The U.S. Environmental Protection Agency has mandated that states must include the use of biological assessments in their water quality laws to assess the biological integrity of aquatic systems. The Floristic Quality Assessment Index (FQAI), which uses wetland vegetation to assess the biological integrity of an ecosystem, has not been tested in Mississippi. The purpose of this study was to test the efficiency of the FQAI in wetlands along a gradient of human influence. Coefficients of conservatism (CC) were assigned to plant species based on their tolerance to disturbance and fidelity to habitat. A negative correlation was found between the FQAI and level of human disturbance for 53 sites surveyed in the summer of 2004. Based on the results of this study, the FQAI and the average CC could be effective tools for monitoring wetland management and restoration and for identifying areas of high conservation value in Mississippi.

>Magister Scientiae - MSc / This work aimed at assessing the response of wetland vegetation productivity to the 2014-2017 climate-induced drought at the Soetendalsvlei wetland system in the Western Cape province of South Africa. To achieve this objective, firstly a literature review on the progress of remotely sensed data applications in assessing and monitoring wetland vegetation productivity was conducted. The review elaborates on the role of remote sensing in monitoring and assessing wetland vegetation productivity, with a detailed discussion of the climate change and variability impacts on wetland vegetation productivity. Accurate assessment results are produced when suitable processing techniques are selected as well as appropriate spatial and spectral resolution for extracting spectral information of wetland vegetation productivity. Secondly, wetland vegetation changes and productivity status was assessed using multi-temporal resolution Landsat series imagery and Normalized Difference Vegetation Index (NDVI) during the wet and dry seasons for the period between 2014 and 2018.

No description available.

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

Vegetation sampling was carried out to determine processes of succession of aquatic and wetland plant species. Different stages of wetland and aquatic vegetation were analyzed in sand pits in the Třeboňsko Protected Landscape Area in the Czech Republic. Moreover different sizes of phytosociologial relevés of aquatic vegetation were analyzed to determine sufficient size for detection of successional changes.

Monitoring and maintaining the health of coastal wetlands is a global concern. The greatest threat to coastal wetlands in the Great Lakes Basin are anthropogenic removal and enrichment. The coastal wetlands in Georgian Bay are relatively undisturbed by humans, but face disturbance caused by reduced annual water-level fluctuations. Since these wetlands are critical habitat for many fish, bird, amphibian, and reptile species, many efforts to accurately monitor and maintain their health have been put into place. Recently, these wetlands have been experiencing an abrupt (~1 m) transition to higher water levels, following 14 years of sustained lows, which allowed trees and shrubs to invade the meadow vegetation zone. This sustained water-level pattern has never occurred in this region before, offering the unique opportunity to study wetlands undergoing a transition, where areas of 10+ years of upland plant species growth was inundated and became part of the wetland habitat. This thesis first investigates how this change in water level affects the distribution of meadow, emergent, floating, and submerged vegetation both in physical space and area. The second chapter of this thesis presents long-term water quality, macrophyte, and fish community monitoring using ecological indices. Water quality and macrophyte indices are robust enough to monitor wetlands undergoing a transition; however, issues arise in the calculation of the wetland fish index, as the changes in macrophyte distribution described in Chapter 1 impact the ability to replicate community sampling using fyke nets. The research done throughout this thesis is highly beneficial in adding to the limited knowledge of key factors impacting macrophyte community shifting. This work also identifies water-level scenarios where managers must adjust sampling protocols to succeed in effectively sampling wetland fish communities. / Thesis / Master of Science (MSc) / The coastal wetlands in the Georgian Bay area are primarily threatened by human development and the removal of annual water-level fluctuations. From 1999-2013, the water level decreased and remained low. In 2014, the water level rose about 1 m, causing flooding of grass and trees that had grown in the meadow zone during the 14 years when the water level was low. The first goal of this thesis is to explain how and why all wetland plants are relocating during this period. The second goal is to make sure that common indicators of wetland health (water quality, plants, and fish) can still be used during a time when flooding of grasses and trees was occurring in wetlands. The findings in this thesis contribute to the ability to predict and understand how the plants will shift within a wetland during a time of flooding, as well as informing managers on appropriate sampling protocols.

The Great Dismal Swamp (GDS) is a forested peatland located in the Atlantic Coastal Plain. Once a mosaic of wetland communities, disturbances (e.g., timber harvesting and ditching) have resulted in altered hydrologic regime, homogenized forest communities, and increased peat subsidence. In response, hydrologic restoration and forest management aim to enhance community composition and function. To help inform these efforts, we investigated variability and drivers of forest communities by surveying vegetation composition and structure, hydrologic indicators, and soil properties at 79 monitoring plots across GDS. Data were augmented with modeled water levels and peat depths. Our results demonstrate red maple (Acer rubrum) dominance across GDS, which decreases tree density, richness, and diversity. However, hierarchical cluster analysis identified four community types: Gum (G), Maple-Gum (M-G), Sweetgum-Maple (SG-M), and Maple (M). These communities differed in tree composition and structure; differences in other growth forms (shrubs, herbaceous, and regeneration) were limited. Modeled water levels failed to explain vegetation differences, but community associations with soil properties suggest that communities exist along a hydrologic gradient. Specifically, the G community likely exists on wetter sites whereas SG-M communities occur at drier locations. Maple-dominated communities (M and M-G; 78% of plots) likely occur across broader hydrologic gradients, explaining their dominance. However, more characterization of hydrology (i.e., time-varying water levels and soil moisture) and other drivers (e.g., site history and soil hydraulics) is needed to further explain community variation. As such, we propose future strategies for long-term monitoring to inform ongoing hydrologic restoration and forest management efforts. / Master of Science / The Great Dismal Swamp (GDS) is a large forested wetland located in southeastern Virginia and northeastern North Carolina. The GDS provides many ecosystem services such as wildlife habitat, biodiversity, water quality and storage, and carbon storage. Prior to disturbance, the GDS was composed of a variety of forest types, including stands dominated by cypress (Taxodium spp.), cedar (Chamaecyparis spp.), and pocosin (Pinus spp.) species. However, land use activities (e.g., ditching, draining, and timber harvesting) have resulted in drier conditions, forests dominated by red maple (Acer rubrum), land subsidence, and increased fire frequency. To restore the GDS to its pre-disturbance state, water control structures have been installed in drainage ditches to increase wetland water levels throughout the swamp. To inform those efforts, research is needed to understand how forest communities will respond to changing hydrology. In this study, we investigated forest composition throughout the GDS and found that four forested communities exist: Gum (G), Maple-Gum (M-G), Sweetgum-Maple (SG-M), and Maple (M). Our findings demonstrate that the M community is the most abundant community at GDS. Where red maple is present in large quantities, the variety of other tree species decreases. Additionally, we found that these communities exist on different degrees of wetness. The G community is located on wet sites, and the SG-M is located on dry sites. The more mapledominated communities (M and M-G) are found across a larger range of wetness conditions. Our findings will inform future monitoring and management efforts at GDS.

Forested peatlands of the Great Dismal Swamp (GDS) have been greatly altered since colonial times, motivating recent restoration efforts. Community structure and function were hydrologically altered by 19th and 20th century ditches installed to lower water levels and enable early timber harvesting. Contemporary forest communities are comprised of maturing remnants from selective timber harvesting that ended in the early 1970s. Red maple (Acer rubrum) has become the dominant species across GDS, encroaching on or replacing the historical mosaic of cypress (Taxodium spp.)/tupelo (Nyssa spp.), Atlantic white-cedar (Chamaecyparis thyoides), and pocosin (Pinus spp.). Moreover, peat soil has been exposed to more unsaturated conditions resulting in carbon loss through decomposition and increased peat fire frequency and severity. Installation of ditch control structures aim to control drainage and re-establish historical hydrology, vegetation communities, peat accretion rates, and fire regime. To help inform restoration and management, we conducted two complimentary studies to test hypotheses regarding hydrologic influences on vegetation, peat depths, and peat fire vulnerability. First, we found thicker peat, lower maple importance, and higher species richness at wetter sites (e.g., higher mean water levels). In our second study, we evaluated the integrated effects of peat properties and water level dynamics on peat fire vulnerability. We found decreased burn vulnerability with increased wetness, suggesting that the driest sites were always at risk to burn, whereas the wettest sites never approached fire risk conditions. Together our findings demonstrate strong hydrologic controls on GDS ecosystem structure and function, thereby informing water level management for restoration goals. / Master of Science / Forested wetlands, like the Great Dismal Swamp (GDS) in eastern Virginia, provide valuable ecosystem services, including wildlife habitat, biodiversity, water quality and storage, carbon storage, and many others. Many of these ecosystems have been lost to land conversion, or hydrologically altered. Ditches installed to lower water levels and enable timber harvesting altered GDS ecosystem services. Lowered water levels changed the forest from a historical mosaic of diverse tree species to a more homogeneous forest dominated by one tree species, red maple. Moreover, GDS’s organic soil (peat) has been exposed to drier conditions resulting in carbon loss through decomposition and increased peat fire frequency and severity. To restore GDS ecosystem services, installation of water control structures in the ditches aim to control drainage and re-establish historical water levels (hydrology), forest cover, peat soil development rates, and fire regime. To help guide this hydrology management, we conducted two complimentary studies to test hypotheses regarding hydrology’s influences on vegetation, peat soil, and peat fire vulnerability. First, we found thicker peat soil, lower red maple prevalence, and more vegetation species at wetter sites. In our second study, we evaluated the integrated effects of peat soil properties and water level dynamics on peat fire vulnerability. We found decreased fire vulnerability with increased wetness, suggesting that the driest site was always at risk to burn, whereas the wettest site never approached conditions for fire risk. Together our findings demonstrate hydrology’s strong controls on GDS ecosystem services, thereby informing water level management for restoration goals.

This thesis is part of the project GA CR P504 / 11/1151 "The role of plants in the greenhouse gas balance Carex fens". The aim of this thesis is to evaluate the seasonal dynamics of Carex acuta belowground biomass in model grassland wetlands (the "wet meadows") near Třeboň. Belowground biomass of C. acuta L. was sampled using the destructive method. The samples were taken on four dates in 2014. On each date, three hummocks of C. acuta and three soil samples in their immediate vicinity were sampled on each date. Live roots had a greater dry weight than decaying roots on all sampling dates. Their total dry weight varied slightly, depending on season. The ratio of live roots to decaying roots did not differ much. The weight of live roots in hummock was almost always higher than that of the dead ones. The dry weight of living roots was always greater in the hummock than below it. Their total weight varied slightly during the year. Aquatic roots formed only a small part of the dry weight of live roots in hummocks. A greater total belowground dry weight found on 21st December 2014, in comparison with 5th August 2014, was associated with a greater amount of rhizomes of other plant species. The shoots increased their dry weight during the year. Maximum weight of tillers was recorded on 8th August 2014. There were no dead shoots on 25th March 2014. Dry weights of dead tillers were largely similar throughout the year. The volumetric soil water content (%) was usually higher in the upper soil layers. The bulk density of the soil was almost identical on all sampling sites, except for the top layer on site 1, where it was considerably lower.

My thesis is a part of the project GACR 206/06/0058 Monitoring of selected heavy metals and risk elements in a wastewater cleaning process in artificial wetlands. The goal is to evaluate temporal and spatial variability of underground biomass of Phragmites australis in the artificial wetland used for wastewater treatment in Slavošovice. The destructive method was used for the sampling. The aboveground biomass was determined from six samples taken at the inflow and six samples at the outflow. The belowground biomass (in 2008) was estimated from two samples taken at the inflow and two samples at the outflow. In 2009, the belowground biomass was determined from six samples taken from the inflow and six samples from the outflow. The analysis of the root structure was determined from 12 samples collected at the inflow and 12 samples of the outflow. The mean total aboveground biomass reached 1039 g.m-2 at the inflow and the 1749 g.m-2 at the outflow. Average total belowground biomass in 2009 reached the inflow 1718 g.m-2 and 1562 g.m-2 at the outflow. The average total length of roots growing from one node to was 284,7 m.m-2 and 324,9 m.m-2 in the inflow and outflow part, respectively. Average specific root length of the inflow was 2589,5 cm.g-1 and the outflow 2956,9 cm.g-1. The average total length of roots reaching the inflow of two kilometers and three kilometers of inflow.