Now showing items 1-12 of 12

    • Convergent Surface Water Distributions in U.S. Cities 

      Bettez, N; Cavender-Bares, J; Chowdhury, RR; Groffman, PM; Grove, JM; Hall, S; Heffernan, JB; ... (17 authors) (Ecosystems, 2014)
      Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However, the scope and consequences of surface water redistribution ...
    • Convergent Surface Water Distributions in U.S. Cities 

      Steele, MK; Heffernan, JB; Bettez, N; Cavender-Bares, J; Groffman, PM; Grove, JM; Hall, S; ... (17 authors) (Ecosystems, 2014-01-01)
      Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However, the scope and consequences of surface water redistribution ...
    • Denitrification and inference of nitrogen sources in the karstic Floridan Aquifer 

      Heffernan, JB; Albertin, AR; Fork, ML; Katz, BG; Cohen, MJ (Biogeosciences, 2012-05-22)
      Aquifer denitrification is among the most poorly constrained fluxes in global and regional nitrogen budgets. The few direct measurements of denitrification in groundwaters provide limited information about its spatial and ...
    • Direct and indirect coupling of primary production and diel nitrate dynamics in a subtropical spring-fed river 

      Heffernan, JB; Cohen, MJ (Limnology and Oceanography, 2010-03-01)
      We used high-frequency in situ measurements of nitrate (NO3-) and dissolved oxygen (DO) from the springfed Ichetucknee River, Florida, to derive multiple independent estimates of assimilatory nitrogen (N) demand, and to ...
    • Direct and Indirect Effects of Dissolved Organic Matter Source and Concentration on Denitrification in Northern Florida Rivers 

      Fork, ML; Heffernan, JB (Ecosystems, 2014-01-01)
      Using a natural gradient of dissolved organic carbon (DOC) source and concentration in rivers of northern Florida, we investigated how terrestrially-derived DOC affects denitrification rates in river sediments. Specifically, ...
    • Ecological homogenization of urban USA 

      Groffman, PM; Cavender-Bares, J; Bettez, ND; Grove, JM; Hall, SJ; Heffernan, JB; Hobbie, SE; ... (17 authors) (Frontiers in Ecology and the Environment, 2014-02-01)
      A visually apparent but scientifically untested outcome of land-use change is homogenization across urban areas, where neighborhoods in different parts of the country have similar patterns of roads, residential lots, commercial ...
    • Hydrologie and biotic influences on nitrate removal in a subtropical spring-fed river 

      Heffernan, JB; Cohen, MJ; Frazer, TK; Thomas, RG; Rayfield, TJ; Gulley, J; Martin, JB; ... (9 authors) (Limnology and Oceanography, 2010-01-01)
      We use a long-term chemical and hydrologic record in combination with longitudinal sampling and highfrequency nitrate (NO3-) measurements from in situ sensors to describe temporal and spatial patterns of nitrogen (N) inputs ...
    • Inference of riverine nitrogen processing from longitudinal and diel variation in dual nitrate isotopes 

      Cohen, MJ; Heffernan, JB; Albertin, A; Martin, JB (Journal of Geophysical Research: Biogeosciences, 2012-03-01)
      Longitudinal and diel measurements of dual isotope composition (δ15N and δ18O) in nitrate (NO<inf>3</inf>-N) were made in the Ichetucknee River, a large (∼8m3 s -1), entirely spring-fed river in North Florida, to determine ...
    • Macrosystems ecology: Understanding ecological patterns and processes at continental scales 

      Heffernan, JB; Soranno, PA; Angilletta, MJ; Buckley, LB; Gruner, DS; Keitt, TH; Kellner, JR; ... (19 authors) (Frontiers in Ecology and the Environment, 2014-02-01)
      Macrosystems ecology is the study of diverse ecological phenomena at the scale of regions to continents and their interactions with phenomena at other scales. This emerging subdiscipline addresses ecological questions and ...
    • Morphological characteristics of urban water bodies: mechanisms of change and implications for ecosystem function. 

      Steele, MK; Heffernan, JB (Ecol Appl, 2014-07)
      The size, shape, and connectivity of water bodies (lakes, ponds, and wetlands) can have important effects on ecological communities and ecosystem processes, but how these characteristics are influenced by land use and land ...
    • On the multiple ecological roles of water in river networks 

      Sponseller, RA; Heffernan, JB; Fisher, SG (Ecosphere, 2013-02-06)
      The distribution and movement of water can influence the state and dynamics of terrestrial and aquatic ecosystems through a diversity of mechanisms. These mechanisms can be organized into three general categories wherein ...
    • Unintended consequences of urbanization for aquatic ecosystems: A case study from the Arizona desert 

      Roach, WJ; Heffernan, JB; Grimm, NB; Arrowsmith, JR; Eisinger, C; Rychener, T (BioScience, 2008-09-01)
      Many changes wrought during the construction of "designer ecosystems" are intended to ensure - and often succeed in ensuring - that a city can provide ecosystem goods and services; but other changes have unintended impacts ...