Specimen Quercus kelloggii survey at Pepperwood Preserve summer 2019

The Dwight Center for Conservation Science at Pepperwood is an ecological institute dedicated to educating, engaging, and inspiring our community through habitat preservation, science-based conservation, leading-edge research, and interdisciplinary educational programs. Our mission is to steward the life and landscapes of the 3,200-acre Pepperwood Preserve and to advance science-based conservation of ecosystems throughout our region and beyond. Purpose of the Study: California black oak, Quercus kelloggii, plays an important role in the lifeways of many indigenous tribes throughout California. Native peoples tend black oaks using Traditional Ecological Knowledge (TEK) to encourage the development and proliferation of specimen oaks. These mature, large, full crowned trees provide a disproportionate amount of ecosystem services, including acorns and habitat, when compared to smaller black oaks. Altered approaches to land management and the cessation of frequent low intensity cultural burns places these specimen oaks at risk from encroachment, forest densification, and catastrophic fire. Procedure: This project is a collaboration between Sonoma State University and the Native Advisory Council of Pepperwood Preserve. Data were collected from 55 specimen black oaks at Pepperwood Preserve in north east Sonoma County. Ecological variables were measured to identify abiotic and biotic drivers of growth habit, scorch height and fire fuels. A certain crown shape is desired by many of today’s traditional gatherers including those represented on the Pepperwood Native Advisory Council. Findings: A hierarchical model approach was used to statistically analyze the effect of encroachment on crown area and live crown ratio. Encroachment was found to have a significant negative effect on both canopy area (p=0.0027) and live crown ratio (p=0.0378). Encroachment did not affect surface and ladder fuel load accumulation since the Tubbs Fire in October 2017 (p>0.05). Neither surface and la