Growth responses of giant sequoia to fire and climate in Sequoia and Kings Canyon National Parks, California

Abstract

I investigated the radial growth responses of giant sequoia (Sequoiadendron giganteum) to fire in Sequoia and Kings Canyon National Parks. Mean ring-width indices were used to compare growth between burned and unburned sites and between four different levels of fire severity. Mean growth increased in all sites in the postburn periods relative to pre-burn periods. Favorable climatic conditions contributed to these growth increases. Post-fire mean growth for four out of seven burn sites, however, was significantly higher than that on unburned sites. In general, lower severity fire resulted in lower magnitude growth increases than those observed after moderate to higher severity fire. Very high severity fire that caused extensive foliage damage resulted in post-burn growth suppressions. Post-fire growth increases occurred whether post-burn years were wet or dry. Fire effects on site conditions may moderate climatic impacts on sequoia growth. Giant sequoia seedling establishment was favored by a combination of high severity fire and wet post-burn conditions.