Hydro Instrument

What is an Environmental Simulation Laboratory?
An Environmental Simulation Laboratory (ESL) allows investigators to conduct mesocosm-scale (larger than small pot or growth-chambers but smaller than large field scale) simulations in an enclosed, climate controlled environment, allowing precise measurement of simulations and manipulation of environmental variables. Conducting simulations on mesocosm-scale allows researchers to move beyond small pot or growth-chamber experiments to more closely examine and study complex interactions between biotic and abiotic processes under controlled conditions. Environmental simulation facilities increase the ability to account for uncertainty in variables present within current ecosystem models.

Soil preparation for invasive species study.Former MS student Brian Sebade preparing soil in one of the lysimeters in preparation for a study on invasive species.

University of Wyoming’s Environmental Simulation Laboratory
The ESL at the University of Wyoming is a large experimental chamber designed to investigate biophysical processes underlying ecosystem dynamics and change. The ESL is a platform for manipulative experimentation using constructed ecosystems; when used in conjunction with complementary field, greenhouse and laboratory research, the ESL facilitates integration of conceptual and quantitative models across different scales of space and time.

The ESL was originally constructed in 1982. During this initial phase of the ESL, the physical shell was constructed consisting of a 7 x 6 m enclosed room with two lysimeter cells that are each 7.3 x 3.0 x 3.0 m deep. HVAC, lighting and temperature/relative humidity controlling hardware was also installed at this time. Research was conducted in the ESL until 1995. Following this period of activity, the ESL had a period of inactivity and became obsolete.

The ESL facility has tremendous potential to advance world-class research at the University of Wyoming in the areas of hydrology, ecology, and earth system science. Application of research from the lab can address both agricultural and disturbed wildland reclamation issues.

Beginning in 2008, funding from the University of Wyoming Office of Research and Economic Development and the Agriculture Experiment Station provided for significant renovations and improvements to the ESL. Heating and cooling systems were replaced and computer and web-based automation of the ESL was installed. These automations allow for remote control and programming of grow lights, temperature and relative humidity while monitoring environmental variables. The ESL plots have been instrumented with TDR (to measure soil moisture), suction lysimeters and mini rhizotron tubes to monitor root structure changes.

Plants growing in 2 ESL lysimeter cells.Plants growing in both lysimeter cells of the ESL as part of an invasive species study.

Currently, the ESL allows investigators to manipulate/measure the following variables:
    Day/Night light cycles
    Precipitation
    Temperature
    Relative Humidity
    Irradiance
    Moisture (using a temporary drip irrigation system)

Management and direction of the ESL is driven by the ESL Steering Committee composed of an interdisciplinary group of faculty from the Department of Ecosystem Science and Management and two external faculty members. The committee oversees development and institution of a management plan and establishes a collaborative structure for participation in ESL research.

Steering committee:
Dr. Ginger Paige, Chair (Ecosystem Science and Management, vadose zone hydrology)
Dr. Ann Hild (Ecosystem Science and Management, shrubland ecosystems, invasion ecology)
Dr. Dave Williams (Ecosystem Science and Management, plant ecophysiology and ecosystem ecology)
Dr. Brian Mealor (Plant Sciences, invasive species ecology, management, and Cooperative Extension)
Dr. Brent Ewers (Botany, ecosystem modeling)
Dr. Pete Stahl (Ecosystem Science and Management, soil ecology, reclamation)

Recent Research
A group of researchers from the University of Wyoming, Department of Ecosystem Science and Management recently completed a research project using the ESL,which examined the response of native grasses to invasive species. Former MS graduate student Brian Sebade, Dr. Ann Hild and Dr. Brian Mealor used the ESL, in concert with two field sites in Wyoming, to determine how S. airoides (a common perennial grass on rangelands in western states) grows when subjected to invasions of Russian knapweed and Canada thistle (two aggressive plant species from Eurasia). Their research will aid in restoration ecology of rangelands throughout the west. This work is published in Ecological Restoration, Sep. 2012 30:3, pp 209-217, "Native Grasses Collected from Invasions Demonstrate Invasion Resistance".

Early rainfall experiments in ESL.Early rainfall experiments in the ESL. Photo taken by Q. Skinner, 1992. The original simulator was not well designed for use in the ESL. Efforts are underway to develop a new simulator.

Moving Forward with the Environmental Simulation Laboratory
The next step is to develop and install a new rainfall simulator for the facility. The original rainfall simulator was not well designed for the ESL and applied rainfall at much higher rates than occur in the northern plains and mountains regions. The addition of new rainfall simulation equipment and method will allow the ESL to manipulate the timing, intensity and duration of rainfall events without over saturating the air in the closed chamber. When coupled with the suite of sensors and hardware already installed, the ESL will allow researchers to measure how a complex system of soils, plants and surface/sub-surface hydrology interact.

The uniqueness of UW’s ESL derives from its potential to address hydrologic processes key to arid and semi-arid systems of the West at this intermediate scale. A fully functioning environmental simulation laboratory, with the addition of a variable intensity rainfall simulator, will allow our researchers to examine hydrologic and ecological mechanisms that occur at a watershed scale in a controlled mesocosm–scale environment.