National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science A Natural Resource Condition Assessment for Sequoia and Kings Canyon National Parks Appendix 11a – Giant Sequoias Natural Resource Report NPS/SEKI/ NRR—2013/665.11a ON THE COVER Giant Forest, Sequoia National Park Photography by: Brent Paull A Natural Resource Condition Assessment for Sequoia and Kings Canyon National Parks Appendix 11a – Giant Sequoias Natural Resource Report NPS/SEKI/ NRR—2013/665.11a Robert A. York Tadashi Moody Dept. of Environmental Science, Policy, and Spatial Informatics Group Management www.sig-gis.com Center for Forestry, UC Berkeley 4501 Blodgett Forest Road Anthony C. Caprio Georgetown, CA 95634 Division of Resources Management and Science Nathan L. Stephenson Sequoia and Kings Canyon National Parks U.S. Geological Survey, Western Ecological 47050 General’s Highway Research Center Three Rivers, CA 93271 Sequoia - Kings Canyon Field Station 47050 Generals Highway #4 John J. Battles Three Rivers, CA 93271 Dept. of Environmental Science, Policy, and Management Marc Meyer UC Berkeley USDA Forest Service, Pacific Southwest 137 Mulford Hall Region Berkeley, CA 94720 1600 Tollhouse Road Clovis, CA 93611 Steve Hanna USDA Forest Service, Giant Sequoia National Monument 1839 South Newcomb Street Porterville, CA 93257 June 2013 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. These reports are of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate high-priority, current natural resource management information with managerial application. The series targets a general, diverse audience, and may contain NPS policy considerations or address sensitive issues of management applicability. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. This document contains subject matter expert interpretation of the data. The authors of this document are responsible for the technical accuracy of the information provided. The parks refrained from providing substantive administrative review to encourage the experts to offer their opinions and ideas on management implications based on their assessments of conditions. Some authors accepted the offer to cross the science/management divide while others preferred to stay firmly grounded in the presentation of only science-based results. While the authors’ interpretations of the data and ideas/opinions on management implications were desired, the results and opinions provided do not represent the policies or positions of the parks, the NPS, or the U.S. Government. 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 report is available in digital format from the Natural Resource Publications Management website (http://www.nature.nps.gov/publications/nrpm/). Please cite this publication as: York, R. A., N. L. Stephenson, M. Meyer, S. Hanna, T. Moody, A. C. Caprio, and J. J. Battles. 2013. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 11a – giant sequoias. Natural Resource Report NPS/SEKI/NRR—2013/665.11a. National Park Service, Fort Collins, Colorado. NPS 102/121034, June 2013 ii Contents Page Figures............................................................................................................................................. v Tables ............................................................................................................................................ vii Appendices .................................................................................................................................... vii Scope of analysis............................................................................................................................. 1 Critical questions ............................................................................................................................ 3 Reference conditions ....................................................................................................................... 5 Predicted stationary age distribution for giant sequoia ............................................................ 5 Repeated prescribed fire effects on giant sequoia regeneration .............................................. 9 High severity disturbance effects on regeneration ................................................................. 10 Burned substrate effects on recruitment ................................................................................ 12 Spatial and temporal analyses ....................................................................................................... 17 Grove locations ...................................................................................................................... 17 Fire Return Interval Departure – the primary metric of grove condition .............................. 17 Snow-dominated precipitation ............................................................................................... 18 Ozone concentration .............................................................................................................. 19 Precipitation and maximum/minimum average temperature ................................................. 19 Climatic water deficit ............................................................................................................ 19 Size structures within groves ................................................................................................. 20 Size structure by agency ........................................................................................................ 20 Departure index shifts- An approach for detecting change in grove size structure ............... 24 Size structures of individual groves ....................................................................................... 24 Analysis of Uncertainty ................................................................................................................ 27 Interactions with other focal resources ......................................................................................... 27 iii Contents (continued) Page Stressors ........................................................................................................................................ 27 Air quality .............................................................................................................................. 28 Land use/fragmentation ......................................................................................................... 29 Climate change ...................................................................................................................... 31 Invasive species ..................................................................................................................... 34 Altered fire regimes ............................................................................................................... 35 Emergent disease complexes ................................................................................................. 36 Giant sequoia in a novel environment ................................................................................... 39 Inter-grove assessment ........................................................................................................... 40 Groves at elevation extremes ............................................................................................ 40 Small groves...................................................................................................................... 40 Groves with extreme fire return interval departures ......................................................... 41 Groves with persistent and large climatic water deficit .................................................... 41 Level of confidence in assessment ................................................................................................ 43 Monitoring and Inventory ...................................................................................................... 45 Basic research ........................................................................................................................ 45 Active adaptive management experiments ............................................................................ 46 Literature Cited ............................................................................................................................. 47 iv Figures Page Figure 1. Predicted and actual age distributions from two locations not experiencing fire during the 20th century (top