http://hdl.handle.net/2027.42/35325 http://deepblue.lib.umich.edu/retrieve/139252 http://hdl.handle.net/2027.42/35325 Search the Channel search http://deepblue.lib.umich.edu/simple-search http://hdl.handle.net/2027.42/60565 Title: Environmental and Management Influences on Fish and Invertebrate Communities in Agricultural Headwater Streams <br/> <br/>Authors: Janssen, Jennifer <br/> <br/>Abstract: Agricultural headwaters in the Midwestern United States are extensively modified to transport water from fields drained by subsurface drainage modifications and facilitate rapid conveyance of floodwaters. The resulting channelized streams, county drains, and farm ditches lack structural heterogeneity important to fish and invertebrate communities and contribute to problems downstream of high sediment and nutrient loads. Alternative drain design and maintenance practices have been developed in attempts to improve the sediment and nutrient processing of agricultural, including the two-stage channel design that features a narrow main channel and adjacent bench to act as a narrow floodplain within the drain. Little is known, however, about the significance of in-channel features on drain fish and invertebrate communities. The goals of this study were to assess what environmental features influence fish and invertebrate communities in agricultural drains; investigate the significance of naturally-formed benches within drain channels; and compare the physical and biotic characteristics of drains with reference streams. Canonical correspondence analysis identified stream size, stream habitat characteristics, and water quality measures as primary environmental characteristics associated with variation among biotic communities. While channel benching was associated with biotic communities, it was not one of the most strongly associated environmental characteristics. Agricultural drains and reference streams were compared using Mann-Whitney U tests, and were found to have few biotic or physical differences. Our findings suggest that alternative channel designs featuring naturally-formed benches within drain channels do little to improve local habitat conditions for invertebrates or improve conditions at a scale relevant to fish. http://hdl.handle.net/2027.42/60564 Title: A Combined Design Approach for Integrating Habitats in Mixed-Use Development <br/> <br/>Authors: Wang, Zhifang <br/> <br/>Abstract: This study contemplates the role of landscape architects in integrating habitats and advocates a new framework to integrate habitats in urban environment. The literature shows two types of design approaches that have been explored for protecting or restoring habitats: landscape-specific approach and organism-specific approach. As each approach has its own strength and weakness, this study suggests a combined design approach using both landscape and organism concerns. The combined design approach is applied in one hypothetical site in the Portland metropolitan area to demonstrate how habitats can be integrated into mixed-use development by innovative design. Accounting for site factors, the site design creates and integrates three habitat types: riparian forest habitats, human habitats, and habitats for Pacific tree frogs. Landscape and organism concerns complement each other in the design solution. http://hdl.handle.net/2027.42/60563 Title: Burn Severity and Terrain: A Spatial Analysis of Forest Fire Burn Severity Trends in the Western United States <br/> <br/>Authors: Koziol, Benjamin <br/> <br/>Abstract: Differenced normalized burn ratio (dNBR) is a remote sensing technique measuring forest fire burn severity – the post-fire effects on local forest ecology. Understanding how dNBR varies across landscapes as fuel, local weather conditions, and terrain changes provides useful insight into the possible application of dNBR as a data source for fuel consumption and emission modeling. This study evaluated dNBR terrain trends in nineteen forest fires in the Western conterminous United States that burned from 2000 to 2003. Terrain variables tested for possible correlation with dNBR included elevation, slope, aspect, and annual incident solar radiation. Linear results proved significant (p < 0.05) for elevation, slope, and annual incident solar radiation but with low coefficients of determination. Categorical analyses of variance found significant mean differences in all severity classes for each terrain variable. Results demonstrate that terrain controls on dNBR in these fires emerge over large scales as terrain alters local vegetation and fire behavior trends http://hdl.handle.net/2027.42/60562 Title: Effects of Land Cover on Aquatic Communities and Food Webs: A Study of Second Order Streams in Southeastern Michigan <br/> <br/>Authors: Crane, Derek <br/> <br/>Abstract: Lotic systems in many regions of the country have experienced habitat degradation and biodiversity loss from impacts brought about from agricultural activity and urbanization. Southeastern Michigan is no exception, as agriculture in the River Raisin watershed and continued expansion of suburban Detroit in the Huron River watershed threaten both systems. To further understand the ecological impact of land use on Midwestern streams I created and compared food webs for nine different second-order tributaries distributed equally across three generalized land use categories including; developed, agricultural, and undeveloped sub-basins of the Huron River and River Raisin. Fish diets (n=410) were analyzed to create the food webs, and weighted quantitative metrics were used to identify differences in fish-invertebrate interactions across streams with differing land use. Although undeveloped streams had higher diversity and less habitat degradation no significant differences were found in weighted quantitative metrics across the three stream categories. Decapoda, terrestrial Hymenoptera, and Chironomidae were the primary prey taxa in all stream categories. Decapods accounted for the majority of biomass consumed and the pattern of their consumption strongly influenced metric scores. Metric values were not significantly related to land use in the sub-basins or local habitat assessment scores. Weighted quantitative metrics may not be applicable in understanding how anthropogenic land use influences aquatic food webs where there is a dominant, tolerant prey taxa