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Providing evidence to improve practice

Individual study: Composition and Production of California Oak Savanna Seasonally Grazed by Sheep

Published source details

Bartolome J.W. & McClaran M.P. (1992) Composition and Production of California Oak Savanna Seasonally Grazed by Sheep. Journal of Range Management, 45, 103-107


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Other biodiversity: Exclude grazers Mediterranean Farmland

A replicated, controlled study in 1982–1985 in mixed savanna, shrubland, and grassland in northern California, USA, found more plant species and higher plant cover in ungrazed plots, compared to sheep-grazed plots. Plants: More plant species were found in ungrazed plots, compared to grazed plots, in autumn-winter grazed pastures in woodland (8 vs 7 species/50 sample points), but there were no differences with spring grazing or in grassland (data not reported). Plant cover was higher in ungrazed plots, compared to grazed plots, within spring grazed pastures in both woodland and grassland (75–88% vs 67–76% cover), and in autumn-winter grazed pastures in woodland, but not grassland (65% vs 58%). Seven of 15 species of plant had different amounts of cover in ungrazed, compared to grazed plots, in one of four habitat-grazing combinations each time. Methods: Two pastures were established in mixed blue oak Quercus douglasii woodland and grassland areas in 1982 and were grazed by sheep from May until October each year, with autumn or spring grazing. Plants were monitored throughout the year in 20 plots within both woodland and grassland in each pasture, with 75 x 75 cm cages to exclude grazers.