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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Performance of Floristic Quality Assessment in Massachusetts Forested Wetlands

Gorss, Carolyn 09 July 2018 (has links)
In order to combat the loss of valuable wetland functions and services, federal, state and tribal governments must have the tools to accurately assess and monitor the condition of wetland ecosystems. One particular method of wetland assessment is Floristic Quality Assessment (FQA), which has been growing in popularity throughout the United States since its creation in the 1970s. FQA relies on vegetative indicators of human disturbance to assess the integrity of an ecosystem. FQA calculations are based on Coefficients of Conservatism (C-scores), professionally-assigned scores ranging from 0-10 that denote a local species' tolerance to anthropogenic disturbance. Despite increasing interest in the use of FQA, few studies have thoroughly tested the performance of FQA, especially in New England. We used the Conservation Assessment and Prioritization System (CAPS), a landscape-based, coarse-scale assessment method, as a basis for evaluating FQA's performance in Massachusetts's forested wetlands. Our objective was to use CAPS Index of Ecological Integrity (IEI) scores (a form of generalized stressor gradient) to evaluate the performance of a variety of FQA indices (biological condition gradients), using C-scores from 7 states in the Northeast, and 2 ecoregions in Massachusetts. Based on our calculations of r-squared, and Spearman's rank analysis, we determined that FQA and C-scores have a moderate to weak relationship with the CAPS index of ecological integrity. Of the 12 indices and metrics we tested, the index with the strongest relationship to the IEI stressor gradient was mean Coefficient of Conservatism. Based on this research a number of suggestions are proposed for improving FQA as it applies to wetland assessment.
2

Created stormwater wetlands as wetland compensation and a floristic quality approach to wetland condition assessment in central Alberta

Forrest, Andrew SM Unknown Date
No description available.
3

Created stormwater wetlands as wetland compensation and a floristic quality approach to wetland condition assessment in central Alberta

Forrest, Andrew SM 11 1900 (has links)
In Alberta, almost all created wetlands accepted as compensation have been naturalized stormwater management facilities. Our investigation of 32 created and natural wetlands in central Alberta determined that created wetlands have steeper shoreline slopes, largely as a result of their primary function as stormwater retention ponds. This resulted in distinctly different vegetation zonation, with the steeper slopes of created wetlands resulting in fewer, narrower wetland vegetation zones. This was reflected in reduced species richness and abundance of wetland songbirds at created wetlands. This study also discusses the development of a Floristic Quality Assessment (FQA) approach, a standardized, quantitative approach to measuring wetland condition, for Albertas Parkland and Boreal natural regions. I present plant survey data from the 32 wetlands as validation of the effectiveness of this approach. This study provides information on current wetland compensation practices and a potential wetland assessment tool; both topics that are directly relevant to the implementation of wetland compensation policies in Alberta. / Ecology
4

Is Ecological Restoration Successful? An Assessment of a Prairie Restoration in Northern Illinois, USA

Hansen, Michael 01 January 2009 (has links)
The prairie communities that once dominated the landscape of Illinois have been reduced to a fraction of their former extent. Subsequently, considerable effort has been invested in the restoration of these lost communities, yet the comprehensive assessment of restoration success has only recently garnered interest. The objectives of this study were 1) to gauge the success of a prairie restoration project by measuring the components of ecological fidelity (structure/composition, function, and durability), and 2) to determine the factors that influenced success. Nineteen prairie plantings (ranging from two to 19 growing seasons old) at The Nature Conservancy's Nachusa Grasslands preserve were chosen for the assessment. Floristic quality was calculated to assess the composition component of ecological fidelity. Aboveground net primary productivity, soil bulk density, total soil nitrogen and total soil carbon were measured to assess the function component (soil measurements were taken at 0-5 and 5-15 cm depths). Results were compared to benchmark values taken from the literature and from samples of remnant prairies. Durability was determined by comparing measurements across a restoration chronosequence. To further evaluate the prairie plantings and restoration success, non-metric multidimensional scaling ordination was used to compare plantings based on their vegetation composition and soil characteristics (prairie remnants were also included in the comparison based on soil characteristics). Values of Mean C and FQI indicated successful levels among younger plantings, but durability was less successful according to the chronosequence. Seed-mix quality had the greatest influence (positive) on composition success. Aboveground net primary productivity levels were successful and durable overall, however, younger plantings exhibited successful levels of production more consistently than older plantings. Aboveground net primary productivity was most influenced (negatively) by the abundance of the exotic C3 grass genera Poa and Bromus. Functional success based on soil characteristics was limited. Soil bulk density, total nitrogen, and total carbon levels all differed among plantings and remnants at both depths, and evidence of levels recovering toward levels of remnants was not detected. The results of this study indicated that some components of ecological fidelity have been successfully restored, while others have not, and using a high-quality seed mix that resembles the species pool of remnant prairie and limiting the abundance of the dominant native C4 and exotic C3 grasses can improve the restoration of plant composition and ecological function in Illinois prairie plantings. The mixed results underscore the importance of examining more than one component of ecological fidelity when measuring success. Long-term monitoring is also recommended for evaluating restoration durability, especially for detecting changes among soil properties over time.
5

COMPARING STAND COMPOSITION AND FLORISTIC QUALITY OF TWO ADJACENT UPLAND OAK-HICKORY WOODLANDS IN SOUTHERN ILLINOIS: OLD-GROWTH AND SECOND-GROWTH DYNAMICS

Kleiman, Leah Rose 01 August 2023 (has links) (PDF)
Illinois has no official parameters for old-growth oak-hickory (Quercus-Carya) forests despite oak-hickory being the historically dominant ecosystem in the forested parts of Illinois (Fralish, 1997; Thompson & Dessecker, 1997). The purpose of this study was to better understand the characteristics of old-growth oak-hickory stands, as well as make management recommendations for preserving the integrity of old-growth forests and shifting second-growth stands to old-growth status. Stand structure analysis was conducted in June and July of 2022 on an old-growth oak-hickory stand (Otey-Grisley Nature Preserve) and nearby second-growth oak-hickory stand (Grisley Woods Land and Water Reserve) near Pittsburg, Illinois using dendrochronology, various stand composition analyses, and floristic assessments to compare the two forests across multiple nodes of inquiry from their canopies to their ground layers. White oak (Quercus alba L.) was of higher importance in the more open old-growth canopy than the closed second-growth canopy which had more shagbark hickory (Carya ovata L.). The old-growth stand had higher floristic quality (mean Coefficient of Conservatism and adjusted Floristic Quality Index) and lower frequency of invasive species than the second-growth stand. The dominant white oak appear to have suppressed the hickories (Carya) for over a century on both sites. However, in the sapling and seedling layer, it appears the oaks and hickories are failing to recruit into the canopy on either site. The average age of the old-growth canopy is 67 years greater than that of the second-growth canopy, the majority of which seeded in after a heavy cut in the early 1940s. The second-growth site rapidly gained early successional species after the logging. The second-growth site could come to resemble the open oak dominated character of the old-growth site. However, this will require management with fire, thinning, and invasive species treatments. The old-growth, where sassafras (Sassafras albidum L.) is crowding the understory, will also require invasive species management, prescribed fire, and thinning if it is to remain the open oak-hickory woodland it is today.
6

Assessment of small scale tallgrass prairie restoration in an urban environment

Mutch, Paul D. 26 October 2007 (has links)
Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence. / February 2008
7

Assessment of small scale tallgrass prairie restoration in an urban environment

Mutch, Paul D. 26 October 2007 (has links)
Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence.
8

Assessment of small scale tallgrass prairie restoration in an urban environment

Mutch, Paul D. 26 October 2007 (has links)
Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence.
9

The Effect of Wetland Size and Surrounding Land Use on Wetland Quality along an Urbanization Gradient in the Rocky River Watershed

Gunsch, Marilyn S. 29 October 2008 (has links)
No description available.
10

L’unicité écologique des communautés végétales comme critère de conservation dans les milieux humides lacustres

Dubois, Raphaëlle 10 1900 (has links)
L’objectif de ce mémoire est de déterminer si l’unicité écologique des communautés végétales est un critère approprié pour prioriser l’allocation des efforts de conservation dans les milieux humides lacustres. Pour répondre à cette question, j’ai utilisé des données d’inventaire végétal dans deux emplacements géographiques situés dans le sud du Québec et pour trois types de milieux humides (i.e., frênaies, aulnaies, tourbières). J’ai d’abord identifié les milieux humides statistiquement uniques en calculant leur contribution locale à la diversité bêta (LCBD). J’ai ensuite mesuré le degré d’association relatif entre les valeurs d’unicité écologique et plusieurs autres critères couramment employés pour déterminer les priorités de conservation, et ce, à l’aide de corrélations de Pearson et de partitionnements hiérarchiques. Les tourbières uniques avaient une grande valeur de conservation dans les deux régions étudiées, alors que les aulnaies et frênaies uniques montraient des signes d’altération de leur composition en espèces. La composition en espèces des sites uniques devrait donc être examinée pour en déterminer la valeur de conservation, puisqu’elle pourrait être affectée par le niveau d’intégrité du paysage. La proportion d’espèces rares ainsi que la présence d’espèces spécialistes sensibles aux perturbations étaient corrélées de façon importante et congruentes avec l’unicité dans les deux régions étudiées. Au contraire, la richesse spécifique était négativement corrélée avec l’unicité, ce qui suggère la nécessité d’un compromis. Une combinaison de critères complémentaires devrait donc être utilisée en plus de l’unicité afin d’identifier l’ensemble optimal de sites à protéger dans un contexte donné. / This study aimed to determine whether plant composition uniqueness is an adequate criterion for assessing conservation priorities in lake-edge wetlands. To answer this question, I used vegetation data from two large datasets of lake-edge wetlands located in southern Québec, which encompassed three wetland types (i.e., ash-dominated swamps, alder-dominated swamps, peatlands). I first identified statistically unique wetlands by computing their local contribution to beta diversity (LCBD). I then measured the relative association between ecological uniqueness values and other criteria commonly used to assess conservation priorities using Pearson correlations and hierarchical partitioning. Unique peatlands had a high conservation value in both study regions, while ash- and alder-dominated swamps showed more signs that their species composition had been altered. The species composition of unique sites should thus be examined closely to determine its conservation value, as it could be affected by the overall integrity of the landscape. The proportion of rare species and the presence of disturbance-sensitive specialist species were appreciably correlated and congruent with uniqueness in both study regions. On the other hand, species richness was negatively correlated with uniqueness, suggesting that there was a trade-off. A combination of complementary criteria should therefore be used in conjunction with uniqueness in order to identify the optimal set of sites to protect in a given context.

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