Response to Management Strategies in Young-Growth Giant Sequoia Stands at Mountain Home Demonstration State Forest – Remeasurement Twenty Years After Treatment

Author

Joshua Soderlund, California Polytechnic State University, San Luis ObispoFollow

DOI: https://doi.org/10.15368/theses.2011.230
Available at: https://digitalcommons.calpoly.edu/theses/676

Date of Award

12-2011

Degree Name

MS in Forestry Sciences

Department/Program

Natural Resources Management

Advisor

Douglas D. Piirto

Abstract

There is limited information on how young-growth giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz)/mixed conifer stands respond to forest management strategies. An applied research study was initiated in 1989 when 35 approximately 0.1 acre (0.04 hectare) plots were installed in six young-growth giant sequoia/mixed conifer stands. The objective of this study was to determine if there was a difference after 20 years between treatments (a) thin only, (b) thin and prescribe burn, and (c) control in terms of the effect on overstory growth and yield, understory plants, tree regeneration and downed woody debris. Analysis of variance (ANOVA) for cubic-foot growth over 20 years showed significant difference (p = 0.016) between the three treatments. Three diversity indices (richness, evenness, and heterogeneity) showed varied results with environmental factors of slope and elevation major variables affecting plant diversity. Regeneration study showed significant seedlings per acre difference (p = 0.010) between treatment (b) and treatments (a) and (c) with white fir (Abies concolor [Gord. & Glend.] Lindl. ex Hildebr.) the majority at 87%. These collected and analyzed data will benefit Mountain Home Demonstration State Forest along with other forest managers who actively manage giant sequoia stands, whether natural or plantation.