Fourteen years of forage monitoring on the California Central Coast shows tremendous variation

Abstract

To better understand forage production (above ground biomass) and precipitation patterns in the Central Coast region of California, the first in a growing network of primary production monitoring sites were established in 2001. The California Central Coast has a Mediterranean climate with cool, moist winters and hot, dry summers, and is dominated by annual grasslands and oak woodlands. By 2010, 12 sites were established across San Luis Obispo County, stratified by different rainfall zones, greater than 635 mm (coastal) to less than 200 mm (inland) for an average year. Forage production was measured each spring. The amount of rainfall varied from site to site, as well as from year to year. Annual rainfall ranged from less than 51 mm to over 1016 mm depending on the site and year. Both annual rainfall and its monthly distribution varied significantly. Total production ranged from a high of 11 201 kg/ha (coastal) to a low of 33 kg/ha (inland). Total annual rainfall and monthly distribution was a major driver of forage production. In addition, residual dry matter (RDM) seemed associated with plant species composition. The percentage of forbs observed at the sites was inversely related to RDM level. This data has helped local ranchers, agricultural commissioners, resource conservation districts and others in making management decisions for rangelands on the Central Coast, ranchers being particularly interested. This data set will also be useful for comparing changes in forage production that may occur due to variation in amount and timing of rainfall in the coming years.

Parent Publication

• Proceedings of the seventh California oak symposium: managing oak woodlands in a dynamic world

Citation

Larsen, Royce; Striby, Karl; Horney, Marc. 2015. Fourteen years of forage monitoring on the California Central Coast shows tremendous variation. In: Standiford, Richard B.; Purcell, Kathryn L., tech. cords. Proceedings of the seventh California oak symposium: managing oak woodlands in a dynamic world. Gen. Tech. Rep. PSW-GTR-251. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 273-281.