This page has only limited features, please log in for full access.
Education: Ph.D. in Ecology from Duke University, Durham, NC (2010); M.S. in Biology (Environmental Science and Policy focus) from George Mason University, Fairfax, VA (2002); B.S. in Biology and Environmental Science from the College of William and Mary, Williamsburg, VA (1997). Interests: As a biogeochemist and an ecosystem ecologist, I am broadly interested in 1) understanding ecosystem responses to environmental changes and 2) applying ecological knowledge to help inform environmental decisions, particularly with regard to restoration, sustainability, and managed ecosystems. In my research, I focus on the movement of nutrients (mainly nitrogen and phosphorus) and the production of greenhouse gases, in natural and human-modified ecosystems, including wetlands, streams, forests, agricultural, and urban ecosystems. I use approaches from ecosystem ecology and biogeochemistry in my work.
Bioretention systems are commonly used to treat and detain stormwater runoff and help mitigate many negative effects of urbanization. The goal of this project is to assess the pollution reduction effectiveness of lined bioretention facilities that have been in use and functioning for four to eight years. Lined bioretention facilities are installed with an impermeable liner below the facility to prevent exfiltration of stormwater into the surrounding soil. Grab samples were taken from seven facilities in Portland, Oregon, over a two-year period to measure the quality of stormwater flowing into and out of the facilities. Results showed decreased concentrations of total suspended solids (TSS; 94%), ammonia (85%), total copper (59%), total zinc (80%), and dissolved zinc (41%). However, the facilities were found to increase levels of nitrate (2,070%) and orthophosphate (141%) in the outflow. Based on this study, effective TSS removal by bioretention facilities does not necessarily equate to equally effective treatment of other pollutants (especially orthophosphate and nitrate). Additional research is necessary to determine the significance of the observed increase in nutrients, understand the underlying mechanisms, and test possible design modifications to improve nitrate and orthophosphate removal.
Emma Kohlsmith; Jennifer Morse; Cara Poor; Jason Law. Stormwater Treatment Effectiveness of Established Lined Bioretention Facilities in Portland, Oregon. Journal of Sustainable Water in the Built Environment 2021, 7, 05021002 .
AMA StyleEmma Kohlsmith, Jennifer Morse, Cara Poor, Jason Law. Stormwater Treatment Effectiveness of Established Lined Bioretention Facilities in Portland, Oregon. Journal of Sustainable Water in the Built Environment. 2021; 7 (2):05021002.
Chicago/Turabian StyleEmma Kohlsmith; Jennifer Morse; Cara Poor; Jason Law. 2021. "Stormwater Treatment Effectiveness of Established Lined Bioretention Facilities in Portland, Oregon." Journal of Sustainable Water in the Built Environment 7, no. 2: 05021002.
Eaters (consumers of food) are responsible for 60% of waste along the food cycle in developed countries. Programs that target individual and household food waste behavior change are essential to addressing such waste. School cafeterias worldwide offer an opportune microcosm in which to educate on food and nutrition skills and change related behavior. No Scrap Left Behind, a cafeteria food waste diversion program, was developed, piloted, and assessed based on measures of both direct and indirect food waste behavior, and attitudes, knowledge, and emotions related to food waste. Participants had positive attitudes towards food waste reduction, engaged in food waste diversion actions, had some knowledge of the impacts of wasted food, and considered their actions important to waste reduction generally. Food waste per student was decreased by 28% over the course of the first year of programming (p = 0.000967), and by 26% in the following year when measured a week before and a week after programming occurred (p = 0.0218). Results indicate that students were poised for food behavior change and that related programming did impact behavior in the short term. Programming may, therefore, help improve student attitudes and skills to develop long-term change as well, although future research should explore this specifically. In comparison with other research on cafeteria programming, results suggest that food waste diversion programming can positively impact students’ dispositions and behaviors, and may be more effective when tailored to the specific population.
Manar Alattar; Jennifer Morse. Poised for Change: University Students Are Positively Disposed toward Food Waste Diversion and Decrease Individual Food Waste after Programming. Foods 2021, 10, 510 .
AMA StyleManar Alattar, Jennifer Morse. Poised for Change: University Students Are Positively Disposed toward Food Waste Diversion and Decrease Individual Food Waste after Programming. Foods. 2021; 10 (3):510.
Chicago/Turabian StyleManar Alattar; Jennifer Morse. 2021. "Poised for Change: University Students Are Positively Disposed toward Food Waste Diversion and Decrease Individual Food Waste after Programming." Foods 10, no. 3: 510.
Dexter H. Locke; Meghan Avolio; Tara L.E. Trammell; Rinku Roy Chowdhury; J. Morgan Grove; John Rogan; Deborah G. Martin; Neil Bettez; Jeannine Cavender-Bares; Peter M. Groffman; Sharon Hall; James Heffernan; Sarah E. Hobbie; Kelli L. Larson; Jennifer L. Morse; Christopher Neill; Laura A. Ogden; Jarlath P.M. O'Neil-Dunne; Diane Pataki; William D. Pearse; Colin Polsky; Megan Wheeler. A multi-city comparison of front and backyard differences in plant species diversity and nitrogen cycling in residential landscapes. Landscape and Urban Planning 2018, 178, 102 -111.
AMA StyleDexter H. Locke, Meghan Avolio, Tara L.E. Trammell, Rinku Roy Chowdhury, J. Morgan Grove, John Rogan, Deborah G. Martin, Neil Bettez, Jeannine Cavender-Bares, Peter M. Groffman, Sharon Hall, James Heffernan, Sarah E. Hobbie, Kelli L. Larson, Jennifer L. Morse, Christopher Neill, Laura A. Ogden, Jarlath P.M. O'Neil-Dunne, Diane Pataki, William D. Pearse, Colin Polsky, Megan Wheeler. A multi-city comparison of front and backyard differences in plant species diversity and nitrogen cycling in residential landscapes. Landscape and Urban Planning. 2018; 178 ():102-111.
Chicago/Turabian StyleDexter H. Locke; Meghan Avolio; Tara L.E. Trammell; Rinku Roy Chowdhury; J. Morgan Grove; John Rogan; Deborah G. Martin; Neil Bettez; Jeannine Cavender-Bares; Peter M. Groffman; Sharon Hall; James Heffernan; Sarah E. Hobbie; Kelli L. Larson; Jennifer L. Morse; Christopher Neill; Laura A. Ogden; Jarlath P.M. O'Neil-Dunne; Diane Pataki; William D. Pearse; Colin Polsky; Megan Wheeler. 2018. "A multi-city comparison of front and backyard differences in plant species diversity and nitrogen cycling in residential landscapes." Landscape and Urban Planning 178, no. : 102-111.
Stormwater ponds and retention basins are ubiquitous features throughout urban landscapes. These ponds are potentially important control points for nitrogen (N) removal from surface water bodies via denitrification. However, there are possible trade‐offs to this water quality benefit if high N and contaminant concentrations in stormwater pond sediments decrease the complete reduction of nitrous oxide (N2O), a potent greenhouse gas, to dinitrogen (N2) during denitrification. This may occur through decreasing the abundance or efficiency of denitrifiers capable of producing the N2O reductase enzyme. We predicted that ponds draining increasingly urbanized landscapes would have higher N and metal concentrations in their sediments, and thereby greater N2O yields. We measured potential denitrification rates, N2O reductase (nosZ) gene frequencies, as well as sediment and porewater chemistry in 64 ponds distributed across eight U.S. cities. We found almost no correlation between the proportion of urban land cover surrounding ponds and the nutrient and contaminant concentrations in the stormwater pond sediments within or across all cities. Regression analysis revealed that the proportion of potential N2 and N2O production that could be explained was under different environmental controls. Our survey raises many new questions about why N fluxes and transformations vary so widely both within and across urban environments, but also allays the concern that elevated metal concentrations in urban stormwater ponds will increase N2O emissions. Urban stormwater ponds are unlikely to be a problematic source of N2O to the atmosphere, no matter their denitrification potential.
Joanna R. Blaszczak; Meredith K. Steele; Brian D. Badgley; James Heffernan; Sarah E. Hobbie; Jennifer L. Morse; Erin N. Rivers; Sharon J. Hall; Christopher Neill; Diane E. Pataki; Peter M. Groffman; Emily S. Bernhardt. Sediment chemistry of urban stormwater ponds and controls on denitrification. Ecosphere 2018, 9, 1 .
AMA StyleJoanna R. Blaszczak, Meredith K. Steele, Brian D. Badgley, James Heffernan, Sarah E. Hobbie, Jennifer L. Morse, Erin N. Rivers, Sharon J. Hall, Christopher Neill, Diane E. Pataki, Peter M. Groffman, Emily S. Bernhardt. Sediment chemistry of urban stormwater ponds and controls on denitrification. Ecosphere. 2018; 9 (6):1.
Chicago/Turabian StyleJoanna R. Blaszczak; Meredith K. Steele; Brian D. Badgley; James Heffernan; Sarah E. Hobbie; Jennifer L. Morse; Erin N. Rivers; Sharon J. Hall; Christopher Neill; Diane E. Pataki; Peter M. Groffman; Emily S. Bernhardt. 2018. "Sediment chemistry of urban stormwater ponds and controls on denitrification." Ecosphere 9, no. 6: 1.
Megan M. Wheeler; Christopher Neill; Peter M. Groffman; Meghan Avolio; Neil Bettez; Jeannine Cavender-Bares; Rinku Roy Chowdhury; Lindsay Darling; J. Morgan Grove; Sharon Hall; James Heffernan; Sarah E. Hobbie; Kelli L. Larson; Jennifer L. Morse; Kristen C. Nelson; Laura A. Ogden; Jarlath O’Neil-Dunne; Diane E. Pataki; Colin Polsky; Meredith Steele; Tara L.E. Trammell. Continental-scale homogenization of residential lawn plant communities. Landscape and Urban Planning 2017, 165, 54 -63.
AMA StyleMegan M. Wheeler, Christopher Neill, Peter M. Groffman, Meghan Avolio, Neil Bettez, Jeannine Cavender-Bares, Rinku Roy Chowdhury, Lindsay Darling, J. Morgan Grove, Sharon Hall, James Heffernan, Sarah E. Hobbie, Kelli L. Larson, Jennifer L. Morse, Kristen C. Nelson, Laura A. Ogden, Jarlath O’Neil-Dunne, Diane E. Pataki, Colin Polsky, Meredith Steele, Tara L.E. Trammell. Continental-scale homogenization of residential lawn plant communities. Landscape and Urban Planning. 2017; 165 ():54-63.
Chicago/Turabian StyleMegan M. Wheeler; Christopher Neill; Peter M. Groffman; Meghan Avolio; Neil Bettez; Jeannine Cavender-Bares; Rinku Roy Chowdhury; Lindsay Darling; J. Morgan Grove; Sharon Hall; James Heffernan; Sarah E. Hobbie; Kelli L. Larson; Jennifer L. Morse; Kristen C. Nelson; Laura A. Ogden; Jarlath O’Neil-Dunne; Diane E. Pataki; Colin Polsky; Meredith Steele; Tara L.E. Trammell. 2017. "Continental-scale homogenization of residential lawn plant communities." Landscape and Urban Planning 165, no. : 54-63.
Peter M. Groffman; Meghan Avolio; Jeannine Cavender-Bares; Neil D. Bettez; J. Morgan Grove; Sharon Hall; Sarah E. Hobbie; Kelli L. Larson; Susannah B. Lerman; Dexter H. Locke; James Heffernan; Jennifer L. Morse; Christopher Neill; Kristen C. Nelson; Jarlath O’Neil-Dunne; Diane E. Pataki; Colin Polsky; Rinku Roy Chowdhury; Tara L. E. Trammell. Ecological homogenization of residential macrosystems. Nature Ecology & Evolution 2017, 1, 191 -191.
AMA StylePeter M. Groffman, Meghan Avolio, Jeannine Cavender-Bares, Neil D. Bettez, J. Morgan Grove, Sharon Hall, Sarah E. Hobbie, Kelli L. Larson, Susannah B. Lerman, Dexter H. Locke, James Heffernan, Jennifer L. Morse, Christopher Neill, Kristen C. Nelson, Jarlath O’Neil-Dunne, Diane E. Pataki, Colin Polsky, Rinku Roy Chowdhury, Tara L. E. Trammell. Ecological homogenization of residential macrosystems. Nature Ecology & Evolution. 2017; 1 (7):191-191.
Chicago/Turabian StylePeter M. Groffman; Meghan Avolio; Jeannine Cavender-Bares; Neil D. Bettez; J. Morgan Grove; Sharon Hall; Sarah E. Hobbie; Kelli L. Larson; Susannah B. Lerman; Dexter H. Locke; James Heffernan; Jennifer L. Morse; Christopher Neill; Kristen C. Nelson; Jarlath O’Neil-Dunne; Diane E. Pataki; Colin Polsky; Rinku Roy Chowdhury; Tara L. E. Trammell. 2017. "Ecological homogenization of residential macrosystems." Nature Ecology & Evolution 1, no. 7: 191-191.
Climate of the northern hardwood forests of North America will become significantly warmer in the coming decades. Associated increases in soil temperature, decreases in water availability and changes in winter snow pack and soil frost are likely to affect soil carbon (C) and nitrogen (N) cycling. Most studies of the effects of climate change on soil function have focused on the upper-organic part of the soil profile (e.g., forest floor), and little is known about effects on deeper mineral soil horizons. We exploited an elevation/orientation gradient at the Hubbard Brook Experimental Forest (New Hampshire, USA) to evaluate how variation in climate, similar to that projected to occur over the next 50–100 years, affects soil C and N pools and transformation rates in different soil horizons of northern hardwood forests. Lower elevation, south-facing plots with higher soil temperature, less soil moisture and snow, and increased frequency of soil freeze/thaw events had less soil inorganic N content and lower potential net N mineralization rates compared to higher elevation, north facing plots. These differences in N pools and fluxes were consistent for all soil horizons, but sensitivity to climate variation increased with soil depth, confirming that assessments of climate change effects that do not consider variation throughout the soil profile are likely to be incomplete and potentially inaccurate. Nitrogen cycling processes were more sensitive to climate variation than C cycling processes, suggesting a decoupling of C and N cycles in coming decades, with important implications for ecosystem function. Soil processes showed greater sensitivity to climate variation in summer than in spring, and in the warmer and less snowy year of sampling, suggesting that the effects of climate change might become more pronounced as temperatures increase and snow fall and water availability decrease in the coming decades.
Jorge Durán; Jennifer Morse; Alexandra Rodríguez; John L. Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany C. Fisk; Myron J. Mitchell; Pamela H. Templer; Peter M. Groffman. Differential sensitivity to climate change of C and N cycling processes across soil horizons in a northern hardwood forest. Soil Biology and Biochemistry 2017, 107, 77 -84.
AMA StyleJorge Durán, Jennifer Morse, Alexandra Rodríguez, John L. Campbell, Lynn M. Christenson, Charles T. Driscoll, Timothy J. Fahey, Melany C. Fisk, Myron J. Mitchell, Pamela H. Templer, Peter M. Groffman. Differential sensitivity to climate change of C and N cycling processes across soil horizons in a northern hardwood forest. Soil Biology and Biochemistry. 2017; 107 ():77-84.
Chicago/Turabian StyleJorge Durán; Jennifer Morse; Alexandra Rodríguez; John L. Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany C. Fisk; Myron J. Mitchell; Pamela H. Templer; Peter M. Groffman. 2017. "Differential sensitivity to climate change of C and N cycling processes across soil horizons in a northern hardwood forest." Soil Biology and Biochemistry 107, no. : 77-84.
Snow cover is projected to decline during the next century in many ecosystems that currently experience a seasonal snowpack. Because snow insulates soils from frigid winter air temperatures, soils are expected to become colder and experience more winter soil freeze-thaw cycles as snow cover continues to decline. Tree roots are adversely affected by snowpack reduction, but whether loss of snow will affect root-microbe interactions remains largely unknown. The objective of this study was to distinguish and attribute direct (e.g., winter snow- and/or soil frost-mediated) vs. indirect (e.g., root-mediated) effects of winter climate change on microbial biomass, the potential activity of microbial exoenzymes, and net N mineralization and nitrification rates. Soil cores were incubated in situ in nylon mesh that either allowed roots to grow into the soil core (2 mm pore size) or excluded root ingrowth (50 μm pore size) for up to 29 months along a natural winter climate gradient at Hubbard Brook Experimental Forest, NH (USA). Microbial biomass did not differ among ingrowth or exclusion cores. Across sampling dates, the potential activities of cellobiohydrolase, phenol oxidase, and peroxidase, and net N mineralization rates were more strongly related to soil volumetric water content (P < 0.05; R2 = 0.25–0.46) than to root biomass, snow or soil frost, or winter soil temperature (R2 < 0.10). Root ingrowth was positively related to soil frost (P < 0.01; R2 = 0.28), suggesting that trees compensate for overwinter root mortality caused by soil freezing by re-allocating resources towards root production. At the sites with the deepest snow cover, root ingrowth reduced nitrification rates by 30% (P < 0.01), showing that tree roots exert significant influence over nitrification, which declines with reduced snow cover. If soil freezing intensifies over time, then greater compensatory root growth may reduce nitrification rates directly via plant-microbe N competition and indirectly through a negative feedback on soil moisture, resulting in lower N availability to trees in northern hardwood forests.
Patrick O. Sorensen; Pamela H. Templer; Lynn Christenson; Jorge Duran; Timothy Fahey; Melany C. Fisk; Peter M. Groffman; Jennifer Morse; Adrien C. Finzi. Reduced snow cover alters root‐microbe interactions and decreases nitrification rates in a northern hardwood forest. Ecology 2016, 97, 3359 -3368.
AMA StylePatrick O. Sorensen, Pamela H. Templer, Lynn Christenson, Jorge Duran, Timothy Fahey, Melany C. Fisk, Peter M. Groffman, Jennifer Morse, Adrien C. Finzi. Reduced snow cover alters root‐microbe interactions and decreases nitrification rates in a northern hardwood forest. Ecology. 2016; 97 (12):3359-3368.
Chicago/Turabian StylePatrick O. Sorensen; Pamela H. Templer; Lynn Christenson; Jorge Duran; Timothy Fahey; Melany C. Fisk; Peter M. Groffman; Jennifer Morse; Adrien C. Finzi. 2016. "Reduced snow cover alters root‐microbe interactions and decreases nitrification rates in a northern hardwood forest." Ecology 97, no. 12: 3359-3368.
Reduced snowpack and associated increases in soil freezing severity resulting from winter climate change have the potential to disrupt carbon (C) and nitrogen (N) cycling in soils. We used a natural winter climate gradient based on elevation and aspect in a northern hardwood forest to examine the effects of variability in soil freezing depth, duration, and frequency on the mobilization of dissolved organic carbon (DOC) and nitrate (NO3−) in soils over the course of 2 years. During a winter with a relatively thin snowpack, soils at lower elevation sites experienced greater freezing and especially variable freeze/thaw cycles, which in turn led to greater leaching of DOC from the organic horizon during the following growing season. In contrast to several previous field manipulation studies, we did not find changes in soil solution NO3− concentrations related to soil freezing variables. Our results are consistent with a soil matrix disturbance from freezing and thawing which increases leachable C. These results build upon previous laboratory experiments and field manipulations that found differing responses of DOC and NO3− following soil freezing, suggesting that mobilization of labile C may suppress NO3− losses through microbial immobilization of N. This research highlights the importance of studying natural variation in winter climate and soil freezing and how they impact soil C and N retention, with implications for surface water runoff quality.
Colin B. Fuss; Charles T. Driscoll; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Timothy J. Fahey; Melany Fisk; Myron J. Mitchell; Pamela H. Templer; Jorge Durán; Jennifer Morse. Nitrate and dissolved organic carbon mobilization in response to soil freezing variability. Biogeochemistry 2016, 131, 35 -47.
AMA StyleColin B. Fuss, Charles T. Driscoll, Peter M. Groffman, John L. Campbell, Lynn M. Christenson, Timothy J. Fahey, Melany Fisk, Myron J. Mitchell, Pamela H. Templer, Jorge Durán, Jennifer Morse. Nitrate and dissolved organic carbon mobilization in response to soil freezing variability. Biogeochemistry. 2016; 131 (1):35-47.
Chicago/Turabian StyleColin B. Fuss; Charles T. Driscoll; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Timothy J. Fahey; Melany Fisk; Myron J. Mitchell; Pamela H. Templer; Jorge Durán; Jennifer Morse. 2016. "Nitrate and dissolved organic carbon mobilization in response to soil freezing variability." Biogeochemistry 131, no. 1: 35-47.
Natural Flood Management (NFM) techniques aim to reduce downstream flooding by storing and slowing the flow of stormwater to river channels. These techniques include a range of measures, including setback stormwater outfalls and the physical restoration of channels and floodplains, to improve the natural functioning of catchments. An additional benefit of NFM measures is the potential reduction in sediment and pollutant delivery to the channel. Urban development releases a variety of heavy metal and nutrient pollutants that enter rivers through stormwater outfalls with adverse effects on the aquatic ecosystem. In this study, the influence of channel modification and quality of the river habitat on the sediment quality surrounding stormwater outfalls was assessed. Sediment samples were taken at several outfalls within the Johnson Creek catchment, Oregon, USA, and analysed for a variety of urban pollutants. The level of river habitat quality and modification at each site were assessed using a semi‐quantitative scoring methodology. Significant increases in pollutant levels were observed at outfalls, with a greater and more variable increase at direct compared to setback outfalls. Removal efficiency of certain pollutants was found to be significantly correlated to the level of habitat quality or modification (for Fe, Ba, Sn, Mg, P, K) indicating that more natural reaches had greater potential for pollutant removal. The findings highlight the multiple benefits associated with NFM and river restoration approaches in relation to sediment quality and pollutant content. © 2016 The Authors River Research and Applications Published by John Wiley & Sons, Ltd.
V. J. Janes; R. C. Grabowski; J. Mant; D. Allen; J. L. Morse; Heather Haynes. The Impacts of Natural Flood Management Approaches on In-Channel Sediment Quality. River Research and Applications 2016, 33, 89 -101.
AMA StyleV. J. Janes, R. C. Grabowski, J. Mant, D. Allen, J. L. Morse, Heather Haynes. The Impacts of Natural Flood Management Approaches on In-Channel Sediment Quality. River Research and Applications. 2016; 33 (1):89-101.
Chicago/Turabian StyleV. J. Janes; R. C. Grabowski; J. Mant; D. Allen; J. L. Morse; Heather Haynes. 2016. "The Impacts of Natural Flood Management Approaches on In-Channel Sediment Quality." River Research and Applications 33, no. 1: 89-101.
Nitrogen (N) supply often limits the productivity of temperate forests and is regulated by a complex mix of biological and climatic drivers. In excess, N is linked to a variety of soil, water, and air pollution issues. Here, we use results from an elevation gradient study and historical data from the long-term Hubbard Brook Ecosystem Study (New Hampshire, USA) to examine relationships between changes in climate, especially during winter, and N supply to northern hardwood forest ecosystems. Low elevation plots with less snow, more soil freezing, and more freeze/thaw cycles supported lower rates of N mineralization than high elevation plots, despite having higher soil temperatures and no consistent differences in soil moisture during the growing season. These results are consistent with historical analyses showing decreases in rates of soil N mineralization and inorganic N concentrations since 1973 that are correlated with long-term increases in mean annual temperature, decreases in annual snow accumulation, and a increases in the number of winter thawing degree days. This evidence suggests that changing climate may be driving decreases in the availability of a key nutrient in northern hardwood forests, which could decrease ecosystem production but have positive effects on environmental consequences of excess N.
Jorge Durán; Jennifer Morse; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany Fisk; Gene E. Likens; Jerry M. Melillo; Myron J. Mitchell; Pamela H. Templer; Matthew Vadeboncoeur. Climate change decreases nitrogen pools and mineralization rates in northern hardwood forests. Ecosphere 2016, 7, 1 .
AMA StyleJorge Durán, Jennifer Morse, Peter M. Groffman, John L. Campbell, Lynn M. Christenson, Charles T. Driscoll, Timothy J. Fahey, Melany Fisk, Gene E. Likens, Jerry M. Melillo, Myron J. Mitchell, Pamela H. Templer, Matthew Vadeboncoeur. Climate change decreases nitrogen pools and mineralization rates in northern hardwood forests. Ecosphere. 2016; 7 (3):1.
Chicago/Turabian StyleJorge Durán; Jennifer Morse; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany Fisk; Gene E. Likens; Jerry M. Melillo; Myron J. Mitchell; Pamela H. Templer; Matthew Vadeboncoeur. 2016. "Climate change decreases nitrogen pools and mineralization rates in northern hardwood forests." Ecosphere 7, no. 3: 1.
Residential yards across the US look remarkably similar despite marked variation in climate and soil, yet the drivers of this homogenization are unknown. Telephone surveys of fertilizer and irrigation use and satisfaction with the natural environment, and measurements of inherent water and nitrogen availability in six US cities (Boston, Baltimore, Miami, Minneapolis-St. Paul, Phoenix, Los Angeles) showed that the percentage of people using irrigation at least once in a year was relatively invariant with little difference between the wettest (Miami, 85%) and driest (Phoenix, 89%) cities. The percentage of people using fertilizer at least once in a year also ranged narrowly (52%–71%), while soil nitrogen supply varied by 10x. Residents expressed similar levels of satisfaction with the natural environment in their neighborhoods. The nature and extent of this satisfaction must be understood if environmental managers hope to effect change in the establishment and maintenance of residential ecosystems.
Peter M Groffman; J. Morgan Grove; Colin Polsky; Neil D Bettez; Jennifer L Morse; Jeannine Cavender-Bares; Sharon Hall; James B Heffernan; Sarah E Hobbie; Kelli L Larson; Christopher Neill; Kristen Nelson; Laura Ogden; Jarlath O’Neil-Dunne; Diane Pataki; Rinku Roy Chowdhury; Dexter H Locke. Satisfaction, water and fertilizer use in the American residential macrosystem. Environmental Research Letters 2016, 11, 34004 .
AMA StylePeter M Groffman, J. Morgan Grove, Colin Polsky, Neil D Bettez, Jennifer L Morse, Jeannine Cavender-Bares, Sharon Hall, James B Heffernan, Sarah E Hobbie, Kelli L Larson, Christopher Neill, Kristen Nelson, Laura Ogden, Jarlath O’Neil-Dunne, Diane Pataki, Rinku Roy Chowdhury, Dexter H Locke. Satisfaction, water and fertilizer use in the American residential macrosystem. Environmental Research Letters. 2016; 11 (3):34004.
Chicago/Turabian StylePeter M Groffman; J. Morgan Grove; Colin Polsky; Neil D Bettez; Jennifer L Morse; Jeannine Cavender-Bares; Sharon Hall; James B Heffernan; Sarah E Hobbie; Kelli L Larson; Christopher Neill; Kristen Nelson; Laura Ogden; Jarlath O’Neil-Dunne; Diane Pataki; Rinku Roy Chowdhury; Dexter H Locke. 2016. "Satisfaction, water and fertilizer use in the American residential macrosystem." Environmental Research Letters 11, no. 3: 34004.
Human drivers are often proposed to be stronger than biophysical drivers in influencing ecosystem structure and function in highly urbanized areas. In residential land cover, private yards are influenced by individual homeowner preferences and actions while also experiencing large-scale human and biophysical drivers. We studied plant nitrogen (%N) and N stable isotopic composition (δ15N) in residential yards and paired native ecosystems in seven cities across the US that span major ecological biomes and climatic regions: Baltimore, Boston, Los Angeles, Miami, Minneapolis-St. Paul, Phoenix, and Salt Lake City. We found that residential lawns in three cities had enriched plant δ15N (P < 0.03) and in six cities higher plant N (%) relative to the associated native ecosystems (P < 0.05). Plant δ15N was progressively depleted across a gradient of urban density classes in Baltimore and Boston (P < 0.05). Lawn fertilization was associated with depleted plant δ15N in Boston and Los Angeles (P < 0.05), and organic fertilizer additions were associated with enriched plant δ15N in Los Angeles and Salt Lake City (P < 0.04). Plant δ15N was significantly enriched as a function of housing age in Baltimore (r 2 = 0.27, P < 0.02), Boston (r 2 = 0.27, P < 0.01), and Los Angeles (r 2 = 0.34, P < 0.01). These patterns in plant δ15N and plant N (%) across these cities suggests that N sources to lawns, as well as greater rates of N cycling combined with subsequent N losses, may be important drivers of plant N dynamics in lawn ecosystems at the national scale.
T. L. E. Trammell; D. E. Pataki; Jeannine Cavender-Bares; P. M. Groffman; Sharon Hall; James Heffernan; Sarah Hobbie; Jennifer Morse; C. Neill; K. C. Nelson. Plant nitrogen concentration and isotopic composition in residential lawns across seven US cities. Oecologia 2016, 181, 271 -285.
AMA StyleT. L. E. Trammell, D. E. Pataki, Jeannine Cavender-Bares, P. M. Groffman, Sharon Hall, James Heffernan, Sarah Hobbie, Jennifer Morse, C. Neill, K. C. Nelson. Plant nitrogen concentration and isotopic composition in residential lawns across seven US cities. Oecologia. 2016; 181 (1):271-285.
Chicago/Turabian StyleT. L. E. Trammell; D. E. Pataki; Jeannine Cavender-Bares; P. M. Groffman; Sharon Hall; James Heffernan; Sarah Hobbie; Jennifer Morse; C. Neill; K. C. Nelson. 2016. "Plant nitrogen concentration and isotopic composition in residential lawns across seven US cities." Oecologia 181, no. 1: 271-285.
The urban heat island (UHI) is a well-documented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single cities surrounded by standardized land cover. Relatively few studies have explored continental-scale climatic patterns within common urban microenvironments such as residential landscapes that may affect human comfort. We tested the urban homogenization hypothesis which states that structure and function in cities exhibit ecological “sameness” across diverse regions relative to the native ecosystems they replaced. We deployed portable micrometeorological sensors to compare air temperature and humidity in residential yards and native landscapes across six U.S. cities that span a range of climates (Phoenix, AZ; Los Angeles, CA; Minneapolis-St. Paul, MN; Boston, MA; Baltimore, MD; and Miami, FL). Microclimate in residential ecosystems was more similar among cities than among native ecosystems, particularly during the calm morning hours. Maximum regional actual evapotranspiration (AET) was related to the morning residential microclimate effect. Residential yards in cities with maximum AET <50–65 cm/year (Phoenix and Los Angeles) were generally cooler and more humid than nearby native shrublands during summer mornings, while yards in cities above this threshold were generally warmer (Baltimore and Miami) and drier (Miami) than native forests. On average, temperature and absolute humidity were ~6 % less variable among residential ecosystems than among native ecosystems from diverse regions. These data suggest that common residential land cover and structural characteristics lead to microclimatic convergence across diverse regions at the continental scale.
Sharon J. Hall; J. Learned; B. Ruddell; K. L. Larson; J. Cavender-Bares; N. Bettez; P. M. Groffman; J. Morgan Grove; J. B. Heffernan; S. E. Hobbie; J. L. Morse; C. Neill; K. C. Nelson; J. P. M. O’Neil-Dunne; L. Ogden; D. E. Pataki; William D Pearse; C. Polsky; R. Roy Chowdhury; M. K. Steele; T. L. E. Trammell. Convergence of microclimate in residential landscapes across diverse cities in the United States. Landscape Ecology 2015, 31, 101 -117.
AMA StyleSharon J. Hall, J. Learned, B. Ruddell, K. L. Larson, J. Cavender-Bares, N. Bettez, P. M. Groffman, J. Morgan Grove, J. B. Heffernan, S. E. Hobbie, J. L. Morse, C. Neill, K. C. Nelson, J. P. M. O’Neil-Dunne, L. Ogden, D. E. Pataki, William D Pearse, C. Polsky, R. Roy Chowdhury, M. K. Steele, T. L. E. Trammell. Convergence of microclimate in residential landscapes across diverse cities in the United States. Landscape Ecology. 2015; 31 (1):101-117.
Chicago/Turabian StyleSharon J. Hall; J. Learned; B. Ruddell; K. L. Larson; J. Cavender-Bares; N. Bettez; P. M. Groffman; J. Morgan Grove; J. B. Heffernan; S. E. Hobbie; J. L. Morse; C. Neill; K. C. Nelson; J. P. M. O’Neil-Dunne; L. Ogden; D. E. Pataki; William D Pearse; C. Polsky; R. Roy Chowdhury; M. K. Steele; T. L. E. Trammell. 2015. "Convergence of microclimate in residential landscapes across diverse cities in the United States." Landscape Ecology 31, no. 1: 101-117.
Although ecosystem services have been intensively examined in certain domains (e.g., forests and wetlands), little research has assessed ecosystem services for the most dominant landscape type in urban ecosystems—namely, residential yards. In this paper, we report findings of a cross-site survey of homeowners in six U.S. cities to 1) examine how residents subjectively value various ecosystem services, 2) explore distinctive dimensions of those values, and 3) test the urban homogenization hypothesis. This hypothesis posits that urbanization leads to similarities in the social-ecological dynamics across cities in diverse biomes. By extension, the thesis suggests that residents’ ecosystem service priorities for residential landscapes will be similar regardless of whether residents live in the humid East or the arid West, or the warm South or the cold North. Results underscored that cultural services were of utmost importance, particularly anthropocentric values including aesthetics, low-maintenance, and personal enjoyment. Using factor analyses, distinctive dimensions of residents’ values were found to partially align with the Millennium Ecosystem Assessment’s categories (provisioning, regulating, supporting, and cultural). Finally, residents’ ecosystem service priorities exhibited significant homogenization across regions. In particular, the traditional lawn aesthetic (neat, green, weed-free yards) was similarly important across residents of diverse U.S. cities. Only a few exceptions were found across different environmental and social contexts; for example, cooling effects were more important in the warm South, where residents also valued aesthetics more than those in the North, where low-maintenance yards were a greater priority.
Kelli L Larson; Kristen C Nelson; S. R. Samples; Sharon Hall; Neil D Bettez; Jeannine Cavender-Bares; Peter Groffman; Marty J Grove; James Heffernan; Sarah Hobbie; J. Learned; Jennifer Morse; C A Neill; L. A. Ogden; Jarlath Oneildunne; Diane E Pataki; Colin Polsky; Rinku Roy Chowdhury; M K Steele; T. L. E. Trammell. Ecosystem services in managing residential landscapes: priorities, value dimensions, and cross-regional patterns. Urban Ecosystems 2015, 19, 95 -113.
AMA StyleKelli L Larson, Kristen C Nelson, S. R. Samples, Sharon Hall, Neil D Bettez, Jeannine Cavender-Bares, Peter Groffman, Marty J Grove, James Heffernan, Sarah Hobbie, J. Learned, Jennifer Morse, C A Neill, L. A. Ogden, Jarlath Oneildunne, Diane E Pataki, Colin Polsky, Rinku Roy Chowdhury, M K Steele, T. L. E. Trammell. Ecosystem services in managing residential landscapes: priorities, value dimensions, and cross-regional patterns. Urban Ecosystems. 2015; 19 (1):95-113.
Chicago/Turabian StyleKelli L Larson; Kristen C Nelson; S. R. Samples; Sharon Hall; Neil D Bettez; Jeannine Cavender-Bares; Peter Groffman; Marty J Grove; James Heffernan; Sarah Hobbie; J. Learned; Jennifer Morse; C A Neill; L. A. Ogden; Jarlath Oneildunne; Diane E Pataki; Colin Polsky; Rinku Roy Chowdhury; M K Steele; T. L. E. Trammell. 2015. "Ecosystem services in managing residential landscapes: priorities, value dimensions, and cross-regional patterns." Urban Ecosystems 19, no. 1: 95-113.
Aquatic ecosystems are sensitive to the modification of hydrologic regimes, experiencing declines in stream health as the streamflow regime is altered during urbanization. This study uses streamflow records to quantify the type and magnitude of hydrologic changes across urbanization gradients in nine U.S. cities (Atlanta, GA, Baltimore, MD, Boston, MA, Detroit, MI, Raleigh, NC, St. Paul, MN, Pittsburgh, PA, Phoenix, AZ, and Portland, OR) in two physiographic settings. Results indicate similar development trajectories among urbanization gradients, but heterogeneity in the type and magnitude of hydrologic responses to this apparently uniform urban pattern. Similar urban patterns did not confer similar hydrologic function. Study watersheds in landscapes with level slopes and high soil permeability had less frequent high-flow events, longer high-flow durations, lower flashiness response, and lower flow maxima compared to similarly developed watersheds in landscape with steep slopes and low soil permeability. Our results suggest that physical characteristics associated with level topography and high water-storage capacity buffer the severity of hydrologic changes associated with urbanization. Urbanization overlain upon a diverse set of physical templates creates multiple pathways toward hydrologic impairment; therefore, we caution against the use of the urban homogenization framework in examining geophysically dominated processes.
Kristina G. Hopkins; Nathaniel B. Morse; Daniel J. Bain; Neil D. Bettez; Nancy Grimm; Jennifer Morse; Monica M. Palta; William Shuster; Anika R. Bratt; Amanda Suchy. Assessment of Regional Variation in Streamflow Responses to Urbanization and the Persistence of Physiography. Environmental Science & Technology 2015, 49, 2724 -2732.
AMA StyleKristina G. Hopkins, Nathaniel B. Morse, Daniel J. Bain, Neil D. Bettez, Nancy Grimm, Jennifer Morse, Monica M. Palta, William Shuster, Anika R. Bratt, Amanda Suchy. Assessment of Regional Variation in Streamflow Responses to Urbanization and the Persistence of Physiography. Environmental Science & Technology. 2015; 49 (5):2724-2732.
Chicago/Turabian StyleKristina G. Hopkins; Nathaniel B. Morse; Daniel J. Bain; Neil D. Bettez; Nancy Grimm; Jennifer Morse; Monica M. Palta; William Shuster; Anika R. Bratt; Amanda Suchy. 2015. "Assessment of Regional Variation in Streamflow Responses to Urbanization and the Persistence of Physiography." Environmental Science & Technology 49, no. 5: 2724-2732.
Nitrogen (N) is the nutrient that most frequently limits the productivity of forest ecosystems. Understanding N cycling and forest response to altered N inputs and climate change is an ongoing research challenge. In several intensively studied forests in northeastern North America, well-characterized N inputs are not balanced by measured N losses, suggesting that an unmeasured N loss pathway such as denitrification may be important. We studied soil denitrification gas fluxes in northern hardwood forests at the Hubbard Brook long-term ecological research site in New Hampshire, USA, and found that denitrification in apparently oxic soils could account for N losses greater than half of annual atmospheric N inputs. Denitrification rates were strongly affected by elevation and season, with higher rates occurring at high elevation plots and during snowmelt. These results suggest that denitrification accounts for a major portion of the increasing amounts of “missing N” reported for this site, and that a significant amount of the anthropogenic N that enters terrestrial ecosystems in northeastern North America is returned to the atmosphere as N2. These dynamics are highly vulnerable to change, however, as soil moisture levels and conditions during snowmelt are changing rapidly along with climate.
Jennifer L. Morse; Jorge Durán; Peter Groffman. Soil Denitrification Fluxes in a Northern Hardwood Forest: The Importance of Snowmelt and Implications for Ecosystem N Budgets. Ecosystems 2015, 18, 520 -532.
AMA StyleJennifer L. Morse, Jorge Durán, Peter Groffman. Soil Denitrification Fluxes in a Northern Hardwood Forest: The Importance of Snowmelt and Implications for Ecosystem N Budgets. Ecosystems. 2015; 18 (3):520-532.
Chicago/Turabian StyleJennifer L. Morse; Jorge Durán; Peter Groffman. 2015. "Soil Denitrification Fluxes in a Northern Hardwood Forest: The Importance of Snowmelt and Implications for Ecosystem N Budgets." Ecosystems 18, no. 3: 520-532.
In northern forests, large amounts of missing N that dominate N balances at scales ranging from small watersheds to large regional drainage basins may be related to N-gas production by soil microbes. We measured denitrification rates in forest soils in northeastern North America along a N deposition gradient to determine whether N-gas fluxes were a significant fate for atmospheric N inputs and whether denitrification rates were correlated with N availability, soil O2 status, or forest type. We quantified N2 and N2O fluxes in the laboratory with an intact-core method and monitored soil O2, temperature and moisture in three forests differing in natural and anthropogenic N enrichment: Turkey Lakes Watershed, Ontario; Hubbard Brook Experimental Forest, New Hampshire; and Bear Brook Watershed, Maine (fertilized and reference plots in hardwood and softwood stands). Total N-gas flux estimates ranged from 100 kg N ha(-1) year(-1) in hardwood wetlands at Turkey Lakes. N-gas flux increased systematically with natural N enrichment from soils with high nitrification rates (Bear Brook < Hubbard Brook < Turkey Lakes) but did not increase in the site where N fertilizer has been added since 1989 (Bear Brook). Our results show that denitrification is an important and underestimated term (1-24% of atmospheric N inputs) in N budgets of upland forests in northeastern North America, but it does not appear to be an important sink for elevated anthropogenic atmospheric N deposition in this region.
Jennifer L. Morse; Jorge Durán; Fred Beall; Eric M. Enanga; Irena F. Creed; Ivan Fernandez; Peter Groffman. Soil denitrification fluxes from three northeastern North American forests across a range of nitrogen deposition. Oecologia 2014, 177, 17 -27.
AMA StyleJennifer L. Morse, Jorge Durán, Fred Beall, Eric M. Enanga, Irena F. Creed, Ivan Fernandez, Peter Groffman. Soil denitrification fluxes from three northeastern North American forests across a range of nitrogen deposition. Oecologia. 2014; 177 (1):17-27.
Chicago/Turabian StyleJennifer L. Morse; Jorge Durán; Fred Beall; Eric M. Enanga; Irena F. Creed; Ivan Fernandez; Peter Groffman. 2014. "Soil denitrification fluxes from three northeastern North American forests across a range of nitrogen deposition." Oecologia 177, no. 1: 17-27.
J. L. Morse; S. F. Werner; C. P. Gillin; Christine Goodale; Scott Bailey; Kevin McGuire; Peter Groffman. Searching for biogeochemical hot spots in three dimensions: Soil C and N cycling in hydropedologic settings in a northern hardwood forest. Journal of Geophysical Research: Biogeosciences 2014, 119, 1596 -1607.
AMA StyleJ. L. Morse, S. F. Werner, C. P. Gillin, Christine Goodale, Scott Bailey, Kevin McGuire, Peter Groffman. Searching for biogeochemical hot spots in three dimensions: Soil C and N cycling in hydropedologic settings in a northern hardwood forest. Journal of Geophysical Research: Biogeosciences. 2014; 119 (8):1596-1607.
Chicago/Turabian StyleJ. L. Morse; S. F. Werner; C. P. Gillin; Christine Goodale; Scott Bailey; Kevin McGuire; Peter Groffman. 2014. "Searching for biogeochemical hot spots in three dimensions: Soil C and N cycling in hydropedologic settings in a northern hardwood forest." Journal of Geophysical Research: Biogeosciences 119, no. 8: 1596-1607.
Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity during the growing season. Soils from lower elevation plots, which accumulated less snow and experienced more soil temperature variability during the winter (and likely more freeze/thaw events), had less extractable inorganic nitrogen (N), lower rates of microbial N production via potential net N mineralization and nitrification, and higher potential microbial respiration during the growing season. Potential nitrate production rates during the growing season were particularly sensitive to changes in winter snow pack accumulation and winter soil temperature variability, especially in spring. Effects of elevation and winter conditions on N transformation rates differed from those on potential microbial respiration, suggesting that N‐related processes might respond differently to winter climate change in northern hardwood forests than C‐related processes.
Jorge Durán; Jennifer Morse; Peter Groffman; John Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany Fisk; Myron J. Mitchell; Pamela H. Templer. Winter climate change affects growing-season soil microbial biomass and activity in northern hardwood forests. Global Change Biology 2014, 20, 3568 -3577.
AMA StyleJorge Durán, Jennifer Morse, Peter Groffman, John Campbell, Lynn M. Christenson, Charles T. Driscoll, Timothy J. Fahey, Melany Fisk, Myron J. Mitchell, Pamela H. Templer. Winter climate change affects growing-season soil microbial biomass and activity in northern hardwood forests. Global Change Biology. 2014; 20 (11):3568-3577.
Chicago/Turabian StyleJorge Durán; Jennifer Morse; Peter Groffman; John Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany Fisk; Myron J. Mitchell; Pamela H. Templer. 2014. "Winter climate change affects growing-season soil microbial biomass and activity in northern hardwood forests." Global Change Biology 20, no. 11: 3568-3577.