Survey of Quercus Kelloggii at Pepperwood Preserve: Identifying Specimen Oaks to Reimplement Traditional Ecological Knowledge and Promote Ecosystem Resilience
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Survey of Quercus kelloggii at Pepperwood Preserve: identifying specimen oaks to reimplement traditional ecological knowledge and promote ecosystem resilience by Cory James O’Gorman A thesis submitted to Sonoma State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Biology Committee Members: Dr. Lisa Bentley Dr. Daniel Crocker Dr. Margaret Purser 4/21/2020 i Copyright 2020 By Cory J. O’Gorman ii Authorization for Reproduction of Master’s Thesis I grant permission for the print or digital reproduction of this thesis in its entirety, without further authorization from me, on the condition that the person or agency requesting reproduction absorb the cost and provide proper acknowledgment of authorship. DATE: ___5/4/2020_______________ ________Cory J. O’Gorman_______ Name iii Survey of Quercus kelloggii at Pepperwood Preserve: identifying specimen oaks to reimplement traditional ecological knowledge and promote ecosystem resilience Thesis by Cory James O’Gorman Abstract 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: 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 ladder fuels nor encroachment variables significantly affected scorch height on the specimen oaks (p>0.05) following the Kincade Fire. Conclusions: This work will allow for the reimplementation of TEK to nurture specific specimen black oaks at Pepperwood Preserve at the discretion of the Native Advisory Council and increase access to land and culturally significant plants by local tribal communities. This has far reaching implications on tribal peoples’ well-being, their ability to engage in cultural practices, and ecosystem health. MS Program Biology Sonoma State University Date: 4/21/2020 iv Acknowledgments I would like to thank the Native Advisory Council of Pepperwood, Clint McKay, Lucy McKay, Dr. Brenda Flyswithhawks, Tek Tekh Gabaldon and L. Frank Manriquez for welcoming me into this project and at their table, and everything they have shared with me. Thank you to the Pepperwood staff for their continued support throughout the project. I would like to give a special thanks to the Honorable Ron Goode and Dirk Charley for sharing their expertise and cultural wisdom, and inviting me to the cultural burn in Mariposa. My wonderfully talented advisor Dr. Lisa Bentley for teaching me so much and challenging me throughout this process, Dr. Margaret Purser, who truly made this interdisciplinary project possible, for all of her guidance along the way, and Dr. Daniel Crocker for all the help with statistics and figures. Finally, I would like to thank my lab mates and everyone who came into the field, and a special thanks to Kylie Kiech for helping from start to finish on so many aspects of the project. v Table of Contents Chapter Page I. Introduction…………………………………………………………………………………………………….….…....1 II. Methods…………………………………………………………………………………………………………....…….7 Study site…………………………………………………………………….…………………………………...7 Location and determination of specimen oaks…………………………..……………………..8 Ecological field measurements……………………………………………….………………………...8 Statistical analysis: hierarchical model approach………………………….…………………..10 II. Results……………………………………………………………………….…………………………………………....11 Plot composition and structure………………………………………………………………………...11 Encroachment on crown area……………………………………………….…………………………..12 Encroachment on live crown ratio..…………………………………………………………………..13 Surface and ladder fuels………………………………..………………………………………………….13 Scorch height…………………………………………………………………………………………………….13 III. Discussion…..……………………………………………………………………………………………………………15 Overall goal of tending trees and incorporating TEK specifically at Pepperwood……………………………………………………………………………………………………..15 Understanding the effects of encroachment on tree and stand structure at Pepperwood………………………………………………………………………………………….………….15 Understanding the effects of wildfire on tree structure…………………………………….16 Recommendations for management in light of TEK………………………………………….18 Management implications for regional tribal communities………………………………20 IV. Works Cited……………………………………………………………………………………………………………23 vi List of Figures Figure Title Page Encroachment on crown area………….…………………………………………………………………………14 vii 1 Introduction Oak woodlands are one of California’s most iconic ecosystems. These communities contain the highest documented species richness of any California ecosystem with over 330 species of animals depending on support from oaks for at least one life stage (Barrett and Plumb 1980). California black oak, Quercus kelloggii, has the widest distribution and altitudinal range of all the oaks in these ecosystems, extending over approximately 780 miles from Eugene, Oregon to Baja (McDonald et al. 1990). Black oak is a keystone species that provides numerous ecosystem services (Crotteau et al. 2015; Long et al. 2017). For example, black oaks provide habitat for the rare Pacific Fisher, Pekania pennanti spp. pacifica, through cavities in the trunk or dead branches. Black oaks also provide habitat and food for other native fauna including deer, black bear and band-tailed pigeons (McDonald et al. 1990, Koenig et al. 1994, Long et al. 2015, 2017). Black oaks are also considered to be a “cultural keystone” species for their role in indigenous peoples’ diet, ceremonial practices and daily life (Garibaldi and Turner 2004, Long et al. 2016, 2017). As a food source, black oak acorns are highly desired for their flavor, high oil content, ease to deshell, pound and grind, as well as their storability (Anderson 1993, Lee 1998, Long et al. 2016). The act of gathering acorns is vital for cultural transmission and remains an important social activity for many tribal members (Anderson 2005, Long et al. 2016). Black oak acorns are incorporated into dances, rituals and ceremonies and the species appears in native mythology (Long et al. 2016). Due to 2 their cultural importance, native peoples throughout present day California use Traditional Ecological Knowledge (TEK) to create ecological conditions that favor black oak survival and persistence while treating the ecosystem as a whole (Anderson 2005, Lake et al. 2017, Long et al. 2017). TEK has been described as “a cumulative body of knowledge, practice, and belief, evolving by adaptive processes and handed down through generations by cultural transmission, about the relationship of living beings (including humans) with one another and with their environment” (Berkes et al. 2000). These cultural practices are much more than land stewardship techniques, but rather, integral pieces of indigenous culture which reflect a reciprocal relationship with the land. Despite its vast range, drought adaptability and cultural significance, black oaks are threatened by climate change and altered approaches to land management. Low rainfall in California from 2012-2016 caused severe drought and higher than average temperatures, leading to intense plant water stress and tree mortality (Asner et al. 2016). Unfortunately, climate change projections for California suggest dry-season climatic water deficits, drought risks and an increase in fire probabilities (Chornesky et al. 2015), making the region more susceptible to devastating environmental impacts and massive carbon emissions. In addition to climate change impacts, changes in land stewardship techniques due to the cessation of native engagement with the land across much of California has 3 resulted in less habitat for many native plants and places entire ecosystems at risk of collapse (Kimmerer and Lake 2001, Anderson 2005, Codding and Bird 2013). Native Californians have been dispossessed of their traditional lands and their ability to maintain cultural practices and autonomy stifled through subjugation of racist land use laws, as well as outright genocide (Fenelon and Trafzer 2014, Norgaard 2014, Madley 2016). Indigenous peoples’ ability to practice their culture depends on access to the land and the continued resilience of the plants and plant communities on which they have depended for millennia (Berkes et al. 2000, Anderson 2005, Garibaldi and Turner 2004, Long et al. 2016, 2017). Tended landscapes may be considered cultural keystone places which play crucial roles in the shared history, identity and memory of indigenous people