Ecohydrology Reading Group

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Ecohydrology Reading Group

• Exploring the climate-soil-vegetation system in
  semi-arid landscapes
• New Mexico Tech, Fall 2003

http//www.ees.nmt.edu/vivoni/ecohydrology.html
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What is ecohydrology?

• Baird and Wilby (1999) Ecohydrology is the
  study of plant-water interactions and the
  hydrological processes related to plant growth
• Rodriguez-Iturbe (2000) Ecohydrology seeks to
  describe the hydrological mechanisms that
  underlie ecological pattern and processes
• Nuttle (2002) Ecohydrology is the subdiscipline
  shared by ecological and hydrological sciences
  that is concerned with the effects of
  hydrological processes on the distribution,
  structure and function of ecosystems, and on the
  effect of biological processes on the elements of
  the water cycle
• Dolman (2003) Ecohydrology seeks to understand
  the interaction between the hydrological cycle
  and terrestrial ecosystems

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Hydro-Ecology or Eco-Hydrology?

• Hydro-Ecology used to describe the study of
  ecological and hydrological processes in rivers
  and floodplains.
• Links between hydrology/biology for understanding
  freshwater biota.
• Study of changes in aquatic ecosystems due to
  river flow regime, water quality, channel
  structure.
• Eco-Hydrology used to describe terrestrial plant
  responses and effects on the land-phase of the
  hydrologic cycle
• Relation between ecosystem patterns and soil
  moisture, climate and soil.
• Vegetation role in water balance, energy
  partitioning and surface fluxes.

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Is it a new discipline?

• Plant ecophysiologists have studied water-plant
  physics for many years.
• Population ecologists have tied community
  dynamics to water availability.
• Surface water hydrologists have recognized effect
  of transpiration on water balance.
• Groundwater hydrologists account for impact of
  plants on saturated zone.
• Agricultural engineers deal with plant-soil-water
  relations in crop systems.

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Is it a new discipline?

• Hydrologists have studied vegetation effects on
• Soil erosion and geomorphology
• Evaporation at land surface
• Infiltration and runoff dynamics
• Atmospheric boundary layer
• Albedo and radiation
• Soil moisture rainfall feedback
• Climate change
• Channel hydraulics

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Ecotones and Hydrology

• Plant-soil-water relations starkly different
  among different ecotones
• Wetland hydrology (peats, fens, bogs, marshes)
• Artic hydrology (boreal forests, tundra)
• Tropical hydrology (rain forests, mangrove
  swamps)
• Semi-arid hydrology (grasses-shrublands,
  succulents)
• Mountain hydrology

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Our working definition.

• Ecohydrology in Semi-arid landscapes is defined
  as

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Ecohydrology for Sustainability
Catchment-based recognizes importance Of water
balance and Integration of response
Catchment Water Management
Sustainability of water resources in semi-arid
regions is of primary importance
Hydrology
Ecosystem Science
Nuttle (2002)
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An Ecohydrology Example

• Classical work by Kuczera et al. (1987) describes
  the effect of land-use change on the catchment
  water yield in Melbourne basins.
• Water yield is sensitive to loss of forests
  (Eucalyptus regnans) due to natural wildfires or
  logging.
• As forest regrows, water yield or annual
  streamflow decreases due to recovery of ecosystem
  evapotranspiration.
• Maximum losses at 25 years after disturbance,
  estimated 100 years for full recovery.

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An Ecohydrology Example
Streamflow Yield Time Series
Kuczera Curve
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Reading Group Topic Areas

• Ecohydrology Theory Mathematical Framework for
  Studying Plant-Soil-Water Interactions. (4
  papers)
• Ecohydrology Studies in Semi-arid Landscapes
  Field observations and modeling within
  water-limited ecosystems. (6 papers)
• Ecohydrology Modeling and Remote Sensing
  Numerical simulations and remote observations in
  semi-arid regions. (2 papers)

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Tentative Readings

• Theory
• Rodriguez-Iturbe Ecohydrology A hydrologic
  perspective on climate-soil-vegetation dynamics
• Eagleson Ecohydrology Darwinian Expression of
  Vegetation Form and Function
• Porporato et al. Ecohydrology of
  water-controlled ecosystems
• Van Wijk et al. Tree-grass competition in space
  and time Insights from a simple cellular
  automata model based on ecohydrological dynamics

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Tentative Readings

• Research in Semi-Arid Landscapes
• Wainwright et al. Plants and water in Drylands
• Schlesinger et al. Plant-soil interaction in
  deserts
• Scott et al. The water use of two dominant
  vegetation communities in a semiarid ecosystem
• Walvood et al. Deep arid system hydrodynamics
  Equilibrium states and response times in thick
  desert vadose zones
• Wilcox et al. Runoff from semiarid ponderosa
  pine hillslope in New Mexico
• Scott et al. Modeling multiyear observations of
  soil moisture recharge in the semiarid Southwest

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Tentative Readings

• Modeling and Remote Sensing
• Cayrol et al. Grassland modeling and monitoring
  with SPOT-4 during SALSA Experiment
• Reynolds et al. Effects of long-term rainfall
  variability on evapotranspiration and soil water
  distribution in Chihuahuan Desert

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Course Design

• Discussion of individual articles lead by a group
  member each week.
• Week 2 Discussion on Rodriguez-Iturbe (2000)
  lead by Enrique
• Each member is responsible for reading each
  article for group discussion.
• We will develop notes from each reading for
  future reference.
• We will contribute to making an Ecohydrology
  Research Agenda at New Mexico Tech.
• Basis for collaborative research and proposals.

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Goals and Objectives

• Familiarize ourselves with on-going ecohydrology
  research through literature review.
• Focus on semi-arid regions where water-limitation
  is crucial for plant survival.
• Tailored to each participant level (e.g. from
  undergraduate to graduate and to faculty)
• Form basis for creative thought and critical
  review of topic areas.
• Contribute to Ecohydrology Research Agenda