Browsing by Author "Cai, Meijun"
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Item Assessing Impacts of Climate Change on Vulnerability of Brook Trout in Lake Superior’s Tributary Streams of Minnesota(University of Minnesota Duluth, 2013) Johnson, Lucinda B; Herb, William; Cai, MeijunWater temperature is generally considered one of the primary physical habitat parameter determining the suitability of stream habitat for fish species, with effects on the mortality, metabolism, growth, behavior, and reproduction of individuals. In this study we assessed the potential threats of climate change on stream temperatures and flow regimes in Lake Superior tributary streams in Minnesota, USA. The study included deterministic models for stream flow and temperature of three study streams (Amity Creek, Baptism River, Knife River), and regional (empirical) models for specific flow and temperature parameters to give better spatial coverage of the region. Information on stream flow, stream temperature, and land cover was used to develop a brook trout presence/absence model to understand the current pattern of distribution of brook trout and predict future distributions under future climate. The hydrology of north shore streams is mainly driven by air temperature and precipitation. Historical air temperatures in the region have a significant upward trend, particularly since 1980. Global climate model (GCM) outputs project a continued increasing trend in air temperature, with an increase in mean annual air temperature of 2 to 3 °C by 2089. The historical precipitation data shows an increasing trend for total annual precipitation at Duluth and Two Harbors between 1900 and 2010, whereas Grand Marais and Grand Portage do not have a clear trend. Based on an analysis of daily precipitation totals, there is some indication of an increasing trend in the number of days in summer with high precipitation (10-20 cm). Both the GENMOM and the ECHAM5 GCMs project overall increases in precipitation of about 15%, but differ with respect to the seasonal distribution of the precipitation changes. A significant and relatively certain impact of climate change is a projected shift in precipitation from snowfall to rainfall. While an increasing trend in precipitation leads to increasing streamflow, the increasing trend in spring and summer air temperature tends to reduce streamflow (by increasing evapotranspiration). Available streamflow records for north shore streams suggest there may be a decreasing trend in mean annual flow and summer low flow, but the trends are not statistically significant. Future projections of streamflow based on the GCM output were mixed, with the deterministic models projecting moderate increases in average stream flow and summer low flow, while the regression models for project a moderate decrease in low flow. Stream temperature analyses for the three study streams based on GCM climate output give the result of fairly uniform seasonal increases in stream temperature to 2089 ranging from 1.3 to 1.9 °C for the GENMOM model to 2.2 to 3.5°C for the ECHAM5 model. Application of the GENMOM climate data to the deterministic stream temperature models produced fairly similar stream temperature changes for the three study sites. The empirical stream temperature study found stream temperature in the north shore region to be influenced by air temperature, catchment size, percentage of woody wetlands, latitude, and soil permeability rate. In response to climate change projected by the GENMOM GCM, the regional stream temperature model projects July mean water temperature to rapidly increase by approximately 1.2oC from 1990s to 2060s, followed by a slight decrease to 2089. The temperature increase was predicted to be the largest in the coastal area of middle north shore region. The brook trout presence/absence model found water temperature to have the strongest influence on trout presence. Brook trout were predicted to be at risk for water temperatures above 18.7oC and be extirpated from streams for temperatures over 20oC. Stream flow was shown to have a negative effect on trout presence, though not as strong as water temperature. Overall, these data predict that brook trout may be extirpated from lower shore area, be exposed to increasing risk in middle shore region, and remain present in upper shore streams from the present to 2089. This work would benefit greatly from a number of modifications to the GCM’s, the spatial data used in the development of both the deterministic and empirical models, and implementation of a more detailed, spatially explicit, hydrologic model. Finally, additional fish data, including cool and warm water assemblage data, along with descriptors of landscape structure (i.e., connectivity) would allow us to assess the areas where cold water species may be threatened by the presence or potential presence of coolwater competitors.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 Comparing Properties of Water Absorbing/Filtering Media for Bioslope/Bioswale Design(Minnesota Department of Transportation, 2017-11) Johnson, Kurt; Cai, Meijun; Patelke, Marsha; Saftner, David; Swanson, JoshDrainage from highways, particularly the first flush of runoff, contains high levels of contaminants such as suspended solids, metals, and organics. To restrict the discharge of polluted stormwater, the National Pollutant Discharge Elimination System (NPDES) State Disposal System (SDS) General Permit issued by Minnesota Pollution Control Agency (MPCA) in 2013 requires that the first inch of stormwater runoff from new impervious should be held on site through infiltration, harvesting or reuse. Multiple types of infiltration materials have been studied in the laboratory and the field, but few studies have considered the application of local materials for best management practices (BMP). The objective of this project is to determine the characteristics of various naturally occurring water adsorbing and filtering media, such as peat and muck, found along road construction projects in northern Minnesota. Salvage and reuse of these materials during road construction will be evaluated for stormwater treatment, including absorption, infiltration, filtration, and pollutant capture, in constructed vegetated slopes along highway right of ways. The naturally occurring material will be compared to leaf and grass feedstock compost.Item Comparison of hybrid poplar wood breakeven prices as affected by current and improved genetics(University of Minnesota Duluth, 2021-05) Lazarus, William F; Nelson, Neil D; Jackson, Jeffrey; Berguson, William E; McMahon, Bernard G; Buchman, Daniel; Cai, MeijunThe impact of improved genetics from the University of Minnesota Duluth Natural Resources Research Institute (NRRI) hybrid poplar breeding program on breakeven hybrid poplar wood prices is discussed in this paper. After a review of previous economic analyses, the breakeven prices are presented that would cover costs other than land rent. Then, factors are provided for adjusting the price to reflect the land rental rate for a given location. The breakeven prices are presented both as stumpage and delivered to a mill. Breakeven delivered prices include the stumpage values plus conventional harvest and transportation costs to a hypothetical processing plant. Breakeven land rental rates are also provided at which poplar production would be profitable at recent aspen stumpage prices. The impact of improved genetics from the University of Minnesota Duluth Natural Resources Research Institute (NRRI) hybrid poplar breeding program on breakeven hybrid poplar wood prices is discussed in this paper. After a review of previous economic analyses, the breakeven prices are presented that would cover costs other than land rent. Then, factors are provided for adjusting the price to reflect the land rental rate for a given location. The breakeven prices are presented both as stumpage and delivered to a mill. Breakeven delivered prices include the stumpage values plus conventional harvest and transportation costs to a hypothetical processing plant. Breakeven land rental rates are also provided at which poplar production would be profitable at recent aspen stumpage prices. The analysis is based on a scenario where a biorefinery/bioproducts company owns and/or leases the land, controls the harvest and transportation of the wood, and delivers the wood to their own mill. The evaluation is based on two hybrid poplar annual growth increments: 3.6 dry tons and 5.4 dry tons per acre per year with a 9-, 10-, or 12-year rotation. 3.6 dry tons per acre per year is yield potential with current genotypes. 5.4 tons per acre per year is yield potential with new Gen 1.0 elite clones from our breeding. Stumpage prices without land cost included are lower than aspen stumpage prices for both unimproved and improved clones. Other things being equal, the improved genetics could be capitalized into a $36.37-per-acre increase in the financially permissible rental rate. Carbon credit markets could further improve returns on hybrid poplar plantations.Item Continued Monitoring of Stormwater Effluents from Filter Media in Two Bioslope Sites(Minnesota Department of Transportation, 2021-06) Cai, Meijun; Patelke, Marsha; Saftner, DavidOver the last thirty years, the Minnesota Department of Transportation (MnDOT) has implemented biofilters along roadways as a stormwater control measure. The state and national regulations require that the biofilters must be able to infiltrate and treat the first inch of rainfall onsite. However, the performance of the biofilters after installation has rarely been studied. An early phase of this project monitored two newly constructed biofilter sites for two years and for three months, respectively. This study extended the monitoring of soil moisture changes and infiltration water quality for another two years (2019-2020). Over the four-year monitoring period, both salvage peat and compost materials showed the capacity to retain the first inch of runoff, and this retention capacity did not change over the study period. The drainage water quality showed significantly temporal trends, particularly phosphorus concentrations, which were declining significantly for both compost and salvage peat. The application of tailing with compost can reduce the phosphorus release. The leachate from salvage peat has similar metal concentrations but much lower phosphorus concentrations (below 100 ppb) than the compost. The lowest chemical concentrations were achieved when the soil mixture contained 10% compost and 10% salvage peat, implying the best stormwater control practice is to limit the organic ratio to around 20%. Findings from this work determined the validity of using peat and compost for future biofilters and can aid in future design.Item Development and Regionalization of In Situ Bioslopes and Bioswales(Minnesota Department of Transportation, 2019-07) Johnson, Kurt W.; Cai, Meijun; Patelke, Marsha; Saftner, David; Cruz, ChanelleThis project is a multi-disciplinary investigation into the use of alternative media for biofiltration systems in Minnesota. Over the last thirty years, the Minnesota Department of Transportation (MnDOT) has implemented biofilters along roadways as a stormwater control measure. These systems must be able to infiltrate and treat the first inch of rainfall onsite to meet state and national regulations. The performance of a biofilter is largely based on its media?s ability to infiltrate water, sustain vegetation, and capture pollutants. To date, MnDOT has relied on sand and compost mixtures for biofilter media components. An early phase of this work identified peat as having similar performance characteristics as compost, making it an ideal alternative. A laboratory testing program was also developed during the early phase of work to determine media properties that could be used to predict biofilter performance. This project focused on characterizing existing biofilters using in situ testing and comparing results to laboratory testing. The comparison of the two methods demonstrated the predictive capabilities of the laboratory regime. This project also included the instrumentation and monitoring of field sites including a newly constructed peat amended biofilter. Findings from this work determined the validity of using peat for future biofilters and can aid in identifying and characterizing other alternative media.Item Differences in Particulate Matter (Dust) Between Non-modified and Light-Modified (170°C) Wood Species(University of Minnesota Duluth, 2018-11-12) Aro, Matthew D; Monson Geerts, Stephen D; French, Suzanne; Cai, MeijunThere has been much speculation on whether the practice of heat modification of various wood species has a direct effect on the dust created when these woods are machined. An initial study was initiated to compare non-modified wood species with their lightly modified (170 °C) counterparts, specifically as a gravimetric characterization of the wood particulate matter (PM) generated through typical cutting practices. Five different species were compared, including: Yellow Poplar, Red Maple, White Ash, Aspen and Balsam Fir. Aerosol wood PM sampling was conducted at the Natural Resources Research Institute (NRRI) as collaboration between the Wood Utilization Materials & Bio-Economy (Wood Group) and the Mineral/Materials Characterization Group, a sub-group within the Minerals – Metallurgy - Mining (M3) NRRI Initiative Group. The study was designed primarily as a first-pass analysis in which size-fractionated sampling, based on aerodynamic diameter of the dust particles, was utilized to evaluate if there were any dramatic differences between the non-modified and light modified (170 °C) wood species.Item Inter-Tree Competition Effects in Hybrid Poplar Genotype Testing(University of Minnesota Duluth, 2022-02) Nelson, Neil D; Buchman, Daniel; Cai, Meijun; McMahon, Bernard G; Berguson, William EThe effects of inter-tree competition on growth in family field trials (FFT), clone trials (CT) and yield blocks (YB) were studied in NRRI experimental field plots in Minnesota, USA. FFT and CT competition is inter-clonal , YB competition is intra-clonal. Two approaches were explored: (1) regression analysis of growth of individual trees versus growth of immediate neighboring trees in FFT and CT; (2) bole volume growth as measured by DBH2 in CT versus YB for the same clones on each site to determine whether inter- clonal competition in CT overestimates tree growth in YB. In CT on five sites planted the same year with the same population of clones (“simultaneous CT”), significant negative slopes, indicating the onset of inter-tree competition, occurred in the fifth and sixth years for the two fastest-growing CT. The top 50th growth percentile clone group in the fastest-growing of the simultaneous CT had a significant negative regression line slope; the lower 50th group did not. The three slower growing CT did not exhibit competition (significant negative slopes) from three through six years. A separate clone trial measured through 9 years showed little evidence of inter-tree competition. The regression slopes in FFT were almost all positive, indicating no inter-tree competition effects from three through ten years of stand age. All significant regression R2 values were low–a maximum of 24 % for CT, 22 % for FFT. Clonal genetic potential for growth likely predominates prior to significant inter-clonal competition, suggesting that randomization of single-tree replications of each clone within each block is effective in evaluating clone genetic growth potential within the initial six years selection window that we have used in our program. There was no significant difference between CT and YB for tree bole volume growth (yield) in a population of clones. There was wide variation in the YB/CT yield ratios between individual clones on a site. Some individual clones exhibited wide variation in YB/CT ratios between different sites, indicating a clone x site interaction for this trait. The commercial clone NM6, used as a check clone in most of our studies, had the widest variation of any clone in YB/CT ratios between sites, ranging from 53 % to 104 %. Of the 22 YB/CT yield ratios for specific clones on 14 sites, only four were above 100 %, indicating a clear trend for CT overestimating yields in YB. The average of the 22 YB/CT ratios was 86 %, again indicating overestimation of YB yield in the CT. The YB/CT ratio for NM6 averaged 79 %, while five elite (fast growing, disease resistant) clones averaged a YB/CT yield ratio of 89 % over the 14 sites. CT/YB yield ratios are too variable to use CT growth as an estimate of growth for specific clones under near commercial conditions (YB).Item Maps of wind-wave height on Minnesota lake shorelines(2022-01-27) Herb, William; Janke, Ben; Cai, Meijun; Stefan, Heinz; Johnson, Lucinda; herb0003@umn.edu; Herb, William; University of Minnesota St. Anthony Falls Lab; University of Minnesota Duluth Natural Resources Research InstituteThis data set provides maps of typical wind-wave height and energy on Minnesota lakes to inform shoreline and near-shore habitat restoration projects. The data set consists of a set of ArcMap shape files which map out simulated wave height and energy parameters for a series of points around the shoreline of 460 lakes in Minnesota, with separate files for annual wave statistics and monthly wave statistics. The wave statistics were calculated for each lake based on airport wind data and the open water distance (fetch) across the lake for each wind direction. Each shapefile contains information on multiple wave statistics, including the mean and significant wave height, the number of days wave height exceeds thresholds, and cumulative wave energy over the time period.Item Mobile Water Treatment Demonstration System for Sulfate Reduction(University of Minnesota Duluth, 2022-08) Cai, Meijun; Rao, Shashi; Post, Sara P; Hanson, Adrian; Chun, Chan Lan; Johnson, Lucinda B; Hudak, George J; Weberg, RolfThe State of Minnesota adopted a sulfate standard of 10 mg/L for wild rice waters in 1973. Although under review, current technology for achieving this standard is a challenge for small industries and municipalities. Membrane-based technologies such as nanofiltration and reverse osmosis are capable of treating water to reach the Minnesota wild rice water sulfate standard; however, they typically require high capital and operation costs. Therefore, there is a need to develop cost-effective sulfate treatment alternatives. The Natural Resources Research Institute (NRRI) has developed a treatment system based on barite chemical precipitation reactions to reduce sulfate levels in water from 60-200 mg/L to below 10 mg/L. This system was demonstrated at bench-scale batch and continuous tests. The data collected from these lab tests were used to scale up the process to a trailer-based modular demonstration treatment system. This study highlights the outcomes of field pilot tests conducted by NRRI using this treatment system. The objectives of the field pilot trials were to: (1) Evaluate the efficacy of the chemical precipitation process when scaled up from 200 ml/min to 2 GPM; (2) Study the effect of co-existing chelating organics of the raw wastewater on barite precipitation reactions; (3) Optimize the chemical reagent dosage levels; (4) Investigate the potential of reusing process sludge to promote precipitation reactions; (5) Identify strategies to minimize scale formation on process equipment; and (6) Estimate the chemical reagent costs. The pilot tests were conducted using effluent from two municipal wastewater treatment plants (WWTP)—the Virginia WWTP and the Grand Rapids WWTP in northeastern Minnesota—from June 2021 until October 2021.Item Quantifying Wave Energy on Minnesota Lakes(2022-01) Herb, William; Janke, Ben; Stefan, Heinz; Cai, Meijun; Johnson, LucindaItem Re-use of Regional Waste in Sustainably Designed Soils(Minnesota Department of Transportation, 2022-04) Saftner, David; Cai, Meijun; Whitcomb, AdamThis project explores the potential re-use of waste materials/by-products as a soil amendment in northeastern Minnesota. The project team identified 23 waste/by-products and collected 15 of but only analyzed 11 because of the possible content of persistent chemicals in some of the materials or the unwillingness of the owner to participate. Peat screenings, peat scrapings, tree bark, harbor dredge sediment, coarse and fine taconite tailings, and street sweepings were characterized in physical, chemical, and biological properties through lab tests. The results showed that none of the studied materials were defined as hazardous based on RCRA (Resource Recovery and Conservation Act) metal levels and contained minimal or undetectable Polychlorinated biphenyls (PCBs), Polycyclic Aromatic Hydrocarbons (PAHs) or Volatile Organic Compounds (VOCs). Peat by-products were efficient in removing metals from stormwater runoff. The relatively high phosphorus content of peat by-products provided sufficient nutrients to plant growth but could be released when mixed with low-phosphorus runoff. Dredge sediment and street sweeping had low organic contents but could remove 90% or more of the copper from the runoff. Tailings could remove 50% or less of the metals. Radish or oat can successfully grow in 28 days with individual materials or a blend of materials, except for fine tailings, which are in a clay form and thus don't filter water well.