Wetlands are very valuable ecosystems as they play an integral role in wildlife habitat, water management and greenhouse gas exchange. The exchange of carbon dioxide between prairie wetlands and the atmosphere is poorly understood. The purpose of this study was to identify rates and trends in the growing season carbon dioxide flux from the riparian and open-water zone of a prairie pothole wetland. In addition to providing core open water and riparian zone CO2 flux measurements, relationships between variations in CO2 flux and characteristics of the wetland���s biological, biochemical and hydrometeorological state were assessed. The CO2 effluxes from the pond during the summer of 2006 were approximately four times greater than in 2005, but were much lower in the early fall. Algal chlorophyll-a concentrations were greater in 2005 than 2006 for all three algal assemblages. The mean chlorophyll-a concentrations in 2005 for epiphyton, phytoplankton and metaphyton were 2.75 �� 0.62 g m-2, 87 �� 24 �� L-1, and 318 �� 187 g m-2 respectively. In 2006 mean concentrations for the same assemblages were 0.008 �� 0.001 g m-2, 8 �� 2 �� L-1, and 27 g m-2 respectively. The amount of DOC in the open water in August of 2005 (140 mg DOC L-1) was 70 times greater than in July of 2005 (2 mg DOC L-1). DOC ranged from 30 to 52 mg DOC L-1 in 2006. Although highly productive, the pond proper appeared to be a source of DOC which is concurrent with literature from littoral zone and shallow inland waters. Soil respiration increased upslope from the wetland to the cropped upland in 2005. Net ecosystem exchange was greater in the cattail ring surrounding wetland than the grass and sedge zone beyond the cattails. The riparian vegetation may have been water stressed in late-July (at the climax of the dry period) when net ecosystem exchange decreased. Diurnal net ecosystem exchange in the riparian zone indicates uptake during the day and emissions at night. From this data it appears that the riparian zone may have acted as a CO2 sink in June, July and August and a source in April. / October 2008

Wetlands are very valuable ecosystems as they play an integral role in wildlife habitat, water management and greenhouse gas exchange. The exchange of carbon dioxide between prairie wetlands and the atmosphere is poorly understood. The purpose of this study was to identify rates and trends in the growing season carbon dioxide flux from the riparian and open-water zone of a prairie pothole wetland. In addition to providing core open water and riparian zone CO2 flux measurements, relationships between variations in CO2 flux and characteristics of the wetland’s biological, biochemical and hydrometeorological state were assessed. The CO2 effluxes from the pond during the summer of 2006 were approximately four times greater than in 2005, but were much lower in the early fall. Algal chlorophyll-a concentrations were greater in 2005 than 2006 for all three algal assemblages. The mean chlorophyll-a concentrations in 2005 for epiphyton, phytoplankton and metaphyton were 2.75 ± 0.62 g m-2, 87 ± 24 µ L-1, and 318 ± 187 g m-2 respectively. In 2006 mean concentrations for the same assemblages were 0.008 ± 0.001 g m-2, 8 ± 2 µ L-1, and 27 g m-2 respectively. The amount of DOC in the open water in August of 2005 (140 mg DOC L-1) was 70 times greater than in July of 2005 (2 mg DOC L-1). DOC ranged from 30 to 52 mg DOC L-1 in 2006. Although highly productive, the pond proper appeared to be a source of DOC which is concurrent with literature from littoral zone and shallow inland waters. Soil respiration increased upslope from the wetland to the cropped upland in 2005. Net ecosystem exchange was greater in the cattail ring surrounding wetland than the grass and sedge zone beyond the cattails. The riparian vegetation may have been water stressed in late-July (at the climax of the dry period) when net ecosystem exchange decreased. Diurnal net ecosystem exchange in the riparian zone indicates uptake during the day and emissions at night. From this data it appears that the riparian zone may have acted as a CO2 sink in June, July and August and a source in April.

Wetlands are very valuable ecosystems as they play an integral role in wildlife habitat, water management and greenhouse gas exchange. The exchange of carbon dioxide between prairie wetlands and the atmosphere is poorly understood. The purpose of this study was to identify rates and trends in the growing season carbon dioxide flux from the riparian and open-water zone of a prairie pothole wetland. In addition to providing core open water and riparian zone CO2 flux measurements, relationships between variations in CO2 flux and characteristics of the wetland’s biological, biochemical and hydrometeorological state were assessed. The CO2 effluxes from the pond during the summer of 2006 were approximately four times greater than in 2005, but were much lower in the early fall. Algal chlorophyll-a concentrations were greater in 2005 than 2006 for all three algal assemblages. The mean chlorophyll-a concentrations in 2005 for epiphyton, phytoplankton and metaphyton were 2.75 ± 0.62 g m-2, 87 ± 24 µ L-1, and 318 ± 187 g m-2 respectively. In 2006 mean concentrations for the same assemblages were 0.008 ± 0.001 g m-2, 8 ± 2 µ L-1, and 27 g m-2 respectively. The amount of DOC in the open water in August of 2005 (140 mg DOC L-1) was 70 times greater than in July of 2005 (2 mg DOC L-1). DOC ranged from 30 to 52 mg DOC L-1 in 2006. Although highly productive, the pond proper appeared to be a source of DOC which is concurrent with literature from littoral zone and shallow inland waters. Soil respiration increased upslope from the wetland to the cropped upland in 2005. Net ecosystem exchange was greater in the cattail ring surrounding wetland than the grass and sedge zone beyond the cattails. The riparian vegetation may have been water stressed in late-July (at the climax of the dry period) when net ecosystem exchange decreased. Diurnal net ecosystem exchange in the riparian zone indicates uptake during the day and emissions at night. From this data it appears that the riparian zone may have acted as a CO2 sink in June, July and August and a source in April.

No description available.

Loss and degradation of wetlands across Canada's prairie pothole region in Canada is severe and accelerating as on-going intensification and expansion of the agricultural land base continues to exert pressure on the remaining wetland resource. Traditionally wetlands have been regarded as unexploited wastelands to be converted to more productive agricultural uses. Although wetlands are now recognized as providing vital functions of a hydrological, ecological and social nature which have economic and social value as well as intrinsic value, difficulties in quantifying these benefits, coupled with readily calculated and realized benefits from agricultural production, result in continuing wetland losses. As well, because wetland benefits accrue to the general public rather than the private land holders who dominate the pothole region, individual owners cannot capture payment for these benefits and thus favor agricultural production over wetland retention. The primary objective of the thesis is to evaluate nonregulatory approaches to encouraging private landowner stewardship on the prairies with respect to wetland retention. From the literature, it is established that a nonregulatory approach to preserving wetlands on private lands is preferable to police power regulation from both a landowner and general public perspective. Several benefits associated with using nonregulatory tools to promote changes in landowner behavior are identified and developed into an analytical framework. Using this framework, six market and moral suasion nonregulatory tools commonly used to encourage landowners to retain wetlands are assessed for their apparent advantages and disadvantages in supporting the primary concerns of landowners faced with a decision whether to enter into a stewardship program. From this assessment, conclusions regarding probable owner acceptability of the mechanisms are drawn, acceptability being a measure for how successful the nonregulatory tools will be in promoting private stewardship of wetlands. The expected landowner appeal of the mechanisms is tested by evaluating their actual owner appeal as implemented in three on-going Canadian stewardship programs. Actual appeal is found to be fairly consistent with results from the literature analysis and conclusions from these results indicate that the mechanisms do vary in their effectiveness to encourage landowners to retain wetlands and thus vary in their ability to secure wetland acreage for protection. Data limitations are encountered in the case studies due to the infancy of stewardship programs in Canada and thus it is concluded that it will take time to demonstrate the effectiveness of nonregulatory mechanisms in promoting private landowner stewardship of wetlands. The evaluation of nonregulatory tools allows a number of recommendations to be drawn with regard to improving stewardship programs in order to effectively encourage landowner participation, the type of data base that needs to be established in order to effectively monitor the success of nonregulatory mechanisms, and opportunities for further investigation in this area of study. / Graduate and Postdoctoral Studies / Graduate

No description available.

This thesis evaluates the surface water hydrology in an artificially drained and farmed prairie pothole wetland located in north-central Iowa as part of the Iowa DNR Wetland Program Development (WPD) project. The purpose of the WPD project was to begin documentation of basic hydrology, wildlife value, and water quality to improve understanding of ecosystem services provided by drained prairie pothole wetlands. The surface water hydrology was evaluated using a daily water balance (PPWB) model. The model development, validation, and applications are described in detail in this thesis. The PPWB model estimates the water depth and duration in the drained wetland. Several sensitivity analyses were performed to evaluate how site-specific factors affect the frequency, depth, and duration of surface ponding in the drained wetland. In the absence of surface inlets, infiltration was found to have a significant impact on ponding, second only to the amount of precipitation in importance. The topography also plays an important role in surface water ponding, with higher ponding durations occurring for larger catchment-to-pothole area ratios. However, the presence of a surface inlet in a drained prairie pothole wetland significantly alters the hydrology and all other ponding factors become negligible. In addition, long-term ponding was evaluated for historic and future hydrologic trends. The long-term simulation showed increasing trends for precipitation and ponding duration. The possible implications of continued farming of drained wetlands were explored using PPWB model sensitivity analysis and long-term simulation results. Agricultural implications include mitigation strategies to balance ecosystem needs with crop production and impacts of the projected future outlook with regards to climate. Environmental implications include insight on impacts of wetland restoration.

This thesis presents an endeavor to design and construct a prototype of an automated road repair vehicle called the Intelligent Pothole Repair Vehicle (IPRV). The IPRV is capable of automatically detecting and filling potholes on road surfaces without operator assistance. An easy-to-construct mechanical means of pothole detection was employed to reduce costs and complexity that have thus far been the primary disadvantage of automated road repair vehicles. A network interface to an Ethernet was designed based on the transmission control protocol (TCP) to enable remote operability of the IPRV. A laptop computer was used onboard the IPRV for control and interfacing using a data-acquisition card installed on it. The Visual Basic® programming language and the Windows application programming interface (API) were used for all the programming requirements of this thesis. The IPRV employs feedback mechanisms for position control and path following. Operation has been designed to incorporate safety mechanisms that ensure that the IPRV automatically stops in the case of a loss of communication link or large network delays. Experiments were performed to test and calibrate the IPRV. The IPRV was designed to detect potholes that have a maximum depth greater than 2 cm.

This thesis presents an endeavor to design and construct a prototype of an automated road repair vehicle called the Intelligent Pothole Repair Vehicle (IPRV). The IPRV is capable of automatically detecting and filling potholes on road surfaces without operator assistance. An easy-to-construct mechanical means of pothole detection was employed to reduce costs and complexity that have thus far been the primary disadvantage of automated road repair vehicles. A network interface to an Ethernet was designed based on the transmission control protocol (TCP) to enable remote operability of the IPRV. A laptop computer was used onboard the IPRV for control and interfacing using a data-acquisition card installed on it. The Visual Basic® programming language and the Windows application programming interface (API) were used for all the programming requirements of this thesis. The IPRV employs feedback mechanisms for position control and path following. Operation has been designed to incorporate safety mechanisms that ensure that the IPRV automatically stops in the case of a loss of communication link or large network delays. Experiments were performed to test and calibrate the IPRV. The IPRV was designed to detect potholes that have a maximum depth greater than 2 cm.

The goal of this study was to assess effects of sediment removal on vegetation communities in Prairie Pothole wetlands in North Dakota to determine if this management technique is providing desired results to create conditions for ideal vegetation communities in wetlands that will benefit wildlife. This project consists of vegetation surveys from seasonal wetlands located in Benson, Eddy. Towner. and Wells counties in North Dakota. Three types of wetlands were surveyed: natural (reference), excavated (treatment), and converted cropland. Vegetation surveys were completed in the shallow marsh and wet meadow zones of seasonal wetlands. Sites were sampled using a modified Daubenmire method. Aerial photos were assessed to determine the occurrence of drawdown cycles in wetland sites. Plant communities were analyzed using non-metric multidimensional scaling and multi-response permutation procedure was used to make comparisons between sites. The wet meadow zones and shallow marsh zones of the three types of wetlands were all significantly different (p<0.016) from one another. In general, restored wetlands show vegetation trends that liken natural wetlands while those that have been allowed to recover without restoration tend to be cattail choked. When examining hybrid cattail specifically visual obstruction scores were approximately four times greater in converted cropland sites versus treatment or reference sites. Vegetation composition indicates hydrologic conditions (fresh to brackish conditions) of specific sites and regional distribution are likely influential factors in wetland plant establishment. / North Dakota State University / U.S. Fish and Wildlife Service / Ducks Unlimited