Special Sessions
The H5II Conference presentations will be organized into groups of presentations with a similar theme. Special Session titles, organizers, and summaries are listed below.
The North American Dendroecological Fieldweek (NADEF): Educational and Research Opportunities to Better Understanding 5-Needle Pines
Organizer: Maegen L. Rochner
Since 1990, the North American Dendroecological Fieldweek (NADEF) has provided intense, hands-on learning experiences in dendrochronology for participants and group leaders from a variety of disciplines and backgrounds. The fieldweek also produces published research and inspires ongoing and related work, often as part of participant theses and dissertations, across North America. For a majority of the fieldweek’s history, the location has moved around the continent, but for four years (2014, 2017–2019) has been based out of the A.L. Mickelson Field Station near Cody, Wyoming. This has allowed for broader, longer-term projects and synthesis in the surrounding Greater Yellowstone Ecosystem (GYE), in support of the fieldweek’s goals to examine forest stress, and to expand and improve the value of dendrochronological records to forest managers in the region. As a part of this ongoing objective, NADEF research has focused on (1) better understanding whitebark and limber pine and (2) examining climatological and ecological change in the GYE. In this special session, we highlight major findings from four years of NADEF research, as well as educational and research opportunities of the fieldweek and general lessons learned, with emphasis on whitebark and limber pine, and whitebark pine ecosystems in the NADEF study region.
From genes to tree-rings: characterizing long-term climate drivers and extreme drought effects on Sierra Nevada whitebark pine
Organizers: Joan Dudney and Liz Milano
Whitebark pine (Pinus albicaulis Engelm.) is threatened by a combination of interacting factors, including white pine blister rust, mountain pine beetle, and climate change. While a majority of research on whitebark has been focused in the Rocky Mountains, populations outside of this region are exposed to markedly different abiotic and biotic conditions. Here we present a Sierra Nevada-wide study of whitebark pine that integrates genetic, physiological and demographic data that capture up to 500 years of climate variation. We sought to explore both the basic biology and recent drought responses of whitebark pine populations. While the southern Sierra Nevada represents the southern latitudinal range limit of whitebark pine, we found that only a small region of the eastern Serra population experienced drought stress. In addition, while climate and topographic variability is high throughout the Sierra, genetic differentiation was surprisingly low across the Sierra Nevada whitebark pine population. Our results can help inform predictions of distributional changes in response to climate change and drought extremes. Species distribution models often omit phenotypic plasticity in growth traits or genomic variation underlying adaptive response, which our data suggest could have profound impacts on responses to changes in climate.
Ecophysiology of five-needle pines
Organizer: Danielle Ulrich
Plant ecophysiology is the study of how the environment interacts with the physiology of a plant. Given increasing variability of both abiotic and biotic environmental factors at high elevations, it is critical that we understand how high elevation five-needle pines respond to and interact with their changing environment. This session focuses on their ecophysiology to identify gaps in knowledge and future research priorities. Improving our understanding of the ecophysiology of five-needle pines will inform drivers of survival and mortality, predictions of species distributions under future climates, and forest ecosystem conservation efforts. Topics featured in this session include:
- Water, carbon, and nutrient use
- Seedling and adult tree growth, survival, and mortality
- Interactions with abiotic environmental factors such as drought, wildfire, high temperature, and snowpack
- Interactions with biotic environmental factors such as bark beetle, white pine blister rust, and competition with co-occurring species
Important historical research in whitebark pine ecology and management
Organizer: Bob Keane
Abstract: We have a unique opportunity to bring together many of the researchers that performed the initial research into the ecology and management of whitebark pine. Most ecological knowledge of the species is actually quite new, less than 50 years old, and many of the first researchers are still living. We propose to have a special session dedicated to a set of six talks from some of the first researchers to conduct research on the species. These scientists will give the papers that they published that most contributed to whitebark pine management.
The myths and realities of whitebark pine and climate change
Organizer: Bob Keane
Perhaps the biggest question in the minds of people interested in whitebark pine is whether it is possible to restore this iconic species in the face of climate change. Considering the species is being attacked by both the exotic white pine blister rust and the native mountain pine beetle throughout its range, how do the projected warming and drying climates change the beetle and rust dynamic and influence the decline. It’s a brand new climate world so all the wisdom and experience that we’ve gained over our careers may not help us figure out what will happen to whitebark pine 50 years from now.
Progress in Restoration and Management of Five Needle Pines
Organizer: Glenda Scott
It is incumbent on natural resource managers to protect and restore imperiled species and the critical habitat which supports them. On public lands, funding and work priorities borrow from our ability to enhance the high elevation five needle pines and the habitats that are critical to their future. Pulling in the knowledge of scientists and experiences of others, resource managers share their approaches, success, challenges in meeting the restoration needs of the five needle tree species present in high elevation ecosystems.
High-elevation white pine communities in the Pacific West Region
Organizer: Jonathan Nesmith
High elevation white pines are foundational species in many high elevation forests and woodlands in the Pacific West Region. Often the dominant species in upper-subalpine communities, the region hosts a diverse assemblage of high elevation white pines including whitebark pine (Pinus albicaulis Engelm.), limber pine (P. flexilis James), foxtail pine (P. balfouriana Grev. & Balf.), and Great Basin bristlecone pine (P. longaeva D.K. Bailey). However, these species are threatened by multiple interacting stressors including the invasive pathogen Cronartium ribicola J.C. Fisch. that causes white pine blister rust, mountain pine beetle (Dendroctonus ponderosae Hopkins), changing fire regimes and the impact of fire suppression, and rapid climate change.
The Pacific West Region has been relatively understudied compared to other areas where these species occur, and there are there are likely important differences in the ecology of these systems that should be considered in management decisions related to the conservation of these species. The goal of this session is to highlight current or recent research on high elevation white pines in the Pacific West Region to better document the current status and potentially divergent population dynamics within the region.
Five needle pine research, monitoring, research, and restoration in national parks
Organizer: Kristin Legg
Five-needle pines occur throughout national parks in the Western United States. This special session is on five-needle pine research, monitoring, and restoration activities that take place on lands managed by the National Park Service. Whitebark pine, is a significant component of upper elevation forests in 11 national park units, and occurs mostly in proposed, recommended, or designated wilderness. Generally, whitebark pine populations have decreased in the Cascade and Rocky mountain parks with less decline documented in the Sierra Nevada’s. In addition, the National Park Service monitors other five needle pine species such as bristle cone, limber, and foxtail pines. Information provided through these efforts are increasing park management’s understanding of what these species provide to park ecosystems and improves their ability to make decisions.
White pine blister rust resistance, genetic variation, and restoration of white pines I & II
Organizer: Richard Sniezko
The six ‘High Five’ white pine species are very susceptible to white pine blister rust (WPBR), caused by the non-native pathogen Cronartium ribicola. The high level of WPBR in many areas suggests that the future of many populations of these species and their associated ecosystems will depend on restoration using seedlots with a high frequency of genetic resistance. Programs to develop resistance in whitebark pine have been underway for two decades, but investigations into resistance in limber pine, southwestern white pine, foxtail pine, Great Basin bristlecone pine and Rocky Mountain bristlecone pine have started only relatively recently. Fortunately, resistance has been found in five of these species, and the search is on for resistance in the sixth. A number of organizations in the U.S. and Canada have tree improvement programs or research underway to develop WPBR resistance to use in restoration and to examine adaptive genetic variation in these species. The work presented here provides the latest update on the resistance and work relating to genetic variation in High Five species and the plans for the future.
Conservation Status, planning, and adaptive management for whitebark pine
Organizer: Diana Tomback
Whitebark pine (Pinus albicaulis) is distributed across more than 32 million ha rangewide and declining rapidly in most regions. Funding whitebark pine conservation and restoration across this expansive distribution will require creative and collaborative approaches, involving federal, corporate, and private funding. Since the first High Five Symposium in 2010, conservation plans and restoration tools for whitebark pine (and limber pine) continue to be developed and refined. New and revised regional, tribal, and agency-based management plans are addressing restoration in rapidly declining populations or aspiring to build resiliency into populations first experiencing white pine blister rust infection.
As we devise and implement the “second generation” of restoration plans, including the National Whitebark Pine Restoration Plan, there are refinements and considerations that could increase the effectiveness of restoration. For example, management and restoration plans should incorporate monitoring and assessments of restoration projects, examining whether goals are met. If not met, new approaches must be devised. Furthermore, given the cost of many projects, restoration planning could consider whitebark pine distributional changes under future climate.
In this special session, invited speakers address several of these topics, including innovative partnerships to fund restoration, the recent development of conservation plans tailored to regional whitebark pine community ecology and cultural or historical values, the importance of monitoring, and adaptive management.
Fire in high-elevation five needle pine ecosystems I & II
Organizer: Alina Cansler
High-elevation five-needle pines of North America are being stressed by multiple factors, including a non-native pathogen (Cronartium ribicola), rapid changes in high-elevation climates, increased bark beetle pressure, and changes in fire regimes. Historical fire regimes in high-elevation five-needle pine ecosystems exhibited regional and local variability in the frequency and severities of fires. In some locations, fire may benefit these species by creating conditions that allow for abundant natural regeneration, but the extent to which fire is necessary or beneficial for regeneration likely varies across species, regions, and local settings. Moreover, it is unclear if current fires are having positive restorative impacts, or decreasing ecological resilience through removal of seed producing mature individuals, which may have had genetically resistant to C. ribicola and others stressors.
This session will provide a broad view of the role and effects of fire in high-elevation five-needle pine ecosystems. In the first five talks of the session, speakers will present results from studies of restoration activities, landscape-scale change assessments, and individual-tree scale modeling of post-fire survival or mortality. The second six talks will focus on empirical studies from contemporary fires that examine post-fire succession and post-fire plant community composition in five-needle pine ecosystems. The session will close with a discussion of the applications of this research to fire management in five-needle pine ecosystems, and how we can improve our understanding of modern fire regimes and fire effects to better inform management and conservation of high-elevation pine species and their ecosystems.
Whitebark Pine Recovery in Canada from Policy to Practice
Organizer: Randy Moody
Whitebark pine recovery and management in Canada follows a somewhat different course than recovery in the U.S. Although the primary threats to the species are the same; Canada has more industrial threats at local scales but conversely also has greater regulatory protection thanks to listing under the federal Species at Risk Act (SARA). This session will cover Canadian progress in recovery with particular emphasis on work at the northern limit of the species, work in protected areas, and disturbance history and whitebark and limber pine recovery.
Celebrating nearly 15 years of Forest Health Protection funded projects I & II
Organizers: Christy Cleaver and Bob Keane
Many believe that the US Forest Service Forest Health and Protection (FHP) whitebark pine restoration funding has resulted in the greatest amount of restoration activities across the range of this iconic species. Millions of dollars have been awarded to various government and private organizations to perform diverse restoration activities in the following categories: (1) Assessing Health: Survey and Monitoring, (2) Operational Cone Collections, (3) Harnessing Rust Resistance, (4) Enhancing Regeneration and Reducing Competing Vegetation, (5) Special Projects, and (6) Education, Outreach, and Technology Transfer. All of these projects are documented on the “One Project at a Time” website (https://database.whitebarkfound.org/). In this special session we feature some of the most important projects funded by this incredibly important FHP funding. We include topics from all six funding categories.
Clark’s Nutcracker Ecology and Seed Dispersal
Organizers: Thomas McLaren and Tyler Williams
The high-elevation corvid species, Clark’s nutcracker (Nucifraga columbiana), is known for its role as a seed disperser for many western conifer species, including a number of five needle pines. During the seed harvesting season of late-summer and fall, nutcrackers harvest and cache tens of thousands of conifer seeds across the landscape for later consumption. Seeds that are not retrieved from caches may germinate and contribute to forest regeneration. The role of nutcrackers in promoting forest regeneration of many white pine species, including whitebark pine (Pinus albicaulis) and limber pine (Pinus flexilis), is currently undergoing active exploration. Studies to understand what factors may impact nutcracker habitat use and behavior are of particular importance to resource managers, who may be tasked with conserving vulnerable white pine species.
This session aims to highlight the state of current research on Clark’s nutcracker ecology, bringing together studies from across the species’ range. Talks will focus on several aspects of nutcracker ecology, including their foraging relationship with various conifer species, the ways in which forest health characteristics determine nutcracker breeding and occupancy dynamics, and understanding their space-use in relation to whitebark pine habitat reduction as well as limber pine metapopulation connectivity. Our goal is to display the variability in nutcracker habitat and resource use as it relates to local conifer availability and forest health. We also hope to aggregate current research on this important seed disperser and its coevolved mutualism with several five-needle pine species of western North America.
