applied. Annual grass seedlings suppressed the newly sod-seeded perennial ryegrass. Sod-seeded perennial ryegrass was successfully established at the site dominated by perennial species within one year after planting. Broadcasting followed by harrowing of seed resulted in a higher percentage of perennial ryegrass than either the Seedmatic chisel drill or Tye double disc drill. Sod-seeded perennial ryegrass did not contribute significantly to yield until one year after planting. Glyphosate gave better control of the species present before planting leading to a higher percentage of perennial ryegrass and improved yield compared to paraquat or close mowing alone when seed was broadcast and harrowed. Fertilization of unseeded plots increased yield but was not cost-effective. / Graduation date: 1994

Thesis (M. Env. Sc.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 1999. / Includes bibliographical references (leaves 104-110).