Browsing by Subject "carbon"
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Item Analysis of Air Pollution Models in the context of Coupled Carbon and Air Pollution Benefits in Multi-scale Urban Systems(2019-08) Fang, AndrewMany subnational state and local governments have taken a leadership role in climate change mitigation through clean energy and climate action policies. Because the majority of carbon emissions come from the burning of fossil fuels, there is potential for ancillary co-benefits of carbon mitigation resulting from the concurrent reduction of co-pollutants. This research focuses on the co-benefit of reducing particulate matter, which globally contributed to 4.2 million premature moralities in 2015. Global cities are simultaneously taking action to improve air quality and mitigate climate change by reducing emissions from energy and infrastructure systems. Cities are uniquely positioned to achieve improved environmental policy by managing carbon, air pollution, and health co-benefits concurrently due to the concentration of people and economic activity in cities. By accounting for the air pollution co-benefits of carbon mitigation, cities may create more political support for reducing emissions and energy use due to the large health benefits of reducing local air pollution exposure. The following dissertation explores these issues to determine how the state-of-the-science tools can be used to inform carbon mitigation actions which have air pollution and health co-benefits. Together, these chapters seek to inform the discussion surrounding the distribution of air pollution and carbon co-benefits in order to design more optimal environmental policies moving forward. The focus of this dissertation is on developing methods for the spatial analysis of air pollution co-benefits across multi-scale urban systems to support their evaluation in the context of carbon mitigation actions.Item Biomass yield and soil microbial response to management of perennial intermediate wheatgrass (Thinopyrum intermedium) as grain crop and carbon sink(2019-12) Bergquist, GalenIWG intermediate wheatgrass (Thinopyrum intermedium (Host) Barkworth & D.R. Dewey; IWG) is a perennial grain crop with an extensive root system that could prevent erosion and nutrient leaching, build soil fertility, and potentially sequester atmospheric carbon. Two field experiments were established in southeastern Minnesota, USA to 1) address management strategies for preventing IWG grain yield decline, 2) quantify plant biomass production of IWG relative to other conventional field crops, 3) determine how this perennial grass may alter soil microbial activity and composition to the benefit of soil organic carbon (SOC) accumulation, and 4) investigate the potential for carbon sequestration. Inter-row cultivation using rotary-zone tillage (RZT) as well as herbicide, burning, and mowing at different times were employed for two years, but none effectively prevented grain yield decline. However, the application of herbicide in spring and fall cultivation had positive impacts on grain, straw, and forage yield (relative to other management treatments). IWG can produce significantly more root biomass than annual grain crops, and even more than alfalfa (Medicago sativa). These large root systems, left undisturbed, were likely responsible for an increase in soil fungal biomarkers and overall microbial biomass after three years of growth. Soil respiration rates and microbial biomass-carbon were greater under IWG in the spring and fall seasons when soybean and wheat had either not emerged yet or were already senesced, providing evidence that perennial grasses may alter soil nutrient cycling by expanding and prolonging soil microbial activity. Particularly, changes in nutrient cycling that increase labile carbon pool sizes and promote SOC formation may, in addition to storage in root biomass, support carbon sequestration in agricultural soils.Item Camp Ripley Sentinel Landscape Climate Resilience Analysis and Strategic Plan Amendments(University of Minnesota Duluth, 2023-07) Bartsch, Will; Cai, Meijun; Johnson, Kris; Nixon, Kristi; Sprague, Tiffany; Wright, Chris; Olsen, Louis; Reed, JaneCamp Ripley is a military training facility located in central Minnesota. It is surrounded by the 750,000-acre Camp Ripley Sentinel Landscape (CRSL). Created in 2015, the CRSL consists of working and natural lands surrounding Camp Ripley with the purpose of protecting the training mission of the facility. The rural character of this landscape is generally compatible with that mission. However, it could be compromised by development, which could diminish habitat quality and raise the potential for conflict with landowners. The ability of Camp Ripley to maintain its mission is also threatened by a changing climate, which is projected to get warmer and wetter with a higher frequency of large precipitation events in the region. To help ensure the viability of the mission, the Natural Resources Research Institute assessed climate vulnerabilities and developed strategies to build and enhance climate resilience. Specifically, we 1) evaluated and selected Global Climate Models (GCM) that are expected to perform well in the region, 2) modeled stream water quantity and quality under different land use and climate scenarios, 3) characterized the landscape using Geographic Information Systems, 4) modeled and identified high-quality habitat for at-risk species, 5) evaluated and ranked parcels for conservation and restoration opportunities, 6) created afforestation plans for individual parcels, and 7) amended the Camp Ripley Strategic Plan with climate resilience language and strategies. Modeling stream quantity and quality under different land use scenarios indicates generally increased flow and sediment and nutrient concentration in scenarios where forest land is converted to agriculture or developed. Modeling under different future climate scenarios generally predicts decreased summer baseflow and increased nutrient and sediment concentrations. A suite of environmental data was acquired and developed to help characterize the landscape and prioritize parcels for conservation or restoration activity. Habitat models were developed for the Red-shouldered hawk, Golden-winged warbler, Northern long-eared bat, and Blanding’s turtle, all listed as at-risk or endangered under the Endangered Species Act. Afforestation plans with carbon sequestration modeling and carbon market participation compensation estimates were completed for two parcels within the landscape, illustrating an economically viable, market-driven solution. Climate resilience language was added to the strategic plan with emphasis placed on the restructuring and expansion of the strategy table while improving alignment with Minnesota’s Climate Adaptation Framework.Item Consequences of nutrient enrichment for soil organic matter cycling in grasslands(2015-07) Riggs, CharlotteHuman activities have increased the availability of nutrients, such as nitrogen (N), phosphorus (P), and potassium (K), worldwide. Since alterations to nutrient cycles influence carbon (C) fixation and decomposition processes, nutrient enrichment affects global C stocks -- such as soil C. Carbon in soil organic matter (SOM) far outweighs vegetative C in the majority of biomes, especially grasslands. Consequently, either positive or negative changes to grassland soil C sequestration could feed back to influence the global C cycle. Unfortunately, the effects of nutrient enrichment on SOM cycling remain uncertain. In my dissertation, I examined the effects of nutrient addition on SOM cycling at participatory sites of the Nutrient Network -- a coordinated, global network of nutrient addition experiments that follow standard protocols for sampling and analysis. I found that the total soil C stock at experimental grasslands worldwide increased in response to the addition of N, P, and K. Furthermore, in a regional study in the US Central Great Plains, I found that N addition decreased microbial decomposition of SOM and tended to increase soil aggregation. Finally, in a laboratory study I found that decreased microbial biomass likely explains the decreased microbial decomposition of SOM in response to N addition. Overall, my results suggest that nutrient enrichment will lead to increased sequestration of soil C in some grassland soils.Item OFR11-02, Potential for Implementation of Mineral Carbonation as a Carbon Sequestration Method in Minnesota(Minnesota Geological Survey, 2011) Thorleifson, L.HarveyMinnesota, with a population of about five million, is a significant source of greenhouse gas emissions, and a state that is vulnerable to climate change, such as the impact that increased frequency or severity of drought or storms would have on agriculture, water supply, wildlife, lake levels, and public security. Minnesota therefore has an interest in reducing our own vulnerability, while concurrently contributing to needed world-wide solutions. As has been stressed, for example, in documents prepared for and by the Minnesota Climate Change Advisory Group, emissions reductions can have multiple benefits, including conservation, cost efficiency, and air quality enhancement, while also directly contributing to mitigation of climate change. Anthropogenic climate change seems already to have begun, however, so adaptation to climate change accompanies mitigation in the climate change policy agenda. Mitigation of greenhouse gas emissions can be achieved through reduced fossil fuel combustion, while concurrently capturing and storing carbon in biomass, or in geologic repositories. It has become apparent that the best approach is likely to be for several options to concurrently be implemented. Minnesota may be well positioned to utilize the mineral carbonation method of geologic carbon sequestration, given the presence of vast tonnages of appropriate rock material in the Duluth region, some of which could be mined for copper, nickel, and platinum group elements, pending the outcome of current permitting procedures. Should these deposits go into production, a slurry of minerals suitable for mineral carbonation of CO2 would be produced as a waste product from the mines. The principal constraint to mineral carbonation at present appears to be cost. Nevertheless, there could be developments in the method, and there could be circumstances in which a particularly favorable mineral carbonation opportunity could coincide with constraints to other aspects of the sequestration procedure, such as considerations regarding transportation, thus possibly making mineral carbonation a conceivable option.Item PERENNIAL FUEL, FEED, AND CEREAL: HIGH DIVERSITY PERENNIALS FOR BIOFUEL AND INTERMEDIATE WHEATGRASS FOR GRAIN AND FORAGE(2019-12) Dobbratz, MichellePerennial crops may counteract negative effects of annual agriculture, such as carbon emissions, water pollution, and erosion, and systems are being developed that supply fuel, feed, and cereal. One source of fuel is cellulosic ethanol from perennial sources, and one source of feed and cereal is intermediate wheatgrass. Regarding cellulosic ethanol, markets are not currently supported by policy, making adoption of these systems largely a matter of carbon storage benefit. Regarding intermediate wheatgrass, little is known about its nitrogen balance and reproductive morphology, complicating long-term management. In the perennial cellulosic ethanol system, I measured aboveground biomass, change in total soil C, soil microbial biomass, and extracellular enzyme activity with and without nitrogen in four species mixture treatments ranging from 1-24 native species at four sites across Minnesota. I found no overall trends, possibly due to variation across sites or due to minimal management over the 12 years since establishment. Over time, soil carbon increased in the shallower depths at one site and decreased in the deeper depths at two sites. I measured plant, tiller, and rhizome densities in plants from sown seed, vegetative propagation, or seed shatter at four sampling times in 1 year old and 2 year old intermediate wheatgrass stands. Tiller density was similar in both stands, but rhizome and propagule densities were greater in the 2 year old stand. Likely, tiller replacement and death rates are equal, but vegetative propagation increases between years, increasing plant population, possibly leading to competition and affecting long-term yield. Also in intermediate wheatgrass, I measured nitrogen in shoot, root, and grain tissue along with soil mineral and mineralized nitrogen in three nitrogen treatments (80 kg N ha-1 in spring, 40-40 kg N ha-1 in spring and summer, and unfertilized control) at four sampling times in 1 year old and 2 year old stands. The spring treatment had greater root nitrogen, but it also had greater lodging. The late fall sampling had the greatest soil nitrogen, and since soil mineral N was low at that time there was likely an influx of organic nitrogen, likely due to root turnover.Item Soil Organic Carbon Responses Following Two Years of Subsurface Tile Drainage Installation in Northwest Minnesota(2022-07) Sherbine, KyleInstallation of subsurface tile drainage systems is growing in Minnesota as a management technique to mitigate the impacts of changing precipitation patterns, and the initial effect of drainage on soil organic carbon cycling is poorly understood. Altering the water table in arable soils may impact biogeochemical cycling and soil processes by changing soil oxygen levels and subsequently, where soil biota can persist. Drainage is likely to expose previously protected soil organic matter (SOM) to microbial decomposition, with unknown consequences for soil carbon cycling and storage. This two-year study tracked changes in SOM pools down to 90 cm in silty clay loams at the University of Minnesota Northwest Research and Outreach Center in Crookston, MN following fall 2019 drainage installation. The objective of this project is to help us evaluate changes in carbon cycling in recently drained soils, and whether drainage is likely to increase or decrease total C stocks. These measurements have implications for grower participation in carbon markets and government programs incentivizing climate-smart agriculture. As bulk soil C stocks may change slowly but active C may change seasonally, we measured potentially mineralizable carbon (PMC) and water-extractable organic carbon (WEOC), indices of labile C, three times per year. Particulate (POM) and mineral-associated organic matter (MAOM), representing short and long-term SOM storage, were measured annually and characterized by their quantity, quality, and relative contribution to total soil organic carbon (SOC). Finally, carbon dioxide (CO2) and methane (CH4) emissions were measured across the 2020 and 2021 growing seasons to observe changes in microbial byproducts. Precipitation across the 2020 growing season (437 mm) was more than double the precipitation across the 2021 growing season (217 mm). We found that PMC and WEOC were significantly influenced by the season in which sampling occurred with higher quantities in spring and lower quantities in fall. The POM characteristics were influenced by drainage treatments with drained plots containing greater quantities (0-30 and 60-90 cm) and a greater relative contribution of POM-OC to total SOC (30-60 and 60-90 cm). The MAOM quality decreased over the two-year study (30-60 and 60-90 cm), but the relative contribution of MAOM-OC to total SOC increased at all depths in the final year. These results indicate POM is more affected by large-scale management decisions, whereas MAOM is affected by shifts over time in local, small-scale processes. Drainage did not significantly affect CO2 or CH4 emissions; however, CO2 emissions were significantly less in 2021 due to decreased precipitation and exceptional drought conditions in Polk County, Minnesota. Overall, we found little evidence of subsurface tile drainage depleting SOM pools or increasing greenhouse gas emissions. Future research should be conducted to evaluate how soil C is affected by subsurface drainage in the long run.Item Solvita and Other Measures as Indicators of Soil N Availability in Minnesota Soils(2016-12) Tu, XinyiSolvita is a commercialized short-term C mineralization test reported to predict potentially mineralizable N (PMN) and thus useful as a basis for N recommendations. Our study compared Solvita results with other measures of available N and potential corn yield, including PMN measured in a laboratory aerobic incubation, soil organic matter, KCl-extractable N, and permanganate oxidizable C. We showed that a 50% water-filled pore space wetting method gave much more reproducible results than the fixed volume method previously recommended. Solvita proved to be a good indicator of mineralizable C and N, but not better than SOM, inorganic N, or POXC in MN soils. Solvita had stronger relationships with these soil measures in coarser textured soils (clay < 35%) and was related to corn yield in corn-corn rotations but not when preceding crops were alfalfa or soybean. At this point, we do not recommend its use as a tool for N recommendations.Item Spring and summer 2019 seston, excretion, and tissue C:N:P data for quagga mussels (Dreissena rostriformis bugensis) in Lakes Michigan and Huron(2023-04-05) Huff, Audrey E.; Zalusky, John; Katsev, Sergei; Ozersky, Ted; huff0114@umn.edu; Huff, Audrey E.; University of Minnesota Duluth Large Lakes ObservatoryData include quagga mussel food, tissue, and excretion C, N, and P concentrations from sites throughout Lakes Huron and Michigan (including Green Bay) in the spring and summer of 2019. Samples were taken along trophic status and depth gradients. Site characteristics analyzed include site depth, seston C, N, and P concentrations, chlorophyll a concentration, water temperature, dissolved oxygen concentration, and mussel biomass.