YOSEMITESCIENCE Innovations in Research & Resource Management Volume 1 z Number 1 z Winter 2011 Volume 1 Number 1 Winter 2011 Table of Contents YOSEMITEScience Innovations in Research & Resource Management Volume 1 ∙ Number 1 ∙ Winter 2011 Feature Articles Published by Yosemite National Park Yosemite, Calif. High-resolution Tools for Understanding Superintendent Geologic Processes 4 Don L. Neubacher Greg Stock, Ph.D. Chief, Resources Management and Science Niki Stephanie Nicholas, Ph.D. Editor Peregrine Falcon Recovery 6 Henrietta DeGroot Sarah Stock Assistant Editor Brenda Ostrom Copy Editors, Layout and Design Yosemite Bog-orchid: The Long Journey to Discovery 7 Karen Dera Alison Collwell, Ph.D., and Peggy Moore Carol Knipper Elizabeth Munding Yosemite Science is an online resources management Climbing Cathedral Peak 10 publication of Yosemite National Park’s Resources David Pettebone, Ph.D. Management and Science Division and is published on an occasional basis and posted on Yosemite’s website. The publication presents recent and ongo- ing research in natural and cultural resources, and What Makes a Vista Scenic? 12 social science. Content is reviewed for basic scien- Kevin McCardle tific soundness, clarity, and completeness but does not undergo anonymous peer review. The facts and views expressed in Yosemite Science are the responsibility of the authors and do not necessar- Piecing Together the Past: ily reflect the policies or views of Yosemite National Chinese Immigrants in Yosemite 14 Park or the National Park Service. Mention of trade Stephanie Guerra names or commercial products does not constitute NPS endorsement. Submissions are welcome from all investigators con- ducting formal research in Yosemite and the broader Sierra Nevada area. To submit article proposals or to send a letter to the editor, please write to the follow- ing address: Departments Editor, Yosemite Science, P.O. Box 700, El Portal, CA 95318 You may also send an email to: From the Chief 3 [email protected] Niki Stephanie Nicholas, Ph.D. www.yosemitescience.org Science Communication 17 Elizabeth Munding Upcoming issues of Yosemite Science will be announced on Twitter. To sub- scribe to Yosemite ‘s Twitter feed, go to Current Park Research 18 http://twitter.com/yosemitescience. Contributors 19 Learn more about Yosemite’s natural and cultural history on the park’s website: www.nps.gov/yose. Flashback 20 Meetings of Interest 21 On the Cover Tuolumne Cascades with Cathedral Peak in the background. See related story on page10. Photo by John D. Sun YosemiteScience From the Chief Science-based Decision Making I am pleased to present the first issue of Yosemite Science. Park scientists and research collaborators are doing exciting work, and we are thrilled to have this opportunity to share some of their progress. In this issue, we highlight work from the Resources Management and Science’s six branches: Physical Sci- ence & Landscape Ecology; Wildlife Management; Vegetation & Ecological Restoration; Visitor Use & Social Sciences; History, Architecture & Landscapes; and Anthropology. Stories include visitor-use re- search on a Class IV climbing route; the recent discovery and documentation of a new Yosemite plant species; and the peregrine falcon recovery effort. Science is a powerful tool in resource management, but it is not a crystal ball. It doesn’t always pro- vide definite answers to make our job of managing park resources easier. What science does, however, is provide the background, context, and tools for us to ask better and more relevant questions, so we can continue to refine park management. It is this continual evolution and learning process that makes sci- ence so powerful and exciting. Although we often must act in the face of uncertainty, we continually adapt our processes as new and better information is available. We know that when scientific information is widely shared, it cre- ates opportunities to connect the best ideas in sound science to the best solutions for managing re- sources. Yosemite has long had a history of doing just that. In the 1920s, park managers implemented an innovate approach to wildlife management. In an effort to protect black bears in the park, feeding ar- eas were established to discourage bears from wan- dering into developed areas where they could pre- sent a danger to visitors. Now we know that it is im- portant to bears’ survival to forage in the wild and maintain their ability to find their own food sources. It is easy to say, in hindsight, that feeding bears was a bad idea, but at the time, it offered a significant measure of protection over other management strategies being employed—namely killing large numbers of bears. While black bears disappeared from many areas in the Western landscape, they re- main in Yosemite. One hundred years ago, we thought that the best way to protect our giant sequoias was to keep them from burning. Now we know that fire is a criti- Niki Nicholas conducts a fish survey using line and tackle and visual surveys cal component in the growth cycle by providing the at Yosemite National Park’s Granite Lakes to determine species present. optimal soil condition that enables seeds to germi- Brook trout (Salvelinus fontinalis ) was the only species observed or caught nate, along with ensuring the space for the trees to during this 2008 survey. survive. As our understanding of bears, sequoias, and other natural and cultural resources continue to im- prove, so do our efforts and methods to protect them. It is the striving, the stumbling, and the dedica- tion to science that makes Yosemite a leader in resource protection. Through inspiration, perspiration, and communication, we continue to arrive at ever better solutions. Each issue of Yosemite Science will share with you with our innovations and insights into how we continue to use the best available infor- mation to protect Yosemite’s natural and cultural resource treasures. Niki Stephanie Nicholas, Ph.D. Chief, Resources Management and Science Volume 1 Number 1 Winter 2011 3 Physical Science & Landscape Ecology High-resolution Imaging Tools for Understanding Geologic Processes By Greg Stock, Ph.D. Yosemite Valley’s impressive granite cliffs, By comparing while stunningly beautiful, also present potentially scans of cliff faces serious hazards to park visitors, employees, and resi- before and after dents. Since 1857, over 700 rock fall events have rock falls, we can been documented in Yosemite Valley, with fifteen precisely deter- associated fatalities and numerous injuries. Park mine the rock fall planning efforts require information on geologic location, volume, hazards, but until recently, monitoring rock-fall ac- and pre-failure tivity was very difficult due to the sheer scale of Yo- geometery. We can semite Valley. Geologists typically would gather also analyze the geologic data of rock faces by climbing them or by geologic structure viewing them with a spotting scope or from a heli- that contributed to Figure 1. Ground-based laser scanner copter. These techniques posed obvious dangers the failure, and use collecting digital topographic data for the but also provided only limited data. However, this information to southeast face of El Capitan, site of several thanks to super-high resolution gigapixel images and assess the hazard of large rock falls in 2010. digital maps produced by laser scanning, we now similar areas. With baseline LiDAR data for most of have unprecedented access to the geological features Yosemite Valley already in place, it is possible to of one of the world’s most famous parks on a laptop quickly rescan a cliff after a rock fall to analyze that computer. event in high resolution. The new imagery was produced using a combi- In collaboration with scientists from the U.S. nation of laser scanning and digital photography. Geological Survey, we have now documented many LiDAR (Light Detection and Ranging) is a relatively rock falls in Yosemite Valley using repeat LiDAR, new mapping technique that utilizes laser scanning including the October 2008 Glacier Point rock fall of the land surface to produce very high-resolution (Figure 2) and more recent rock falls near Half digital topographic maps. The laser scanner can be Dome and the Royal Arches. placed either in an airplane, yielding a bird’s-eye In addition to laser scanning, new advance- view of the landscape, or mounted on a tripod on ments in high-resolution digital photography allow the ground surface and aimed up at the cliffs (Figure for photo-documenting the walls of Yosemite Valley 1). We have utilized both techniques in Yosemite, in unprecedented detail. As part of The Yosemite and integrated the results to provide full three- Extreme Panoramic Imaging Project, a collaborative dimensional representation of Yosemite Valley’s project between the National Park Service and Los complex morphology. The resulting images are use- Angeles-based photographers from xRez Studio, gi- ful for mapping previous rock falls and simulating gapixel panoramic photographs were captured for potential future rock falls, but the real value of the all of the major cliff faces in Yosemite Valley. A pri- technique comes from repeating scans through time. mary goal of this project was to produce high- resolution baseline im- agery of Yosemite Val- ley’s cliffs to aid geolo- gists in documenting and understanding the fre- quent rock falls in Yo- semite Valley. On a single day in May 2008, photographic teams positioned them- selves on the landscape Figure 2. Photograph showing the source area for the October 2008 Glacier Point rock fall (left) and repeat to shoot images simulta- LiDAR analysis showing amount of change between pre- and post-rock fall scans (right). The total volume of this neously to ensure uni- rock fall is calculated to be 5663 ± 36 cubic meters. 4 YosemiteScience Figure 3. High-resolution gigapixel photograph of the southwest face of El Capitan (left), and the corresponding LiDAR-based digital topographic map of the area (right).