Burns bog is a large sphagnum peat bog occupying approximately 4,000 ha of the Fraser River delta in south-western British Columbia. The area has been extensively disturbed by peat extraction, landfilling and other land-uses. Much of the bog remains in a natural or semi-natural state. As such it represents one of the largest single tracts of underdeveloped land in the Corporation of Delta. Land development and growth in the municipality has been rapid in the past ten years. Because the Burns bog area was not well known and the pressures for development of the area were mounting, this study was initiated in January 1975. Available existing environmental and land-use information pertaining to the Burns bog area was reviewed and collated. Basic vegetation and wildlife inventories were carried out in the area, and a cover map of extant vegetation was prepared. Several aspects of peatland ecology were investigated. These included the determination of the rate of spagnum peat accumulation, an estimate of the energy (caloric content) of the peat stored with Burns bog, and net primary productivity. The bog was found to be floristically interesting and to be quite unlike most of the remaining underdeveloped areas of the Fraser River lowland. Because of its large size, waterlogged character, and location between the Fraser River, Boundary Bay and the foreshore areas of Roberts and Sturgeon banks, Burns bog is believed to be an important natural refuge for many species of birds. The area is an important loafing area for waterfowl, particularly mallard, pintail, and teal, and is a nesting area for a number of raptorial , passerine and other birds. Perhaps one of the more important birds of Burns bog is the greater sandhill crane, which nests in the bog in small numbers. Burns bog supports a number of mammal species. In addition to a variety of "common" small mammals, the area supports a small number of black bear, and Columbian black-tailed deer which are believed to be isolated populations. The land-use patterns of lands surrounding the bog area are believed to be of key importance to bird and mammal life in the area. For example many species of birds (ducks, raptors and sandhill cranes) and mammals (Columbian black-tailed deer and eastern cottontail rabbit) feed at the interface between the forested sections of the bog and the neighbouring agricultural lands. The agricultural character of these peripheral lands appears to influence use of the bog by various wildlife species. The peat samples analysed were found to be high in nitrogen and minerals, although these nutrients were not believed to be available for plant utilization. The volume of peat in the bog was crudely estimated to be 108.8 hm3 . The dry weight of this material was estimated to be 3,949,440 metric tons, and the caloric content of this material was found to be approximately 20,023.76 G. cal. This figure is believed to be the approximate amount of energy stored as peat in the bog. The sphagnum peat accumulation rate and net primary productivity appeared to be considerably higher at hummock sites as compared to wet depressional areas. The average rate of accumulation of ten samples (six hummock and four -wet depression sites) was found to be .43 cm/yr, while the average net primary productivity was 128.8 g/m2 /yr. The vegetation and wildlife of the bog are largely determined by the land-use practices surrounding and within the bog. For example, "improving" the drainage of the area for the agricultural reclamation of the peatland, or for other purposes will probably result in the rapid decomposition and subsidence of the drained peat. The increased availability of nutrients, and drier conditions will consequently alter the vegetation and wildlife species distribution in the bog. / Land and Food Systems, Faculty of / Graduate

No description available.

Burns Bog covers approximately 3,000 hectares between the Fraser River and Boundary Bay in Delta, BC. An ecologically unique ecosystem, its hydrology and ecology have been widely disturbed. Hydrology strongly shapes the character and distribution of vegetation and Sphagnum growth. This study investigated measures of hydrology, including water table residence times and cumulative moisture deficits, to quantify intuitive relationships between moisture stress and ecological zones. Regression analysis of quantitative field observations reveal statistically significant relationships between cumulative moisture deficits and several key bog plant species and Lodgepole pine (Pinus contorta) diameter at breast height, signifying that these relationships can be used to predict the potential for vegetation recovery. Sphagnum height measurements reveal the unexpected observation that most growth occurs during the cool moist winter and early spring. This study contributes to the hydrological management of Burns Bog and will help to guide the location and mechanisms of restoration efforts.

Disturbance plays integral role in the vegetative communities and succession in northern Alberta. Fire is the most common natural disturbance, and oil industry disturbance is a rapidly increasing anthropogenic disturbance on the landscape. In situ extraction of deep oil sands is increasing across Alberta, and with it, minimum disturbance sites used for seismic exploration and natural gas extraction also increase. To determine how these sites recover after disturbance, a 21 year chronosequence was established to address the following questions: 1) How do the plant communities differ between natural bogs, recently burned bogs, and bogs disturbed by `minimum disturbance petroleum industry activities? 2) How do the environmental conditions compare between undisturbed bogs, burned bogs, and bogs disturbed by `minimum disturbance' petroleum industry activities? 3) What is the revegetation pathway of minimum disturbance sites disturbed over the 21 year period? 4) What is the revegetation pathway of the burned bogs over the 21 year disturbance span? and 5) How does the (anthropogenic) minimum disturbance revegetation pathway compare to that of the (natural) fire disturbed bogs? To answer these questions 55 stands were sampled. The plant species were identified and abundance recorded, water chemistry was analyzed, shade recorded, depth to water measured, and oldest trees aged. Bog plant communities and environmental conditions at sites surveyed are similar to one another. Burned bogs were also similar in chemistry, vegetation, and physical traits of the sites. Minimum disturbance sites were quite varied in plant species and environmental conditions studied. A minimum disturbance revegetation could not be determined due to the amount variation in plant species and abundances between minimum disturbance sites of the same age. Burned bogs showed more predictable species interactions: Polytrichum strictum establishes early and subsequently declines. Sphagnum fuscum becomes dominant between 15 and 20 years after disturbance, and Picea mariana returns to burned sites between 1 and 5 years after fire and continues to increase in density. Minimum disturbance sites do not recover in a predictable manner, and some sites become rich fens. It is not clear if these sites will return to the pre-disturbance mature bog community, but burned bogs have a community closely resembling a mature bog after 20 years of revegetation. Documentation of pre-disturbance conditions and operational protocols is recommended in order to further understand sources of cation rich waters that could yield rich fen habitats.

The restoration of drained afforested blanket bogs is a cost-effective management approach in peatland conservation that aims to restore key ecosystem functions such as biodiversity and carbon storage and sequestration. Although arthropods are one of the most abundant and widespread animal groups in peatlands, little research has been carried out to assess their response to the variety of restoration management techniques that have been applied in afforested blanket bogs. We assessed the effectiveness of restoration by investigating the restoration trajectory of arthropod assemblages in formerly afforested blanket bog. We first looked at the long-term trajectory of arthropod assemblages, as well as carabid and moth taxa, in a chronosequence of tree-felled/drain-blocked treatments. Then, we looked at the short-term response of arthropod and carabid assemblages in treatments under varying regimes of brash management. General arthropod assemblages, and the functional traits of carabids and moths, were used to further investigate what type of biotic and abiotic parameters might be of importance during restoration. Lastly, we looked at potential biondicators of restoration progress to be used in restoration monitoring. The long-term restoration trajectory showed that typical bog assemblages are yet to be achieved due to persistence of generalists, as well as absence of bog specialists. Divergence in assembly trajectory was found at 18 years since onset of restoration, suggesting the emergence of an alternative state. Short-term restoration shows that brash might act as temporary habitat at early stages, where carabids favour lower structurally complex habitats than arthropods. Broad patterns of moth distribution revealed trait syndromes associated with blanket bog, whilst abiotic components such as vegetation structure, temperature, plot perimeter and blanket bog connectivity were found to be key for arthropod assemblages. The latter suggests potential legacy and edge effects associated with the restoration process. Arthropods and carabids showed high habitat specificity and fidelity, providing high bioindicator potential for restoration progress. This thesis shows that typical bog arthropod assemblages largely rely on habitat microstructure, particularly Sphagnum mosses, and associated microclimates for survival. Management can provide temporary refuge for arthropods, but the re-establishment of peat-forming vegetation and water table depth is essential for the return of typical bog assemblages. Though trade-offs might be encountered in the long-term restoration of peatland functions, a restoration framework is provided for the monitoring of arthropod assemblages.

No description available.

No description available.

This clinical study is composed of two different trials. In the first we investigated and described the perioperative stress response in dogs undergoing elective orchiectomy and ovariohysterectomy. In the second trial we evaluated the efficacy of a commercial dog synthetic appeasing pheromone for the control of the perioperative stress response. The aim of this trial is to describe the behavioural, neuroendocrine, immune and acute phase stress responses in dogs undergoing elective surgery in normal clinical practice conditions. Sixteen dogs were submitted to elective orchiectomy or ovariohysterectomy using a standardized surgical protocol. Each animal was confined to the Intensive Care Unit during pre- and post-surgery, and its perioperative behavioural, neuroendocrine, immune and acute phase responses studied. Behavioural categories, cortisol, prolactin, white blood cells, C-reactive protein and haptoglobin variations were evaluated. Values at different times were compared with basal values shown by the dog in its usual environment. Communicative and explorative behaviours showed high pre-surgery occurrence and were inhibited post-surgery. Decreases in post-surgery activity, interactive behaviours and changes in waking/sleeping patterns were observed. Compared to basal values, cortisol showed a significant increase both during pre- and post-surgery confinement in the ICU cage, being the most sensitive marker of psychological stress. Prolactin values were characterised by a significant decrease at early post-surgery time. The immune response was characterised by long-term neutrophilia and monocytosis, but by short¬term lymphopenia and eosinopenia, limited to early post-operative period. With regard to the acute phase response, both C-reactive protein and haptoglobin showed a post-surgery long-term increase. Changes in behavioural, hematological and biochemical markers showed that perioperative stress represents a major challenge for dog welfare. Surgery, together with its related perioperative procedures, is known to be a major source of stress for dogs. Both psychological and physical stressors activate the behavioural, neuroendocrine, immune and acute phase responses in dogs undergoing elective surgery. A synthetic dog¬appeasing pheromone (DAP) has been marketed to control dog stress response. Its efficacy has been demonstrated recently in many different contexts. We therefore hypothesized that it could also control the perioperative stress response in dogs undergoing elective surgery. For this purpose we studied the behavioural, neuroendocrine, immune and acute phase responses in dogs undergoing elective orchiectomy or ovariohysterectomy. We analyzed the pre- and postoperative variations in behavioural categories, cortisol, glucose, prolactin, white blood cells, haptoglobin and C-reactive protein. A standardised surgery setting was used. Of the results obtained, the behavioural and the prolactin responses showed to be influenced by the DAP treatment. The dogs treated with the synthetic pheromone were more likely to be alert and visually exploring after surgery, and their prolactin response to perioperative stress was significantly lower (P ≤ 0.05), when compared with the animals receiving the placebo treatment. The HPA axis, immune and acute phase responses were unaffected by the treatment. These results suggest that the dog-appeasing pheromone modifies the behavioural and the neuroendocrine lactotropic perioperative stress responses in dogs undergoing elective surgery. Thus, the use of this product in a clinical setting could improve their recovery and welfare.

This research has examined the historical vegetation of two Eastern Otago sites below the regional treeline, with the aim of addressing questions about the distribution and spread of native tussock grasslands prior to human arrival in New Zealand c. 800 yr BP. Pollen and phytolith (plant opaline silicate) proxies have been extracted from peat cores at Swampy Summit and Clarks Junction to provide a record of vegetation spanning the Holocene. Using multiple proxies and two sample sites has allowed for comparisons of the record of vegetation from within sites and between sites. A record of the modern pollen rain was also gathered from localised moss polsters at Swampy Summit in order to reconcile modern pollen assemblages and transport patterns with historical findings. It became clear from the research that the record of vegetation inferred from phytoliths was not analogous to the pollen-based records, which supported the hypothesis that vegetation reconstructions based solely on pollen may be unreliable. Good pollen preservation in the sediments allowed for the identification of over 50 taxa, although only Chionochloid forms were identifiable to a family level in the phytolith records. Poaceae pollen was abundant throughout the Clarks Junction record, suggesting grassland had persisted at this site during the Holocene, while Poaceae pollen at Swampy Summit was minimal and sporadic. Phytoliths at Swampy Summit show grasses have persisted at the site thoughout the Holocene, at times in much greater proportions than the pollen record would suggest, while Chionochloid phytoliths only become common near the top of the record, possibly reflecting increasing dominance of this taxa after human disturbance. In contrast to Swampy Summit, the Clarks Junction phytolith record reflects a more stable presence of grasses throughout the Holocene, with Chionochloid forms present throughout. Phytoliths appear to be a more reliable proxy for local vegetation, with both sites indicating a Holocene presence of grasses below the regional treeline prior to human arrival in New Zealand. In comparison, the pollen record appears to indicate a more regional pattern of vegetation, with the grassland pollen record complicated by pollen dispersal and deposition factors.

Thesis (M. A.)--University of North Carolina at Greensboro, 2006. / Title from PDF title page screen. Advisor: Roy S. Stine; submitted to the Dept. of Geography. Includes bibliographical references (p. 60-65)