John Knowles

INSTAAR Affiliate

  • Research Ecologist, USDA ARS Southwest Watershed Research Center



  • PhD: University of Colorado, Boulder, 2015
  • MA: University of Colorado, Boulder, 2009
  • BA: Vassar College, 2003

Contact Information

(Office) 303 735-5688


Ecohydrology; Ecosystem Ecology; Micrometeorology; Watershed Hydrology

Research Interests

My research incorporates eddy covariance, isotopic, geographic information systems (GIS), remote sensing, and modeling techniques to investigate the multi-scale impacts of climate change and management practices on water and nutrient cycling at Earth’s surface.




John Knowles, Russell L. Scott, Rebecca L. Minor, Greg A. Barron-Gafford 2020: Ecosystem carbon and water cycling from a sky island montane forest. Agricultural and Forest Meteorology, 281: 107835. DOI: 10.1016/j.agrformet.2019.107835

John Knowles, Russell L. Scott, Joel A. Biederman, Peter D. Blanken, Sean P. Burns, Sabina Dore, Thomas E. Kolb, Marcy E. Litvak, Greg A. Barron-Gafford 2020: Montane forest productivity across a semi-arid climatic gradient. Global Change Biology, 26(12): 6945-6958. DOI: 10.1111/gcb.15335

John Knowles, Peter D. Blanken, Corey R. Lawrence, Mark W. Williams 2019: Evidence for non-steady-state carbon emissions from snow-scoured alpine tundra. Nature Communications, 10(1): 1306. DOI: 10.1038/s41467-019-09149-2

Ravindra Dwivedi, Chris Eastoe, John Knowles, Lejon Hamann, Tom Meixner, Paul A. Ferré, William E. Wright, Guo-Yue Niu, Rebecca Minor, Greg A. Barron-Gafford, Nate Abramson, Bhaskar Mitra, Shirley A. Papuga, Michael Stanley, Jon Chorover 2021: An improved practical approach for estimating catchment-scale response functions through wavelet analysis. Hydrological Processes, 35(3): e14082. DOI: 10.1002/hyp.14082

Greg A. Barron-Gafford, John Knowles, Enrique P. Sánchez-Cañete, Rebecca L. Minor, Esther Lee, Leland Sutter, Newton Tran, Patrick Murphy, Erik P. Hamerlynck, Praveen Kumar, Russell L. Scott 2021: Hydraulic redistribution buffers climate variability and regulates grass-tree interactions in a semiarid riparian savanna. Ecohydrology, 14(3): e2271. DOI: 10.1002/eco.2271

Housen Chu, Xiangzhong Luo, Zutao Ouyang, W. Stephen Chan, Sigrid Dengel, Sébastian C. Biraud, Margaret Torn, Stefan Metzger, Jitendra Kumar, M. Altaf Afrain, John Knowles, Donatella Zona, [70 total authors] 2021: Representativeness of eddy-covariance flux footprints for areas surrounding AmeriFlux sites. Agricultural and Forest Meteorology, 301-302: 108350. DOI: 10.1016/j.agrformet.2021.108350

Russell L. Scott, John Knowles, Jacob A. Nelson, Pierre Gentine, Xi Li, Greg Barron-Gafford, Ross Bryant, Joel A. Biederman 2021: Water availability impacts on evapotranspiration partitioning. Agricultural and Forest Meteorology, 297: 108251. DOI: 10.1016/j.agrformet.2020.108251

Julia C. Yang, Troy S. Magney, Dong Yan, John Knowles, William K. Smith, Russell L. Scott, Greg A. Barron-Gafford 2020: The photochemical reflectance index (PRI) captures the ecohydrologic sensitivity of a semi-arid mixed conifer forest. Journal of Geophysical Research: Biogeosciences, 125(11): e2019JG005624. DOI: 10.1029/2019JG005624

Patrick C. Murphy, John Knowles, David J. P. Moore, Kevin Anchukaitis, Dan L. Potts, Greg A. Barron-Gafford 2020: Topography influences species-specific patterns of seasonal primary productivity in a semiarid montane forest. Tree Physiology, 40(10): 1343-1354. DOI: 10.1093/treephys/tpaa083

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Theses & Dissertations



Past Courses

  • GEOG 1001: Climate and Vegetation This course will provide you with an introduction and overview of Earth’s vegetation and climate system. Throughout the course, we will emphasize the many linkages and feedbacks between Earth’s living biota and climate, and we will discuss the global distribution of vegetation. Topics will include radiation, temperature, winds and pressure, the water cycle, vegetation, and climate change.
  • GEOG 1011: Landscapes and Water This course will introduce you to the sciences of hydrology and geomorphology, which are two branches of physical Geography that deal with Earth surface processes. In the first few weeks, we will discuss deep-seated geologic processes, which build mountain ranges and volcanoes, and generate earthquakes along plate boundaries. For the remainder of the semester, we will focus on near-surface processes that serve to modify and wear down Earth’s surface, such as weathering, soil erosion, landslides, floods, and glaciation.
  • GEOG 3251: Mountain Geography Mountain geography presents a geographic overview of major mountain ranges in the world, and provides an introduction to the physical, biological, and anthropogenic processes that shape these mountain environments. Changes in the mountain environment caused by humans will be evaluated and current strategies to minimize these impacts will be discussed.
  • GEOG 3601/ENVS 3600/ATOC 3600: Principles of Climate This course describes the basic components of the climate system: the atmosphere, ocean, cryosphere, and lithosphere. A specific focus is placed on the basic physical processes that determine climate and the link between the components of the climate system, including the hydrologic cycle and its role in climate, climate stability, and global change.
  • GEOG 4241/GEOL 4241: Principles of Geomorphology This course covers glaciers, weathering, tectonic geomorphology, slope processes, rivers, hillslope hydrology, and the effects of wind. The material is based in physics and chemistry, and therefore you must be prepared to think quantitatively. Laboratory exercises will provide experience in making measurements and going through simple calculations relevant to surface processes.
  • GEOG 3511: Introduction to Hydrology The objective of this course is to provide a balanced view of hydrology that includes a description of the physical processes of precipitation, evapotranspiration, snowmelt, infiltration, groundwater and surface water runoff, and a coherent presentation of the theories and techniques that are used in practice.