Publication Type: Oral Presentation
Abstract: Restoring riparian wetlands has been one of the conservation measures for mitigating the adverse environmental effects of agriculture on water quality. However, targeting is necessary because restoration costs and water quality benefits of riparian wetlands are spatially variable across locations. This study develops an integrated economic-hydrologic modeling framework to examine the targeting of riparian wetland restoration in agricultural watersheds. Within the framework, a farm economic model is developed to quantify the restoration costs in terms of forgone cropping returns. A riparian wetland module is developed within the Soil and Water Assessment Tool (SWAT) to examine the water quality impacts. The modeling framework is empirically applied to the 53-km2 upper Canagagigue Creek watershed in southern Ontario of Canada. Our results show that at a 30% sediment abatement goal, 66 hectares of riparian wetland need to be restored with agricultural value losses at $19,000 per year. With a sediment abatement goal of 50%, the wetland restoration area increases to 229 hectares and the forgone agricultural values are about $63,000 per year. The results also show that the priority locations for wetland restoration not necessarily overlap existing wetlands based on the joint distribution of economic costs and water quality benefits from wetland restoration. The results have important policy implications for targeting wetland restoration in agricultural watersheds. The integrated modeling framework could also serve as a policy analysis tool for conservation organizations and governments to better design and implement similar conservation programs.

Publication Type: Abstract
Abstract: The shrub Ligustrum sinense (Chinese privet) is recognized as a threat to natural ecosystems throughout the Southeastern USA. This study focused on the impact privet has had on Tennessee River Gorge riparian soil microbial communities and select processes they catalyze. Soils were collected from plots with high densities of privet and from plots where privet was removed five years earlier. Microbial carbon transformations were quantified using 14C-lignocellulose (from Quercus alba) mineralization. Element pools (CNS) were measured by elemental analysis. Exchangeable cations, Ca2+, Mg2+, and K+ were determined by AA. Soil moisture content was also measured. Rates of cellulose mineralization were approximately 87% greater than those of lignin. Lower rates of cellulose mineralization were observed for soils from plots with no privet. The same trend was not observed for lignin mineralization. Ca2+ and Mg2+ concentrations were lower in soils from plots with privet, while K+ was unaffected. Total C was lower in the litter of plots containing privet and total S was higher. Moisture content was lower in soils of plots with privet. This data suggests that Ligustrum sinense growing in Tennessee River Gorge riparian soils has an impact on soil microbial communities and several key soil nutrient pools found there.

Publication Type: Abstract
Abstract: This study investigated biodiversity patterns within urban riparian bushland corridors in Sydney, Australia, in order to assess the influence of variation in riparian corridor width. Terrestrial macroinvertebrates and plants were sampled at 18 sites of varying corridor width within the Ku-ring-gai Local Government Area. Comparison of narrow corridors with large remnants enabled ecological changes resulting from urban encroachment to be identified. Data on ant morphospecies revealed minimal variation in richness between sites of differing corridor width, but significant changes in faunal composition, particularly for corridors less than 20 m in width. Narrower corridors exhibited reduced rates of species turnover, particularly at the urban-bushland interface, thus supporting the concept of biotic homogenisation resulting from urban edge effects. Analysis of floristic biodiversity is currently being used to supplement the ant morphospecies data. Abiotic factors (e.g. soil properties) and landscape influences (e.g. adjacent and upstream landuse) will also be assessed. Differences in the responses of invertebrates and plants to variation in corridor width and other environmental factors is of significant importance to environmental planning. Formulating optimum riparian corridor widths for biodiversity conservation in urban landscapes will likely require compromise between the habitat requirements of various taxa and consideration of a site’s unique environmental characteristics.

Publication Type: Oral Presentation
Abstract: Changes in land management and the economic impacts of four beneficial management practices (BMPs), namely riparian buffers, forage conversion, crop rotation, and tillage practices, were investigated for farms within the South Tobacco Creek watershed near Miami, Manitoba, Canada. The watershed covers an area of 75 km2 (7, 500 ha), 71% of which is under cultivation. Wheat, canola, flax, barley, and oats are the major crops in the area with noticeable increases in forage production and pasture land in recent years. Production functions for these major crops and present cost, return, and net benefit without and with these BMPs implemented were estimated and incentives that may be required for the implementation of such BMPs within that watershed were discussed.

Publication Type: Abstract
Abstract: With over half of humanity now residing in cities and growing, urban environments present a unique challenge for conserving our planet’s biodiversity. Riparian systems are of particular interest because of the ecological services they provide to both people and an array of other animals and plants. We chose to study urbanization effects on riparian systems along an urban gradient within metropolitan Cincinnati, Ohio, U.S.A. Based on our research, we report on how breeding avian diversity and composition responds 1) locally to woody vegetation structure and composition, and 2) across the landscape to the vegetative and built aspects of the urban environment, at four different scales (50, 100, 250, and 500 m). We employ the HERCULES land cover dataset to focus on elements of the biophysical structure of the urban environment – buildings, building type and vegetation – separately. In order to ascertain potential mechanisms, we explore how life-history characteristics permit some species to utilize and even thrive in urban areas while others cease to exist based on the following functional groups: migration, feeding, brooding strategy, and endemism. We provide management recommendations for land managers, landscape architects, urban planners, and citizens that can enhance native species diversity around urban streams.