Long-term seedfall, establishment, survival, and growth of natural and planted ponderosa pine in the Colorado front range

Seedfall, natural regeneration establishment, and growth of planted seedlings was observed from 1981 to 2001 under shelterwood and seedtree overstories in a replicated study in ponderoso pine in the Manitou Experimental Forest in the Colorado Front Range. Good seed crops were produced only every 4 to 6 years, With almost no viable seed produced in intervening years. With seed Predation, only 14% of total seedfall was available for germination. Shelterwood overstories containing between 6 and 14 m(2) ha(-1) stem basal area over scarified seedbeds provided optimal conditions for natural seedling establishment. Survival and growth of planted seedlings was much better than that of natural seedlings. However, poor survival and slow initial growth may require many years to establish a fully stocked forest of natural seedlings.