About

Jim Heffernan is a faculty member at Duke University Program in Ecology, providing interdisciplinary training in all aspects of ecology. His work encompasses physiological and behavioral ecology, population and evolutionary ecology, community and landscape ecology, biogeochemistry, and ecosystem and global change ecology. His research highlights include studying the genetics of adaptation, ecological forecasting of forest communities, tracking birds and storms, and understanding ecosystems in flux. He is involved in various symposia, seminars, and outreach activities aimed at advancing ecological science and education.

Research topics

• Ecology
• Geography
• Environmental science
• Biology
• Environmental resource management
• Agroforestry
• Environmental planning
• Mathematics
• Business
• Geology
• Atmospheric sciences
• Meteorology

Selected publications

• Experimental evidence for grazer control of algal stable states in Florida’s spring-fed rivers

  Hydrobiologia · 2026-03-19

  article
  PublisherDOI

• StreamPULSE Sensor Data and Metabolism Estimates for Rivers and Streams

  HydroShare Resources · 2025-07-05

  dataset
  PublisherDOI

• Sustainability and Biodiversity

  Elsevier eBooks · 2023-09-13 · 1 citations

  book-chapter
  PublisherDOI

• Woody Plant–Soil Relationships in Interstitial Spaces Have Implications for Future Forests Within and Beyond Urban Areas

  Ecosystems · 2023-11-16 · 1 citations

  article
  PublisherDOI

• North Carolina Coastal Plain Ditch Types Support Distinct Hydrophytic Communities

  Wetlands · 2023-06-01 · 8 citations

  articleSenior authorCorresponding
  PublisherDOI

• North Carolina Coastal Plain ditch types support distinct hydrophytic communities

  Research Square · 2023-01-17 · 1 citations

  preprintOpen accessSenior authorCorresponding

  Abstract The drainage ditches of the North Carolina Coastal Plain retain some ecological structural characteristics of the wetlands they often replace. We surveyed 32 agricultural, freeway, and forested ditch reaches across this region for hydrologic indicators, soil organic matter, and plants. All showed at least some hydrologic indicators and had soil organic matter, especially swampy forests. Twenty-nine of 32 had hydrophytic herbaceous plant assemblages according to US Army Corps of Engineers wetland delineation standards. These herbaceous assemblages differed significantly across site types, and responded to both landscape level factors, like nearby development coverage, and local level factors, like apparent mowing. The US National Hydrography Dataset and the National Wetlands Inventory did not include most sample sites, and mischaracterized most they did include as natural waterbodies. Despite limited information about extent of these ditches, high variability and apparent management impact suggest that human potential to design wetland structure of these manmade aquatic ecosystems throughout the North Carolina Coastal Plain, and beyond, could be large.

  PublisherOA PDFDOI

• Respiration regimes in rivers: Partitioning source‐specific respiration from metabolism time series

  Zenodo (CERN European Organization for Nuclear Research) · 2022-09-07

  datasetOpen accessSenior author

  This repository hosts preprocessed input data and model codes of the paper: "Respiration regimes in rivers: Partitioning source‐specific respiration from metabolism time series" <br> Limonology and Oceanography, 2022.<br> DOI: 10.1002/lno.12207

  PublisherDOI

• CSV data for Bernhardt et al. 2022 (PNAS)

  Figshare · 2022-01-01

  datasetOpen access

  One of six datasets required to reproduce the plots and analyses in Bernhardt et al. 2022: "Light and flow regimes regulate the metabolism of rivers". See "Code and RDS data for Bernhardt et al. 2022" for complete workflow. These CSV versions of the datasets are included separately, for those who wish to analyze outside of R.<br><br>

  PublisherDOI

• Respiration regimes in rivers: Partitioning source‐specific respiration from metabolism time series

  Zenodo (CERN European Organization for Nuclear Research) · 2022-09-07

  datasetOpen accessSenior author

  This repository hosts preprocessed input data and model codes of the paper: "Respiration regimes in rivers: Partitioning source‐specific respiration from metabolism time series" <br> Limonology and Oceanography, 2022.<br> DOI: 10.1002/lno.12207

  PublisherDOI

• Light and flow regimes regulate the metabolism of rivers

  Proceedings of the National Academy of Sciences · 2022 · 201 citations

  • Environmental science
  • Atmospheric sciences
  • Ecology

  Mean annual temperature and mean annual precipitation drive much of the variation in productivity across Earth's terrestrial ecosystems but do not explain variation in gross primary productivity (GPP) or ecosystem respiration (ER) in flowing waters. We document substantial variation in the magnitude and seasonality of GPP and ER across 222 US rivers. In contrast to their terrestrial counterparts, most river ecosystems respire far more carbon than they fix and have less pronounced and consistent seasonality in their metabolic rates. We find that variation in annual solar energy inputs and stability of flows are the primary drivers of GPP and ER across rivers. A classification schema based on these drivers advances river science and informs management.

  PublisherOA PDFDOI

Recent grants

• Collaborative Proposal: MSB-FRA: Alternative Ecological Futures for the American Residential Macrosystem

  NSF · $267k · 2017–2020

• Collaborative Research: Watershed, estuarine, and local drivers of coastal marsh establishment and resilience

  NSF · $350k · 2015–2018

• Collaborative Research: Controls on Delivery and Fate of Water, Nitrogen, and Calcium in a Spring-Fed Karst River

  NSF · $86k · 2009–2013

• Collaborative Research: The Ecological Drill Hypothesis: Biotic Control on Carbonate Dissolution in a Low Relief Patterned Landscape

  NSF · $230k · 2014–2018

• Collaborative Research: Ecological Homogenization of Urban America

  NSF · $227k · 2012–2016

Frequent coauthors

• Matthew J. Cohen

  University of Florida

  49 shared

• Peter M. Groffman

  The Graduate Center, CUNY

  42 shared

• Kristen C. Nelson

  Minnesota Department of Natural Resources

  29 shared

• Emily S. Bernhardt

  Duke University

  26 shared

• Christopher Neill

  21 shared

• Sarah E. Hobbie

  University of Minnesota

  20 shared

• Sharon J. Hall

  Arizona State University

  20 shared

• Jeannine Cavender‐Bares

  University of Minnesota System

  20 shared

Education

• PhD, School of Life Sciences

  Arizona State University

  2007

• BA, Ecology and Evolutionary Biology

  Cornell University

  2000