- Contributor: Elise Gornish
The winter annual grass Taeniatherum caput-medusae (L.) Nevski, commonly known as medusahead, is one of the most dominant invasive range species in the West. Despite a broad understanding of medusahead impacts we have limited understanding of how environmental conditions and management strategies influence medusahead population dynamics. This insight is key if we are to ultimately forecast changes in medusahead abundance and spread under various conditions. Using periodic matrix models, we are investigating how density and habitat type (grassland vs. oak woodland) and defoliation influence population dynamics. First year results show strong density dependence ranging from positive to negative depending on time of year with oak woodland habitat suppressing medusahead population growth much more than open grassland.
Check out the video for more!
- Author: Ben Granholm
At the end of May trained SFREC staff along with members of Cal Fire conducted a prescribed burn to manage vegetation on the center. There are many advantages to conducting a burn rather than other management practices. These advantages include the ability to kill off weed-seed violations and remove any unwanted species that threaten the native species in an ecosystem. However, with the current air-quality regulations and state of drought, a prescribed burn can be difficult to get approved this time of year. SFREC had a burn scheduled last week that was postponed to a later date because of these difficulties.
The burned area will be used to look at the utility of spring burns to manage vegetation and eliminate invasive species such as medusa head and star thistle as well as look at the success rate of the native species after the invasion and burn.
We thank the members of Cal Fire for working with our staff to conduct a safe and successful burn.
- Author: Jeremy James
- Author: Maddison Easley
Small black dots can be seen from afar amidst the Lower Ranch fields at the Sierra Foothill Research & Extension Center. Upon closer inspection, those spots morph into fuzzy, knob-kneed, curious little calves that are sure to insight many cries of “Awwwwe!” from visitors.
However, to a seasoned rancher those cute calves are a testament to the worthwhile blood, sweat, and tears that were shed leading up to a successful delivery. A healthy calf is the ultimate goal of any cow-calf manager, but once those critters finally do take their first breaths, the work has just begun…again.
In the Sierra Foothills, healthy calves signify a greater achievement - the triumph over a bacterial disease called epizootic bovine abortion (EBA). Extensive research has been conducted on this economically devastating problem, with annual losses in the range of 45,000 to 90,000 calves in the state of California alone.
EBA is commonly termed “foothill abortion” due to the regional outbreaks affecting only foothill, semi-arid and mountainous ranges of California, parts of Nevada, and southern Oregon. Through studies and research efforts by scientists associated with UC Davis, known information and management strategies have made slow, yet very significant progress since the recognition of EBA in the 1960's. For example, the culprit of EBA has been identified as the soft-shelled tick Ornithodoros coriaceus – explaining the climatic limitations of the disease so far.
Faculty and site conditions at SFREC have provided the ideal atmosphere for useful data collection. Staff Research Associate Nikolai Schweitzer is charged with the task of checking the irrigated fields daily for signs of aborted fetuses.
“It's important to be highly aware and check the fields at least twice a day. The scavengers in this area move in quickly!” said Schweitzer.
All aborted fetuses are transported to UC Davis for additional lab tests to accurately determine if EBA was the cause of death. Infected cows do not show signs of the disease during pregnancy because the bacteria is transmitted to the immature fetus where it proliferates and results in a late-term abortion.
Fortunately, the outlook for the candidate vaccine is very promising. The release of an effective EBA vaccine in the future will save ranchers countless hours of disappointment and headaches, while beefing up their worn wallets! This will be another significant feat for the cattle industry, SFREC, UCANR, and animal scientists in the West.
- Author: Maddison Easley
Water - the focus of countless issues, headlines, and studies - is arguably a more precious resource than gold.
Individuals involved with the University of California's Division of Agriculture and Natural Resources are actively evaluating management practices to ensure and develop water-wise irrigation methods. At the Sierra Foothill Research and Extension Center, many research projects have focused on water quality, runoff, and irrigation efficiency. A current project led by Livestock Farm Advisor Larry Forero monitors surface runoff and soil moisture content in flood irrigated pastures at SFREC.
Gold may be in high demand - with the current value exceeding $1320 per ounce - but once water becomes scarce, it is truly priceless. By taking the initiative to research innovative water management practices and develop a better understanding of sustainable irrigation methods, SFREC and the entire UCANR division are enabling water availability and conservation for the future.