Vegetation change over time in naturally-regenerating Coast Redwood communities

Abstract

VEGETATION CHANGE OVER TIME IN NATURALLY-REGENERATING COAST REDWOOD COMMUNITIES by Kristin K. Hageseth Less than 5% of the Pacific coast's original old-growth coast redwood (Sequoia sempervirens) forests remain and regenerating redwood forests are subject to timber harvest. This research measured native species recovery in stands of different ages compared to old-growth stands in redwood forests in Mendocino County, California. Dominance, density, frequency, and diversity of overstory and understory species were collected over the summer flowering season of 2007 in the Big River Watershed and surrounding regions. ANOVA and regression analyses demonstrated that several stand and understory parameters, including tree density, canopy cover, and understory richness, approached old-growth levels without human intervention. Exotic species were less common in older stands, allowing native plant species to dominate. Whether natives can out-compete more recently introduced non-natives in younger stands requires further study. These findings suggest restoration within regenerating redwood communities of the Big River Watershed may benefit from allowing natural succession.