Redacted for Privacy John D
Total Page:16
File Type:pdf, Size:1020Kb
AN ABSTRACT OF THE THESIS OF James R. LaBor for the degree of Master of Science in Entomology presented on March 18, 1002. Title: _Habitat Associations of Riparian Beetles (Coleoptera) at Big Beaver Creek Research Natural Area, North Cascades National Park, Washington. Redacted for Privacy John D. Lattin Abstract approved: Redacted for Privacy " Jeffrey C. Miller Beetle diversity and habitat associations of five prevalent riparian plant communities were examined along the lower reaches of Big Beaver Creek Research Natural Area, North Cascades National Park, Washington. These communities were defined by dominant tree species, and included Alder Swamps, Cedar-Hemlock Forests, Douglas-fir Forests, Gravel Bars, and Willow-Sedge Swamps. Monthly samples were taken with pitfall traps from 10 randomly selected patches per habitat during the snow-free periods (mid-June through mid-October) of 1995 and 1996. A total of 8,179 non-necrophagous beetles was collected, comprising 4 families and 290 species. Four families Staphylinidae (43%), Carabidae (31%), Elateridae (12%), and Anthicidae (6%) accounted for 92% of all individuals. Four families encompassed 65% of all species Staphylinidae (31%), Carabidae (19%), Elateridae (8%),arid Leiodidae (7%) A few species accounted for the majority of individuals. Almost 51% of individuals were found among just 20 species. The five most abundant species in each habitat accounted for 33% (Alder Swamps) to 71% (Gravel Bars) of individuals. Beetle abundance and species composition differed among habitats. Abundance ranged from 1,530 (Cedar- Hemlock Forests) to 2,071 (Alder Swamps) . Abundance per trap per month varied from 16 (Willow-sedge Swamps) to 27 (Alder Swamps) . Species richness was lowest in Douglas- fir Forests (76) and highest in Alder Swamps (119) Simpson's 1-D index ranged from 0.74 (Douglas-fir Forests) to 0.96 (Alder Swamps). Species were categorized as detritivores, fungivores, herbivores, omnivores, predators, and unknowns. Individuals and species of predators and fungivores were generally numerically dominant. Herbivores and omnivores contributed few species and individuals. Gravel Bars virtually lacked fungivores and were the only corrirriunity with many (more than 30%) detrivorous individuals. Two patterns of seasonal abundance were evident. Abundance was highest in June in the two open habitats, Gravel Bars and Willow-Sedge Swamps, thereafter sharply and continuously declining into October. Abundance peaked during September in the forested habitats. Baseline data was acquired about the North Cascades National Park beetle faunas, furthering Park goals to perpetuate habitat and community assemblage integrity. In a larger context, this information has also enriched the understanding of the arthropod faunas of the Pacific Northwest. ©Copyright by James R. LaBonte March 18, 2002 All Rights Reserved Habitat Associations of Riparian Beetles (Coleoptera) at Big Beaver Creek Research Natural Area, North Cascades National Park, Washington. James R. LaBonte A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Presented March 18, 2002 Commencement June, 2002 Master of Science thesis of James R. LaBonte presented on March 18. 2002 APPROVED: Redacted for Privacy CØ,Major Professor, representing Entomology Redacted for Privacy r professor, representing Entomology Redacted for Privacy Ch gy Redacted for Privacy Dean o/Gduate School I understand that my thesis will become part of the permanent collection of Oregon State university libraries. My signature below authorizes release of my thesis to any reader upon request. Redacted for Privacy s R. LaBonte, Author ACKNOWLED1ENTS I owe a great debt to my graduate committee members, especially John D. Lattin and Jeffrey C. Miller. I could not have accomplished this arduous task without their freely given advice, encouragement, time, and effort. Dr. Lattin also generously enabled me to acquire financial support arid resources. Furthermore, he ensured I had ready access to the Oregon State Arthropod Collection to aid my identification efforts. This study could not have been accomplished without the extraordinary efforts of the North Cascades National Park personnel. Reed GiLesne' s great appreciation of the value of arthropod knowledge for the Park and subsequent support made the Big Beaver Creek Riparian Arthropod Survey possible. Sherry Bottoms, Brenda Cunningham, Ron Holmes, and Kathleen McEvoy labored long and hard to place and maintain the pitfall traps. They also collected, processed, mounted, and labeled the thousands of beetle specimens I identified. I could not have completed this task without their unstinting labor, dedication, skills, and enthusiasm. Ron Holmes also provided much of the information for the study area descriptions, refreshed my memory on the study protocols, and supplied the graphics relating to Big Beaver Creek Research Natural Area. Dr. Gregory J. Brenner was not only responsible for much of the study' s design, but provided analytical advice and personal encouragement. above and beyond the call of duty. The Skagit Environmental Endowment Commission provided the funding for the first year of this study. The National Park Service provided personnel and other resources in support of both years of the study, as well as providing funding for the second year of the survey. Oregon State University and the Entomology Department funded my graduate research assistantship through the course of the study and subsequent identification work, as well as providing office space and equipment. As is true of anyone engaged in research requiring insect identification, my debt to insect taxonomists and systematists, living and deceased, is incaluable. Lastly, I wish to thank my friends, colleagues, and co-workers who have encouraged, nudged, prodded, and done all else necessary to keep my nose to this grindstone. TABLE OF CONTENTS Page CHAPTER 1: INTRODUCTION ................................ 1 Section 1: Insects as subjects for biodiversity and ecological studies ................. 1 Section 2: Insects and riparian habitats .......... 3 Section 3: Beetles as subjects for investigating terrestrial riparian habitats .......... 6 Section 4: The rationale for a study of the beetles and other insects of the North Cascades National Park, WA ............. 9 Section 5: Objectives ............................ 10 CHAPTER 2: METHODS .................................... 12 Section1: Characteristics of the study site .....12 Section2: Sampling design and protocols .........18 Section3: Beetle identification and biological data..................................26 Section4: Analysis ..............................29 CHAPTER 3: RESULTS .................................... 32 Section1: Sampling effort .......................32 Section2: Patterns of individuals ...............32 Section3: Species diversity patterns ............52 Section4: Family diversity patterns .............60 Section5: Species-specific patterns.............76 Section6: Trophic patterns ......................81 CHAPTER 4: DISCUSSION ................................. 85 Section 1: Sampling protocols .................... 85 Section 2: Family and species profiles ........... 97 Section 3: Spatial and temporal beetle abundance and diversity .............. 152 Section 4: Applications and future studies......177 LITERATURE CITED ...................................... 188 LIST OF FIGURES Figure Page 1. Location of Big Beaver Creek Research Natural Area in North Cascades National Park, Washington ........................................ 13 2. Oblique aerial view of Big Beaver Creek R.N.A. looking West, up the watershed, from above Ross Lake, North Cascades National Park, Washington ........................................ 15 3. Plant association types of Big Beaver Creek R.N.A., North Cascades National Park, map from Vanbianchi and Wagstaff 1988 ................................. 19 4. Beetle pitfall trap locations, Big Beaver Creek R.N.A., North Cascades National Park, Washington........................................ 24 5. Trap days per habitat ............................. 33 6. Individual beetles per habitat .................... 50 7. Phenology of beetle individuals ................... 51 8. Per cent beetle individuals per month per habitat........................................... 53 9. Beetle species richness per habitat ............... 55 10. Values of the Shannon-Weiner Index per habitat. .56 LIST OF FIGURES (Continued) Figure Paae 11. Values of Simpson' s l-D Index per habitat ......... 58 12. Values of the J'Eveness Index per habitat ........ 59 13. Beetle family richness per habitat ................ 63 14. Overall relative abundance of beetle families ..... 65 15. Beetle family phenology patterns, both years ...... 66 16. Relative family abundance per habitat, both years............................................. 67 17. Beetle family relative abundance per habitat, 1995 .............................................. 69 18. Beetle family relative abundance per habitat, 1996 .............................................. 70 19. Overall relative species richness of beetle families .......................................... 71 20. Overall relative family species richness per habitat........................................... 73 21. Beetle family relative species richness per habitat, 1995 .....................................74 22. Beetle family relative species richness per habitat, 1996.....................................75