Master of Science (MS), Wright State University, 2018, Biological Sciences

Macroinvertebrates are important contributors to wetland ecosystems due to their role in decomposition, nutrient cycling, and as a food resource for other organisms. Several studies have analyzed the macroinvertebrate communities in created wetlands, but few have evaluated them in the context of trophic structure in both created and natural wetlands. The objective of this study is to better understand benthic macroinvertebrate community composition and trophic structure in created and natural wetlands. My central hypotheses were that macroinvertebrate communities in created wetlands would have (1) differing composition and (2) less complex trophic structure with shorter food-chain length compared to natural wetlands. Macroinvertebrates and soil cores were collected from five created and two natural depressional marshes. I assessed macroinvertebrate community characteristics such as diversity and composition, and functional feeding group composition. I used stable isotope analysis to determine food-chain length and other trophic metrics. Soil cores were used to determine bulk density, texture, and the C:N profile of the soil in the wetlands. Through a combination of univariate (e.g. ANOVA) and multivariate analyses (e.g. NMDS, PERMANOVA) these conclusions were met: (1) Macroinvertebrate taxa composition differed statistically between wetland types (p= 0.05); (2) FCL did not differ significantly between wetland types. In addition, functional feeding group composition was trending toward significance (p = 0.095), and soils were found to be distinct between wetland types (p= 0.043), with bulk density being a strong driver of that relationship (p= 0.012). These results show that in these wetlands, macroinvertebrate species present are different, however the overall function they provide are very similar between wetland types. The habitat characteristics in created wetlands that are known to quickly develop (e.g. plant community composition) were similar to the natural we (open full item for complete abstract)

Committee: Katie Hossler Ph.D. (Advisor); Yvonne Vadeboncoeur Ph.D. (Committee Member); Volker Bahn Ph.D. (Committee Member); John Stireman Ph.D. (Other) Subjects: Ecology; Entomology; Environmental Science; Environmental Studies

Master of Science, The Ohio State University, 2009, Environmental Science

Constructed, created and restored wetlands are gaining popularity due to multiple benefits they provide. However, there is a concern that wetlands increase mosquito breeding in urban areas. This is especially due to the recent concern regarding mosquito borne viral encephalitis and other diseases. Published studies to quantify mosquito population in constructed and natural wetlands are inconclusive. This study quantified the population of mosquitoes from two experimental flow-through created wetlands and two stormwater fed wetland at the Olentangy River Wetland Research Park (ORWRP) in Columbus, Ohio in summer. Sampled mosquitoes were identified to species level to investigate their disease vector potential. The study also compared mono specific and multispecies small (1 m2) mesocosms being used for another experiment. The flow-through created wetlands were less conducive to mosquito breeding compared to the pond (p<0.00001) and stormwater wetland (p=0.002). Outflow regions and emergent vegetation sites in the flow-through wetlands were most conducive to mosquito breeding than were inflows (p=0.009) and floating vegetation sites (p=0.023). Mixed vegetation communities (Sparganium eurycarpum, Juncus effusus, and Schoenoplectus tabernaemontani) rather than mono specific Typha communities provided most conducive environment for mosquito breeding (p<0.0001). Mesocosm plots with steady inflow (10 cm depth) and with deep water (20 cm) in summer and shallow water (5 cm) in spring had higher mosquito densities than did mesocosm plots with pulsed flow (10 cm depth with inflow rate according to the river stage) and deep water (20 cm) in spring and shallow water (5 cm) in fall. Among water quality parameters, conductivity (p=0.004) and, to a lesser extent, dissolved oxygen (p=0.052) correlated with mosquito larval density (adjusted R2 of 0.67). Six mosquito species identified in all water bodies were Cx. pipiens, Cx. salinarius, Cx. restuans, Ur. sapphirina, An. quadrimaculatu (open full item for complete abstract)

Committee: Parwinder Grewal PhD (Advisor); Timothy Buckley PhD (Committee Member); Woodbridge A. Foster PhD (Committee Member); William J. Mitsch PhD (Committee Member) Subjects: Environmental Science

Doctor of Philosophy, The Ohio State University, 2009, Environmental Science

Wetlands are important ecosystems in our landscape because of the broad array of ecosystem services they provide to humans and the environment. Wetlands have unique biotic and abiotic chemical interactions among soil, water, and vegetation that, combined with long retention times that are characteristic of wetlands, allow for nutrients, metals, and organic pollutants to be removed from the water column, resulting in cleaner water. The same characteristics that make wetlands so efficient at improving water quality also provide anaerobic conditions and organic substrate that is optimal for methanogenesis, the microbial production of the greenhouse gas (GHG) methane (CH4). The objective of this dissertation is to investigate the biogeochemistry, specifically water quality improvement and CH4 emissions, of natural and created wetlands in tropical and temperate climates. Five tropical treatment wetlands dominated by floating aquatic plants and constructed to deal with a variety of wastewaters were compared for their effectiveness in treating organic matter and nutrients in the Parismina River Basin in eastern Costa Rica. Wastewaters were from a dairy farm, a dairy processing plant, a banana paper plant, and a landfill. Four of the five wetland systems were effective in reducing nutrient levels of effluents before water was discharged into rivers. Ammonia nitrogen (N) levels in water entering most wetlands were considerably higher than ambient (i.e., riverine) levels; concentrations were reduced by as much as 92% in the wetlands, which retained, at a maximum, more than 166 g NH4-N m-2 y-1. Nitrate N removal occurred in low concentrations in the inflows (less than 1 mg-N L-1). Phosphate phosphorus (P) was effectively reduced through the wetlands (92 and 45% reductions through dairy farm wetlands, 83% reduction through banana paper wetlands, and 80% reduction through dairy processing wetlands). Retention of phosphate ranged from 0.1 to 10.7 g-P m-2 year-1 in the treatment (open full item for complete abstract)

Committee: William J. Mitsch PhD (Advisor); Nicholas T. Basta PhD (Committee Member); Richard P. Dick PhD (Committee Member); Jay F. Martin PhD (Committee Member) Subjects: Biogeochemistry

Doctor of Philosophy, The Ohio State University, 2006, Environmental Science

The effect of hydrologic conditions on nitrogen biogeochemistry was investigated in two identical 1-ha surface-flow created riverine wetlands in Columbus, Ohio, USA. These wetlands, created in 1993-1994, are fed with water from Olentangy River. For two years (2003-2004), both wetlands experienced seasonal (winter-spring) controlled hydrologic flood pulses followed by one year (2005) in which they received a steady flow rate of water. Nitrogen gas flux measurements were made in plots distributed along a transverse gradient (edge plots and high marsh plots with alternate wet and dry conditions, and low marsh plots and open water plots with permanent flooding). Highest average N2O fluxes were observed in high marsh plots followed by edge plots, open water plots , and low marsh plots. In permanently flooded plots without vegetation, nitrous oxide fluxes were low, regardless of flood pulse conditions.N2O fluxes were higher in plots with vegetation than in plots without vegetation only when plots were inundated. Denitrification in all plots was significantly correlated with soil temperature and was significantly correlated with the nitrate concentration in the inflow surface water in the growing season in permanently flooded zones. Highest mean denitrification rates were observed in the low marsh and open water zonesfollowed by high marsh and edge zones. In permanently flooded areas, denitrification rates were significantly higher near the inflow than near the outflow. Denitrification appeared to be nitrogen limited in low marsh, high marsh and edge plots, but both carbon and nitrogen limited in open water. NO2- + NO3- mass retention was similar under pulsing and steady flow conditions. Total nitrogen (TN) retention was lower under pulsing than steady flow conditions as a result of an export of organic nitrogen occurred under pulsing conditions. Aboveground biomass productivity in the pulsing year was significantly lower than in the steady-flow flow. Belowground biomass p (open full item for complete abstract)

Committee: William Mitsch (Advisor) Subjects:

Master of Science, The Ohio State University, 2010, Environmental Science

Riparian wetland creation and restoration have been proposed as a means to mediate aquatic nitrate (NO3-) pollution from non-point runoff. Excess nitrate concentrations from the US Midwest are known to cause hypoxia in the Gulf of Mexico. Denitrification by anaerobic microbial communities in wetland soils results in the permanent removal of NO3- through reduction to NO, N2O, and N2. Denitrification rates were quantified using the in situ acetylene inhibition technique at 12 locations in three wetland/riverine sites at the Olentangy River Wetland Research Park, Columbus, OH for one year. Sites included two created flow-through experimental wetlands and one bottomland forest/river-edge site. Points were spatially distributed at inflows, center, and outflows to include permanently flooded open water, intermittently flooded transitions, and upland. Annual median (mean) denitrification rates were significantly higher (p<0.001) in flooded zones of the wetlands (266 (415) µg N2O-N m-2 h-1) compared to the transition zones (58 (37.5) µg N2O-N m-2 h-1, respectively). Median wetland transition zone denitrification rates did not differ significantly (α=0.05) from the riverside or upland site. Wetland denitrification rates peaked in spring during the period of highest concentration of nitrate-nitrogen caused by nitrogen fertilizer application and runoff (for the months of April-June, median rates ranged from 240-1010 µg N2O-N m-2 h-1 in the permanently flooded zones). A nitrogen mass balance analysis showed that while 57% of surface water N was retained by the wetlands, only about 2% of N entering the wetlands was permanently removed through denitrification.

Committee: William J. Mitsch PhD (Advisor); Ulo Mander PhD (Committee Member); Li Zhang PhD (Committee Member) Subjects: Biogeochemistry; Ecology; Environmental Science; Gases

Doctor of Philosophy, The Ohio State University, 2007, Environmental Science

The effect of delivering influent water to a wetland as seasonal pulses or as a continuous steady-flow on hydroperiod, water chemistry, avian use, plant primary production, and plant community structure was investigated in a whole-ecosystem study involving a 3-ha created riparian wetland at the Schiermeier Olentangy River Wetland Research Park at The Ohio State University in Columbus, Ohio USA during 2003 through 2006. A simulation model was then developed using short-term measurements of river and wetland stage to predict long-term patterns of succession within the wetland. The natural hydroperiod of the riparian wetland was varied in 2005; its natural flood-pulses were removed and replaced with an artificial steady-flow supplied by submersed pumps. In 2004 the wetland received 27 m of inflow followed by 20 of inflow in the steady-flow year 2005. The nutrient removal rate was higher for nitrate-nitrogen, total nitrogen, and total phosphorus during the year with flood-pulsing than during the steady-flow year. A greater removal of NO 3 -and TP occurred in the emergent marsh section of the wetland than the open water section. Conversely TN increased through the emergent marsh and decreased through the open water. There was greater avian use of the wetland during pulsing than steady-flow conditions. The guild of bird species most affected was shorebirds. Peak observed shorebird use corresponded to dry conditions in the wetland in the later part of the growing season during migration. Primary productivity of macrophytes was compared among the 2004 pulsing hydroperiod year, the 2005 steady-flow year, and in 2006 when natural pulsing was again restored. The wetland was significantly more productive (α = 0.05) during pulsing compared to steady-flow conditions. The simulation model predicted water depth (based on precipitation, potential evapotranspiration, river stage, and overland outflows), calculated the growth of trees and emergent macrophytes (based on water depth and (open full item for complete abstract)

Committee: William Mitsch (Advisor) Subjects: