Water Use by Eastern Redcedar
Increasing concern about limited water supplies for human use and our natural resources has heighted interest in water demands of eastern redcedar trees, which are rapidly encroaching in the grasslands of the Great Plains and Midwest.
The Research Approach
We conducted intensive measurements on trees and soil and measured water flowing off two watersheds —a grassland and a grassland encroached by eastern redcedar trees.
Soil Water Content
We measured soil water content at 15-minute intervals on the grassland and the grassland encroached by Red Cedar trees. Eighteen soil water stations were evenly split between the two watersheds.
Water Use by Individual Trees
Instrumentations for measuring water use by individual trees was installed to measure sap flow. We measured water use by trees of different sizes and trees grown in open-canopy and closed-canopy stands.
Watersheds were equipped with an H flume, stage recorder, datalogger, rain gauge, and sensors for solar radiation, wind speed & direction, soil temperature, air temperature, and relative humidity.
Soil water content is lower where Red Cedar trees have encroached Red Cedar trees used water year-round, averaging 0.5-21 gallons/day — more for larger trees in less dense stands
Only heavy rains break through the tree canopy to the ground. Rain captured by trees does not run off to replenish streams or groundwater.
Red Cedar trees can thrive in various soil types and tolerate extreme temperatures and drought, but young Red Cedars area no match for fire.
Of particular interest:
NREM 2884: How Eastern Redcedar Encroachment Affects the Water Cycle of Oklahoma Rangelands
WREC 101: Eastern Redcedar Encroachment and Water: Update of 2010 Research
Oklahoma Water Resources Center
Researchers in the department of Natural Resource Ecology and Management measured water use and interception of redcedar trees in stands of different densities to learn how redcedars affect the quality and quantity of water falling in the watershed.
See what they found inside this leaflet.
These NREM department faculty are part of the Oklahoma Water Resources Center and the Division of Agricultural Sciences and Natural Resources.
Researchers: Chris Zou, Rodney Will, Donald Turton, and David Engle
Department of Natural Resource Ecology & Management and
The Oklahoma Water Resources Center
Oklahoma State University