<p>Whether through sea level rise, farmland abandonment, or wetland restoration, agricultural soils in coastal areas will be inundated at increasing rates, renewing connections to sensitive surface waters and raising critical questions related to environmental tradeoffs. Wetland restoration in particular is often implemented not only to promote wildlife habitat, but also to improve water quality through nutrient removal, especially in agricultural catchments. The microbial process of denitrification is the central mechanism of nitrogen removal in wetlands and flooded soils, and can be seen as a potential environmental benefit of flooding agricultural lands. While denitrification undoubtedly can remove nitrogen from soil and surface water, higher soil moisture or flooding in wetland soils can also increase the production of greenhouse gases, specifically nitrous oxide and methane, representing a potential environmental tradeoff. Understanding the likely benefits of denitrification and the likely greenhouse gas costs of wetland restoration could help inform environmental policies concerning wetland restoration. </p> <p>Determining whether restored wetlands are larger sources of greenhouse gases compared to contrasting land use types (agriculture and forested wetlands) was the first goal of this dissertation (Chapter 2). We measured gas fluxes from soil and water to the atmosphere, and related environmental variables, in four sites over two years to estimate fluxes of the three major greenhouse gases. We found that carbon dioxide was the major contributor to the radiative balance across all sites, but that in the agricultural site and one of the forested wetland reference sites, nitrous oxide was the second most important contributor. Many studies have shown that methane is more important that nitrous oxide in most freshwater wetlands, as we found in the other forested wetland reference site and in flooded parts of the restored wetland. Overall, we did not find higher greenhouse gas fluxes in the restored wetland compared to agricultural soils or forested wetlands.</p> <p>The controls over nitrous oxide are especially complex, because it can be produced by two complementary processes, nitrification and denitrification, which generally occur under different conditions in the environment. In Chapter 3, we determined the soil and environmental factors that best predicted nitrous oxide fluxes for a subset of our data encompassing gas fluxes measured in November 2007. We found that soil temperature and soil carbon dioxide flux, along with ammonium availability and denitrification potential, were good predictors of nitrous oxide (adj R<super>2</super>=0.81). Although the nitrous oxide model did not perform as well when applied to data from another sampling period, we expect to further develop our modeling efforts to include possible non-linear temperature effects and a larger range of environmental conditions. </p> <p>In Chapter 4, we present results of a stable isotope tracer experiment to determine the relative contribution of nitrification and denitrification to nitrous oxide fluxes in these different land use types, and to determine the response of these processes to changing soil moisture. We added two forms of nitrogen-15 to intact soil cores to distinguish nitrification from denitrification, and subjected the cores to drainage or to a simulated rain event. We found that across the range of soil moisture, the fraction of nitrous oxide produced by denitrification did not change, but within each soil type there was a response to the simulated rain. In mineral soils, the nitrous oxide fraction increased with increasing soil moisture, with the highest mole fraction [N₂O/(N₂+N₂O)] in the agricultural soils, while in the organic soils there was no change or even a decrease. The fraction of nitrous oxide derived from coupled nitrification-denitrification increased with increasing soil moisture, and was much higher than that from denitrification alone in the more organic soils. This suggests that, in these saturated acid-organic soils, nitrification plays an important and underappreciated role in contributing to nitrous oxide fluxes from freshwater wetlands. The results from the laboratory experiment were consistent with patterns we saw in the field and help explain the differential contribution of nitrification and denitrification to nitrous oxide fluxes in different land use types in coastal plain wetlands of North Carolina. </p> <p>Overall, we found that both nitrification and denitrification contribute to nitrous oxide fluxes in coastal plain wetlands in North Carolina, and that nitrification is an especially important source in acid-organic soils under both field-moist and saturated conditions. Although freshwater wetlands, with an average nitrous oxide mole fraction of 0.08, are generally seen as being insignificant sources of nitrous oxide, our study sites ranged from 0.10 to 0.30, placing them closer to agricultural fields (0.38; Schlesinger 2009). Although the ecosystems in our study produced more nitrous oxide than expected for freshwater wetlands, we found no significant tradeoff between the local water quality benefits conferred by denitrification and the global greenhouse gas costs in the restored wetland. These results suggest that, from a nitrogen perspective, wetland restoration in coastal agricultural lands has a net environmental benefit.</p> / Dissertation

Wetlands cover a broad of areas, including aquatic and terrestrial ecological systems. Many people and agencies are attracted the natural resources value and begin the action to protect it. In 2007, the Construction and Planning Agency Ministry of the Interior¡]CPAMI¡^in Taiwan announced 75 sites as ¡§National Wetlands of Importance¡¨. Currently the Wetland Conservation Law draft completed of 2010. In the future the wetlands conservation and mitigation mechanism will be definite. Wetland conservation is not only a government duty but also the resporsibility of the Private Sector and Citizen. Sometimes non-government organization and community often face private land ownership, lack of income and problems with Taiwan¡¦s current laws and regulation. Many wildlife habitats and critical wetlands are not owned by government, such as Aogu Wetland, therefore many researchers begin to promote the idea of "public trust" as one of the models for wetland sustainable management. In this study use public trust management model to combine wetland conservation maintain wetland ¡§no net loss¡¨. The common consensus and co-management mechanism between public and private sectors become crucial issues. Major research methods used Depth-Interview with different field experts to find the solution and feasibility of the proposed framework. Wetland public trust is a tool advocating the collaboration and cooperation among public, non-profit organizations, enterprise, government to improve the outcomes of environmental conservation, which can be oversee by particular authorities This study proposes wetland public trust as an appropriate framework and integrates tax system to improve the wetland conservation models in Taiwan.

Alkylphenol polyethoxylates (APEOs), a class of nonionic surfactants, have been widely used for industrial, agricultural and household applications. The biodegradation metabolites of APEOs, such as nonylphenol and octylphenol, are more persistent and known to disrupt endocrine function in wildlife and human. These compounds are also recognized as endocrine disrupting chemicals (EDCs). The objectives of this study were to investigate the distribution and removal efficiencies of EDCs, including nonylphenol diethoxylates (NP2EO), nonylphenol monoethoxylates (NP1EO), nonylphenol (NP) and octylphenol (OP), of wastewater treated by the constructed wetland systems along the Dahan River and around the Dapeng Bay, respectively. In addition, the method of risk quotient was used to evaluate the potential ecological risk of APEOs to aquatic organisms in current study. The water samples collected from 32 sampling sites in the Dapeng Bay National Scenic Area including Datan, Pengcun and Linbain right bank constructed wetlands. The samples were then concentrated by solid phase extraction, and analyzed for target compounds by HPLC/fluorescence. According to the results, nonylphenol diethoxylates, nonylphenol monoethoxylates, nonylphenol and octylphenol were found approximately equal to 29.9, 47.3, 20.5 and 57.7 %, respectively of the samples from three constructed wetlands with concentrations ranged from <3.3 to 968.7, <3.3 to 226.5, <1.3 to 238.4 and <1.0 to 1458.7 ng/L, respectively. Temporal variation of APEOs showed a decreasing in the order of summer¡Öspring¡Öwinter¡Öautumn. The removal efficiencies of APEOs in these constructed wetlands showed a decreasing order of Datan wetland¡ÖPengcun wetland¡ÖLinbain right bank wetland. In addition, the samples collected from 18 sampling sites from the constructed wetlands along the riparian of Dahan River including Daniaopi, Hsin-Hai Bridge Phases I and II constructed wetlands. According to the results, nonylphenol diethoxylates, nonylphenol monoethoxylates, nonylphenol and octylphenol were found approximately equal to 91.9¡B84.8¡B17.1 and 73.7 %, respectively of samples collected from three constructed wetlands with concentrations ranged from <3.3 to 11191.5, <3.3 to 6069.0, <1.3 to 671.0 and <1.0 to 5581.9 ng/L, respectively. The removal potential of APEOs in these constructed wetlands showed a decreasing order of Hsin-Hai Bridge Phases II¡ÖDaniaopi¡ÖHsin-Hai Bridge Phases I constructed wetland. Regarding the ecological assessment in this research, the calculated risk quotients were up to 30 times higher in the constructed wetland systems of Dahan River than those in the Dapeng Bay National Scenic Area, indicating that the existing concentrations of these EDCs in wetland systems might cause potential ecological risks to aquatic organisms. Furthermore, the decreasing risk quotient from influent to effluent indicating the capabilities of treating alkylphenolic compounds in these constructed wetlands.

Swine wastewater is one of the major pollutions in Taiwan. The abundant nutrition and organic matters in it may lead eutrophication of water body. Meanwhile, the low dissolved oxygen level and high suspended solids concentration may also make it more difficult to handle the wastewater treatment. At present facility of swine wastewater in Taiwan is the three-process treatment which includes the solid-liquid separation, anaerobic digestion, and activated sludge system. Even though the three-process treatment is widely used, the efficiency of sediment and filter effectively to remove the nutrition, e.g., ammonia and phosphate is still in question. On the other hand, the activated sludge system is a difficult technique that the swine farmers can¡¦t easily to operate. Based on these reasons, an efficient swine wastewater treatment process should be established. In this study, we replace the activated sludge system in three-process treatment with the horizontal biofilter (HBF) and subsurface system constructed wetland (SFSCW) to assess the practicability of improving the traditional process. HBF is a fix-biofilm system which is superior to the suspended growth of activated sludge system by its simple operation and no need to return the sludge from the final clarifier. Porosity in the gravel of SFSCW and the root zone of Canna indica can also help to remove the nutrients from the outflow of HBF. The tested HRT (hydraulic retention time) has been controlled at about 30 hours and results show that SS, BOD and COD removal efficiencies as 84.07%, 86.48%, and 68.45%, respectively. HBF and SFSCW provided approximate 70~80% and 10~20% removal efficiencies, respectively. This design of combining HBF and SFSCW system has high potential to treat the swine wastewater, and adding the backwash unit may further facilitate the operation in the future.

The objectives of this study are to investigate the biodiversity in different unit of treatment systems, and to detect the function in a salt water type of constructed wetland. We investigated the benthic invertebrate community in different stage from 2010 July to 2011 May, while the parameters of TKN, NH3-N, organic nitrogen, TP, TOC and particle size were measured in the sediments of each sampling site at the same time in the wetland system. The results show that concentrations of organic matter and nutrients in the sediments were increased with time monthly. In May of 2010, the concentration of NH3-N were found the highest one(ANOVA, p<0.05). The particle size in sampling site 1 were the highest (ANOVA, p<0.05), while in November of 2010 all sampling sites were found exhibiting significantly different with other months (ANOVA, p<0.05). Further more, for the diversity of benthic invertebrate, we found that the parameter of the temperature was strongly negatively related to the species diversity, species abundance and species evenness, respectively (r=-387[H¡¦]¡F-533[d]¡F-438[J¡¦] ). The species diversity was increased with organic nitrogen concentrations in the sediments (r=0.492[TKN]¡F0.408[NH3-N]¡F0.493[org-N]), and were negatively related to the parameters of DO and particle size(r=-0.402[Particle size]¡F-0.287[DO] ). In addition, PCA shows that the parameters of particle size¡Borg-N¡BNH3-N¡BTKN and TOC were all important factors. Generally, it was concluded that the constructed systems, which is functioned of wetland was wastewater treatment mainly, exhibit no significant function in biodiversity.

Aogu Farm was built on reclaimed land. Because of its rich ecological resources, Aogu was defined as a "Major Wildlife Habitat" in Chiayi County by the Forest Service and is also expected to reduce carbon in the plan for the flatland forest. Power pumps are currently used to irrigate and cultivate the area. However, after becoming the Forest Recreation Area in the future, Aogu Farm has to reduce the influence of human beings. However, if the Taisugar Company doesn¡¦t support the plan of Forest Service or abandons farming and stops the pumping power, the Aogu Wetlands will suffer the crisis of coastal inundation. Hydrological models have their own characteristics. For example, inundation models for regional drainage using one-dimensional channel flow, two-dimensional overland flow, and runoff in the mountains all can be assessed to solve the inundation problems in the coastal lowlands. Nevertheless, the Aogu Wetlands, the Case Study area, has both a dry season and a wet season even in the lowland. When rainstorms occur, the area is unable to discharge the water by gravity but can depend only on pumps to discharge the water into the sea. Therefore, based on the need to manage water, hydrological surveys must be conducted to assess the hydrological impact of continuous rainfall on the Aogu Wetlands and to provide reference information to assist in the management. In the thesis, I use both the Geographic Information System (GIS) and the Storm Water Management Model (SWMM) as analysis tools. Moreover, the different regions are further divided into watershed and the route of drainage, establishing two kinds of models of watershed hydrology for precipitation simulations. Finally, to compare these two methods, the Arc Hydro and SWMM models are used in watershed analysis.

This high-resolution biogeochemical study investigated spatial and temporal variability in the mixing interface zones within a wetland-aquifer system near a municipal landfill in the city of Norman, Oklahoma. Steep biogeochemical gradients indicating zones of enhanced microbial activity (e.g. iron/sulfate reduction and fermentation) were found at centimeter-scale hydrological and lithological interfaces. The small resolution study was achieved by combining passive diffusion samplers with capillary electrophoresis for chemical analysis. The spatial and temporal variability of biogeochemical processes found at the interfaces was evaluated in a depth profile over a period of three years. Correlations between geochemical parameters were determined using Principal Component Analysis (PCA) and the principal factors obtained were interpreted as a dominant biogeochemical process. Factors scores were mapped by date and depth to determine the spatial-temporal associations of the dominant processes. Fermentation was the process controlling the greatest variability in the dataset followed by iron/sulfate reduction, and methanogenesis. The effect of seasonal and hydrologic changes on biogeochemistry was evaluated from samples collected in a wet/dry period from three locations exhibiting upward, downward, and negligent hydrologic flow between aquifer and wetland. PCA was used to identify the principal biogeochemical processes and to obtain factor scores for evaluating significant seasonal and hydrological differences via analysis of variance. Iron and sulfate reduction were dominated by changes in water table levels and water flow paths, whereas methanogenesis and bacterial barite utilization were dominated by season and associated with a site with negligible flow. A preliminary study on microbial response to changes in geochemical nutrients (e.g. electron acceptors and electron donors) was conducted using in situ microcosms with the purpose of quantifying iron and sulfate reduction rates. Problems encountered in the experiment such as leaks in the microcosms did not allow the determination of respiration rates, therefore the experiments will be repeated in the future. The results suggest that iron and sulfate reduction were stimulated with the addition of sulfate and ferrihydrite (electron acceptors) and acetate and lactate (electron donors). This research demonstrates the importance of assessing biogeochemical processes at interface zones at appropriate scales and reveals the seasonal and hydrological controls on system processes.

Understanding the role of freshwater wetlands in the global carbon cycle has become more important as evidence of climate change grows. In this paper, we examine the burial and decomposition of particulate organic matter (POM) in a temperate, siliciclastic, seasonal wetland. High POM abundances are found in silt layers, while sand units preserve very little POM. The POM distribution with depth is compared to the biogeochemistry of sediment porewater with depth. POM acts as a driver for reduction reactions within the wetland soil. Porewater biogeochemistry and POM decomposition are controlled by seasonal changes in the level of the water table which cause seasonal shifts in the oxic/anoxic boundary. At the oxic/anoxic boundary, reoxidation of FeS minerals in the soil cause rapid POM decomposition at the average minimum water table level in the late summer and early fall. Variation in the minimum depth of the water table from year to year may account for fluctuating POM numbers in the upper silt layers. The results from this study can be used to predict seasonal water level fluctuations in ancient wetland and to explain recurrence horizons in peat.

Wetland park is developed and beginning revitalized in the field of the park and green land, there are more and more trends particularly to apply to the coastal area of the west of our country, seeing that the expectation that the land uses is ardent , a lot of planning units and undertook business are beginning to be exposed to such a new park concept gradually, But to originally storing in the production of the economic worth and activity in the wetland is not clear and bright, so that the deviation promptly in the initial stage of planning , and the collection of the environment data does not really perfect, soon careless entry the detail design, or construct directly. How to take the rational planning procedure and overall self-criticism of wetland under the situation of different in unit's technological quality of planning, it is undoubtedly a topic that is worth studying! The planning way and quality of the wetland park in Taiwan are different, and the goal is inconsistent, the local government organization and planning units play important roles on wetland park decision making, and often have great influence in the final planning achievement. However, whether members of the leading wetland park project have a professional background or master in the relevant field? For wetland ecology, planning and design, land suitable are analysis, even is people's demand considered? And how to operate integrated land planning and management, I'm afraid that also remains to be discussed. So, with the collection of the wetland park cases, and find out about the characteristic of the domestic wetland environment, including the natural and humane condition discussion, and preliminary draw up a set of planning factors of wetlands park, it is eight module groups altogether, to go deep into the environmental topic , ecological spatial distribution, research of planning methods, the investigation of historical changes, self-criticism of the application aspect, tools using, theory and in the understanding of community participation, in order to adjust the direction of wetland park planning further , let the wetland park have rationality even more. The planning module groups of the wetland park is probing into how rational the planning content of wetland park, This text takes river bank park of area in Xingren of Chia-yi city as an example, use overlap analysis and module groups to probe into the rationality of its planning content, finally put forward the integrated management strategies for the reference in the follow-up management operation. But does not judge the quality of the park according to that, expect that can give consideration to the human demand and bio-diversity conservation in the planning of the wetland park in the future.

The disappearance of the wetlands of Taiwan have reflected all kinds of biological drifting about aimlessly. We have to take action for protecting the wetlands, due to there are less than before. In the face of the wetlands that there are not much left, we must treasure and offer protection. The action that a lot of wetlands protection at present is going on. We need to invest more research and monitoring, and should investigate the state of wetland health that file, expect that can utilize limited resources more effectively during the process of protecting. This research expects to build the index system constructing out a set of Taiwan wetlands and assessing to the characteristic of the wetland of Taiwan. After consulting the domestic and international relevant index system, this research drafts preliminary wetland health assessment system. Through Delphi method, gathering opinions and suggestions from experts and scholars this research could set up the health assessment indicators of Taiwan artificial wetlands. Index system is divided into environment and management two general parts, and is categorized into six major indexes groups, including organism, water, soil, environment, management and social economy, amounts to 18 indexes. In the case of Zo-Zai Wetland Park, in Kaohsiung, Taiwan, we applied this index system to inspect the health degree of Zo-Zai Wetland Park and its index results. Assessing the result for being 'good' in health, and cause the unhealthy projects of wetland include restoration species grow up degree, the distribution of the invasive species, the water quality situation, the hydrology situation and the maintenance funds of the wetland . The whole but the speech, the continent Zo-Zai Wetland Park still belongs the health, but influence the wetland healthy factors still need to monitor continuously in order to maintain wetland health quality. This research hopes to diagnose the health state of the wetlands, through health assessment indicators system and regular wetland monitoring, Then designing the wetland follow-up planning and management strategies to result the wetlands¡¦ problems earlier. Finally, it hopes to help restoring the wetlands in Taiwan.