Blue oak, a tree native only to California, is notoriously slow-growing, and its low regeneration rate has prompted concern about the species’ future survival in some areas of the state. We studied the use of fencing (exclosures) to protect seedlings from herbivores and promote faster growth. Placing exclosures 2 and 4 feet in diameter around blue oak seedlings increased their height and canopy area when compared to a control without exclosures. The 4-foot exclosures increased growth (height and canopy area) compared to the 2-foot exclosures. It appeared that exclosures reduced damage from both wild and domestic herbivores, resulting in accelerated growth rates.

In some California locations, the natural regeneration of blue oak is limited by the ability of small seedlings to survive long enough to become larger saplings. This study evaluated the growth and survival of different age classes of seedlings. We found that over a 7-year period, older blue oak seedlings had a much higher survival rate than younger seedlings. Under this study’s conditions, however, the height of younger seedlings increased while that of older seedlings decreased. These results suggest that once a seedling survives approximately a decade and becomes established, it is much more likely to remain alive compared to newly germinated seedlings. Nonetheless, its height growth rate may be extremely slow.

Sixty percent of cattle not dewormed within 4 months of sampling were shedding parasite eggs or larva. The prevalence of shedding varied greatly for different types of internal parasites. Prevalence of shedding for major Strongylate nematodes was 54%; thread-necked intestinal nematodes, 6%; lungworms, 0.8%; coccidia, 18.1%; and tapeworms, 2.1%. Anthelmintic (deworming) treatments lowered prevalence compared to untreated cattle, but the major Strongylate nematodes and coccidia were still sufficiently prevalent that the resulting pasture contamination would restrict the potential success of control programs.