Grazing Goats with Virtual Fencing in Timbered Landscapes to Control Unwanted Brush While not Impacting the Growth or Mortality of Coniferous Trees

The purpose of this project was to determine whether grazing goats in timbered landscapes can control unwanted brush encroachment while not having a negative impact on the growth or mortality of desired coniferous tree species, primarily Douglas fir and Redwood. Additionally, the goats were confined to the test areas using the innovative technology of virtual fencing. The desired outcomes were to determine if goats could be utilized to reduce the use of herbicides to control unwanted vegetation and reduce the use of fossil fuel dependent, high-cost mechanical removal of unwanted vegetation.

The study sites included the following: 1) Oregon white oak and California black oak woodlands with heavy Douglas fir tree encroachment, where the fir trees were less than 5 years of age (the goal was to use goats to eat young Douglas fir trees where firs are unwanted); 2) timber ground with redwood trees that were less than 5 years of age threatened by brush encroachment (the goal was to use goats to eat brush but not harm young Redwood trees) and 3) Douglas fir trees under the age of 5 years and threatened by brush encroachment (the goal was to use goats to eat brush but not harm young Douglas fir trees).

Through this research, we found that in the timber ground, the goats do not cause significant damage to desired Douglas fir and Redwood trees but did cause significant damage to unwanted brush species.  In the oak woodland with heavy Douglas Fir encroachment, we found that while there was some damage to young Douglas fir trees in areas where they are not desired, damage was not significant enough to have the desired impact. We also found that there was significant damage to the young Oregon white oaks and the young California black oaks. If our hypotheses are correct, timberland owners could use goats as an ecologically friendly method for treating brush encroachment.

This project provided information for producers on the value of virtual fencing. This showed reduced time and labor, allowing for an efficient and easy method of rotating goats.

The purpose of this project was to determine whether grazing goats in timbered landscapes could control unwanted brush encroachment while not having a negative impact on the growth or mortality of desired coniferous tree species, primarily Douglas fir and Redwood. Additionally, the goats were confined to the test areas using the innovative technology of virtual fencing. The desired outcomes were to determine if goats can be utilized to reduce the use of herbicides to control unwanted vegetation and reduce the use of fossil fuel dependent, high-cost mechanical removal of unwanted vegetation.

The study sites included the following: 1) Oregon white oak and California black oak woodlands with heavy Douglas fir tree encroachment, where the fir trees are less than 5 years of age (the goal was to use goats to eat young Douglas fir trees where firs are unwanted); 2) timber ground with redwood trees that are less than 5 years of age threatened by brush encroachment (the goal was to use goats to eat brush but not harm young Redwood trees) and 3) Douglas fir trees under the age of 5 years and threatened by brush encroachment (the goal was to use goats to eat brush but not harm young Douglas fir trees).