#6

Walter D. Koenig

Hastings Reservation, University of California Berkeley, Carmel Valley, CA 93924

Between 1997 and 2015, I exhaustively surveyed all valley oaks (Quercus lobata) on and in the vicinity of Hastings Reservation, upper Carmel Valley, that were saplings or larger. A total of 3420 trees within an area of approximately 800 ha were marked and measured, for an average of 4.27 trees/ha. Ages of trees were estimated based on 85 trees on which we placed dendrometers measuring radial growth over a period of 25 years. Based on these estimates, mean (± SD) age of trees was 159 ± 106 years. Only 3% of trees were estimated to be <50 years old, but 32% were <100 years old, and 9% were >300 years old. Although age estimates are rough, these data suggest that despite appearances, there has been a fair amount of regeneration of this species during recent times, including both the university (1937 – present; 20% of trees) and ranching (1850 – 1937; 49% of trees) eras, while 14% of trees date back to the early European era (1542 – 1769) and ~2% to the Native American era (pre-1542). Observations of saplings tall enough to evade grazing by deer remain scarce in the area; however, the few that have been found have achieved growth out of the seedling stage within only a few years. Given that seedlings can survive in the grassy undergrowth for decades, and that once trees are sufficiently tall to avoid being grazed down by deer they may survive for 500 years or more, it may not be as surprising as thought that trees in the intermediate stage between seedling and sapling are rare.