National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science Bryophyte Floristics and Ecology in Grand Canyon National Park Natural Resource Technical Report NPS/SCPN/NRTR—2012/602 ON THE COVER Left: Widforss Trail, North Rim, Grand Canyon NP Right top: Grimmia anodon and Grimmia alpestris (dry) on Kaibab Limestone Formation Right middle: Syntrichia ruralis (wet) on base of a one-seed juniper trunk, Rim Trail, South Rim, Grand Canyon NP Right bottom: Syntrichia ruralis and Grimmia anodon (wet) on Kaibab Limestone Formation Photography by Theresa Clark Bryophyte Floristics and Ecology in Grand Canyon National Park Natural Resource Technical Report NPS/SCPN/NRTR—2012/602 Theresa Ann Clark Northern Arizona University Department of Biological Sciences P.O Box 5640 Flagstaff, AZ 86001-5640 July 2012 U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Fort Collins, Colorado The National Park Service, Natural Resource Stewardship and Science office in Fort Collins, Colorado publishes a range of reports that address natural resource topics of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and envi- ronmental constituencies, and the public. The Natural Resource Technical Report Series is used to disseminate results of scientific studies in the physical, biological, and social sciences for both the advancement of science and the achievement of the National Park Service mission. The series provides contributors with a forum for displaying comprehensive data that are often deleted from journals because of page limitations. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientif- ically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. This report received formal peer review by subject-matter experts who were not directly involved in the collec- tion, analysis, or reporting of the data, and whose background and expertise put them on par technically and scientifically with the authors of the information. Views, statements, findings, conclusions, recommendations, and data in this report do not necessarily reflect views and policies of the National Park Service, U.S. Department of the Interior. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U.S. Government. This project was funded by the National Park Service through the Colorado Plateau CESU Cooperative Agree- ment #H1200-004-0002 (Task NAU-227). This report is available from Southern Colorado Plateau Network (http://www.nature.nps.gov/scpn/products. cfm), and the Natural Resource Publications Management Web site (http://www.nature.nps.gov/publications/ nrpm/) on the Internet. Please cite this publication as: Clark, T. A. 2012. Bryophyte floristics and ecology in Grand Canyon National Park. Natural Resource Technical Report NPS/SCPN/NRTR—2012/602. National Park Service, Fort Collins, Colorado. NPS 113/115895, July 2012 ii Bryophyte Floristics and Ecology in Grand Canyon National Park Contents Figures ............................................................................................................................................................................. v Tables .............................................................................................................................................................................. ix Errata...............................................................................................................................................................................xi Abstract ........................................................................................................................................................................ xiii Acknowledgments ........................................................................................................................................................ xv 1 Introduction ................................................................................................................................................................. 1 1.1 Background: Ecological role of bryophytes in the arid Southwest ............................................................................. 1 1.2 Gaps in understanding bryophyte floristics of Grand Canyon National Park ............................................................. 3 1.3 Gaps in understanding rock bryophyte ecology in the forests of Grand Canyon National Park.................................. 3 2 Study area: Grand Canyon National Park .................................................................................................................. 7 2.1 Location .................................................................................................................................................................. 7 2.2 Climate .................................................................................................................................................................... 7 2.3 Geology ................................................................................................................................................................... 9 2.4 Vascular plant communities ................................................................................................................................... 10 2.4.1 Riparian and wetland habitats ....................................................................................................................... 10 2.4.2 Desert scrub and grassland ............................................................................................................................ 11 2.4.3 Pinyon-juniper woodland ............................................................................................................................... 12 2.4.4 Ponderosa pine forest .................................................................................................................................... 12 2.4.5 Mixed conifer forest ....................................................................................................................................... 12 2.4.6 Subalpine forest ............................................................................................................................................. 13 2.5 Previous bryological work in Grand Canyon National Park ...................................................................................... 13 3. Bryophyte floristics in Grand Canyon National Park ............................................................................................. 15 3.1 Objectives ............................................................................................................................................................. 15 3.2 Methods ................................................................................................................................................................ 15 3.2.1 Historic collection review ............................................................................................................................... 15 3.2.2 Modern floristic collecting .............................................................................................................................. 15 3.2.3 Floristic analysis .............................................................................................................................................. 18 3.3 Results ................................................................................................................................................................... 18 3.3.1 Historic collection review ................................................................................................................................ 18 3.3.2 Modern collections ......................................................................................................................................... 21 3.3.3 Floristic results ................................................................................................................................................ 21 3.3.4 Catalog of Accepted Taxa ............................................................................................................................... 27 3.3.5 Catalog of Excluded Taxa ................................................................................................................................ 49 3.4 Discussion .............................................................................................................................................................. 51 3.4.1 Distribution of bryophytes in Grand Canyon National Park .............................................................................. 51 3.4.2 Diversity of bryophytes in Grand Canyon National Park ................................................................................... 51 Contents iii 3.4.3 Common species and typical habitats of bryophytes in the six collection regions of Grand Canyon National Park .............................................................................................................................................. 54 3.4.4 Common bryophyte species of riparian and wetland habitat in Grand Canyon National