National Park Service U.S. Department of the Interior Natural Resource Program Center Terrestrial Vegetation and Soils Monitoring at Fort Bowie National Historic Site 2008 Status Report Natural Resource Technical Report NPS/SODN/NRTR—2010/368 ON THE COVER Fort Bowie National Historic Site, Arizona. NPS/J.A. Hubbard. Terrestrial Vegetation and Soils Monitoring at Fort Bowie National Historic Site 2008 Status Report Natural Resource Technical Report NPS/SODN/NRTR—2010/368 Authors J. Andrew Hubbard Sarah E. Studd Sonoran Desert Network National Park Service 7660 E. Broadway Blvd., #303 Tucson, AZ 85710 Cheryl L. McIntyre Sonoran Institute 7650 E. Broadway Blvd., #203 Tucson, AZ 85710 Editing and Design Alice Wondrak Biel Sonoran Desert Network National Park Service 7660 E. Broadway Blvd., #303 Tucson, AZ 85710 September 2010 U.S. Department of the Interior National Park Service Natural Resource Program Center Fort Collins, Colorado The National Park Service, Natural Resource Program Center publishes a range of reports that ad- dress natural resource topics of interest and applicability to a broad audience in the National Park Ser- vice and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Technical Report Series is used to disseminate results of scientifi c 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 com- prehensive 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 informa- tion is scientifi cally credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. This report received informal peer review by subject- matter experts who were not directly involved in the collection, analysis, or reporting of the data. Views, statements, fi ndings, conclusions, recommendations, and data in this report do not necessarily refl ect 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 report is available from the Sonoran Desert Network website, http://www.nature.nps.gov/im/units/sodn, as well as at the Natural Resource Publications Management web site, http://www.nature.nps.gov/publications/NRPM. Please cite this publication as: Hubbard, J. A., S. Studd, and C. McIntyre. 2010. Terrestrial vegetation and soils monitoring at Fort Bowie National Historic Site: 2008 status report. Natural Resource Technical Report NPS/SODN/ NRTR—2010/368. National Park Service, Fort Collins, Colorado. NPS 424/105492, September 2010 ii Terrestrial Vegetation and Soils Monitoring at Fort Bowie NHS: 2008 Status Report Contents Figures ....................................................................................................................................v Tables ....................................................................................................................................vii Acronyms ...............................................................................................................................ix Executive Summary ...............................................................................................................xi Acknowledgements .............................................................................................................xii 1 Introduction .......................................................................................................................1 1.1 Background .......................................................................................................................... 1 1.2 Goals and objectives ............................................................................................................ 1 1.3 Scope of this report ............................................................................................................. 2 1.4 Fort Bowie NHS overview .................................................................................................... 2 1.5 Natural resource management issues .................................................................................8 2 Methods ............................................................................................................................11 2.1 Response design ................................................................................................................. 11 2.2 Sampling design ................................................................................................................ 11 3 Results ...............................................................................................................................17 3.1 Vegetation monitoring results .......................................................................................... 17 3.2 Soil monitoring results ....................................................................................................... 17 3.3 Management assessment points ....................................................................................... 17 3.4 Estimates of power and species detectability .................................................................. 17 4 Discussion .........................................................................................................................27 4.1 Classifying the Fort Bowie landscape ............................................................................... 27 4.2 Annual grass cover ............................................................................................................. 28 4.3 Integrity of the cultural landscape ................................................................................... 29 4.4 Mesquite invasion and conversion to shrubland ............................................................. 29 4.5 Exotic invasive plants ........................................................................................................ 32 4.6 The missing factor: Fire ...................................................................................................... 32 4.7 Site stability ........................................................................................................................ 33 4.8 Protocol assessment .......................................................................................................... 33 4.9 Are terrestrial vegetation and soils within the range of natural variability? ...............34 5 Literature Cited ................................................................................................................35 Appendix A. Supplementary Data Tables ................................................................................39 Appendix B. Plot Locations ....................................................................................................... 63 Contents iii Figures Figure 1.1. Fort Bowie National Historic Site....................................................................................................... 1 Figure 1.4.1. General map of Fort Bowie NHS. ................................................................................................... 2 Figure 1.4.2. Topography of Fort Bowie National Historic Site. ......................................................................... 3 Figure 1.4.3. Major soil types at Fort Bowie National Historic Site .................................................................... 4 Figure 1.4.4-1. Monthly precipitation, Douglas Bisbee International Airport (~50 miles from Fort Bowie NHS), 2003–2008. ................................................................................................................................... 5 Figure 1.4.4-2. Channel cutting resulting from intensive runoff event in Siphon Canyon, 2007 .................... 5 Figure 1.4.7. Fort Bowie in 1894 ........................................................................................................................... 7 Figure 1.5.4. Vegetative response a few days after a prescribed fi re in mixed-grass prairie ......................... 10 Figure 2.1. Terrestrial vegetation and soils monitoring plot design. .............................................................. 12 Figure 2.2.1. Allocation of monitoring plots at Fort Bowie National Historic Site ......................................... 13 Figure 2.2.3. Sampling frame for terrestrial vegetation and soils monitoring at Fort Bowie National Historic Site. ......................................................................................................................................... 14 Figure 3.1.1. Lifeform cover in terrestrial vegetation monitoring plots at Fort Bowie NHS, 2008 ................ 19 Figure 3.4.3. Species area curves for cover and frequency data collected on terrestrial vegetation and soils plots, Fort Bowie NHS, 2008 ....................................................................................................... 24 Figure 3.4.4. Two new species for the park were identifi ed during fi eld sampling: single threeawn (Aristida schiedeana, top) and woolyspike balsamscale (Elionurus barbiculmus, bottom). ...........25 Figure 4.1-1. Vegetation