Year of Award

2017

Document Type

Thesis

Degree Type

Master of Science (MS)

Other Degree Name/Area of Focus

Forestry

Department or School/College

W.A. Franke College of Forestry and Conservation

Committee Chair

Christopher R. Keyes

Commitee Members

Christopher R. Keyes Edwin J. Burke Mark D. Coleman Deborah S. Page-Dumroese

Publisher

University of Montana

Subject Categories

Natural Resources and Conservation

Abstract

Management and restoration practices in even-age ponderosa pine (Pinus ponderosa Lawson & C. Lawson) stands in the Intermountain West can be improved by developing a more thorough understanding of the effects of soil amendment treatments on tree growth and soil properties. Biochar is a charcoal- soil amendment that is created by burning woody biomass in an environment with limited oxygen through a process known as pyrolysis. Biochar has been recommended as a soil amendment for a number of reasons; including increased water and nutrient retention, and building soil aggregates. However, the effects of biochar on temperate forest soils and ponderosa pine growth, both alone and in conjunction with applying fertilizer and retaining masticated woody biomass , are not well studied. The purpose of this study is to explore tree growth and soil physio-chemical effects of biochar, fertilizer, and masticated wood as soil amendments surface applied to mature ponderosa pine trees in western Montana, USA, and discuss the implications of these amendments as practical methods in the western United States. We found that masticated wood had significant effects on 2-year change in DBH and basal area. High-rate biochar amendments improved carbon pools and at 10-20 cm compared to the control. The high-rate biochar and high-rate biochar with fertilizer treatment increased forest floor pH compared to the masticated wood treatment, and the high-rate biochar treatment increased Ca at the 10-20 cm soil depth compared to the fertilizer treatment. The masticated wood treatment increased organic matter compared to fertilizer at the 10-20 cm soil depth. The low-rate biochar treatment increased Mg at the 0-10 cm soil depth compared to the fertilizer treatment. High-rate biochar improved soil moisture by 57%.

Resilience to drought is a topic of increasing concern and research, which necessitates the need for techniques that can evaluate fine-scale growth periods in water limiting environments and shed light on how these periods are altered by restoration treatments. Considering the variety of dendrometer tools, finding the correct one can be a challenge. Automated (electronic) and mechanical (non-electronic) varieties exist, but mechanical dendrometers are expensive and often times more complex and/or precise than the nature of the study necessitates. The Hook and Screw point dendrometer developed by Reineke (1932) and circumferential dendrometers such as Vernier bands and logger tapes are low-cost and practical mechanical alternatives to automated dendrometers. However, limited information exists on the methodological and practical differences among these types. We compared these three dendrometers by measuring intra-seasonal growth of 40 ponderosa pines by collecting diameter measurements on 14 occasions between May 13, and August 3, 2016. We found the Vernier band and the Hook and Screw dendrometer to be comparable in accuracy, closely followed by the Logger tape. The Logger tape is the least expensive option of the three, and Vernier bands are the most expensive. The Hook and Screw is the most time-consuming method. The nature of the project will greatly influence the selection of dendrometer type. Therefore, pros and cons of each option should be weighed against one another to determine the most appropriate choice of tool.

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© Copyright 2017 Haley C. Anderson, Christopher R. Keyes, Edwin J. Burke, Deborah S. Page-Dumroese, and Mark D. Coleman