Holly Barnard photo portrait
Associate Professor of Geography • Fellow of INSTAAR • Faculty of Hydrologic Sciences • Ecohydrology; Stable Isotope Geochemistry; Forest Hydrology; Tree Physiology • Ph.D. Oregon State University, 2009
Physical Geography
holly.barnard@colorado.edu
303-735-7062 INSTAAR RL-1, room 151

Research Interests

My research is focused on investigating how vegetation processes affect water flow dynamics and pathways in soil and streams, and conversely, how water flow paths affect vegetation function in mountainous terrain. The ultimate goal is to improve our knowledge of how changes in land-use and/or climate will affect water resources and ecosystems. This interdisciplinary research uses state-of-the-art techniques to reveal patterns and processes at scales ranging from the leaf to the watershed. Some current topics include: evapo-transpiration partitioning using stable isotopes; impact of bark beetle outbreaks on forest water yield in southern Wyoming; and examining the influence of micro-climate on tree function using stable isotope analysis of tree rings.

What's New

The Barnard Ecohydrology lab is growing! We are always looking for well-qualified, enthusiastic students to join our group. Undergraduates interested in research experience or potential senior projects should contact Dr. Barnard.

Potential graduate students are encouraged to contact Dr. Barnard in advance of applying to the department to discuss research project and funding opportunities.

"What's New" updated February 2011

Recent Courses Taught

  • Fall 2022  GEOG 3511  Intro to Hydrology
  • Spring 2022  GEOG 5161 Research Design in Geography
  • Fall 2021  GEOG 3511 Intro to Hydrology
  • Spring 2021  GEOG 5161 Research Design in Geography
  • Fall 2020  GEOG 4371/5371 Forest Geography
  • Spring 2020  GEOG 3511  Intro to Hydrology
  • Spring 2020  GEOG 5100  Special Topics: Writing and Presenting in Physical Science
  • Fall 2019  GEOG 1001  Environmental Systems: Climate and Vegetation

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Recent Publications

Exploring Environmental Factors That Drive Diel Variations in Tree Water Storage Using Wavelet Analysis

CU Boulder Authors: Barnard, Holly Rene
All Authors: Harmon RE; Barnard HR; Day-Lewis FD; Mao D; Singha K
Publication Date: 2021-08-25
Type: Journal Article

Summer runoff generation in foothill catchments of the Colorado Front Range

CU Boulder Authors: Barnard, Holly Rene
All Authors: Bukoski IS; Murphy SF; Birch AL; Barnard HR
Published in: Journal of Hydrology
Publication Date: 2021-04-19
Type: Journal Article

The influence of land cover and storm magnitude on hydrologic flowpath activation and runoff generation in steep tropical catchments of central Panama

CU Boulder Authors: Stallard, Robert; Barnard, Holly Rene
All Authors: Birch AL; Stallard RF; Bush SA; Barnard HR
Published in: Journal of Hydrology
Publication Date: 2021-03-10
Type: Journal Article

Precipitation Characteristics and Land Cover Control Wet Season Runoff Source and Rainfall Partitioning in Three Humid Tropical Catchments in Central Panama

CU Boulder Authors: Stallard, Robert; Barnard, Holly Rene
All Authors: Birch AL; Stallard RF; Barnard HR
Published in: Water Resources Research
Publication Date: 2021-02-01
Type: Journal Article

Increasing plant water stress and decreasing summer streamflow in response to a warmer and wetter climate in seasonally snow-covered forests

CU Boulder Authors: Barnard, Holly Rene
All Authors: Christensen L; Adams HR; Tai X; Barnard HR; Brooks PD
Published in: Ecohydrology
Publication Date: 2020-10-20
Type: Journal Article

Assessing plot-scale impacts of land use on overland flow generation in Central Panama

CU Boulder Authors: Barnard, Holly Rene; Stallard, Robert
All Authors: Bush SA; Stallard RF; Ebel BA; Barnard HR
Published in: Hydrological Processes
Publication Date: 2020-10-16
Type: Journal Article

Long-term hydrological response to forest harvest during seasonal low flow: Potential implications for current forest practices

CU Boulder Authors: Barnard, Holly Rene
All Authors: Coble AA; Barnard H; Du E; Johnson S; Jones J; Keppeler E; Kwon H; Link TE; Penaluna BE; Reiter M
Published in: Science of the Total Environment
Publication Date: 2020-08-15
Type: Journal Article

The pantropical response of soil moisture to El Nino

CU Boulder Authors: Barnard, Holly Rene
All Authors:
Solander KC; Newman BD; de Araujo AC; Barnard HR; Berry ZC; Bonal D; Bretfeld M; Burban B; Candido LA; Celleri R...
  • Solander KC
  • Newman BD
  • de Araujo AC
  • Barnard HR
  • Berry ZC
  • Bonal D
  • Bretfeld M
  • Burban B
  • Candido LA
  • Celleri R
Published in: Hydrology and Earth System Sciences
Publication Date: 2020-05-11
Type: Journal Article

Water Table Depth and Bedrock Permeability Control Magnitude and Timing of Transpiration-Induced Diel Fluctuations in Groundwater

CU Boulder Authors: Barnard, Holly Rene
All Authors: Harmon R; Barnard HR; Singha K
Published in: Water Resources Research
Publication Date: 2020-05-01
Type: Journal Article

Transpiration- and precipitation-induced subsurface water flow observed using the self-potential method

CU Boulder Authors: Barnard, Holly Rene
All Authors: Voytek EB; Barnard HR; Jougnot D; Singha K
Published in: Hydrological Processes
Publication Date: 2019-06-30
Type: Journal Article

Reevaluating growing season length controls on net ecosystem production in evergreen conifer forests

CU Boulder Authors: Molotch, Noah Paul; Barnard, Holly Rene
All Authors: Barnard DM; Knowles JF; Barnard HR; Goulden ML; Hu J; Litvak ME; Molotch NP
Published in: Scientific Reports
Publication Date: 2018-12-19
Type: Journal Article

A sprinkling experiment to quantify celerity-velocity differences at the hillslope scale

CU Boulder Authors: Barnard, Holly Rene
All Authors: van Verseveld WJ; Barnard HR; Graham CB; McDonnell JJ; Brooks JR; Weiler M
Published in: Hydrology and Earth System Sciences
Publication Date: 2017-11-27
Type: Journal Article

A sprinkling experiment to quantify celerity–velocity differences at the hillslope scale

CU Boulder Authors: Barnard, Holly Rene
All Authors: van Verseveld WJ; Barnard HR; Graham CB; McDonnell JJ; Brooks JR; Weiler M
Published in: Hydrology and Earth System Sciences
Publication Date: 2017-11-27
Type: Journal Article

Topoclimate effects on growing season length and montane conifer growth in complex terrain

CU Boulder Authors: Molotch, Noah Paul; Barnard, Holly Rene
All Authors: Barnard DM; Barnard HR; Molotch NP
Published in: Environmental Research Letters
Publication Date: 2017-05-01
Type: Journal Article

Topographically driven differences in energy and water constrain climatic control on forest carbon sequestration

CU Boulder Authors: Barnard, Holly Rene
All Authors: Swetnam TL; Brooks PD; Barnard HR; Harpold AA; Gallo EL
Published in: Ecosphere
Publication Date: 2017-04-01
Type: Journal Article

The role of stable isotopes in understanding rainfall interception processes: a review

CU Boulder Authors: Barnard, Holly Rene
All Authors: Allen ST; Keim RF; Barnard HR; McDonnell JJ; Brooks JR
Published in: Wiley Interdisciplinary Reviews: Water
Publication Date: 2017-01-01
Type: Journal Article

Dissolved organic matter transport reflects hillslope to stream connectivity during snowmelt in a montane catchment

CU Boulder Authors: Barnard, Holly Rene; McKnight, Diane Marie
All Authors: Burns MA; Barnard HR; Gabor RS; McKnight DM; Brooks PD
Published in: Water Resources Research
Publication Date: 2016-06-01
Type: Journal Article

Examining diel patterns of soil and xylem moisture using electrical resistivity imaging

CU Boulder Authors: Barnard, Holly Rene
All Authors: Mares R; Barnard HR; Mao D; Revil A; Singha K
Published in: Journal of Hydrology
Publication Date: 2016-05-01
Type: Journal Article

The relative contributions of alpine and subalpine ecosystems to the water balance of a mountainous, headwater catchment

CU Boulder Authors: Burns, Sean; Williams, Mark W; Barnard, Holly Rene; Blanken, Peter David
All Authors: Knowles JF; Harpold AA; Cowie R; Zeliff M; Barnard HR; Burns SP; Blanken PD; Morse JF; Williams MW
Published in: Hydrological Processes
Publication Date: 2015-10-30
Type: Journal Article

Influence of Leaching Solution and Catchment Location on the Fluorescence of Water-Soluble Organic Matter

CU Boulder Authors: Barnard, Holly Rene; McKnight, Diane Marie
All Authors: Gabor RS; Burns MA; Lee RH; Elg JB; Kemper CJ; Barnard HR; McKnight DM
Published in: Environmental Science and Technology (Washington)
Publication Date: 2015-04-07
Type: Journal Article

Complex terrain alters temperature and moisture limitations of forest soil respiration across a semiarid to subalpine gradient

CU Boulder Authors: Barnard, Holly Rene
All Authors: Berryman EM; Barnard HR; Adams HR; Burns MA; Gallo E; Brooks PD
Published in: Journal of Geophysical Research: Biogeosciences
Publication Date: 2015-04-01
Type: Journal Article

Climatic and landscape influences on soil moisture are primary determinants of soil carbon fluxes in seasonally snow-covered forest ecosystems

CU Boulder Authors: Barnard, Holly Rene
All Authors:
Stielstra CM; Lohse KA; Chorover J; McIntosh JC; Barron-Gafford GA; Perdrial JN; Litvak M; Barnard HR; Brooks PD...
  • Stielstra CM
  • Lohse KA
  • Chorover J
  • McIntosh JC
  • Barron-Gafford GA
  • Perdrial JN
  • Litvak M
  • Barnard HR
  • Brooks PD
Published in: Biogeochemistry: an international journal
Publication Date: 2015-04-01
Type: Journal Article

Topography alters tree growth-climate relationships in a semi-arid forested catchment

CU Boulder Authors: Barnard, Holly Rene
All Authors: Adams HR; Barnard HR; Loomis AK
Published in: Ecosphere
Publication Date: 2014-11-01
Type: Journal Article

PARduino: a simple and inexpensive device for logging photosynthetically active radiation

CU Boulder Authors: Barnard, Holly Rene
All Authors: Barnard HR; Findley MC; Csavina J
Published in: Tree Physiology: an international botanical journal
Publication Date: 2014-06-01
Type: Journal Article

The nocturnal water cycle in an open-canopy forest

CU Boulder Authors: Barnard, Holly Rene
All Authors:
Berkelhammer M; Hu J; Bailey A; Noone DC; Still CJ; Barnard H; Gochis D; Hsiao GS; Rahn T; Turnipseed A...
  • Berkelhammer M
  • Hu J
  • Bailey A
  • Noone DC
  • Still CJ
  • Barnard H
  • Gochis D
  • Hsiao GS
  • Rahn T
  • Turnipseed A
Published in: Journal of Geophysical Research: Atmospheres
Publication Date: 2013-09-16
Type: Journal Article

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