Effects of Cattle and Deer on Regenerating Mixed Conifer Clearcuts

Abstract

Study began in 1977 at Blodgett Forest Research Station near Georgetown, California, to look at the effects of cattle and deer grazing on mixed conifer plantations. Cattle graze the study area from June 1 until about September 20 each year. Deer are primarily migratory, passing through the study area in March and April and again in October and November each year. The results of treatments on two clearcuts indicate cattle do not harm tree regeneration. Browsing on trees occurred, but no significantly higher numbers of trees were browsed by cattle and deer than by deer alone. White fir seedlings were browsed the most heavily. No trampling damage occurred. Browsing has made no difference in overall tree seedling height or basal diameter between treatments. Brush cover was significantly reduced on grazed treatments on both clearcuts. On 641E, cattle and deer grazing together made a further significant reduction in brush cover over deer grazing alone. The reduction in brush cover has had no effect on tree seedling heights or basal diameters yet. Tree height, basal diameter, and browsing and trampling damage will continue to be monitored, as will brush cover and species composition. Results from this study indicate however, that proper cattle grazing does not harm tree regeneration on young mixed conifer plantations and furthermore cattle grazing may be used as a vegetation management tool in reducing brush on these clearcuts.