Reaction to Competition
Tanoak generally is classed as tolerant of shade (22). It is aggressive and well fitted by its reproductive habits, vigor, and shade endurance to compete for possession of the ground (31). Although tanoak can endure considerable shade throughout life, it grows best with top light. In conifer stands where it has an equal opportunity to grow, it can compete with redwood and Douglas-fir (23). In dense stands, natural pruning produces long clear boles.
Tanoak can reproduce from both seed and sprouts and thus maintain itself in a wide range of forest types and successional stages. Under dense conifer stands it is often abundant (610 to 5300 stems/per hectare; 240 to 2,100/acre) (29), and continuous input of new seedlings can maintain or increase stocking (13). After the overstory is logged or burned, even small tanoaks can respond, and tanoaks of all sizes may dominate disturbed areas. Because of its ability to respond to disturbance and to reproduce and grow in the shade, it is considered to be a climax species in Douglas-fir, redwood, and mixed-conifer forests.