Germination Characteristics of Selected California Oak Species

Abstract

Germination phenology of selected California oaks was studied by planting acorns at three different elevations in the Sierra Nevada (98, 725, 1260 m) and Santa Lucia (23, 560, 1360 m) ranges in California. Two patterns of germination phenology were observed, fast and slow. Quercus dumosa and Q. douglasii germinated (extruded a root) immediately after planting in late October-November at all elevations, exemplifying the fast type. Quercus lobata, Q. chrysolepis, Q. wislizenii and Q. agrifolia germinated in late November-January at the lowest elevation and in January-February at the highest elevation exemplifying the slow type. Quercus kelloggii germinated in February at all elevations. The slow type species germinated during the period of low temperatures of winter at the elevation where they naturally occurred. Stratification treatment on the slow type Q. agrifolia, Q. wislizeniz and Q. chrysolepis acorns showed that longer stratification induced quicker ger- mination after planting, though the time from the beginning of stratification to 100% germination was not reduced by the length of stratification periods. Quercus agrifolia required the shortest time before germination among these three species. Epicotyl dormancy was not found in the California oaks studied.