Fire history and stand structure in the Huachuca Mountains of Southeastern Arizona Item Type text; Thesis-Reproduction (electronic) Authors Danzer, Shelley Rae, 1951- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 07/10/2021 13:00:38 Link to Item http://hdl.handle.net/10150/278665 INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. 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Contact UMI directly to order. UMI A Bell & Howell Informadcn Company 300 North Zeeb Road, Ann Aibor MI 48106-1346 USA 313A761-4700 800/521-0600 FIRE HISTORY AND STAND STRUCTURE IN THE HUACHUCA MOUNTAINS OF SOUTHEASTERN ARIZONA by SheUey Rae Danzer A Thesis Submitted to the Faculty of the SCHOOL OF RENEWABLE NATURAL RESOURCES In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE WITH A MAJOR IN WATERSHED MANAGEMENT In the Graduate College THE UNIVERSITY OF ARIZONA 1998 UMI Number: 1389763 UNO Microform 1389763 Copyright 1998, by UMI Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. UMI 300 North Zeeb Road Ann Arbor, MI 48103 7 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under the rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgement the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained by the author. SIGNED:_SIGNED: DvoQQcz^^ APPROVAL BY THESIS COMMITTEE This thesis has been approved on the date shown below; Uj. Dr. Thomas W. Swetnam Date Associate Professor of Dendrochronology 3a# Dr. D. Phillip Guertiiy Associate Professor of Watershed Management Dr. Malcobn J. Zv/olj^sm J Professor of Watershed M^iagement 3 ACKNOWLEDGMENTS I would like to thank Fort Huachuca and the U.S. Forest Service for support of this project and particularly to Sheridan Stone, Wildlife Biologist and Research Coordinator at Fort Huachuca. Without his continued support this project would not have been possible. I would also like to thank my committee members. Dr. Tom Swetnam my major advisor, for taking me into the fire history lab, for instill the firebug in me, and for his continual guidance; Dr. Phil Guertin, for his patience, and fiiendship; and Dr. Malcolm Zwolinski for always having an open door, and an answer to my questions. Chris Baisan helped with every aspect of this project, fi"om fieldwork, to helping me learn dendrochronology, to reviewing copies of this thesis. The many others in the Laboratory of Tree-Ring Research who helped with other aspects of this project fi^om field work, to thesis reviews, to moral support, include Henri Grrissino-Mayer, Kiyomi Morino, RenaAim Abolt, Mark Kaib, Steve Leavitt, James Riser, Jim Speer, Rex Adams, and Robert Shea. I appreciate all of your help and cherish your fiiendship, and wish you all the best in your futures. DEDICATION This thesis is dedicated to my children, Leland and Jola Danzer. Remember always, that you can reach your goals! Go for it! 5 TABLE OF CONTENTS LIST OF FIGURES 8 LIST OF TABLES 9 ABSTRACT 10 1. INTRODUCTION 11 1.1 Overview 11 1.2 Purpose of This Study 12 1.3 Questions Addressed by This Research 13 1.4 Organization of Thesis 15 2. BACKGROUND 16 2.1 The Role of Fire in Ponderosa Pine Forests 16 2.2 Factors aflFecting forest structure 16 2.2.1 Anthropogenic Factors Contributing to Changes in Forest Structure 17 2.2.2 Effects of Climatic Variation on Forest Structure 18 2.3 The Role of Lightning 21 3. METHODS AND MATERIALS 22 3.1 Cultural and Natural Background 22 3.1.1 Physical Setting 22 3.1.2 Geology 22 3.1.3 Climate 23 3.1.4 Vegetation 23 3.1.5. Land-Use History 24 3.1.5.1 Anthropogenic Disturbance 24 3.1.5.1.1 Apaches and fire 24 3.1.5.1.2 Early Euro-American Settlement and Grazing.. 26 3.1.5.1.3 Logging 29 3.1.6 Establishment of the Forest Reserves 30 3.1.7 Site Description and Location 31 3.2 Field Methods 33 3.2.1 Tree-ring Chronology Development 33 3.2.2 Fire History Reconstruction 34 3 .2.3 Stand Structure Characterization 35 3.2.3.1 Stand Density Measurements 37 6 TABLE OF CONTENTS-continued 3.2.3.2 Additional Samples 39 3.3 Laboratory Methods 39 3.3.1 Increment Cores 39 3.3.2 Cross-sections 41 3.4 Statistical Analysis 42 3.4.1 Measures of Central Tendency 43 3 .4.2 Modeling the Fire-Interval Distribution 43 3.4.3 Percentage-Scarred Classes 44 3 .4.4 Period of Best Sample Replication 45 3.4.5 Climate - Fire Pattems 46 3 .5 Analysis of Stand Structure using Tree Age Distributions 47 3.6 Analysis of Tree Species Composition 48 4. RESULTS 49 4.1 Master Tree-Ring Chronology 49 4.2 Fire History 49 4.2.1. Record of Fire Events 49 4.2.2 Fire Event Synchroneity 50 4.2.3 Seasonality of Fires 52 4.2.4 Summary Statistics 55 4.2.5 Superposed Epoch Analysis 59 4.3 Stand Dynamics 62 4.3.1 Stand Structure Analysis 62 4.3.1.1 Tree Age Distribution 64 4.3.1.1.1 Tree Composition and Age Structure on the Fort Huachuca Site 68 4.3.1.1.2 Tree Composition and Age Structure on the Miller Peak Wilderness Site 70 4.3.2 Tree Composition Based on Importance Values 73 4.3.3 Assessment of Inner Rings 75 5. DISCUSSION 76 5.1 Spatial Distribution of Fires 76 5.2 Relationship Between Climate and Fire Synchroneity 79 5.3 Location of Fire Ignitions 81 5.4 Stand Dynamics 83 5.4.1 Pattems of Tree Growth 83 5 .4.2 Effect of Fire on Stand Development 85 5.4.3 Regeneration in FHA 86 7 TABLE OF CONTENTS-continued 5.4.4 Regeneration in MPW 89 5.4.5 Site Productivity and Fire 92 6. CONCLUSIONS 93 6.1 Fire History and Stand Structure 93 6.2 Management Implications and Recommendations 95 ABBREVIATIONS USED IN TEXT 98 REFERENCES 99 8 LIST OF FIGURES FIGURE 1 Map of Garden Canyon study area 32 FIGURE 2 Fire history composite of all fire events for Garden Canyon 51 FIGURE 3 Seasonality of fire events 54 FIGURE 4 Fire interval distributions for entire study site and for upper and lower sites individually 60 FIGURE 5 Superposed epoch analysis of entire period of best sample replication 61 FIGURE 6 Age distribution and species composition for each transect in FHA 65 FIGURE 7 Age distribution and species composition for each transect in MPW 66 FIGURE 8 Cumulative tree age distributions 67 FIGURE 9 Comparison of the Garden Canyon fire history composite with the McClure Canyon fire history composite 78 9 LIST OF TABLES TABLE 1 Summary statistics for Garden Canyon watershed 56 TABLE 2 Temporal analysis of sub-periods of entire GCW, upper and lower sites. 58 TABLE 3 Transect characteristics 63 TABLE 4 Percent species composition by transect 69 TABLE 5 Percent seedling distribution by transect 71 TABLE 6 Measurements of basal area and stand density for each transect 72 TABLE 7 Importance values 74 TABLE 8 Large fires in the Huachuca Mountains since 1970 87 10 ABSTRACT Historically, wildfires in mixed conifer forests of Southwestern sky islands were fi-equent events. Dendrochronological methods were used to reconstruct fire regimes and stand age structures in the Huachuca Mountains of Southeastern Arizona. Pre- settlement {i.e., before ca. 1870) fire intervals ranged fi-om 4 to 10 years, with many fires spreading over the entire sample area. Stand age distributions show an increase in more shade-tolerant tree species.