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Showing 1 to 5 of 5 (0.054 seconds)Spelling suggestions: "subject:"turns oog"" "subject:"turns gog""
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An ecological and land use study of Burns bog, Delta, British ColumbiaBiggs, Wayne Griffin January 1976 (has links)
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
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Tree removal as a tool of ecological restoration in Burns Bog, Delta B.C.Danyluk, Angela 07 May 2012 (has links)
Burns Bog (the Bog) is a 2800 ha protected peatland in Delta, British Columbia. Globally unique due to its form, size, chemistry, flora and fauna the Bog is distinct and managed as a wetland. In 2005, a large fire consumed 200 ha of peatland after which birch (Betula pendula) and pine (Pinus contorta) trees grew in great densities. Within the fire zone piezometers were installed to monitor water levels below the surface. A high water level promotes peat-forming processes and in 2009 water levels dropped significantly. In 2010, a 75m x 50m experimental plot within the fire zone was cleared of birch and pine trees to investigate the impacts of tree removal on bog hydrology and plant communities. Higher water levels and positive bog plant growth at the experimental site was observed in 2010 and 2011 when compared to the control site where trees remained intact.
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Restoration of Burns Bog : cumulative moisture deficit as an indicator of vegetation recovery and peat growthDilley, Laura 10 June 2014 (has links)
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.
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The paleoecology of a raised bog and associated deltaic sediments of the Fraser River DeltaHebda, Richard Joseph January 1977 (has links)
In this study, three cores obtained from Burns Bog just south of the Fraser River in Delta, British Columbia, were analyzed palynologically. The paleoecology of the bog was reconstructed from the results of these analyses, together with data from vegetation studies of the bog, pollen rain and surface pollen spectrum investigations of selected wetland environments, as well as pollen tetrad and pollen productivity studies of bog ericads.
The vegetation of Burns Bog was sampled by estimating species cover in
selectively placed 100 m² quadrats. These field data were used in combination with an air photographic mosaic to map the eight vegetation types of the area. The palynomorph "fingerprints" of selected wetland environments, determined from pollen rain and surface pollen spectrum studies, were used to recognize analogous phases recorded in cores. Tetrad diameter and pollen productivity data for bog ericads assisted in recognizing ecologically significant ericad species that distinguished wet and dry raised bog phases.
The study shows that Burns Bog has developed on Fraser River deltaic deposits which appeared above sea level just after 5,000 years BP. The seemingly synchronous emergence of the three core sites and a locality in adjacent Boundary Bay indicate a possible relative sea level decrease at this time. The silty emergent sediments are characterized by high percentages of Pinus and Picea pollen deposited by river water, and Cyperaceae pollen from local Scirpus and Carex stands. Following this emergence, sedges colonized the area, forming a sedge peat containing abundant Cyperaceae pollen. At the western end of the bog, a salt marsh developed
(4,125 ± 110 BP) in response to a marine advance. This was possibly caused by a shut-off of fresh-brackish water from the Fraser River when the delta reached Point Roberts. In the eastern section of the bog, at the foot of Panorama Ridge, the sedge phase was only transient. A Myrica-Spiraea-Lysichitum swamp developed, remaining until very recently. After the sedge phase in the central part of the bog, Myrica and Spiraea thickets appeared; these were subsequently replaced by Sphagnum bog at 2,925 ± 85 years BP. In the western end of the bog, sedges were replaced by heaths, predominantly Ledum. At the foot of Panorama Ridge, Sphagnum arrived very recently. Pines seem to have invaded all sites at the 2.00 m level.
The AP pollen spectrum shows that the regional upland vegetation remained unchanged throughout the history of Burns Bog until settlers cleared the forests. On the delta, however, fluctuations in alder pollen were probably associated with alder colonization of levees and swamps near the channels.
Fire has played an important role in bog ecology. Natural Sphagnum accumulation processes are modified because fire destroys the vegetation of slightly higher, dry sites. Unburned wet depressions then become centers of peat accumulation. These sites eventually rise above the surrounding burned areas, which are converted to depressions.
A model for raised bog development is proposed for the Fraser Lowland. The prograding delta-front is colonized by emergent aquatics growing on silts. This phase is followed by the advent of a sedge swamp perhaps containing some wetland grasses. Eventually, shrubs such as Myrica and Spiraea begin to appear, accompanied in the later stages by Ledum groenlandicum. Increased acidity of the substrate due to peat accumulation promotes Sphagnum, which eventually takes over and results in the establishment of raised bog conditions.
This study, the first detailed outline of raised bog development in western North America, provides a framework for further investigations of bogs in the area. / Science, Faculty of / Botany, Department of / Graduate
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Multispectral imaging of Sphagnum canopies: measuring the spectral response of three indicator species to a fluctuating water table at Burns BogElves, Andrew 02 May 2022 (has links)
Northern Canadian peatlands contain vast deposits of carbon. It is with growing urgency that we seek a better understanding of their assimilative capacity. Assimilative capacity and peat accumulation in raised bogs are linked to primary productivity of resident Sphagnum species. Understanding moisture-mediated photosynthesis of Sphagnum spp. is central to understanding peat production rates. The relationship between depth to water table fluctuation and spectral reflectance of Sphagnum moss was investigated using multispectral imaging at a recovering raised bog on the southwest coast of British Columbia, Canada. Burns Bog is a temperate oceanic ombrotrophic bog. Three ecohydrological indicator species of moss were chosen for monitoring: S. capillifolium, S. papillosum, and S. cuspidatum. Three spectral vegetation indices (SVIs) were used to characterize Sphagnum productivity: the normalized difference vegetation index 660, the chlorophyll index, and the photochemical reflectance index.
In terms of spectral sensitivity and the appropriateness of SVIs to species and field setting, we found better performance for the normalized difference vegetation index 660 in the discrimination of moisture mediated species-specific reflectance signals. The role that spatiotemporal scale and spectral mixing can have on reflectance signal fidelity was tested. We were specifically interested in the relationship between changes in the local water table and Sphagnum reflectance response, and whether shifting between close spatial scales can affect the statistical strength of this relationship. We found a loss of statistical significance when shifting from the species-specific cm2 scale to the spectrally mixed dm2 scale. This spatiospectral uncoupling of the moisture mediated reflectance signal has implications for the accuracy and reliability of upscaling from plot based measurements. In terms of species-specific moisture mediated reflectance signals, we were able to effectively discriminate between the three indicator species of Sphagnum along the hummock-to-hollow gradient. We were also able to confirm Sphagnum productivity and growth outside of the vascular growing season, establishing clear patterns of reflectance correlated with changes in the local moisture regime. The strongest relationships for moisture mediated Sphagnum productivity were found in the hummock forming species S. capillifolium. Each indicator Sphagnum spp. of peat has distinct functional traits adapted to its preferred position along the ecohydrological gradient. We also discovered moisture mediated and species-specific reflectance phenologies. These phenospectral characteristics of Sphagnum can inform future monitoring work, including the creation of a regionally specific phenospectral library. It’s recommended that further close scale multispectral monitoring be carried out incorporating more species of moss, as well as invasive and upland species of concern. Pervasive vascular reflectance bias in remote sensing products has implications for the reliability of peatland modelling. Avoiding vascular bias, targeted spectral monitoring of Sphagnum indicator species provides a more reliable measure for the modelling of peatland productivity and carbon assimilation estimates. / Graduate
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