Oak Seedlings Can Be Established on Grazed Rangelands
The IssueFor nearly 100 years, there has been concern that several native California oak species are not regenerating adequately to sustain populations. Inadequate regeneration could adversly affect woodlands, resulting in conversions to shrub fields or bare pastures. A principal factor believed to significantly contribute to poor oak regeneration in California is livestock grazing. Since approximately 80% of California's oak woodlands are privately owned and the principal activity on many of these lands is livestock grazing, it is vital to understand how oaks can be regenerated in the presence of livestock. Such information will help ensure that our oak woodlands remain healthy and productive.
What Has ANR Done?The UC Integrated Hardwood Range Management Program (IHRMP) has conducted several research studies at the Sierra Research and Extension Center to identify grazing management practices and seedling protection techniques that will allow outplanted oak seedlings to survive from the seedling to the sapling stage, even in areas grazed by cattle. Studies have examined whether or not individual seedlings can be successfully protected in grazed pastures; how the timing of grazing affects damage; how tall seedlings must be before livestock can be reintroduced into planted areas; and how livestock movement and congregation patters can be impacted by water placement, supplements and salt blocks.
Oaks and Livestock Can Be Raised SimultaneouslyResearch suggests that cattle will damage both planted and “volunteer” oaks, but that damage varies by season, with less damage during the winter when deciduous oaks don’t have leaves. Damage is also influenced by stocking density (the number of cattle per unit area) and cattle distribution patterns. Unprotected oak saplings appear relatively resistant to cattle damage in low- to moderately-grazed pastures if they are at least 6.5-ft tall and smaller seedlings can be protected with fencing or individual protectors.
These and other steps can greatly enhance the chances for regeneration success. Together, these findings suggest that in some situations cattle and oaks can be raised simultaneously if grazing management practices are tailored to minimize damage, or seedlings are physically protected from animals.
Supporting Unit:Integrated Hardwood Range Management Program
Doug McCreary, Natural Resources Specialist
Sierra Foothill Research and Extension Center
8279 Scott Forbes Road, Browns Valley, CA 95918 phone: 530 639-8807
fax: 530 639-2419