Improving Gambel Oak Ranges for Elk and Mule Deer by Spraying with 2,4,5-TP

Abstract

Areas of Gambel oak vegetation in northwestern Colorado were sprayed with 2,4,5-TP to evaluate effects on plant abundance and deer and elk use 2 and 5 years after treatment. Grasses increased in abundance 44% after 2 years; shrubs and forbs decreased 29 and 15%, respectively. After 5 years, grasses and shrubs were 17 and 7%, respectively, above pretreatment levels of abundance; forbs were 4% below. Total vegetation on the treated area decreased 4% after 2 years, while a 5% increase was recorded after 5 years. Elk and deer use on the sprayed area increased 73 and 16%, respectively, 2 years after spraying. After 5 years elk use was 11% above pretreatment levels and deer use was 21% below. If 2,4,5-TP is used to spray Gambel oak to modify plant composition and increase elk or deer use, the area should be resprayed at 3-year intervals, indefinitely, if the improved situation is to be maintained.