Reconciling human landscapes with wildlife needs can demand innovative solutions. Enhancing wildlife conservation in agricultural landscapes requires habitat restoration; returning marginal farmlands to wetlands in a way that remains productive for farmers can aid existing strategies. This study develops and explores the feasibility of an ecological design to rehabilitate wet, poor quality farmland into a wetland that can serve as wildlife habitat while producing a crop. Research targets methods of biophysical site restoration that are feasible for farmers to initiate; identification of temperate wetland crops with potential to meet economic and ecological criteria; and parameters for meeting farmers' needs in terms of management and desirability. Scientific literature on wetland and restoration ecology is examined and integrated with agricultural studies and interview responses from landowners involved in alternative food production. Primary data collection for design development centers on coastal British Columbia, where competing land uses have degraded many former wetlands while the region's fertile soils support prolific, diversified farming. Qualitative, semi-structured interviews with key informants involved in local food production were conducted as part of a participative research process in order to get input and feedback throughout design development. A case study site was chosen in a seasonally flooded agricultural watershed outside of Duncan, B. C. A design is proposed that combines five habitat types with a naturalized cropping system. Major findings include the potential use of many wild and native plants as crops, as a way to provide sufficient economic returns and maintain ecological sustainability. Current opportunities for wetland agriculture include niche marketing, added value products, agrotourism, and increasing sales through farm reputation. Possible deterrents include product marketing, and the unfamiliarity of the plants from a farming perspective, where levels of acceptable damage imposed by fluctuating water conditions, weed competition, and herbivory are undetermined. Participant response was positive overall with regards to the design and preliminary results indicate that such a system could be feasible. Public interest and technical ability to create an agricultural wetland exist; developing creative marketing for such products in North America appears to be the primary challenge. The design is thus proposed as a long-term study to minimize risk for interested landowners. Redesigning human landscapes to include wild species is an important step towards a more sustainable society.

A boreal forest wetland (L979) was flooded in 1993 at the Experimental Lakes Area, Ontario to imitate a hydroelectric reservoir and to study the effects of flooding on greenhouse gas production and emission. Flooding initially caused CO₂ and CH4 emission rates to increase and changed the wetland from a small, natural carbon sink to a large source of carbon. The increased production of greenhouse gases in the peatland also caused the majority of the peat to float to the surface creating floating peat islands, within 4 years of flooding. The floating peat islands are a larger source than the central pond of CH4 to the atmosphere due to the high water table and small oxidation zone as compared to the earlier undisturbed peatland. The floating peat islands had an average flux of 202 ± 66 mg C-CH4/m²/day comparable to rates measured in 1995. Methane flux rates are spatially and temporally variable ranging from ?117 to 3430 mg C-CH4/m²/day. The variability is partly due to episodic releases of gas bubbles and changes in overlying pressure from the water table. The development of floating peat islands created an underlying water pocket. The water pocket increased water movement between the central pond and the peatland and led to increased peat temperatures and methane oxidation, and removal of debris from the water pocket. DIC, CH4, and O₂ concentrations, and δ13C-DIC, δ13-CH4, and δ18O-O₂ values in the water pocket were similar to values in the central pond. Before flooding, the δ13C-CH4 values from the peatland ranged between ?36 and ?72? indicating that about 65 to 90% of the methane was oxidized before flooding. After flooding, the median δ13C-CH4 value from the floating peat islands was ?52? indicating that about 30% of the methane was oxidized before it was emitted to the atmosphere. Since the floating islands are now vegetated, photosynthesis and transport via plants allow the movement of oxygen into the peat islands Methane oxidation in the central pond was similar in 2001 and 2002. DIC and CH4 isotope mass budgets from June 3 to September 23, 2002 indicate that inputs were smaller than outputs at L979. Calculated net DIC and CH4 production in the central pond was 8490 and 432 kg C, with δ13C-DIC of -18. 5 ? and δ13C-CH4 of -32. 5?. Decomposition of peat was the source of DIC and CH4. O₂ saturation levels indicate that the pond is always undersaturated and that respiration dominates the system; however, the δ18O-O₂ also indicates that photosynthesis is an important process in the central pond of L979. The peat islands contributed about 90% of the total CH4 flux, whereas the open water areas contributed 10%. This indicates that formation of peat islands in a hydroelectric area can significantly affect the greenhouse gas emissions to the atmosphere. The average flux of CH4 from the entire wetland in 2002 was 202 ± 77 mg C-CH4/m²/day, equivalent to 44 ± 17 g C-CH4/m²/year (year = 220 days). This is higher than preflood values of 0. 5 g C-CH4/m²/year in 1992, and the early post-flood value of 8. 9 g C-CH4/m²/year in 1993/1994. The wetland continues to emit methane after ten years of flooding at higher than preflood rates.

Dissolved oxygen (DO) is one of the most important environmental factors necessary to sustain aquatic life. The Southern Grand River is characterized with extensive marshes. This study focuses on the Dunnville Marsh in the Southern Grand River. The spatial and temporal variation in dissolved oxygen was studied in the Dunnville Marsh and the Grand River over a one year cycle during 2007 to 2008. Dunnville Marsh exhibited little influence on the oxygen regime of the river. The Grand River; however, could influence the oxygen regime in the marsh during the spring when waters are high but exerts little influence during the rest of the year. There were no great differences in DO between the wetland and the river during the high water spring melt period; however notable differences occurred in the summer and fall. Oxygen stable isotopes and diel O2 measurements showed that ecological factors probably were influencing the DO cycle in Dunnville Marsh, whereas both ecological and weather factors influenced the cycle in the Grand River. Monthly δ18O-DO data from the river revealed a shift towards atmospheric equilibrium compared to the wetland. These data exhibited less photosynthetic activity in the fall and more photosynthetic activity during the summer. The wetland showed higher photosynthetic activities in the summer than the river. Nitrogen input from the agricultural areas was low at most of the time and had minimal influence on the DO in the Dunnville Marsh. Despite low nitrogen input the attenuation ability of the Dunnville Marsh was apparent, presumably due to plant uptake, especially in the northern part of the marsh. Based on the δ18O-water signature in late April (after the flood season) it appears river water extended about two-thirds along the main stream well into Dunnville Marsh. River water, probably inundates a significant part of the Dunnville Marsh in early April (flood peak), when water flow was more than 10 fold higher than later in April following the peak flood season. River water can be intruded into the marsh and brought the DO to similar saturations as in the river in spring.

Public recognition of the value of wetlands has risen quickly over the past 25 years and numerous policies and programs have been developed to address threats to the quantity and quality of wetlands. However, management of wetland resources located on private land often involves a perceived conflict between social and private interests since landowners usually cannot benefit economically from keeping wetlands on site unless they convert them to alternative uses such as agricultural crops. In order to avoid further degradation and ensure the various environmental benefits wetlands provide, there is a need for government intervention by delivering effective policies. This will be realized through an effective economic valuation process for wetland benefits.<p> This thesis investigates wetland and riparian zones management, with greater emphasis placed on the Prairie Pothole Region (PPR) of Saskatchewan where the majority of the land is privately owned. Using data from a survey of landowners, the perceived cost of conserving wetland and associated riparian zones is quantified through their willingness to accept (WTA) compensation for a proposed 10-year economic incentive-based program. In addition, the role of landowner and farm characteristics on this perceived cost of conservation has also been assessed. As indicated by the results from two probit models that were developed, per acre payment has a significant positive effect on the probability a landowner will accept the program offer; the average payment respondents required being $32.58/acre. Other factors such as the landowners previous experience dealing with the wetland, personal preferences correlated with economic benefits and landowners who have an heir to take over the farm are also found to have significant impact on their participation decision. For those respondents who did not complete the WTA question, past relative experience, knowledge about wetlands, age, and the agricultural region the farm is located are revealed to be factors that affect to the provision of an explicit answer.

Pothole wetlands are ubiquitous throughout the Prairie Pothole Region and since 1900, 40-70% of potholes in the region have been drained to increase agricultural production. This thesis describes factors influencing spatial and temporal variations in wetland water quality and characteristics of drainage water. Research was conducted at Smith Creek watershed, southeastern Saskatchewan, where there has been controversy over recent renewed efforts to drain wetlands. Following snowmelt in 2009, 67 wetlands were sampled to determine whether spatial variations in wetland water quality were attributable to land cover, permanence classes, and surface drainage characteristics. Wetlands with cropped uplands had greater TP and K than wetlands with wooded and grassed uplands; TP, TDN, and DOC were higher in seasonally than permanently ponded wetlands; and salts were lower in wetlands with wooded uplands compared to wetlands with cropped and grassed uplands. Measurements of water quality of one permanently ponded wetland over a 20 week period in 2008 showed that the wetland acted as a solute trap. Variations in salts and DOC were influenced by hydrological processes such as runoff, evaporation, and shallow groundwater seepage, whereas variations in nitrogen, phosphorus, and bacteria were influenced by biotic, sorption, and hydrological processes. The experimental drainage of this wetland in November 2009 demonstrated that its water quality was an important control of drainage water quality. Further, the wetland ditch acted as a simple conduit, i.e., little solutes loss or gain occurred along it. In spring 2009, water quality along seven ditches and five natural connections that form between wetlands (termed spills) was compared. Concentrations of most solutes were similar, except TDN, DOC, HCO₃^-, K⁺, and Ca²⁺ that were higher in ditches than spills. Minimal changes in water quality along ditches and spills occurred, likely due to the low temperatures occurring in spring that restrict biotic processing and sorption. Notably, because ditches connect wetlands to streams, as opposed to spills that connect adjacent wetlands, ditches have a greater potential to contribute to downstream solute loading. Wetland drainage efficiency and wetland water quality were deemed the factors critical to determining solute exports via ditches. Results of wetland water quality and drainage characteristics can be useful to future modeling exercises and could be used to inform wetland drainage practices and policies.

<p>Although microbes may strongly influence wetland phosphorus (P) cycling, specific microbial communities and P metabolic processes have not been characterized in wetlands, and microbial P cycling is poorly understood across global ecosystems, especially in soils. The goal of this work is to test the effects of stress and growth factors on microbial communities in wetlands, and on microbial P metabolism and P cycling at ecosystem scales in wetland soils and beyond. I conducted field and laboratory research experiments in wetland soils, which by definition lie along gradients between terrestrial and aquatic ecosystems, and I explicitly compared results in wetlands to adjacent ecosystems to improve inference and impact. </p><p> To test relationships between microbial communities, soil stress and resource supply, I compared the distribution and abundance of uncultured bacterial communities to environmental factors across a range of wetland soils including a well-characterized P enrichment gradient, and restoration sequences on organic soils across freshwater wetland types. The strongest predictor of bacterial community composition and diversity was soil pH, which also corresponded with the abundance of some bacterial taxa. Land use and restoration were also strong predictors of bacterial communities, diversity, and the relative abundance of some taxonomic groups. Results from wetland soils in this study were similar to both terrestrial and aquatic ecosystems in the relationship of pH to microbial communities. However, patterns of biogeography I observed in wetlands differed from aquatic systems in their poor relationships to nutrient availability, and from terrestrial ecosystems in the response of microbial diversity to ecosystem restoration.</p><p> Accumulation of inorganic polyphosphate (PolyP) is a critical factor in the survival of multiple environmental stresses by bacteria and fungi. This physiological mechanism is best characterized in pure cultures, wastewater, sediments, and I used 31P-NMR experiments to test whether similar processes influence microbial P cycling in wetland soils. I surveyed PolyP accumulation in soils from different wetland types, and observed PolyP dynamics with flooding and seasonal change in field soils and laboratory microcosms. I found PolyP accumulation only in isolated pocosin peatlands, similar to patterns in the published literature. I observed rapid degradation of PolyP with flooding and anerobic conditions in soils and microcosms, and I characterized the biological and intracellular origin of PolyP with soil cell lysis treatments and bacterial cultures. While degradation of PolyP with flooding and anaerobic conditions appeared consistent with processes in aquatic sediments, some seasonal patterns were inconsistent, and experimental shifts in aerobic and anaerobic conditions did not result in PolyP accumulation in soil slurry microcosms. Similar to patterns in wetlands, I found prior observations of PolyP accumulation in published 31P-NMR studies of terrestrial habitats were limited to acid organic soils, where PolyP accumulation is thought to be fungal in origin. Fungal accumulation of PolyP may be useful as an alternative model for PolyP accumulation in wetlands, although I did not test for fungal activity or PolyP metabolism. </p><p> To evaluate relationships between microbial P metabolism and growth, I compared concentrations of P in soil microbial biomass with the soil metabolic quotient (qCO2) by compiling a large-scale dataset of the carbon (C), nitrogen (N) and P contents of soils and microbial biomass, along with C mineralization rates across global wetland and terrestrial ecosystems (358 observations). The ratios of these elements (stoichiometry) in biomass may reflect nutrient limitation (ecological stoichiometry), or be related to growth rates (Biological Stoichiometry). My results suggest that the growth of microbial biomass pools may be limited by N availability, while microbial metabolism was highly correlated to P availability, which suggests P limitation of microbial metabolism. This pattern may reflect cellular processes described by Biological Stoichiometry, although microbial stoichiometry was only indirectly related to respiration or metabolic rates. I found differences in the N:P ratios of soil microbial biomass among ecosystems and habitats, although high variation within habitats may be related to available inorganic P, season, metabolic states, or P and C rich energy storage compounds. Variation in microbial respiration and metabolic rates with soil pH suggests important influences of microbial communities and their responses to stress on metabolism and P cycling.</p><p> My dissertation research represents early contributions to the understanding of microbial communities and specific processes of microbial P metabolism in wetlands, including PolyP accumulation and Biological Stoichiometry, which underpin microbial cycling of P and C. Together, my research findings broadly indicate differences in microbial P metabolism among habitats in wetlands and other ecosystems, which suggests the prevailing paradigm of uniform P cycling by microbes will be inadequate to characterize the role of microbes in wetland P cycling and retention. While I observed some concomitant shifts in microbial communities, PolyP accumulation, and microbial stoichiometry with soil pH, land use, and habitat factors, relationships between specific microbial groups and their P metabolism is beyond the scope of this work, but represents an exciting frontier for future research studies.</p> / Dissertation

In recent years, many construct wetlands in Taiwan have been built for the purposes of wastewater treatment, river water purification, and ecology conservation. To evaluate the effectiveness of constructed wetlands on water purification, frequent water quality monitoring is needed. In this study, the multivariate statistical analysis was applied to evaluate the contaminant removal efficiency in a constructed wetland, and the time series method was then used to predict the trend of the indicative pollutant concentration in the wetland. Multivariate statistical analysis simplifies the original data into representative factors, or hive off the similarity between data to cluster, and then identify clustering outcomes. In this study, an artificial wetlands at the site around an old bridge locates at the Kaoping River Basin was used as the study site. The statistical software SPSS 12.0 was used to perform the multivariate statistical analysis to evaluate water quality characteristics of its. Results from this study show that the removal efficiency for the total coliforms (TC) of System A and B was 98%, 55% for biochemical oxygen demand (BOD), 53% for chemical Oxygen demand (COD), 55% for ammonia nitrogen (NH3-N), and 39% for total nitrogen (TN). Moreover, suspended solids (SS) couldn¡¦t be removed in both A and B systems. The box-and-whisker plot indicates that the water quality of inflow was unstable and variable; however, outflow was turning stable with its flow direction. The major pollutant indicators, except SS, were all in a decreasing tendency. The paired t-test shows p value of each item were lower than 0.05, except total phosphorus (TP) in System A, nitrate nitrogen (NO3-N) and Chlorophyll a (Chl-a) in System B. The correlation parameters from TN, nitrogen oxides (NOx), NO3-N and nitrite nitrogen (NO2-N) and so on were all higher than 0.7. The factor analysis of SPSS shows that 17 water-quality items of the study site could obtain four to six principal components, including nitrate nutrition factor, phosphorus nutrition factor, eutrophication factor, organic factor, and environmental background factor, the major influencing components are nutrition factor and eutrophication factor. The ponds of the study site were classified into two or three clusters depend on in-and-out flow location. This study attempted to establish a forecasting model of wetland pollutants concentration through the time series (ARIMA), results show that the outcome of the B7 pond was better than others. Results indicate that the ARIMA model can be used to simulate the trend of treatment efficiency using the wetland system. Experience and results obtained from this study would provide solutions for water quality control.

In Taiwan, more than 20% of the major rivers are mildly to heavily pollute by domestic, industrial, and agricultural wastewaters due to the low hook-up rate of public underground sewerage systems in rural areas. Thus, constructed or engineered wetlands have been adopted as the major alternatives to cleanup polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems to polish the secondary wastewater effluents to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before they discharge into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks of organics and metals. In this study, water, sediment and macrophytes samples were collected from the major wetland basins in KRRBCW. The quarterly investigation (from 2007 to 2009) results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g., total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g., Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O2/m2-d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TP). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that an increase in microbial diversities in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradually disappearing of E. coli was also observed along the flow courses through the natural attenuation mechanisms. The factor analysis of SPSS 12.0 shows that 17 water-quality items of the study site could obtain four to six principal components, including nitrate factor, phosphorus factor, eutrophication factor, organic factor, and environmental background factor, the major influencing components are nutrition factor and eutrophication factor. The ponds of the study site were classified into two or three clusters depend on in-and-out flow location. This study attempted to establish a forecasting model of wetland pollutants concentration through the time series (ARIMA), results show that the outcome of the B7 pond was better than others. Results indicate that the ARIMA model can be used to simulate the trend of treatment efficiency using the wetland system. Experience and results obtained from this study would provide solutions for water quality control. Thus, the wetland system has a significant effect on water quality improvement and is capable of removing most of the pollutants from the local drainage system before they are discharged into the downgradient water body. Other accomplishments of this constructed wetland system include the following: providing more green areas along the riversides, offering more water assessable eco-ponds and eco-gardens for public, and rORPabilitating the natural ecosystem. The Kaoping River Rail Bridge Constructed Wetland has become one of the most successful multi-function constructed wetlands in Taiwan. The experience obtained from this study will be helpful in designing similar natural treatment systems for river water quality improvement and wastewater treatment.

Iron reduction is an important redox reaction in anaerobic environments for both biological and chemical cycling of elements such as carbon. However, the controls on the rate and extent of iron reduction are poorly understood and unlike other major terminal electron accepting processes, iron reduction has the added complexity that its oxidized form (ferric iron) exists primarily as one of several solid phases in environments with pH greater than 3. Thus, the distribution and form of ferric iron minerals are important controls on iron reduction in natural systems. For the first phase of this research a series of sequential chemical extractions was performed on a core taken from a landfill-leachate-contaminated wetland-aquifer system at the Norman Landfill, Norman, OK. The phases targeted by the sequential extractions consist of easily water soluble salts and ions present in the soil solution; weakly acid soluble iron (such as siderite and ankerite); easily reducible iron (such as ferrihydrite and lepidocrocite); moderately reducible iron (such as goethite, akageneite, and hematite); organically bound iron; magnetite; and pyrite. The second phase of this research involved creating in situ microcosm experiments that exposed native microbial communities to a test solution amended with 2-line ferrihydrite (Fe5HO8∙4H2O), electron donor (lactate and acetate), and a conservative tracer for a period of eleven days. The kinetics of iron reduction were then evaluated over time and the resulting changes in microbial community structure documented through DNA and RNA analysis. Results document the spatial distribution of iron phases at the contaminated wetland-aquifer interface. Results of the sequential extractions indicate that ferrihydrite was present throughout the core. Accordingly, ferrihydrite was used in subsequent experiments on in situ microcosms to evaluate the kinetic controls on the microbial reduction of ferrihydrite. The results of these experiments show that microbial communities actively responded to the introduction of the amended ferrihydrite solution by increasing their community size and reducing ferrihydrite to an iron (II) phase in increasing amounts over an eleven day period.

Taiwan is an island surrounded by sea. Due to the topography, the coastal wetlands distribute almost around the west seashore, and some at the estuary of the east seashore. The coastal wetland is a transitional area between territory ecosystem and marine ecosystem. The environment of the coastal wetland is influenced by tide and season, thus the distribution of vegetations here exhibits a dynamic equilibrium. This study attempts to investigate the distribution and composition of the vegetation and the appearance of the habitat environment at the coastal wetland of Taiwan. According to the results, 173 species belonging to 50 families have been recorded. This indicates that the diversity of the marsh vegetation at the coastal wetland is low. Most of the species belong to Gramineae, Compositae and Cyperaceae. Paspalum vaginatum and Phragmites karka are the most dominant plant at coastal marsh environments. According to the results of detrended correspondence analysis (DCA) and cluster analysis (CA), 16 vegetation types including one subtype and one transitional type are classified. The habitats of these vegetation types can be classified into five types, namely tidal fresh water marsh, fresh water-salt marsh, wet meadow, salt marsh and submerged environment. Most of these vegetation types have only one major dominant species. The distribution of the marsh vegetation features a belting pattern, which is mainly limited by the maximum of their salt tolerance from coastal toward inland, or estuary toward headwaters. Subsequently, it can by influenced by soil moisture and pH value. Furthermore, the vegetations are influenced by many additional environmental factors, resulting in a mosaic distribution of vegetation types. The marsh vegetation is processing at an unstable and developing period. Because the coastal wetland is seriously disturbed by human activities, the environmental variation becomes greater. Therefore, the transitional vegetations were observed frequently. Finally, the development pressure due to economic demand is the major cause that makes coastal wetland disappeared. It is urgently needed to protect this sensitive natural resource.