Monday, October 22

---

Plenary Session

Introduction to California Oak Diversity
California’s oaks are fascinating, diverse and beautiful. These fine trees and hardy shrubs inhabit millions of acres from San Diego to the Siskiyous, from the Pacific coast across the Central Valley into the foothills, valleys and canyons of the Sierra Nevada.

It is my privilege to introduce eight of California’s tree-sized oaks with images displaying their unique, defining physical characteristics, habitat preferences, natural history and cultural relevance.

Species include: Black oak (Quercus kelloggii), Blue oak (Q. douglasii), Canyon live oak (Q. chrysolepis), Coast live oak (Q. agrifolia), Engelmann oak (Q. engelmannii), Interior live oak (Q. wislizeni), Oregon oak / Garry oak (Q. garryana), and Valley oak (Q. lobata).

Pamela Muick

Pam is an educator, naturalist and writer whose life has been shaped by California’s oaks. In the 1970s, she coordinated one of the state’s first valley oak restorations in Sonoma County. At UC Berkeley, she completed a statewide oak regeneration survey. While completing her dissertation research she consulted on oak restoration and management projects and co-authored “Oaks of California.”

After receiving her Ph.D. she served as executive director of Solano Land Trust and California Native Plant Society.  Since 2006, Pam has focused her energy teaching upcoming generations of Californians the joys of biology and environmental science (Contra Costa College & Solano College). She hikes among the oaks weekly.

Back to top

---

The California Acorn Survey: What 39 Years of Counting Acorns Can Tell You
Since 1980, my colleagues and I have been counting acorns in California oaks with the goal of understanding patterns of acorn production, at both proximate and ultimate levels, focusing in particular on the ecology and evolution of masting behavior---the synchronous production of seeds by a population of plants. I will summarize some of the issues we have been interested in and how our results, which now encompass estimates of acorn production on over 1000 trees of 7 species of California oaks each year, have allowed us to address those issues. In particular, our work has revealed a great deal about both the proximate factors driving variable acorn production and the drivers of spatial synchrony---the geographic scale of masting behavior observed in oaks and other species of forest trees.

Walt Koenig

Ph.D., UC Berkeley 1978
Assistant Professor, Occidental College, 1981-82
Research Zoologist and Adjunct Professor, UC Berkeley, 1982-2008
Senior Scientist, Cornell Lab of Ornithology and Dept. of Neurobiology and Behavior, Cornell University, 2008-2017

Back to top

---

 Assessing the Climate Change Vulnerability of California’s Oak Vegetation Types
Thorne, JH, H Choe, RM Boynton, MW Schwartz

Climate change in California is bringing warmer temperatures, less snowpack, a longer wildfire season, and introducing more stochastic precipitation into its typically variable annual precipitation. California’s diverse and ecologically important oak species are exposed to these pressures and natural resource managers are challenged to consider what the impacts portend and whether any landscape treatments could reduce risk to the major vegetation types that oaks dominate or inhabit. We worked with natural resource managers to develop a tool that permits identification of variable levels of climate risk on the landscape, and that permits the use of a portfolio of land management techniques to be applied strategically or experimentally. This talk presents an evaluation of climate risk to California’s major oak vegetation types. We evaluate climate projections, select a set that brackets projected future conditions, and use landscape scale maps of major vegetation types to define current suitable and stressful climate conditions, based on the frequency of climates that each vegetation type currently occupies. We then examine what areas of each type’s distribution are projected to enter stressful conditions, based on the current climate classification. We can identify and map areas expected to enter stressful climatic conditions and those that remain within commonly experienced climates. These climate risk maps can be combined with each species’ characteristics to assess vulnerability of the vegetation type overall. We demonstrate the use of the output maps for a number of climate mitigation and adaptation land management applications.

James H. Thorne

Jim Thorne is a Research Scientist at the University of California, Davis with expertise in vegetation mapping, climate change, species-environment interactions; land use, and landscape dynamics. Jim has worked on several large mapping projects in California including the 1989 GAP Analysis (version 1), inventories of the Mojave desert, and digital rendering of the 1930s Wieslander Vegetation Type Maps. These VTM maps provide some of the most accurate range maps for oak species in California. He recently served as a science editor for California’s 4th Climate Vulnerability Assessment.  He has participated in or led numerous studies and assessments for the state of California, including work with the Department of Fish and Wildlife as well as the Department of Forestry and Fire Protection. He has published or co-published over 125 journal articles, book chapters, and technical reports.

Back to top

---

Concurrent Session Track A: Global Oak Diversity

Evolution of the World’s Oaks: Phylogeny and Biogeography of the Genus Quercus
Andrew Hipp, Paul S. Manos, Min Deng, Michael Avishai, Jeannine Cavender-Bares, Andrew Crowl, Thomas Denk, Socorro Gonzalez, Antonio Gonzalez-Rodriquez, Guido Grimm, Marlene Hahn, John D. McVay, Hernando Rodriguez Correa, Marco Simeone, Victoria Sork

The three years since the Eighth International Oak Society Conference has seen numerous publications on the phylogenetic history of oaks in the Americas, Europe, and Asia. Many of these utilize a reduced-representation genomic technique (RAD-seq) that has yielded strong resolution within clades, providing detailed continent-scale understandings of the timing and ecology of oak diversification. This talk will present combined data from species representing all major clades, along with updated hypotheses about the timing of major oak diversifications. Special attention will be given to broad-scale diversification patterns and the placement of previously unsampled taxa, primarily in Europe (sections Cerris and Ilex) and Mexico (sections Quercus and Lobatae).

Andrew Hipp

Andrew Hipp is the Senior Scientist in Plant Systematics and Herbarium Curator at The Morton Arboretum. His work utilizes the Tree of Life (phylogenetics) to understand plant diversification.

Back to top

---

Neotropical Oaks Phylogeography and Conservation
Genus Quercus (Fagaceae) distributes from the Holartic region through the Tropics. Along its distribution Quercus species represent fundamental elements of various ecosystems such as temperate deciduous forest, pine oak forest, cloud forest and montane forest. Neotropical oak species distribute from the Mexican Transition Zone down to the Colombian Andes. This study shows the phylogeography of six representative species of the Neotropical oaks from Mexico, Costa Rica and Colombia using chloroplast-based molecular markers and describes the conservation status of Mexican oak species by ex situ and in situ strategies. Genetic diversity and structure, gene-flow patterns and historical demography patterns were described for the above mentioned species. Complementarily, expected impacts on the Mexican oak species distribution by climate change were described using ecological niche modelling. Our results suggests that Neotropical oak species have undergone complex dispersal events from Mexico down to Central America, defined by climatic oscillations during the Pleistocene glacial and interglacial transitions. Understanding the migration patterns of the Neotropical oak species in response to climatic oscillations is fundamental to enhance the preservation of Neotropical oak species facing Global Climatic Change by the implementation of both in situ and ex situ conservation strategies.

Hernando Rodríguez Correa

Hernando Rodríguez Correa is a full time associate professor in the Escuela Nacional de Estudios Superiores Unidad Morelia at the Universidad Nacional Autónoma de México. His research focuses in the study of the Neotropical oak species evolution, particularly the phylogeography, biogeography and macroecology of Quercus species distributed from Mexico down to the Colombian Andes. His main interests relate to the effects of the transition between mountain systems (highlands vs. lowlands), the altitudinal zonation and the geological and climatic dynamics of oak species’ current distributions and the implications to their conservation.

Back to top

---

Major Asian Lineages of the Beech Family
The oaks are only part of the considerable diversity found within the Fagaceae. Two large genera (Lithocarpus and Castanopsis) are found in Asia, from the subtropics of continental China to the tropics of Southeast Asia, stretching from Assam in the west to the island of New Guinea in the east. This presentation will review the considerable species richness and interesting geographic distribution of these lineages, as well as dig into some current research. The fruits of stone oaks (Lithocarpus) can be almost identical to temperate oak acorns but several lineages have developed exceptional nut morphologies. Genetic studies indicate that despite being insect-pollinated, stone oaks are similarly prone to interspecific introgression as temperate oaks and that geographic location is more important than taxonomic identity for cytoplasmic genomes. Ongoing studies indicate a trade-off between mechanical and chemical protection of the seed and with several independent convergent evolution events for a unique fruit trait. Tropical chestnuts are also similar to temperate chestnuts in many respects with a few species dominating forests in parts of Indochina and Indonesia. Finally, the trig oak (Trigonobalanus) is a fascinating relictual lineage consisting of three species existing in tiny relictual populations remotely scattered from Hainan Island through Southeast Asia to Borneo with a bizarre one in South America.  With the advent of genomic analyses in the family and evidence of genomic conservatism, comparative studies between temperate and tropical lineages within and across genera will provide some exciting insights in the future.

Chuck Cannon

Dr. Chuck Cannon is an expert on Lithocarpus working as the Director of the Center for Tree Science at the Morton Arboretum. He worked in Southeast Asia for over 30 years and  co-organized the IUFRO Conference on Fagaceae Genetics and Genomics in November, 2017 in Shanghai.

Back to top

---

The Oaks of Vietnam: Origin, Evolution and Genomic Diversity
Joeri Sergej Strijk, Damien D. Hinsinger

Over the past three years, significant progress has been made in understanding one of the world’s major biodiversity hotspots of oak species. Indochina as a single geographic unit, holds the largest number of species and genera in Fagaceae in all of Asia, with Vietnam being home to well over a 150 species alone (more than a third of which belong to Quercus). The upcoming new edition of the Flora of Cambodia, Laos and Vietnam, set to be completed at the end of 2019, will be the first comprehensive regional treatment of oaks and related genera in over seventy years. Since the last treatment by Lecomte, we have explored, described and categorized more systematically in this region than ever before, and made enormous progress on our global understanding of Quercus evolution, genomics, diversity and ecology. By combining phylogenomics, molecular dating and traditional taxonomy, we can now take a bird’s-eye view of this enormous diversity and begin to understand the diverse origins and unique evolutionary composition of the oaks of Vietnam. 

Joeri Sergej Strijk

I am working as an Associate Professor in Biodiversity Genomics at Guangxi University in Nanning, China. My team and I are working on understanding complex, mainly tropical, tree families like Fagaceae. I have been working on Asian Fagaceae (starting on the genus Lithocarpus) since coming to China for a postdoctoral fellowship back in 2011. Since then, I have collected and studied Fagaceae all over Asia. I am currently completing the Flora of Cambodia, Laos and Vietnam, and the Flora of Singapore, for the Fagaceae. In addition, I am building a online webportal set to gather all information on Asian species of Fagaceae (www.asianfagaceae.com), incorporating everything from detailed images and descriptions, to ecology, biogeography, taxonomy, systematics and genomics. The completion of this will take several years, and involves collaborators throughout Asia, Europe and the Americas.  

Back to top

---

Concurrent Session Track B: Urban Oak Habitats

Re-Oaking Silicon Valley: Building Climate Resilience with Oaks in Cities 
Erica Spotswood, Robin Grossinger

Could restoring lost oak ecosystems play a role in climate adaptation strategies for cities? Here, we explore this opportunity in Silicon Valley, California. Over the next few decades, the urban forests of California will require transformation as existing trees adapted to temperate climates become increasingly inappropriate for hotter, drier conditions. Requiring little water after establishment, oaks may be an excellent choice for the future urban forest. Oaks are also tolerant of drought and sequester more carbon than most other common urban trees in California. Over last century, oaks were felled across Silicon Valley as woodlands were converted to orchards and then urbanized, eliminating much of this habitat from our cities. Building on the foundation developed by SFEI’s historical ecology research, we compare the historical structure and composition of Silicon Valley oak woodlands to contemporary urban forests to quantify the extent of ecosystem transformation. We show that despite dramatic shifts in species composition, and a near-complete loss of understory vegetation, canopy cover of the contemporary urban forest remains similar, making it possible to re-oak our cities without dramatically increasing the number of trees. Both beautiful and functional, native oaks can be excellent choices for streetscapes, backyards, and landscaping. Oaks are also foundation species, forming the base of the most diverse habitat type in California. Providing an array of specific guidelines for urban forestry and landscaping, this project begins to envision how we could design the more ecologically healthy and resilient cities of the future.

Erica Spotswood

Erica Spotswood is an Applied Ecologist at the San Francisco Estuary Institute where she leads projects related to urban ecology and ecological resilience. Current projects address how regional planning can integrate with local project-scale design, and how urban greening efforts can be coordinated to contribute to broader regional goals. Her areas of expertise include urban ecology and plant community ecology. Before joining SFEI, Erica conducted postdoctoral research with Katherine Suding, and received her PhD from the University of California at Berkeley in the department of Environmental Science, Policy and Management. Prior to graduate school, Erica worked for the Wildlife Conservation Society in Central Africa, and as a Peace Corps volunteer in West Africa.

Back to top

---

Seed to Seedling: Inspiring Kids While Growing Oaks for Our Future 
For over 30 years, the Sacramento Tree Foundation’s Seed to Seedling program has recruited classes of kindergarten through fourth grade students to grow acorns into seedling oak trees. While growing the native oak seedlings inside their classrooms, teachers lead students through our curriculum which focuses on our native California oaks and the benefits of trees in the urban forest. The program generates high-quality, genetically appropriate seedling oak stock for Sacramento, California area reforestation and for specific efforts such as oak re-establishment following the 2017 Wine Country fires. With a simple, low cost program model, our curriculum and program can be easily adapted to other oak communities and students around the world. Urbanization is the number one threat to California’s oak woodlands and urban forestry projects that focus on this keystone tree species can help stabilize and grow oak populations in urban areas. This holistic program ensures the continuity of our native oak heritage and brings oaks into the city, into our classrooms, and into the hearts of the next generation.

Pamela Sanchez

Pamela Sanchez is a graduate of University of California, Davis, in Environmental Horticulture & Urban Forestry. She is an International Society of Arboriculture Certified Arborist - Municipal Specialist, and has been talking to folks about trees on behalf of the Sacramento Tree Foundation for over 10 years.

Back to top

---

Effects of Human Plantings and Weather Variation on Gall Wasps and Leaf Miners on Oaks 
Oak trees host an amazing diversity of insects, many of which specialize on Quercus species. Oak species and genotypes are commonly planted far from where an acorn was produced. Urban plantings, restoration sites, and plantings anticipating climate change each cause this to happen. What evidence exists that provenance of oak plantings affects herbivores such as galls and leaf miners? And what other factors, such as weather, predators, and geographic isolation affect the populations of these insects? I present evidence from three common garden studies of oaks conducted at different scales. Provenance of oaks matters to herbivores, but predominantly at large genetic scales. Predators are of key importance to populations of gall wasps and leaf miners, and isolated trees can maintain a great diversity of galls and miners. Creating habitat for oak herbivores (at least the ones that do not kill trees) can be a great benefit of planting native oaks, and many of those insects are nearly as charismatic as their host trees!

Ian Pearse

Ian Pearse works on plants and the insects that interact with them. He has worked for many years on oak trees, trying to understand how they defend themselves against herbivores, how they produce mast seeding events, and how to promote their populations.

Back to top

---

Value of Oaks to Wildlife in the Urban Forest of Sacramento, California
Daniel A. Airola, Steven E. Greco

Urban development occupies over 375,000 ha (6%) of California's Central Valley, and expansion continues to displace natural and agricultural landscapes. The value of urban areas as habitat for native wildlife and the characteristics that determine their values, however, remain little-studied. I present information from studies of bird use of native oaks in urban Sacramento. One study showed a strong association between the abundances of oak canopy and 20 insectivorous neotropical migrant songbirds. Migrants also strongly selected oak as a foraging substrate.  Another study showed that during the non-breeding season, certain birds are restricted to mixed oak and riparian woodland in natural settings, but 13 species occur or are substantially more abundant in the urban forest when native oaks are present. Another study showed that urban California Scrub-Jays (Aphelocoma californica) traveled up to 660 m to harvest and cache acorns and dispersed thousands of acorns from groups of bearing oaks. Most sprouted acorns in urban gardens are removed as weeds, but jays play an important role in establishing oaks in less intensively managed urban lands, contributing to habitat quality for other species. Together, these results demonstrate previously undocumented importance of native oaks to urban wildlife and suggest that protecting oaks and increasing their use in future urban plantings in the Central Valley could provide substantial habitat benefits for native birds.

Daniel A. Airola

Daniel Airola is a Certified Wildlife Biologist who has worked in conservation in Northern California for nearly 40 years. Mr. Airola conducts independent research and conservation programs for birds in urban areas and other human-altered landscapes. Oak-related studies have focused on the importance of native oaks to migratory songbirds and oak acorn dispersal by urban populations of the California Scrub-Jay. He has conducted a 15-year study on the remnant Purple Martin breeding population in Sacramento, and roosting use of urban parks by migrating Turkey Vultures. He is also currently studying breeding populations of the Threatened Tricolored Blackbird in the Sierra Nevada foothills. He is the Editor of the Central Valley Bird Club Bulletin, which publishes articles on bird identification, status, distribution, ecology, and conservation for birders, conservationists, and researchers. He also serves on the Boards of several environmental and conservation organizations.

Back to top

---

Poster Session

Physiological and Gene Expression Response of Valley Oak (Quercus lobata) Seedlings to Water Stress 

Alayna Mead, Juan Peñaloza Ramirez, Megan Bartlett, Jessica W. Wright, Lawren Sack, and Victoria L. Sork

Drought can be a strong environmental stressor on plants. Many responses to drought are conserved and species-wide, while others differ among populations because of dissimilar local environments. This study tests whether seedlings of valley oak (Quercus lobata), a widely-distributed California endemic, sampled from regions of different climate conditions differ in their response to water stress. Acorns were collected from six populations with contrasting climates, grown in a greenhouse, and four seedlings from each were exposed to soil-drying or well-watered treatments. After 10 days, we compared specific ecophysiological traits and levels of gene expression (RNA-seq) among populations. Seedlings under water stress had a lower leaf water potential and turgor loss point, but populations were not significantly different from each other, indicating a generalized species-wide response for these traits. In contrast, the set of genes identified as differentially expressed in response to water stress differed significantly among populations. Additionally, groups of genes with similar expression patterns that may be regulated together were identified using weighted gene co-expression networks. Several of these gene “modules” responded differently to water stress among populations, identifying potential differences in gene network regulation and providing insight into how unmeasured physiological responses of populations may differ. This study provides evidence that valley oak populations are genetically different in their response to water stress. If these differential responses affect growth and survival, the projected increase in drought in California will likely affect each local population differently. Such information will help inform the development of management strategies for oak populations.

Alayna Mead

Alayna Mead is a PhD student in Victoria Sork’s lab at the University of California, Los Angeles currently studying gene expression in response to water stress in oaks. She received a BS in biology from Auburn University and an MS in biology at University of California, Los Angeles before starting the PhD program.

Back to top

---

Effects of Variation in Bud Burst and Flowering Phenology on Acorn Production in a Savanna Population of Valley Oak, Quercus lobata Née
Andy Lentz, Victoria Sork

Climate is a major determinant in the timing and synchrony of bud burst, leaf emergence and flowering in most plant species. Timing can shape the length of the growing season and synchrony can influence pollination success and acorn production. In this study of 100 Quercus lobata adults in an oak savanna at the University of California Sedgwick Reserve, Los Olivos, California, we monitored dates of leaf budburst and elongation as well as emergence of male catkins and female flowers from 2007-2018 to address these questions.  First, how much does the start date of budburst vary among years and individuals? Second, how much does the timing and synchrony of flowering vary across years and among individuals? Third, do early and later flowering valley oak individuals show a reduction in acorn production? Fourth, to what extent does temperature explain timing and synchrony of bud burst and flowering?  Our population shows phenological variation across years with some, but not complete, synchrony among individuals in a given year. Populations showed greater synchrony in the timing of flowering than in leaf development. Individuals that were less synchronous by flowering either earlier or later than the majority of the population had reduced acorn production. Inter-annual variation was due to a combination of temperature and years since last large acorn crop.  Within a year, timing and synchrony of flowering was strongly influenced by the tree’s microclimate. This strong impact of temperature on phenology suggests climate change will influence growth and reproductive success.

Andy Lentz

A volunteer naturalist at Sedgwick Reserve, University of California, Santa Barbara, a part of the University of California Natural Reserves System. He was a member of the first graduating class of docents in 2000 and volunteers working with K-12 and adult groups. He holds a certificate as a California Naturalist. Besides his oak phenology observations, he coordinates a team of volunteers collecting data for the California Phenology Project.

Back to top

---

Oaks as a Pilot Group for Developing Conservation Gap Analysis Methodologies
Oaks (Quercus spp.) play an integral role both ecologically and economically in the United States, but also pose significant conservation challenges, since acorns are recalcitrant and therefore maintained most successfully in living collections rather than seed banks. In response to observations of declining wild populations, The Morton Arboretum and Botanic Gardens Conservation International, U.S., with support from the U.S. Forest Service, initiated the development of a gap analysis methodology to identify necessary conservation activities for U.S. native oaks. Publication of the Red List of U.S. Oaks provided the perfect jumping-off point for deeper analysis of this group. We compiled oak accessions data, including wild provenance information, from more than 160 botanic gardens and arboreta globally. Wild collection sites for at-risk oaks were extracted from these accessions data and compared against the natural distribution of each species. These analyses revealed potential geographic and ecological gaps among ex situ collections, enabling prioritization of species and, importantly, populations for future collecting efforts. We also developed standardized methods for the storage, summary, and comparison of data regarding each at-risk species’ in situ populations including range, demography, threats, and current conservation actions. By combining ex situ and in situ results, this gap analysis highlights key areas of need by genus, region, and species, and provides a starting point for the formation of species-specific conservation action plans.

Emily Beckman

Graduated with a B.S. in Environmental Science and a Studio Art minor in 2014. She proceeded to work as an assistant floral designer with a Chicago-based event florist, and as an independent researcher for an agricultural services consulting company. In 2015 she came to The Morton Arboretum, completing IUCN Red List assessments for North American native oaks. She then gained funding from the U.S. Forest Service and began working full time on a conservation gap analysis of native U.S. oaks. This project was concluded in 2017 and has been extended to include the assessment of 10 more tree genera in 2018. Emily spent her childhood in small-town New Mexico where she discovered her love of nature through hiking and camping among the mesas. She is now looking to further her passion for and knowledge of plants by pursuing a graduate degree in the coming year.

Back to top

---

Climatic and Soil Factors shape the Demographical History and Genetic Diversity of Quercus liaotungensis in North China
Jia Yang, Lucía Vázquez, Guifang Zhao

Understanding the effects of ecological factors on species demography and genetic property can provide valuable insight into the evolutionary trajectory and conservation of a species under environmental changes. Here, we sequenced two nuclear genes and four chloroplast DNA fragments for 105 samples from 21 populations of Quercus liaotungensis across its distribution range, and combined coalescent-based Bayesian analysis and approximate Bayesian computation (ABC) simulation as well as ecological niche modeling (ENM) to study genetic patterns and demographic history of this oak species. Multiple linear regressions were used to seek correlations between genetic diversity and ecological variables in Q. liaotungensis. Based on the genetic data, we found two major genetic clusters among populations of Q. liaotungensis, which might be triggered by different temperature and precipitation seasonality but not associated with geographical locations. Demographic reconstructions and ENM suggested an expansion-decline trend of this species during the Pleistocene climatic oscillations. Multiple linear regressions indicated that genetic diversity of Q. liaotungensis was significantly positive with temperature seasonality and soil pH but negative with precipitation, suggesting rapid responses to ecological changes and strong drought-tolerance of this oak. Our study highlights the impacts of Pleistocene glaciations on demographic history of plant species in North China, and indicates climatic and soil conditions as major factors shaping genetic diversity and population structure of Q. liaotungensis.

Jia Yang

A postdoctoral scholar at Northwest University, China. He got his doctoral degree at Northwest University in May 2017 and have published two papers in relation to phylogeography and evolution of the Chinese oaks. He is interested in the phylogeography, population genetics and phylogeny of the Chinese oak species.

Back to top

---

Fate of California Black Oaks in Large Wildfires
Jonathan W. Long, Angela White, Gina Tarbill

Mature California black oak trees are vulnerable to high severity fires but depend on low-severity fires to limit conifer encroachment. This “Goldilocks” relationship makes it hard to predict the future supply of ecosystem services provided by mature black oaks, including acorns harvested by Native Americans and habitat for vulnerable species such as the California spotted owl and Pacific fisher. Large fires with extensive patches of high severity have become more common in the Sierra Nevada, and more such disturbances are expected. We studied responses of black oaks to the Rim Fire of 2013 and the King Fire of 2014. We hypothesized that large and very large black oak trees would decline sharply in severe patches but not in low severity patches, with intermediate survival in moderately burned areas. Within the Rim Fire, we found that both moderate and high-severity patches resulted in high rates (70-80%) of top-kill of oaks with less than 10% of stems surviving. About 9-20% of black oaks appeared to be fully killed across burn severity classes. Although climate change and severe fire are expected to favor black oak regeneration over conifers, the black oak socio-ecosystem is vulnerable to losing natural capital and productivity as mature oak trees are replaced by resprouts. This vulnerability is not easily reversed, but active management is an important strategy for promoting resilience to fire and maintaining services, both before and potentially after, large fires.

Jonathan W. Long

A research ecologist with the Pacific Northwest Research Station in Davis, California. He leads a variety of interdisciplinary research projects to help managers restore forests and wetlands to support important social and ecological values. In recent years, he has produced a report on restoring California black oak in a partnership with the North Fork Mono Tribe and other experts, studied the effects of large fires on forests and watersheds, and developed science-based strategies for restoring forests landscapes in the Pacific West. He has worked previously for the Rocky Mountain Research Station, University of Arizona Cooperative Extension, and the White Mountain Apache Tribe in Arizona, United States.

Back to top

---

Mitigating Drowned Oaks
Ken Knight, Tim Robinson

In 2004, the Cachuma Operations and Maintenance Board completed a project at Bradbury Dam resulting in raising the elevation of Cachuma Lake in Santa Barbara County by three feet during surcharge events.  879 Quercus agrifolia and Quercus lobata trees were initially killed by the rising waters and another 1405 oaks were determined to be at-risk.   The 2,284 impacted oaks were required to be mitigated in a rural open area around the lake on a two-to-one ratio totaling 4,722 by 2025, including an 18% mortality rate. This poster describes the mitigation process begun in 2005, with annual results of plantings, maintenance costs (plantings, labor,materials and supplies), survival rate (82% in 2015), program challenges and lessons learned from 2005 to 2017, and projections to 2025.

Ken Knight

A Registered Consulting Arborist #507 and Board Certified Master Arborist WE6394AM providing oak tree restoration consulting services to the Cachuma Operations and Maintenance Board since 2012.  Mr. Knight has developed criteria for a revised planting and maintenance program, protecting trees from deer grazing and gopher attacks, collected and grown native acorns for future projects, and developed and implemented inventory and evaluation procedures, and ongoing staff training programs.  With an ISA Risk Assessment Qualification, Mr. Knight also assists with protected oak impacts for COMB capital development projects. Mr. Knight has also provided consulting services to over 200 other public and private clients, and serves as President of the Non-Profit organization Your Children’s Trees, and as Technical Advisor to its companion organization Your Children’s Trees at the University of California at Santa Barbara.

Back to top

---

Functional Trait Variation of Quercus castanea Née along a Climate Gradient in the Cuitzeo Basin, Michoacan, Mexico
Libny Ingrid Lara De La Cruz, Felipe García Oliva, Antonio González Rodríguez

Quercus castanea is a Mexican red oak with a wide geographical and altitudinal distribution that occupies contrasting environments. Locally it is the most abundant oak species in the Cuitzeo basin, in Central Mexico. This basin has an area of about 4000 km2 and shows a highly heterogeneous climate, topography and vegetation. Therefore, Q. castanea represents a suitable species to study patterns of phenotypic variation in response to climate at a landscape level. We hypothesized that climate gradients across the distribution of Q. castanea within the basin promotes functional trait variability between different populations either through phenotypic plasticity or local adaptation. We quantified leaf chlorophyll concentration, basal area, leaf mass, leaf area, specific leaf area, leaf thickness and the Huber value in 209 individuals from 22 populations of Q. castanea throughout the basin and associated trait variation with environmental and geographic predictors. Despite the relatively small geographical scale, our results revealed a strong differentiation among populations in the studied functional traits. The strongest variation found was in leaf area and Huber value. Precipitation of the driest month and soil water holding capacity are the variables that have the major effect on the functional traits. This study agrees with other studies showing that environmental heterogeneity is a major source of variation in functional traits.

Libny Ingrid Lara De La Cruz

A Ph.D. student at UNAM-Morelia, in Mexico. She is interested in ecology and evolutionary biology. She works on landscape genomics of Quercus castanea, a Mexican red oak, to assess local adaptation of populations and understand how environmental and geographic characteristics structure the genetic variation.

Back to top

---

Future Climate Change will Reduce Growth of the California Endemic Valley Oak (Quercus lobata) 
Luke Brown, Jessica W. Wright, Paul Gugger, Victoria L. Sork

In response to climate change, plants must either rapidly adapt to new conditions, acclimate, move, or face the threat of extirpation. In this study, we focus on the California endemic valley oak (Quercus lobata) and determine the degree to which future climate change will impact the growth of valley oak populations. We integrate data from common garden experiments with > 6,000 trees from 95 populations with genomic data across 10,000 single nucleotide polymorphisms (SNPs) to predict how valley oak populations will respond under future climate change scenarios. We estimate climate transfer functions (i.e., predicted plant response to a change in climate) and how climate transfer functions interact with genetic variation. Our results indicate a predicted increase in maximum temperature of the hottest months will lead to a reduction in growth of valley oak across its range. Importantly the predicted magnitude of these declines in growth vary based on genotype, indicating important within-species genetic variation in response to climate that can be used to guide conservation actions. We identify valley oak populations and SNPs that may confer resilience to future climate scenarios. In conclusion, we show that climate change is likely to have a negative effect on valley oak growth and survival if no management or conservation actions are implemented. However, the predicted reductions in growth may be mitigated in management, reforestation, or restoration projects by selecting provenances or genotypes likely to be resilient to climate change.

Luke Browne

Browne's research focuses on the ecology, evolution, and conservation of plants. He is interested in understanding how types of global change, like habitat loss and climate change, will impact the genetic diversity of plant species and consequently influence their ability to survive and adapt to these changes. He uses a combination of field-based observational and experimental studies to investigate the processes that influence genetic diversity and how genetic diversity in turn impacts plant growth and survival. As a postdoc at the La Kretz Center for California Conservation Science at UCLA, he works with the California endemic oak Valley oak (Quercus lobata) to determine how future changes in climate may affect growth of Valley oak populations, how current levels of genetic diversity may allow this species to adapt to climate change, and how we can improve the conservation of this species by incorporating genomic information into habitat restoration and management plans.

Back to top

---

Don't Ask, Don't Tell Is Not the Best Policy
Pamela Allenstein, Matthew Lobdell, Abby Meyer, Amy Highland

It matters how and where public gardens obtain plants. As responsible stewards of living plant collections held in public trust, they commit to accountability and transparent documentation in their policies and operations. Best practices include documenting known provenance, linking permits and agreements which demonstrate legal and ethical plant acquisitions, use, and distribution. Open communication and transparent policies regarding collections management build trust among collaborators for mutual benefit, and help to safeguard vulnerable natural resources.

Pamela Allenstein

Pam Allenstein has managed the Plant Collections Network at the American Public Gardens Association since 2000. She leads the application and peer site review process for accrediting collections. Pam promotes the Standards of Excellence in Plant Collections Management developed by the Network. She collaborates with the United States Department of Agriculture (USDA) Agricultural Research Service and the USDA Forest Service in collecting and conservation activities. In 2012, she organized a national issues forum which focused on Convention on Biological Diversity guidelines and their implications to public gardens. Pam holds a MS in Public Gardens Administration and a BS in Ornamental Horticulture.

Back to top

---

An overview of drippy blight disease of red oaks
Rachael Sitz, Whitney Cranshaw, Jane Stewart

Drippy blight is a newly recognized condition that seriously affects several kinds of red oak (e.g., Quercus rubra, Q. palustris). Our work describes drippy blight disease by explaining the symptoms, identifying the causal agents and their lifecycles, as well as exploring the epidemiology. Symptoms on Northern red oak and pin oak include stunted growth, witches’ brooms, and branch dieback; in severe cases, it contributes to entire tree failure. Furthermore, the massive oozing from infected branches creates sticky film on leaves and surfaces under the tree canopy. We show that two organisms, a kermes scale insect (Allokermes galliformis) and the bacterium Lonsdalea quercina, are the causal agents of drippy blight. In Colorado, we found that the pin oak kermes scale has a one year lifecycle, and is sessile for much of its life. As this insect is likely a poor disease disseminator, we explored generalist insects for their ability to carry the pathogenic bacterium. Insects from three orders and eight families were contaminated with the bacterium, and likely play a role in disease dispersal.

Rachael Sitz

Rachael Sitz is a post-doctoral researcher with the USDA Forest Service and Colorado State University where she is involved in studies on the insect and microbe causal agents of deciduous tree diseases. Currently, her work focuses on thousand cankers disease of black walnut and drippy blight disease of oak. These study systems allow her to integrate basic plant pathology and entomology to answer applied research questions. Broadly, she is interested in (1) determining epidemiology and management for emergent tree diseases, and (2) explaining how microbes interact with each other or insects to produce disease.

---

New Oak Cultivars 2018
The International Oak Society (IOS) is the International Cultivar Registration Authority for the genus Quercus and as such is responsible for registering new oak cultivars as well as maintaining up to date records on all oak cultivars. Each year we collect specimens from collectors, nurserymen, breeders and hobbyists in an effort to stay up on new selections. In addition, we scour the internet and patent offices in search of patented oak selections that otherwise would not come to our attention. A significant part of the registration process is proper publication of each new cultivar. A presentation such as this and the subsequent Journal article satisfies these requirements as well as informs our membership of exciting new introductions. Informing members, nurserymen and collectors alike about new introductions keeps the passion alive for growing oaks and helps further the cause of the IOS. 

Ryan Russell

Ryan Russell is a Horticulturist for the City of Columbia, Missouri and is an International Society of Arboriculture Certified Arborist. He is a current International Oak Society Board Member, co-editor of Oak News & Notes, member of the Editorial Committee and chair of the Taxonomy Committee. Ryan, with co-registrar Eike Jablonski (former IOS President), is responsible for seeking out new cultivars, making sure the registration process is performed properly and keeping a correct and up to date register of oak cultivars. Ryan is responsible primarily for the Americas and Eike is responsible for cultivars originating from the rest of the world. 

Back to top

---

Predisposition To decline: Predicting AOD Occurrence with Environmental Factors
Nathan Brown, Elena Vanguelova, Samantha Broadmeadow, Sandra Denman

In the United Kingdom, Acute Oak Decline (AOD) has caused much concern, due to its distinctive symptoms and its potential to impact oak species that form the largest component of native broadleaf woodland. Affected trees have lesions in the phloem caused by necrogenic bacteria. Lesions are associated with both external stem “bleeding” and the galleries of the two-spotted oak buprestid (Agrilus biguttatus). Decline complexes involve multiple biotic and abiotic factors, which combine to reduce host vigor. In order to investigate forest decline, it is necessary to take a systems approach by considering biotic agents and in addition their interactions with environmental factors that may initially predispose host trees. Here, we test the extent to which AOD is influenced by environmental predisposition factors traditionally associated with oak decline. These are often factors that reduce water availability. During 2013 and 2014 extensive surveys were undertaken, which systematically visited oak woodlands across England and Wales. More than 500 locations have been used to assess relationships with soil type, climatic factors and pollutant deposition, notably atmospheric nitrogen, using logistic regression GAM models. This spatial study re-emphasizes the importance of predisposition factors in decline syndromes and has guided on-going investigations at site and tree levels.

Sandra Denman

Sandra Denman is a Project Leader and Senior Research Scientist with Forest Research in the United Kingdom. She obtained a PhD in Plant Pathology from the University of Stellenbosch, South Africa. She has extensive experience in soilborne and stem canker diseases. Her main interests are causes, effects and management of oak declines, where she uses a holistic research approach. Her specific interests are on the pathology and microbiological interactions in acute oak decline and chronic oak decline.

Back to top

---

Ancient Introgression Among Two Distantly Related White Oak Species (Quercus sect. Quercus) in Southern California: When and How Much?
Oaks are well known for their propensity to hybridize with other oak species when in sympatry but the question is whether hybridization results in long-term interspecific gene exchange or is limited to infrequent, discrete events. Studies of ancient introgression are particularly informative because they provide evidence of the extent to which interspecific gene flow is incorporated into the genome across subsequent generations. Here, we report ancient admixture between California scrub oak (Quercus berberidifolia) and the more distantly related Engelmann oak (Q. engelmannii).  These species show a complex pattern of hybridization and introgression along fine-scale habitat and climatic gradients in southern California. Our goal is to study ancient introgression using genome-wide DNA sequence data and estimate the timing and duration of periods of secondary contact throughout their evolutionary history to better understand the dynamics of introgression. One way to gain such insight is through a demographic modeling approach that tests the likelihood of alternative historical scenarios that could best explain the patterns of gene exchange between species. We sampled 24 trees from each species from spatially separated locations throughout southern California. Using Genotyping-by-Sequencing, we then generated ~30,000 SNPs to compare the Site Frequency Spectra (SFS) of these species using the coalescent-based approach implemented in the program dadi. By utilizing these tools, we have identified multiple episodes of admixture beginning in the Pleistocene epoch. This study provides evidence of two species where recurrent interspecific gene exchange is present over the course of their evolutionary histories and not simply a contemporary phenomenon.

Scott O'Donnell

Scott O'Donnell is a Ph.D. candidate in the department of Evolutionary Biology at UCLA.  The primary focus of his dissertation is the exploration of the evolutionary impacts of hybridization and introgression between oak species using whole-genome data.     

Back to top

---

High Quality Genome Assembly and Annotation of a California Endemic Oak, Quercus lobata
Sorel Fitz-Gibbon, Victoria Sork, Aleksey Zimin, Daniela Puiu, Matteo Pellegrini, Shawn Cokus, Paul Gugger, Steven Salzburg

Oaks represent a valuable natural resource across the Northern Hemisphere with a large research community studying their genetics, systematics, ecology, conservation, and management. Our goal is to provide a high quality, publicly available genome and annotation of valley oak, Quercus lobata Née. Having produced a high quality assembly using both Pacific Biosciences (PacBio) and Illumina sequencing data, we followed up using Dovetail Genomics to generate a Hi-C dataset for additional scaffolding with their HiRise scaffolder.  The initial de novo Illumina/PacBio hybrid assembly was generated using MaSuRCA 3.2.1 and resulted in 3,258 scaffolds of length >1 kb totaling 861 Mb and N50 scaffold size of 1.95 Mb (G = 730 Mbp). Scaffolding with HiRise increased NG50 scaffold size from 1.9 Mbp to 74.6 Mbp in 2,028 scaffolds. The 12 longest scaffolds likely correspond to the 12 chromosomes and contained 813 Mbp (96%) of sequence. Analysis of linkage maps for Q. robur and Q. rubra positioned across the 12 scaffolds supports their correspondence to oak chromosomes. BUSCO analysis found 92% of conserved genes are present in a single copy.  We will present results of our ongoing detailed annotation effort, which includes the use of 1) PacBio long reads to obtain full length transcripts for multiple tissues in order to help define precise gene structures, 2) higher coverage Illumina RNA-seq data in order to capture low expression gene models, 3) similarities to proteins from complete genomes of closely related trees as well as generally to NCBI’s non-redundant database and 4) RepeatModeler based repeat masking. Functional annotation will make use of similarities to well curated datasets and will include careful attention to gene family annotation. We will also present comparisons of the Quercus lobata genome with other available Quercus genome assemblies.

Sorel Fitz-Gibbon

Sorel Fitz-Gibbon has worked on genomics of all types of organisms, starting with assembling one of the first archaeal genomes, Pyrobaculum aerophilum published in 2002. Oaks have been her focus for several years now.

Back to top

---

Miocene Divergence and Pleistocene Introgression of Two Deciduous Oak Species from Section Cerris in China
Oaks are famous for extensive interspecific introgression and hybridization, which has been widely studied in Europe and North America. However, in East Asia, another hotspot region with high species diversity of oaks, similar issues have not been comprehensively resolved. Here, we used both bi-parentally inherited nuclear microsatellite markers and maternally inherited chloroplast DNA fragments to determine the interspecific relationship of Quercus acutissima and Q. chenii, two deciduous oak species endemic to East Asia from section Cerris. We detected a clear species boundary between these two species based on Bayesian cluster analysis using nuclear data. A relatively higher degree of introgression from Q. chenii to Q. acutissima was revealed along the northern distribution margin of Q. chenii, supplemented by principal component analysis and maximum-likelihood estimation of hybrid index. Approximate Bayesian computation of nuclear markers strongly supported the scenario of Miocene divergence and range expansions, and Pleistocene admixture between these two species. Although chloroplast markers did not show a species-specific lineage relationship, the majority of shared haplotypes with narrow distribution were identified in the putative secondary contact region revealed by nuclear markers. Our findings show that oak species in section Cerris from East Asia have experienced a long and complicated evolutionary history, which was closely related to incomplete lineage sorting and historical introgression triggered by repeated range contractions, expansions, and migration, along with large scale climatic changes throughout the Neogene. Chinese oaks show similar phylogeographic responses to oaks on other continents, but unique geological and local climate changes create slightly different patterns.

Yao Li 

Yao Li is a Ph.D. student majoring in botany from Nanjing Forestry University, China. Now he is a visiting student at the University of California, Los Angeles. He is highly interested in the taxonomy and evolutionary history of oaks. His recent research focuses on the phylogeography and population genetics of three oak tree species from section Cerris in China.

Back to top

---

Concurrent Session Track A: Lightning Talks (5 minute oral presentations)

Root Sucker Cutting Propagation of Dwarf Oak Species as an Alternative to Seed Propagation for Ex-situ Conservation
Many of the dwarf, suckering oak species have restricted ranges and face various threats in their often highly specific habitat requirements, resulting in many being of great conservation concern. Infrequent seed production or consistently non-reproductive populations are hindrances in developing ex-situ germplasm collections from wild-collected material. We have found that propagation of these species by establishing root suckers excised from plants in-situ is remarkably easy compared to conventional rooting of branch cuttings, with nearly a 100% yield when adequate material is available. A small, vigorous sucker preferably under 20 cm tall is carefully severed from the periphery of the parent plant with at least a 6-10 cm segment of the subterranean stolon, and the foliage reduced to minimize transpiration. The cut end of the stolon is dipped in 0.01% IBA. For rooting media, 100% coarse grade perlite or 100% Profile™ Greens Grade™ has proven successful under intermittent mist combined with adequate air circulation. In most cases, root initiation readily occurs in 3-5 months, after which they are transplanted into suitable potting media. This method has worked equally well on suckers collected in late summer with hardened current season growth as well as dormant material collected in mid-winter.  This propagation technique enhances Peckerwood Garden’s conservation efforts with species from west Texas including Quercus intricata, Q. hinckleyi, Q. toumeyi, and Q. fusiformis as well as sandhill scrub species in the southeastern US including Quercus minima, Q. chapmanii, Q. inopina, Q. pumila, Q. myrtifolia, and Q. margaretta.

Adam Black

Adam has served as director of horticulture at Peckerwood Garden in Hempstead, Texas since January 2016, working to transition the formerly private collection of valuable plants from Mexico and beyond into a public botanical garden incorporating ex-situ conservation collections as well as promoting a diverse and exciting landscape of underutilized plants. He previously served as horticulturist for a number of years at Kanapaha Botanical Gardens in Gainesville, FL and more recently managed the forest pathology/forest entomology laboratories at the University of Florida, while also co-owner of Xenoflora LLC, a former rare plant mail order nursery that introduced many new plants to cultivation.

---

Using the IUCN Red List to Assess the Global Status of Oaks
Christina Carrero, Diana Jerome, Murphy Westwood

The International Union for Conservation of Nature (IUCN) Red List is a globally recognized, objective system for assessing the extinction risk of plant and animal species based on past, present, and projected threats. We evaluated each oak species’ risk of extinction by conducting literature reviews, analyzing species ranges, and conferring with local experts. These assessments serve as a baseline for our current understanding of the state of the worlds oak species and an authoritative guide for future conservation action. Our goal is to assess all of the world's roughly 450 oak species. In 2017, we completed assessments for all 91 native species of United States oaks and published The Red List of U.S. Oaks report, which detailed the distributions, population trends, and threats facing all 91 native oak species in the U.S. We have now focused on assessing the rest of the oaks of the Americas (~180 species) and the oaks of Asia. There are over 30 species that are likely Data Deficient, meaning they lack sufficient information to assign them a threatened or a non-threatened category. These species need oak expert contribution to complete their assessment and more accurately determine their threat status and need for future conservation.

Christina Carrero

Christina Carrero is a Tree Conservation Research Aide at The Morton Arboretum. As part of the IUCN/SSC Global Tree Specialist group, she is responsible for assessing oaks globally for the IUCN Red List of Threatened Species. Christina completes literature reviews, communicates with oak experts, and compiles data of the world’s oaks to evaluate their threat of extinction and suggest conservation action. She first started with The Morton Arboretum as a Science Conservation Intern in April of 2017 before moving to a role with the Global Trees Conservation Program. She graduated from Denison University in Granville, Ohio with a Bachelor’s of Science.

Back to top

---

Combining Molecular Data to Reconstruct the Evolution of Oaks
Damien D. Hinsinger, Joeri S. Strijk

Oaks are one of the first groups described by Linnaeus, but both their diversity and their history remain largely unknown, especially in understudied regions, like Asia. Despite recent advances in our understanding of Northern American and Chinese oaks evolution, major questions remain, notably concerning the divergence among and inside the different sections/subgenera as currently recognised, and their relationships. Herein, we investigated the diversity and evolution of the genus Quercus using a low-coverage  whole genome shotgun sequencing (WGS).  We recovered both complete chloroplasts and Nuclear Ribosomal Cistrons by a genome-skimming approach, and performed a k-mer analysis using the AAF method for a representative subset of species from each section. This combination of approaches and data showed that hybridization patterns are common at various levels in different sections, the sections Ilex and Cerris being the most affected. We estimated the divergence and diversification of oaks to occur during the mid-Eocene climatic optimum. This suggests that global cooling experienced by oaks since the end of Eocene triggered their diversification by isolating continental flora previously connected through the boreotropical forests biome. This study highlights the potential of low-coverage WGS for reconstructing evolutionary history in oaks, but also in the other genera in Fagaceae, as well as the complex history of the genus, tightly linked to the past climate changes. We hope these results, looking backward in time, will provide insights to the oak-interested community of scientists and practitioners, and will aid in helping oaks to adapt to current and projected global changes.

Damien D. Hinsinger

Damien D. Hinsinger’s main research interest is to understand how the biodiversity we observe today has evolved. Is disjunct biogeography due to neutral (geological or climatic events) or to selective pressures (divergent selection)? What is the time-scale of diversification for a group of species, like a genus? Did climatic variation during the Cenozoic and quaternary glaciations influence species in a specific area more strongly than in other areas? Because these questions could be applied to groups, he studies several tree’s families, but also other organisms. He uses methods ranging from phylogenetics to population genetics, with several types of markers (AFLP, nuclear DNA, cpDNA, genetic data), combined with geological and other biological data to infer and date phylogeographic scenarios. Currently, he is more specifically interested in the analysis of Next-Generation Sequencing (NGS) data, as these provide very powerful tools to answer evolutionary questions, such as fine-scale speciation patterns or complex reticulate evolution.

Back to top

---

Sharing Oak Woodland Research through a Popular Website
Devii Rao, Bill Tietje, Luke Macaulay

The University of California Oak Woodland Management website has been a valuable extension tool and currently receives over 56,000 visitors a year. It is a repository of 29-years (1989 to 2017) of research and outreach data on the ecology, management, and conservation of California’s eight million acres of oak woodlands, a rich landscape providing cultural, economic, and environmental values. However, staff turnover and changes in website design have occurred leaving a need for an update and re-design. To address this issue, University of California Cooperative Extension recently received a Renewable Resources Extension Act Capacity Grant to update the website and to expand its reach to new groups. This entailed redesigning the website to update its appearance, adding the latest oak woodland research, expanding our audience within groups who already use the website, and promoting the website to groups who have not historically used it. Target groups include the ranching community, winegrape growers, Master Gardeners, and members of the California Naturalist Program. With a new look and expanded reach, the Oak Woodland Management website will increase knowledge of oak woodland conservation and improve the ability of local land managers across the state to more effectively manage their oak woodlands.

Devii Rao

Rao is the University of California Cooperative Extension Livestock and Natural Resources Advisor serving San Benito, Monterey, and Santa Cruz counties, on California's Central Coast. Her research and education programs focus on improving economic and ecological sustainability of ranching. In particular, she is working on issues related to rangeland weed management, livestock management during drought, livestock health, and livestock grazing to benefit natural resources.

Back to top

---

Highlights of a California Landowner’s Twenty-two Year Oak Woodland Conservation Project
An estimated 80% of California oak woodlands are privately owned. The presenter and her partner became part of that number in August, 1994 when they moved to a small twenty acre parcel in northern California. From the beginning they appreciated the oak woodland as a vital force provisioning the local ecosystem with food in various forms and providing less visible services such as sequestering of carbon and ameliorating local weather extremes. During the first year on the land, they took an informal inventory of oaks on the property and found many mature oaks with diameter at breast height (DBH) of 25 to over 65 inches, fewer oaks with a DBH of 8 to less than 25 inches and no trees with a DBH of less than 8 inches. Their concern about the lack of young oaks crystalized into an oak conservation project. Over the next twenty-two years, the presenter and her partner developed a simple protocol, requiring few resources, that has succeeded in adding over 150 young oak trees ranging from 2 feet to 30 feet in height. The presenter will describe their experiences and the benefits and disadvantages of each method they experimented with for planting, protecting and inventorying young oaks.   The presenter and her partner hope that sharing our experiences in oak conservation will inspire and inform other land owners to become involved in oak conservation. 

Diane S. Pepetone

Diane S. Pepetone has been an amateur naturalist since she won first prize in the 6th grade science fair for her project “Nature in My Own Backyard” which at that time was in rural upstate New York. From 1973 to 1979, Pepetone taught life sciences in a London, England middle school and led the school’s Nature Club. Fast forward to 1995 when Pepetone and her partner began an oak conservation project on 20 acres in northern California.  In 2001 Pepetone, inspired by their oak conservation project, wrote and performed a one-woman play about oaks in northern California, called “And Who Will Heal the Ground: an Earth Play about Humans and Oaks”. In 2014, Pepetone completed the University of California Naturalist program. Currently Pepetone works with the California Energy Commission developing information systems to track results of their building energy efficiency standards, and continues with her oak conservation work.

Back to top

---

The Great Oak Count and The OakWell Survey: Comprehensive Surveys of Palo Alto’s Native Oaks 
In Silicon Valley, over the last two centuries, once prevalent oak woodlands have been largely eliminated, first by agricultural conversion and later by rapid development and urbanization. Twenty years ago, a dedicated group of volunteers conducted The OakWell Survey, a city-wide inventory of coast live oaks, valley oaks, blue oaks, and California black oaks, in order to create a baseline for future evaluation of changes in Palo Alto’s native oak population. Today, there is increasing recognition that re-integrating oaks in our parks and urban landscapes promises a host of benefits, both for wildlife and for people. As a first step, Canopy and partners have revived the comprehensive survey of native oaks in Palo Alto - The Great Oak Count. We actively educate the community about the importance of native oak trees and how to properly care for them. And by engaging residents to use our new Tree Plotter tool and inviting Citizen Scientists to gather data on the number, size, and locations of oaks in Palo Alto, we gain community support and valuable data collection. This effort will reveal the native oak population changes, and help inform urban forest managers and re-oaking efforts for the coming decades. The last wave of urban tree plantings 50-75 years ago is nearing the end of its lifespan and we now have the chance to shape our environment once again. With hundreds of years behind us, we move forward to the new generation of oak plantings and oak advocates.

Elise Willis

Willis is a Certified Arborist and Community Forestry Program Manager at Canopy, a nonprofit based in Palo Alto, CA, where she manages several tree survey, planting, and community engagement programs. Elise thoroughly researched The OakWell Survey, then began the design, launch, and ongoing management of The Great Oak Count and Canopy Tree Plotter tool. Before Canopy, Elise provided building permit plan check and full analysis/recommendations for tree planting goals and reducing tree and hardscape conflicts for the City of Palo Alto Urban Forestry group. She has a B.S. in Forest Resources and Conservation from the University of Florida.

Back to top

---

Species Boundaries Between Three Sympatric Oak Species at the Northern Edge of their Distribution in China
Oaks are important timber trees with wide distributions in China, but few genetic studies have been conducted on a fine scale. This presentation will introduce the genetic diversity and differentiation of three sympatric oak species (Quercus aliena Blume, Quercus dentata Thunb. ex Murray, and Quercus variabilis Blume) in their northern distribution in China using seventeen bi-parentally inherited nSSRs markers and five maternally inherited chloroplast DNA (cpDNA) fragments. Both the cpDNA and the nSSRs show a high level of genetic differentiation between different oak sections. The chloroplast haplotypes are clustered into two lineages. Clear species boundaries are detected between Q. variabilis and either Q. aliena or Q. dentata. The sharing of chloroplast haplotype H1 between Q. aliena and Q. dentata suggests very recent speciation and incomplete lineage sorting or introgression of H1 from one species to another. The nSSRs data indicate a complete fixation of variation within sites for all three oak species and that extensive gene flow occurs within species whereas only limited gene flow is detected between Q. aliena and Q. dentata and nearly no gene flow can be detected between Q. aliena and Q. variabilis  and between Q. dentata and Q. variabilis. Prezygotic isolation may have contributed to the species boundaries of these three sympatric oak species.  

Fang Du

Fang Du is trained in population genetics and obtained a joint PhD from the University of Bordeaux & Biogeco INRA, France and Lanzhou University, P.R. China in 2010. After graduation Fang Du started her career in Beijing Forestry University and established the first Molecular Ecology lab in the university, mainly focused on genetic dynamics of Chinese oaks.

Back to top

---

Addressing Roots of Threats to Oaks
Jen Bayer, Hilary Bayer

For forty years, Magic has engaged in oak habitat stewardship on 1,000+ acres of Stanford University lands. We began with an eye to sustaining existing California native oak populations by planting acorns and seedlings where natural regeneration was failing. Soon we realized that more was necessary. We defended oaks against cattle, rodents, vandals, weeds, and fire. We advocated to prevent their removal to make way for roads and buildings. We irrigated through punishing droughts—first worse than any in the prior 800 years, second worse than any in the prior 1200—exacerbated by record heat. We’ve watched helplessly as an introduced pathogen (Phytophthora ramorum) takes its toll. Having come to see the forest for the trees, we’ve increasingly seen the globe for the forest. In response we’ve shifted emphasis from what we do on the land to what we do with hearts and minds out of which humans are driving global ecosystem disruption. Twenty thousand volunteers have learned with us to work for common good. Through oaks they have reconnected to a natural world increasingly concealed and mediated by technology. They have been motivated to think ecologically about everything from daily habits to underlying questions of value. While we take satisfaction in having established thousands of trees, hundreds of which now tower over us, we know that only by altering ideas about what humans want and how we can get it, and actions we generate from them, have we any hope of securing the oaks’ and our own future.

Jen Bayer and Hilary Bayer

Jen Bayer and Hilary Bayer are Program Associates at Magic, a Palo Alto-based public service organization that demonstrates how people may apply science to questions of value. Both have participated for more than a decade in “Planting for the 2nd Hundred Years,” an oak habitat stewardship project conducted by Magic on Stanford University lands. For five years they’ve shouldered leadership roles in the project.

Back to top

---

Wither the Mighty Oak? Examining Trends in Large Hardwood Trees in Northern California and Southern Oregon, USA
This presentation examines trends in large oak trees within mixed conifer-hardwood forests of northern California and southern Oregon, USA. Several hardwood species support wildlife species of concern such as the Pacific fisher and northern spotted owl and are also important to Native American tribes. Having evolved under frequent fire regimes, many hardwood trees have depended upon fires to arrest overtopping by conifers, yet they are vulnerable to top-kill by intense fires. Many forests in the region have experienced conifer encroachment and densification on the one hand, and severe wildfires on the other; both trends threaten mature trees and the ecological services they provide. We test whether declines in several large hardwood species are evident in long-term forest monitoring data collected through the Forest Inventory and Analysis program across forests in this region that historically experience frequent fires and supported fisher. We analyze changes in the abundance of shade-intolerant California black oak (Quercus kelloggii) and Oregon white oak (Quercus garryana), along with more shade-tolerant species including canyon live oak (Quercus chrysolepis). We hypothesize that declines will be larger in the shade-intolerant species and most pronounced in plots that recently experienced wildfire. However, we consider how other mortality agents, including sudden oak death in Mendocino County and drought-related bark beetle outbreaks in the southern Sierra Nevada may complicate these interactions. Achieving a more complete understanding of these dynamics will help to develop strategies to promote resilience to climate change and associated disturbances.

Jonathan W. Long

Jonathan W. Long is a research ecologist with the Pacific Northwest Research Station in Davis, California. He leads a variety of interdisciplinary research projects to help managers restore forests and wetlands to support important social and ecological values. In recent years, he has produced a report on restoring California black oak in a partnership with the North Fork Mono Tribe and other experts, studied the effects of large fires on forests and watersheds, and developed science-based strategies for restoring forests landscapes in the Pacific West. He has worked previously for the Rocky Mountain Research Station, University of Arizona Cooperative Extension, and the White Mountain Apache Tribe in Arizona.

Back to top

---

Common Names for Oaks in Western Europe - and the Spanish Problem
Most Western European languages have a name that covers all trees in the genus Quercus. Some languages have few names for oaks, others have many. This difference usually reflects the number of species native to the areas where each language has developed. In languages where only one name exists for Quercus, the name is joined to another word to describe a different species (e.g. oak is used for cork oak, holm oak, Turkey oak, etc.). In languages where many names for different species exist, a general name for all oaks was retained (e.g. "quercia" in Italian, "chêne" in French, "carvalho" in Portuguese). Spanish is the exception: many names exist for different species, but no name covers all oaks. In general usage, a name for one species or group of species is adopted as a general name for oaks, and different names are chosen for this purpose in different Spanish-speaking regions: "roble" in Spain and Latin America, "encino" in Mexico. This obliges one to state that an "alcornoque" (Quercus suber) is a "roble" (Quercus robur), which would be equivalent to saying that a Californian is a Texan!
In this lightning talk I will review this situation, discussing the etymology and meaning of common names for oaks in the major Western European languages, and I will highlight the problem that exists in Spanish. In conclusion, I will present a solution to the problem, introducing a name for oaks in Spanish first proposed in a blog by Teo Marañón in 2014.  

Roderick Cameron

Cameron first became interested in oaks on inheriting his father’s oak collection in 2008. He has served on the Board of the International Oak Society since 2012, and is currently Curator of Grigadale Arboretum in Argentina. As Website Editor for the IOS he has published numerous blog posts and articles on different aspects of oak culture, and he has also contributed articles to International Oaks, the IOS Journal. He is bilingual in English and Spanish and is familiar with French, Portuguese, German, and Italian. His Interest in the diversity and origin of common names for oaks in various languages has grown in parallel with his interest in oaks themselves.

Back to top

---

Evaluating the Impact of Emergent Disease on Microbial and Insect Populations in the Tree Ecosystem
The escalating emergence of new pathogens is becoming a major threat to tree populations. These new diseases will not only have a devastating effect on tree populations but may consequently impact the many important organisms that are dependent on them. Acute Oak Decline (AOD) is a relatively newly defined disease affecting the United Kingdom’s two native oak species, Quercus robur and Q. petraea. The focus here will be on the impact that this disease may be having on the wider oak community and how we can use this information to help conserve oak woodlands for the future. Oak trees were selected from various AOD affected woodlands across the UK. Bacterial and fungal endophytes within the leaves and inner bark were determined using next generation sequencing. By comparing endophytic communities of healthy trees to those with AOD we can better understand the impact that this potentially devastating disease may be having. Identifying beneficial microbes that could either reduce disease or promote tree growth could be developed into a much-needed biological control for AOD. This talk will also briefly explore the influence of oak tree genetics on the composition and abundance of insect herbivores and endophytes associated with oak trees in the UK. Phenological and morphological measurements of the host tree were taken, insect herbivore species were recorded, and microbial endophytes were identified using next generation sequencing. This information will enable us to better understand oak communities and will help us to predict the possible impact of climate change on oak woodlands in the UK.

Shyamali Roy

Roy earned her BSc in biology from Royal Holloway (University of London) in 2010 and with a passion for forest conservation went on to study an MSc in conservation and forest protection at Imperial College London. In 2013, she started an internship with Botanic Gardens Conservation International (BGCI) undertaking the Red List assessment of the Betulaceae family. Shyamali is currently a final year PhD student in the department of biological sciences at the University of Reading. She is interested in the influence of tree genetics and emergent disease on the insect and microbial communities associated with trees. Specifically, she is interested in the impact of the disease Acute Oak Decline on the associated microbial community of oak trees in the UK. 

Back to top

---

Managing Sudden Oak Death: Selected Studies on What Works, and What Doesn't
Many treatment methodologies have been proposed to both prevent and cure oaks infected with Phytophthora ramorum, causal agent of sudden oak death. Bark scribing, a technique used in California to treat citrus infected with Phytophthora for nearly 100 years, seemed to show promise, especially after pilot studies seemed to show better than 80% efficacy in the field. However, controlled, replicated studies done on branches of mature oaks show that the situation is much more complicated than expected. Oaks are surprisingly good at killing P. ramorum, even if they do not always survive infection. Our results cast doubt upon the purported efficacy of bark scribing as a treatment technique, even in such “proven” systems as citrus.

Steven Swain

Swain is the Environmental Horticulture Advisor for Marin and Sonoma Counties, in California.  He brings a breadth of perspectives to his work in forest pathology, having been introduced to Phytophthora ramorum while working in industry in the mid 1990’s, then working in both research and extension positions at University of California Davis, UC Berkeley, and UC Cooperative Extension. Most of his research over the last fifteen years has focused on practical aspects of treating trees and greenwaste infected with Phytophthora species.

Back to top

---

Intimate Encounters with Wild Oaks: TreeGirl Nude Photography with Fantastical, Famous and Ancient Oaks 
Ancient Oaks are ecological treasures, but not often enough do we appreciate them for their unique character and aesthetic beauty as living beings with whom we can mindfully interact. As a photographer, TreeGirl has captured herself and other women intertwined nude in intimate connection with some of the world's most fantastical, famous, and ancient oaks. She will share with us her photographs and each individual tree's unique natural history.

Julianne Skai Arbor

Arbor, aka TreeGirl, is known for her fine art nude photography of herself and other women intertwined with trees all over the world. (Oaks are her favorite!) She is an ISA Certified Arborist, California Naturalist, Forest Ecotherapist, interdisciplinary conservation educator, and author of TreeGirl: Intimate Encounters with Wild Nature, which highlights 50 tree species, their natural history, ethnobotany and conservation status as well as the ecopsychology of the human-tree relationship. www.treegirl.org

Back to top

---

Oaks in the Mix: Championing Quercus within a Diverse Living Collection
The thirty-four acre University of California Botanical Garden (UCBG) is one of the most diverse landscapes in the world. As a member of the UC Berkeley Natural History Museum System, UCBG serves as a “living museum” displaying over 10,000 taxa, including many rare and endangered species. The majority of UCBG accessions are wild-collected (with documented locality data) and hence provide an invaluable resource for scientists and students from around the world. UCBG’s Quercus collection is a particular point of pride - as is its inclusion in the Multisite Quercus Collection of the Plant Collections Network, a network of botanical institutions striving to preserve global plant diversity. UCBG stewards 174 Quercus accessions, representing over 70 wild-sourced taxa. The Garden’s collection is notable for the richness in species from Mexico and Central America, many of which are significantly underrepresented in living collections. In addition, diverse oaks from Asia, Europe and the United States are integrated throughout the Garden’s other geographical collections. Through ongoing collaborations with research and conservation partners, UCBG continues to build this flagship collection. Highlights of these collaborations - and the exceptional collection itself - will be presented.

Vanessa Handley

Dr. Vanessa Handley is the Director of Collections & Research at the University of California Botanical Garden (UCBG).  Vanessa completed her doctoral degree in plant biology at UC Berkeley, with a research focus on molecular mechanisms of disease resistance. Her current research centers on plant evolution and conservation and she collaborates with colleagues at California Academy of Sciences and UC Berkeley on projects in California and internationally. Before joining UCBG, Vanessa enjoyed a decade as a biology professor at a small liberal arts institution, Holy Names University. At HNU, Vanessa served as Chair of the Division of Math and Science and was instrumental in reinvigorating the Division’s plant science curriculum. Outside the academic realm, Vanessa has run a landscape design business and led botany tours for a natural history travel company.

Back to top

---

Concurrent Session Track B: In-depth Case Study: The Oaks of Apple Park

 

The Oaks of Apple Park
One of Steve Jobs’ last visions to be realized is the diverse forest surrounding the new Apple main campus, now known as Apple Park. These trees were sufficiently important to Mr. Jobs that he hand-selected a Senior Arborist to oversee the growth, and installation of the trees. The Senior Arborist in turn convinced Mr. Jobs of the value of vastly diversifying the forest, as a way to protect it, over the the next century or more, from the largely unknowable effects of climate change. A wise investor hedges their bets. But Mr. Jobs, famous for his love of design and aesthetics, made clear this was to be no Arboretum, with lots of individual specimens of a taxa, but no overall design coherence. Whatever trees were to be used at Apple Park needed to be used in quantity. In this Workshop, I would like to present both the process, and the outcomes of introducing dozens of new oak types to California, through the Apple Park landscape. This workshop will cover 25 years of observing and trialling oaks on the San Francisco Bay Peninsula, with special emphasis on work done at Stanford University. The journey will be depicted with hundreds of unique photographs, with questions taken throughout. Please join Apple’s Senior Arborist, Dave Muffly, on an unexpected journey to creating a corporate campus landscape that fully embraces ecological adaptation to climate change.

Dave Muffly

Dave Muffly was born and raised in rural Nebraska. Dave attended Stanford University, earning a Mechanical Engineering degree, before venturing into ecology shortly after college. For decades, Dave assisted in managing an oak reforestation project for Stanford University, learning the realities of planting native oaks on the San Francisco Bay Peninsula. He also helped organize the distribution of tens of thousands of bare root fruit trees to school children throughout California. Dave became a certified arborist in 1998, and proceeded to delve deeply into urban forestry. After designing and overseeing installation of 1,000 drought adapted trees in low income East Palo Alto, Dave created the Oaktopia nursery to bring new trees, particularly oaks, to California. Dave was discovered by Steve Jobs, and now thousands of those Oaktopia trees form the diverse backbone of the Apple Park landscape.

Back to top

---

Workshops

Climate Change and California Native Cultures Uses of Oaks: Food, Art, and Tribal Identity
Frank Lake, Don Hankins

This workshop will bring together California tribal oak practitioners and artists to share their knowledge, stories, and experiences with oaks for their cultural identity as “Acorn people.” Invited tribal presenters will demonstrate traditional uses of oak materials for artistic inspiration, cultural identity, and others providing acorn processing and cooking demonstrations. Conference workshop participants will be able to learn of different oak materials used to make products’ like cooking implements, tools, oak gall toys, basketry sticks, etc., and acorn use demonstrations when talking with tribal practitioners and artists. Participants will also learn about how climate change, resource management and other socio-ecological factors affect the living cultural experiences California tribes have with oaks. This workshop will provide an opportunity to learn of California tribal cultural practices and oak-themed art. 

Frank Lake

Frank received a Bachelor of Science degree from University of California-Davis (1995) in Integrated Ecology and Culture with a minor in Native American Studies. In 2007 he completed his Ph. D. graduate degree from Oregon State University, Environmental Sciences Program. He works on tribal and community forestry and related natural resource issues. His research focuses on restoration ecology and the incorporation of traditional knowledge into wildland fire and forest management in the Pacific Northwest and northern California, with an emphasis on the Klamath-Siskiyou bioregion. He has a research interest in wildland fire and management effects on tribal acorn food systems. Recently, his focus is how tribal traditional knowledge can be incorporated in to scientific climate change and food security research to support tribal adaptation and mitigation strategies. Frank is an oak steward, tribal acorn gatherer and artist.

Back to top

---

Developing a Global Fagaceae Working Group
At the IUFRO Conference on Fagaceae Genetics and Genomics in November 2017 at the Chenshan Botanical Garden in Shanghai, a proposal was developed to create a multi-disciplinary international working group on the beech family (Fagaceae). The purpose of the working group is to develop common standards, protocols, materials, genetics markers, etc for future work in the Fagaceae to improve our ability to compare and work across studies, species, institutions, and continents. A white paper will already be available by the time of the meeting. The purpose of the workshop will be to provide a forum for a structured and targeted discussion to get input from the broader community of oak scientists and enthusiasts.

Chuck Cannon

Chuck is an expert on Lithocarpus, including systematics, phylogeography, and historical climate change modeling. He co-organized the IUFRO conference in November 2017 and led the discussion about the creation of a Global Fagaceae Working Group and will be leading the writing of the white paper.

Back to top

---

Open Science Protocols for Contributing to Informal Oak Research Networks
This workshop will introduce participants to a range of open protocols that are available for monitoring oaks and oak woodlands. These address many of the major questions in oak ecology, including oak regeneration, climate change adaptation, diseases and pathogens, and response to prescribed fire and wildfire. The research methods will span the gamut from citizen science to researcher-driven studies, with a particular emphasis on the middle ground for those who want to collect valuable high-quality data with a minimum of resources. Open protocols are well suited to small organizations, land managers and practitioners, as well as property owners interested in the health and dynamics of local stands as well as contributing data to growing datasets. There will be a focus on questions and campaigns specific to California oaks, but the topics and many of the protocols will be broadly applicable. Expect an active workshop, emphasizing interactive sharing of ideas and experiences. There will also be a hands-on portion providing an opportunity to test out several of the discussed protocols on the grounds of the University of California, Davis Arboretum and Public Garden.

Prahlada Papper

Through his work in the University of California, Berkeley's Ackerly Lab, California Phenology Project, and the California Naturalist program, Prahlada Papper has extensive experience working across levels of scientific research. From the lab and the field to collaborative work with local and regional conservation groups and land trusts to public participation citizen science projects, these are methods designed to simultaneously gather critical data on a broad scale, engage and educate the public, and inform management objectives.

Back to top

---

Structural Pruning of Oaks
The purpose of this workshop is to describe and demonstrate current structural pruning strategies to improve architecture on young, medium-aged, and older trees. We will focus on the long-term response of trees to pruning and show many real-world examples from California and across the world.  We discuss not only what and how to improve structure and reduce the likelihood for failure, but also how the tree is likely to respond. From training young trees to managing mature ones, structural pruning to guide and manage tree architecture should be the primary goal each time a tree is pruned. We will show you how to create a well-structured tree that is aesthetically pleasing and supports the crown so it grows old gracefully. This ensures that the tree will provide the greatest benefits at the lowest cost. We will be working in the field pruning examples of young oak trees on the UC Davis campus.

Brian Kempf

Brian Kempf is the founder and director of the Urban Tree Foundation, founding partner in Wood Architecture LLP and partner in Pioneer Pot Inc. Brian has worked to improve cultural practices for the production of plants and training of trees both in orchards and the urban setting. He is the co-author of 'Guideline Specifications for Nursery Tree Quality', Strategies for Growing a High-Quality Root System, Trunk, and Crown in a Container Nursery and the text book 'Structural Pruning: Guide to the Green Industry'. In his resident city of Visalia, California, Brian has planted approximately 10,000 trees over the last decade. His planting endeavors include Downtown Visalia, neighborhood street trees, municipal waterways, habitat restoration, and shade trees on school campuses. Brian received a degree in Geography with an emphasis in Regional Analyses from the University of California, Davis.

---

Establishing a Consortium of ex situ Conservation Collections for Threatened North American Oaks
Murphy Westwood, Matt Lobdell, John Clark, Pam Allenstein, Abby Meyer, Sarada Krishnan, Jessica Wright, Naomi Fraga, Tim Boland

Oaks are exceptional species that cannot be seed banked through conventional methods. As such, ex situ living collections are critical for safeguarding germplasm of threatened species. However, very few oak collections today have high conservation value and many accessions are of unknown or garden origin, further diminishing conservation value. A 2017 ex situ survey by The Morton Arboretum, BGCI-US and the US Forest Service revealed that of the 28 most threatened U.S. oaks, one-third were represented by fewer than 10 wild-origin plants, and five species were not represented in a single collection in North America. Despite the currently poor state of threatened oak collections, we have the networks, expertise, and guidelines in place to activate a coordinated, scientifically informed consortium of collections dedicated to preserving the genetic diversity of our native oak species. This workshop will bring together stakeholder networks (e.g. American Public Gardens Association, Botanic Gardens Conservation International-US, Center for Plant Conservation, and others), who will present on the botanical expertise, collections, databases and communication platforms that can be leveraged to establish this collections consortium. The results of the recent US oak ex situ survey will be presented to identify current gaps in living collections. Participants will break into working groups to discuss issues like climate change resiliency of collections, collection design and layout, research applications, seed collection strategies, germplasm exchange, and data tracking and reporting needs. An open discussion forum will conclude the session, allowing for synthesis of working group conclusions and establishing next steps.

Murphy Westwood

Westwood runs the Global Tree Conservation Program at The Morton Arboretum. She holds a PhD in Plant Developmental Genetics from Cambridge University (UK), an MS in Taxonomy and Biodiversity from Imperial College London (UK), and a BS in Environmental Policy and Behavior from the University of Michigan. She has 10 years of experience in plant research and conservation at botanical gardens in the US and Europe. She has conducted fieldwork on three continents. She led the IUCN Red List of US Oaks and works to improve the conservation value of ex situ oak collections at the Arboretum and around the world. She is Chair of the Plant Conservation Professional Section for the American Public Gardens Association, a Conservation Officer for the Center for Plant Conservation, a member of the IUCN Global Tree Specialist Group, and a Global Tree Conservation Officer for Botanic Gardens Conservation International.

Back to top