University of Montana ScholarWorks at University of Montana Graduate Student Theses, Dissertations, & Professional Papers Graduate School 1979 Comparative ecology of structural groups : compositional patterns in the Swan Valley forests Montana Bruce P. McCune The University of Montana Follow this and additional works at: https://scholarworks.umt.edu/etd Let us know how access to this document benefits ou.y Recommended Citation McCune, Bruce P., "Comparative ecology of structural groups : compositional patterns in the Swan Valley forests Montana" (1979). Graduate Student Theses, Dissertations, & Professional Papers. 6167. https://scholarworks.umt.edu/etd/6167 This Thesis is brought to you for free and open access by the Graduate School at ScholarWorks at University of Montana. It has been accepted for inclusion in Graduate Student Theses, Dissertations, & Professional Papers by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact [email protected]. COMPARATIVE ECOLOGY OF STRUCTURAL GROUPS: COMPOSITIONAL PATTERNS IN THE SWAN VALLEY FORESTS, MONTANA by Bruce McCune Presented in partial fulfillment of the requirements for the degree of Master of Arts University of Montana 1979 Approved by: Dean, Graduate School Chairman, Board of Examiners Date ' UMI Number: EP36968 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMT DMUMWtation PliblMhiing UMI EP36968 Published by ProQuest LLC (2013). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest' ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106 - 1346 ABSTRACT McCune, Bruce, K.A. March, 1979 B)tanf Comparative ecology of structural groups: compositional patterns in the Swan Valley forests, Montana Director: James R. Habeck The compositional patterns of structural groups in the Swan Valley are very weakly correlated* Evidence in support of this was derived from 1) correlations of dissimilarity matrices, 2) correlations of stand placement on ordinational axes, and 3) comparison of stand groups defined by cluster analysis* dhile one can roughly predict tie composition of one layer based upon the composition of another layer, different structural groups do not change composition across environmental gradients at the same "rate" or in the same pattern* Several reasons for this poor correlation are suggested* Tie various structural groups are controlled by different sets of environmental factors* Rates of biotic response to disturbance differ between structural groups* Essentially random historical factors probably weaken compositional parallels between structural groups* Species richness was greatest in the bryoid layer, decreasing sequentially in higher strata. Species equitability was roughly the same for all structural groups* Beta diversity paralleled species richness for all structural groups except for epiphytes* Epiphytes had a high alpha diversity but low beta diversity* Differences in species diversity between structural groups were related to differences in the degree of environmental differentiation at the levels of each structural group* independently defined types for structural groups were not related by either a simple hierarchy or a one-to-one correspondence* Groups defined by cluster analysis did not correspond strongly with a regional system of habitat types* Hryophytes and lichens are of questionable utility as indicator species for purposes other than air pollution indication* The statement that hryophytes and lichens are more sensitive (narrower tolerance ranges) to their environment than vascular plants is apparently without substantial support except with respect to air pollution* 11 ACKMOWLEDSCXSVTS Joe Antes provided much of the foundation and inspiration for this work. The care and thought with uhcih hi built that foundation is clearly evident to me and is a model for us all. I am honored by and thankful for Joe allowing me the opportunity to build further on his work. I would like to thank Dr. J. R. Habeck, my thesis director, tor his patience and assistance, and a careful review of an early draft of this work. 1 commend him also for his tolerance and permissiveness of my "floating along on a theoretical level", a luxury which I appreciate. The other members of my committee. Or. David E. Bilderback and Dr. Donald 0. Loftsgaarden, both contributed valuable suggestions for improving my thesis. Dr. Bilderback has boen encouraging and supportive throughout my undergraduate and graduate career at the University of Montana. Dr. Loftsgaarden teaches an excellent year-long statistics course which I had the pleasure to take. The lichen work in this study would have suffered greatly had I not been lucky enough to have Dr. Mason E. Hale, Jr. as a teacher during my first summer of field work in the Swan. Besides helping with the names of the local lichens, hi s guidance and savvy in lichenological matters have proven invaluable. I am also indebted to Dr. Charles D. Bird, Dr. Theodore L. Esslinger, Dr. Irwin M. Brodo, Dr. John w, Thomson, Dr. Richard C. Harris, Dr. Lawrence Pike, Mr. Thomas Trana, Roger Rosentreter, i i i and )ennls Dunlap for assistance with problems in lichen identification. In addition. Or. «obert Ireland was kind enough to help me with the problematic moss genus, My thanks also to Patricia Xuir and Roger Rosentreter tor their constructive comments after reading a draft of this thesis. IV TABLE OF CONTENTS ABSTRACT • ............................... ii ACKNOWLEDGEMENTS....................................... H i LIST OF T A B L E S .......................................... Vi LIST OF F I G U R E S ....................................... vii CHAPTER I. INTRODUCTION ................... CHAPTER II. LITERATURE REVIEW ......................... 4 CHAPTER III. STUDY A R E A ................................. 7 Geology ...................7 S o i l s ........................................... 7 Climate ..... ...... 11 Vegetation ..«.•• ........... ...... 11 Anthropogenic influences ...........13 CHAPTER IV. M E T H O D S ...................... 15 Composition sampling ................. ....15 Data analysis ...............20 RESULTS AND D I S C U S S I O N .......... 24 A. Compositional correlations • • . • . * 24 Correlation of dissimilarity matrices . 24 Correlation of stand placement on ordinational axes ...........25 Cluster analysis .............30 Correlations between structural groups in the literature .......... 30 Why are structural groups poorly correlated? ..............37 B. Diversity .................41 Alpha d i v e r s i t y ............ 43 Beta diversity ..............44 Equitability .......... ........ 48 C. Resource utilization by structural groups . 53 D. Implications concerning habitat typing . 59 E. Bryophytes and lichens as indicator species 61 F. Species responses .............63 Epiphytes ................63 Bryoid layer ..............66 G. Host-epiphyte relations ..........69 LITERATURE CITED ...... ......................... 75 APPENDIX A — Bryophytes of the Swan Valley ...... 83 APPENDIX B — Lichens of the Swan Valley .......89 LIST OF TABLES Table Page 2 1. Coefficients of determination (r ) for correlations between dissimilarity values of structural groups.... 26 2 2. Coefficients of determination (r ) for correlations between stand placement on an ordinational axis (moisture) 28 2 3. Coefficients of determination (r ) for correlations between stand placement on an ordinational axis (stand age)........................................................28 4. Species counts, beta diversity, and equitability for each structural group ............................................... 42 2 5. Coefficients of determination (r ) for correlations between species richness of structural groups ............ 52 6. Percent of possible interspecific correlations within and outside of each structural group ............................ 57 V I LIST OF FIGURES Figure Page 1. Map of study area with stand l oc ati on s....................8 2. Geological features of the study area, surface map and east-west section .......................................... 9 3. Monthly averages for temperature and precipitation at Swan Lake Weather S t a t i o n ........................... 10 4. Sampling arrangement used for all s t a n d s .......... 17 5. Scatter diagram and simple regression line for correla­ tion between stand dissimilarity values from the herb and tree l a y e r s .......................................27 6. Cluster analysis of the tree layer compared with stand clusters based on other structural groups ............ 31 7. Cluster analysis of the shrub layer compared with stand clusters based on other structural groups ............ 32 8. Cluster analysis of the bryoid layer compared with stand clusters based on other structural groups . 33 9. Cluster analysis of epiphytes compared with stand clusters based on other structural groups ............ 34 10. Dominance-diversity curve for the total Swan Valley s a m p l e .................................................. 49 11. Dominance-diversity curves for each structural group . 50 12. Constellation diagram