Thesis (M.S.)--Humboldt State University, 2006. / Includes bibliographical references (leaves 91-97). Also available via Humboldt Digital Scholar.

Apesar de vários estudos já terem examinado os efeitos de queimadas naturais, respostas das aves, como variação do padrão da comunidade, guilda trófica e das espécies, ao manejo de fogo ainda não foram investigadas em reservas do Cerrado, Este trabalho teve como objetivo comparar a avifauna em trechos de campo sujo manejados (aceiros) e não manejados por fogo no Parque Nacional das Emas, Brasil Central. Este é o primeiro trabalho a avaliar os efeitos do manejo do fogo prescrito sobre comunidades de aves no Cerrado. Foram selecionados 12 locais de estudo. Em cada local, havia um transecto no aceiro e outro em campo sujo não manejado. Uma amostra consistiu em percorrer um transecto de 800m a pé, anotando as aves detectadas visual ou auditivamente a 15m do observador. Frequência de ocorrência e abundância das espécies e das guildas tróficas, riqueza total, abundância total da comunidade de aves e composição de espécies encontradas nos dois ambientes foram comparadas. No total, foram 881 registros e 41 espécies de aves. A riqueza e a abundância total de aves foram significativamente menores em aceiros. Houve diferença na composição de espécies de aves entre campos não manejados por fogo e aceiros. Dentre as guildas tróficas, os onívoros foram mais frequentes em campos não manejados. Granívoros, nectarívoros e onívoros foram mais abundantes em vegetação não manejada. Das 21 espécies analisadas separadamente, a coruja Athene cunicularia foi a única indicadora de aceiros e também mais frequente e abundante em aceiros. Por outro lado, foram identificadas quatro espécies indicadoras de campos sujos não manejados (Melanopareia torquata, Xolmis cinerea, Neothraupis fasciata e Coryphaspiza melanotis). Tais espécies podem ser usadas como indicadores ecológicos do regime e histórico do fogo e podem fornecer informações se os objetivos das ações de manejo do fogo estão sendo atingidos. Sete espécies foram mais frequentes e oito espécies foram mais abundantes em campos não manejados. Três dessas espécies são endêmicas do Cerrado (M. torquata, N. fasciata e Cypsnagra hirundinacea) e quatro estão sob algum grau de ameaça e são altamente sensíveis a distúrbios (Polystictus pectoralis, Alectrurus tricolor, C. melanotis e C. hirundinacea). Assim, cuidado e atenção devem ser redobrados para essas espécies, pois possuem alto valor para conservação e menor frequência ou abundância em aceiros. A menor riqueza e abundância de aves encontrada em aceiros devem estar relacionadas ao menor uso desse habitat, indicando menor disponibilidade de recursos como alimento, reprodução e abrigo, dado que o fogo altera a estrutura e composição da vegetação. Isso demonstra uma diminuição da qualidade do ambiental geral dos aceiros, provocada pela sua atual forma de manejo. Propomos que a queima dos aceiros seja feita em intervalos de 3 anos, em vez de 1 2 anos como tem sido realizada. Dessa forma, seria mantida a função dos aceiros como controle e barreira efetiva de incêndios e também para conservação da biodiversidade. / Several studies have investigated the effects of natural fires on Cerrado birds. However, avian responses to fire management have not been examined. We compared birds found in firebreaks (fire managed areas) and in fire unmanaged grasslands, in Parque Nacional das Emas, Central Brazil. This is the first study to evaluate the effects of prescribed fire on the Cerrado avifauna. We selected 12 study sites. We established one transect in the firebreak and another one in an unmanaged grassland area in each study site. Each bird count sample consisted of walking through an 800m transect recording birds seen or heard 15m from the observer. Species richness, total bird abundance, species composition, feeding guilds abundance and frequencies of occurrence and species abundance found in firebreaks and unmanaged grasslands were compared. In total, 881 individuals and 41 species were recorded. Species richness and total abundance were significantly lower in firebreaks. Species composition was different between firebreaks and unmanaged grasslands. Omnivores were more frequent and more abundant in unmanaged grasslands. Granivores and nectarivores were more abundant in unmanaged grasslands. Twenty-one bird species were analyzed separately, one of which (Athene cunicularia) was indicator of firebreaks and also more frequent and abundant in firebreaks. On the other hand, we identified four indicator species of unmanaged grasslands (Melanopareia torquata, Xolmis cinerea, Neothraupis fasciata and Coryphaspiza melanotis). These species might be used as ecological indicators of fire regime and history, and also give information if fire management goals are being achieved. Seven species were more frequent and eight species were more abundant in unmanaged grasslands. Three of them are endemic of Cerrado (M. torquata, N. fasciata and Cypsnagra hirundinacea) and four of them are highly sensitive to human disturbances and threatened with extinction in some degree (Polystictus pectoralis, Alectrurus tricolor, C. melanotis e C. hirundinacea). Caution must be redoubled to these species, as they are of high conservation priority and less frequent and abundant in firebreaks. The lesser avifauna complexity in firebreaks than in unmanaged areas might be connected to the low use of this habitat, thus indicating lower resource availability, such as food, sites for reproduction and refuge. This is because fire changes vegetation structure and composition. We propose that firebreaks should be burnt every 3 years, instead of 1-2 years. In this way, fire management would keep its function as effective fire barriers and would also keep biodiversity conservation.

Leafy spurge (Euphorbia esula L.) is a costly noxious weed to manage in the Northern Great Plains; it invades rangelands and displaces native and desirable vegetation. Our first objective was to test the recommended full rate and half rate of selected herbicides applied in September following a spring burn on a leafy spurge invaded plant community. Our second objective was to determine if raffinate (desugared beet molasses) applied to leafy spurge invaded rangeland would attract cattle to consume leafy spurge. The aminocyclopyrachlor with chlorosulfuron treatment had the best leafy spurge control at the full rate, with stem density reductions of 95 percent for both sites nine and twelve months after treatment. The salt block treatment had the best success at reducing leafy spurge stem density. Herbicides can be the most common and effective type of management; however, manipulating livestock to graze noxious weeds converts a weed into a useable forage.

No description available.

No description available.

The purpose of this study has been to test public perceptions of both scenic quality and recreational acceptability of southwestern ponderosa pine forests exibiting one-to-five years of recovery from both light and severe fire. Public fire-effects information documents were also constructed and tested. Appropriate ponderosa forest areas in Arizona were selected and randomly photographed. Population samples, drawn from Tucson, Arizona, first read fire-ecology or "control" information brochures and then rated forest scenes on 1-to-10 scales for scenic quality and for acceptability for selected forms of outdoor recreation. Respondents finally answered a short fire-knowledge, fire-attitude questionnaire. Ratings were subjected to SBE analysis (Daniel and Boster, 1976), and analysis of variance was applied to both ratings and questionnaire results. The clearest distinction drawn, for both scenic quality and recreational acceptability, is between light-fire and severe-fire effects. Light fire improves scenic quality for a 3-to-4 year period, while severe fire seriously detracts from scenic quality for an unknown length of time exceeding the 5-year period tested. Recreational acceptability is differentiated according to the recreational activity selected: camping is nearly twice as sensitive to severe fire effects as scenic quality, and is somewhat disrupted by light fire effects; picnicking is second-most impacted by severe fire effects; hiking or backpacking is affected by severe fire to about the same degree as scenic quality; nature study is least affected. Picnicking, hiking and nature study are not significantly affected by light fire. Provision of fire-effects information does not significantly affect scenic or recreational evaluation of forest burn areas. The fire-effects information brochures produced general "halo" effects on both fire knowledge and fire attitude in the groups sampled. Fire knowledge shifted toward the expert position that fire effects are less severe than generally believed. Fire attitude shifted toward the expert position of greater tolerance for fire in ponderosa ecosystems. Results show prescribed burning as generally acceptable. The results of this study demonstrate distinctions between affect (perceptual evaluations) and cognition (questionnaire response). Scenic and recreational evaluations emerge as clearly distinct entities.

A moderately intense, broadcast, understory, prescribed burn in 3 previously unburned ponderosa pine stands in southeastern Arizona felled or consumed 50% of all ponderosa pine snags ≥ 15 cm dbh. Large moderately decayed snags were most susceptible to burning. Large snags in the early stages of decay were preferred as nest sites by cavity-nesting birds. Numbers of live woody plants were reduced by 40%, mortality was greatest among shrubs and small trees. Canopy volume was reduced by 19%, the greatest impact was below 5 m. No species of cavity-nesting birds, or birds that associated with understory vegetation disappeared in the first season after burning, but 3 species decreased, and 1 species increased in abundance. The minor impacts of a single treatment with broadcast understory burning on bird populations will be ephemeral, but a repeated burns could have greater, and more lasting effects on the avian community.

Polycyclic (or polynuclear) aromatic hydrocarbons (PAHs) are environmental pollutants produced during the incomplete combustion of organic matter. Since many of these compounds have been shown to be mutagenic and/or carcinogenic, an investigation was initiated into determining the PAH content and mutagenicity of the ash that remains after sugar cane crop burning, and the soot deposited on toll booths by vehicle exhaust emissions. Due to the large amount of sugar cane farming in the Natal coastal region and that the favoured method of disposing unwanted leafy trash is crop burning, concern was expressed as to the nature of the residue that is formed. PAHs have been identified in the residues from combusted wood and straw and, due to their intrinsic similarity to sugar cane, it was considered that the burning of sugar cane could generate PAHs. It is well documented that vehicle exhaust emissions exhibit mutagenic properties and PAHs have been identified as the major contributors of this observed mutagenicity. Since a toll plaza is an area of high traffic density, it was considered to be an ideal location for an investigation into the build-up of particles emitted by the passing vehicles, and to study to what extent the operators are exposed to harmful compounds. In addition, this sample acted as a control, since the detection of PAHs and mutagenic activity in the soot would be an indication that the correct experimental techniques were being employed. Samples were collected on site. The sugar cane ash was collected off a field immediately after burning had taken place, and the soot was collected either by scraping the toll booth walls and surrounding areas or by wiping the surfaces with cotton wool swabs. The organic portion of the samples was separated from the inorganic and carbonaceous substances by extraction into a suitable solvent; the use of both acetone and dichloromethane was investigated. The extracts were divided into two portions - one was used for the analysis of PAHs and the other for determining mutagenic activity. Analysis for PAHs involved subjecting the extracts to a sample clean-up routine and the use of a number of analytical techniques to characterise the components. The mutagenic properties of the samples were investigated by means of two bacterial mutagenicity tests: the Salmonella typhimurium assay (the Ames test) and a new commercially available test kit, the SOS Chromotest. A number of PARs were identified in the extracts by means of reverse phase high performance liquid chromatography (HPLC) with both ultraviolet and fluorescence detection, the latter being the more sensitive method. Mutagenic activity was detected for both samples in the Ames test and for the toll booth soot in the SOS Chromotest, and this observed mutagenicity was attributed to the presence of the PAHs. / Thesis (M.Sc.)-University of Natal, Durban, 1992.

Fire plays a key role in the ecology of the Everglades and is a ubiquitous tool for managing the structure, function, and ecosystem services of the Greater Everglades watershed. Decades of hydrologic modifications have led to the alteration of plant community composition and fire regime in much of the Everglades. To create a better understanding of post-fire recovery in sawgrass (Cladium jamaicense) communities, sawgrass marshes in the northern Everglades were studied along a chronosequence of time since fire and along a nutrient gradient. Areas closer to a water nutrient source and with fewer mean days dry contained greater total and dead aboveground graminoid biomass whereas live graminoid biomass was greater in areas with less time since fire and with fewer days dry. Post-fire characteristics of sawgrass marshes can provide insight on the effectiveness of fire management practices in the maintenance and restoration of quality habitat in the northern Everglades. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

The effects of fire on vernal herbs of the mesic forests of eastern North America are poorly understood. I studied the influence of prescribed fire on species richness, abundance of rare and common species, and density of exotics in the vernal herbaceous layer. To determine these effects, three sites in central Kentucky were surveyed prior to and following one of three treatments: spring burn, winter burn, or negative control. I conducted low-intensity spring burns in April 2010 and winter burns in February 2011. I used chi square analyses to test for changes in species richness, abundance of rare species, abundance of common species, and abundance of Glechoma hederacea, an exotic herb. I used multiple logistic regressions to test for the effect of burn severity on the abundance of two of the most common herbs, Erythronium americanum and Viola sororia sensu lato. The abundance of rare species increased significantly after fire treatment, with a 2% greater increase on burned plots than control plots (p < 0.05), and showed a 40% greater increase in plots burned in winter than plots burned in spring. However, there was no significant difference in overall species richness due to fire or to the season in which the prescribed fire was conducted. There were no significant differences in the density of common species or Glechoma hederacea due to fire treatment or due to fire season. There were also no significant differences in the abundances of Erythronium americanum or Viola sororia sensu lato due to burn severity. Changes in the abundance of rare species due to fire might suggest that prescribed burns may slightly increase the diversity of vernal herbs in eastern mesic forests. Changes in the abundance of rare species due to fire season might suggest that prescribed fires conducted prior to emergence may further increase the diversity of vernal herbs in the eastern mesic forest.