Research in Context
Quest for Plant Material
Botanical Explorations and Plant Collections
Although the focus of most research projects on tree species resilience has been heat tolerance, there are more aspects regarding adaptability to new climate conditions. Such as flooding and sharp fluctuations in temperature. Warm conditions can be followed by an abrupt drop in cold temperature. Therefore according to researchers, exploration for suitable tree species, should not be limited to warmer and drier areas to the south but extended to mountain plains and steppes.
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France
Thierry Lamant, a French forester with expertise on oak trees, based on his experience on the genetic conservation of trees at arboreta and the International Oak Society, suggests that similar environmental conditions are encountered in semi-arid areas at high altitudes (ArboRencontre de Seine-et-Marne 2022, page 8). They can be characterized as cold deserts (Sottosanti 2023).
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Thierry Lamant precises that these environmental conditions “can be found in the backcountry of the Mediterranean, the Balkans, the center of Spain, north Africa, Cyprus, the Middle East and in Iran. An even greater reservoir in terms of biodiversity can be found in the Chihuahua desert in America.” (ArboRencontre de Seine-et-Marne 2022, page 8).
[1] According to oak trees expert Thierry Lamant a great reservoir in terms of biodiversity can be found in the Chihuahua desert in America. Image credit: Navarro, Jesus M (2025). Northern Mexico’s Chihuahua region features vast desert landscapes, pine forests, and the dramatic Sierra Tarahumara...[Online image]. Shutterstock. https://www.shutterstock.com/image-photo/northern-chihuahua-region-features-vast-desert-2621279659
​​[2] Semi-arid areas at high altitudes have environmental conditions that correspond to future climate conditions. Plateaus in higher altitudes in the Mediterranean region may be a source for species and ecotypes with resilience. Image credit: Sophia Vardaki, (2024). Lasithi plateau in NE Crete, end of summer.
​​​​​​​​​United Kingdom
Kew Gardens, London
Similarly, Kevin Martin and fellow researchers in Kew Gardens also consider the steppes and high plains of Iran, Romania, Georgia, Kazakhstan and Azerbaijan, a field where future explorations of resilient species and genotypes should be carried out (Martin 2024, Martin and Sjöman 2025, Martin 2025). The team of the Kew Gardens who carry the responsibility of preserving the garden's rich tree collection and the integrity of its landscape, has already conducted such trips. Also the city of Altamira in Spain has been identified as comparable the predicted climate conditions at the Kew Gardens in 2090 (Martin and Sjöman 2025). The specific areas for sourcing material have been identified through analysis and assessment described in the website page Species Distribution Modeling. ​
Image credit: Masyura, N. (2023). Road in the old mountain village of Lahij. Ismailly. Azerbaijan. [Online image]. Shutterstock. https://www.shutterstock.com/image-photo/road-old-mountain-village-lahij-ismailly-2362758787
Image credit: Vastram(2021). View of Lahij village in Azerbaijan.[Online image] Shutterstock. https://www.shutterstock.com/image-photo/view-lahij-village-azerbaijan-2086885966
Image credit: Shijo S Jose (2025). Dense Pine Forest and Lush Mountains in Azerbaijan.[Online image] Shutterstock. https://www.shutterstock.com/image-photo/dense-pine-forest-lush-mountains-azerbaijan-2642048325
[3,4,5] Landscapes in the mountain areas of Azerbaijan. According to researchers associated with the Kew Gardens, high plateaus in some countries of E. Europe and W. Asia should be targeted for botanical exploration.
[6] Current environmental and climate conditions in Altamira, Spain are comparable to predicted conditions for the Kew Gardens in 2090. Image credit: Nito (2021). An aerial view of the Altamira Castle in Elche, Spain, and the famous Palmeral, known as Palm Grove of Elche in English, a public park with many palm trees. [Online image] Shutterstock. https://www.shutterstock.com/image-photo/aerial-view-altamira-castle-elche-spain-2046794216
Forestry England, Westonbirt Arboretum
In the field of forest conservation and adaptation to the climate, Forestry England has organized botanical expeditions for wild seed collecting. With the aim of improving tree collection and its conservation value, Westonbirt National Arboretum has collaborated with international partners. Since 2000 it has enriched its collection with trips to the Mediterranean Region (Turkey, Italy, Greece), Far East (Japan, Taiwan) and the Americas (Chile, USA). In September 2024 a team travelled to Greece in search of wild seeds of nine Acer species (maples). Material from populations of species A. campestre, A. platanoides and A. pseudoplatanus may prove valuable for studying response to future climate change (Forestry England n.d.).
​​[7] Mountains in mainland Greece can be a source for wild tree seed collection. Mt. Taygetos is home to very rare Acer hyrcanum subsp. reginae-amaliae. Image credit: A.Vardakis (2017). Landscape at the village of Dimitsana, Taygetos mountain
Netherlands
At the Dutch project "CSI Trees: Future proof trees", specific work packages have been assigned to the goal of finding and utilizing new genetic material. Actions that have been planned are:
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contacting institutes with databases in the countries with interesting biomes
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new genetic plant material searched and imported based on physiological search profile.
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imported genetic material to be validated in measurement line
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involvement of the tree nursery industry
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new material reproduced by participating tree growers and
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market introduction of new trees with legal support from the Wageningen University (Wageningen University and Research n.d.)​​​​
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Definition. A biome is an area of the planet that can be classified according to the plants and animals that live in it.
USA
University of California in Davis
​Although most plant explorations will be conducted through international cooperation, surveys in different and diverse environments inside a country can also provide new species for testing (Martin 2024). As is the case with research at California’s University of California in Davis where plant material was collected from native species in the state of Texas.
In 2019 Emily Griswold, a senior horticulturalist of the University's Arboretum and Public Garden led a team that collected plant material from more than 40 tree species in arid regions in west and central Texas to start propagating them back in the Arboretum nursery.
The selection for Texas native trees, not commonly grown in California, was based on their ability to survive to more adverse climate conditions than the current in California.
"For the Texas trees that end up thriving on campus, the team plans to share information and propagation materials with the horticulture and nursery industries for commercial production — to benefit our region and eventually our backyards. " (Dawson 2023).
The research on tree species for the climate of the future is integrated in the long-term planning of the campus (Burke et al 2023).
​​​​​[8] Desert landscape in the state of Texas. Image credit: Wix Studio Images Database
Stanford University
With a long history of planting trees at the campus, the Stanford University has developed a series of strategies for the future viability of its forest. To this effect various resources are being utilized:
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The long history of horticulture in California in planting and testing a diverse palette of trees from all over the world
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research on trees grown in the private Apple park in Cupertino CA, mainly oak species. Located at approximately 25 kms to the SE of the campus, it serves as living and learning laboratory for a large number of tree species.
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regenerative tree plantings on the campus that have begun as early as the beginning of 2000's
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According to the recently updated University's Tree Report, the areas with the projected future climate at Stanford are
"in southern California, the American Southwest together with northwestern Mexico, and regions around the Mediterranean Sea, into western Eurasia. These are areas where monsoonal rainfall occurs during the summer, to varying degrees, in addition to regular winter rains."
Assisted migration of foundational tree species from the climate analog regions could be, after testing and research, protect and even augment the tree landscape at the campus. (Muffly 2025).
[9] University campuses is another field besides botanical gardens where the challenge of trees and climate change is addressed. Through research and long-term planning for their landscape. Image credit: Wix Studio Images Database
FURTHER NOTES
It is possible that similar efforts for new species or ecotypes, could greatly benefit by “plantsmen” who endeavor in botanical explorations. World renown flora experts like ELeftherios Dariotis comes to mind, with their knowledge of niches in the wild and lesser-known taxa (Gay 2023).
​​​​​​FOREST TREES RESEARCH
​In research on the resilience of the French forests, strategies on assisted migration of tree species populations is employed. (Musch and Paillassa 2025, Musch 2025). Even species further away from Europe are targeted, such as species in the North African or Middle East coasts in the Mediterranean basin.
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The French Organization for forestry, named the project of assisted migration in honor of Jean Giono, the author of the legendary short story "The Man who Planted Trees" (Project Giono Resources).
[10] A plant sculpture with the art of mosaïculture, dedicated to the work by Giono "The Man who Planted Trees". Designed by Mrs Lise Cormier and realized by the team of Mosaïcultures Internationales de Montréal (MIM). Montreal Botanical Garden,
Quebec, Canada. MIM Exhibition, 2013 edition. Image credit: A. Vardakis (2013).
With the strategy of assisted migration, opportunities emerge for the preservation of endangered rare tree species. Such notable examples that have attracted attention are:
- Wollemi pine, Wollemia nobilis
Through the network of botanical gardens this Australian species has been planted in far away locations around the world. Locations in the UK, in Atlanta and elsewhere have been chosen taking into account, the climate changes ahead. The widest possible range of genetic diversity found in the wild population is therefore preserved (Forestry England, Offord and Zimmer 2024). In a recent study the focus has been on the Wollemi pine and "the willingness of amateur gardeners to grow rare and threatened species and report on the results. Such enthusiasm could potentially be harnessed to extend metacollections to home gardens, especially where botanic gardens are limited in planting space or resources for data collection" (Offord & Zimmer, 2024).
[11] Sakoulis, A. (2021). Zelkova abelicea is a species of tree in the family Ulmaceae and is referred to by the common names Cretan zelkova and on Crete proper as abelitsia [Online image]. Shutterstock. https://www.shutterstock.com/image-photo/zelkova-abelicea-species-tree-family-ulmaceae-2078924158
PRIVATE SECTOR
Even in private landscape constructions and design, the same challenges for sourcing resilient plant material have to be met. A notable example is the design and construction of terrace gardens at Narbonne in the south coast of France. In order to ensure the future viability of plantings at the Château Capitoul, garden designer James Basson cooperated with Olivier Philippi, an authority on Mediterranean flora. He undertook sourcing for suitable hardy species in Greece, Gibraltar, Cyprus and various locations with corresponding environment conditions. Although seeds and plant material were obtained for shrub and aromatic species and installed a plot at the garden for prior testing. However for the tree species it was not possible to ensure plant material with likewise provenance. New trees were provided through more conventional channels. In a recent event of heatwave they were among the new plantings to suffer most. ​​​​​​(Fayolle 2025, Scape Design n.d., Chateau Capitoul Hotel 2024).
[12,13] Pseudodictamnus acetabulosus (top) and Teucrium capitatum (bottom). Maquis and phrygana shrubs sourced from more arid areas are utilized in garden projects with the purpose of resilience to future climate conditions.
REFERENCES
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PAPERS
​​​​​​Offord, C. A., & Zimmer, H. C. (2024).
Home gardens contribute to conservation of the critically endangered Wollemi Pine: Evaluation of a botanic garden-led horticultural release programme.
Plants, People, Planet, 6(1), 116–127.
https://doi.org/10.1002/ppp3.10410
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ArboRencontre de Seine-et-Marne. 2022. “Plantations d’arbres et changement climatique.” CAUE77, Conseil d'Architecture, d'Urbanisme et de l'Environnement de Seine-et-Marne, Arbres de Seine-et-Marne. June 23, 2022.
https://www.calameo.com/caue77/read/005988181bff7e9c28abd
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Wageningen University & Research. CSI Trees: climate trees with future. Kick-off poster.
https://www.wur.nl/en/show/kick-off-poster-csi-trees.htm
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YOUTUBE CHANNELS
Martin, Kevin and Sjöman, Henrik (2025, July 14).
Thinking in tree time | Kew.
Royal Botanic Gardens, Kew.
https://www.youtube.com/watch?v=KZXfpuMJJm8
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Musch, Brigitte and Paillassa, Eric (2025, June 27).
Adapter la forêt française au changement climatique : ressources et expérimentations.
Université Virtuelle Environnement et Développement Durable (UVED).
https://www.youtube.com/watch?v=-aBEJENZE6U
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Martin, Kevin (2025, September).
What are the climate risks to trees and therefore which urban trees should we plant for the expected future climate? [Video].
Trees and Design Action Group (TDAG)
https://www.youtube.com/watch?v=z8N2UKdO5X8
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UNIVERSITY AND RESEARCH WEBSITES: ARTICLES, REPORTS, WEBINARS
Burke, Mary., Socolofsky Kathleen, Segar Bob, Griswold Emily, Griffith Lucas, Stromberg Ingrid, and Nishimura Kelly. 2023. “Living Landscape Adaptation Plan.” University of California Davis, Campus planning. March 2023.
https://campusplanning.ucdavis.edu/living-landscape-adaptation-plan
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Dawson, Brenda. 2023. “How UC Davis Is Growing a Tree Canopy for Tomorrow’s Climate. When’s the best time to plant trees? Now, 20 years ago and 20 years in the future.” University of California, College of Agricultural and Environmental Sciences. March 22, 2023.
https://caes.ucdavis.edu/news/how-uc-davis-growing-tree-canopy-tomorrows-climate
Fondation Franklinia (2023).
Conservation of Zelkova abelicea in Crete.
https://fondationfranklinia.org/en/projet-zelkova-crete/
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Forestry England (n.d.)
Wollemi pines at Bedgebury.
https://www.forestryengland.uk/bedgebury/wollemi-pines​
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Forestry England (n.d.)
Westonbirt Arboretum seed collection expeditions.
https://www.forestryengland.uk/westonbirt/seed-collection-expeditions
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Forestry England (n.d.)
Expedition to Greece - Westonbirt Arboretum.
https://www.forestryengland.uk/westonbirt/expedition-greece
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Kennis Online magazine. 2023. "The quest for climate-resilient urban trees." Wageningen University and Research. CSI Trees: Future proof trees research project. 2023.
https://magazines.wur.nl/ko-magazine-2023-en/the-quest-for-climate-resilient-urban-trees
​Kozlowski, G., Gratzfeld, J., Bétrisey, S., Christe, C., Fazan, L., Frey, D., Garfì, G., Gerber, E., Kozlowski, E., Löwy -Yamama, M., & Siegel, N.-H.-R. (2023).
Botanic Gardens Conservation International (BGCI)
Zelkova - an ancient tree Global status and conservation action.
https://www.bgci.org/wp/wp-content/uploads/2023/02/Conservation-Action-Plan_-Zelkova.pdf
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Martin, Kevin. 2024.
“Selecting Climate Resilient Trees for Royal Botanic Gardens, Kew: Evidence-Based Approaches to Tree Selection.”
International Association of Arboriculture (ISA) Science and Research Committee (SRC) and Arboriculture Research and Education Academy (AREA). Streamed live on April 29, 2024.
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Muffly David and Patel Sairus. May 2025
Stanford University
Land, Buildings & Real Estate
Stanford Arboretum Tree Report: A Climate-Forward Approach to Future Planting
ARB-Tree-Report-2025.pdf. on Google Docs.
https://drive.google.com/file/d/18SY8xvgFKRbU7PPhAxOF3f-CRd1nkkv1/view
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Musch, Brigitte. 2025.
Université Virtuelle Environnement et Développement Durable (UVED)
Comment adapter la forêt face au changement climatique ? https://www.uved.fr/fileadmin/user_upload/Documents/pdf/Transcriptions/Arbres/MOOC_UVED_Arbres_Transcription_Musch.pdf
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Université Virtuelle Environnement et Développement Durable (UVED)
MOOC "ARBRES"
Adapter la forêt française au changement climatique : ressources et expérimentations. 2025.
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Toomer, S., Freeth, T.H., Martin, K.W.E., 2024.
Royal Botanic Gardens, Kew.
Planting for the Future: Kew's Landscape Succession Plan.
https://spaces.hightail.com/receive/11KbKvSWwp
https://www.kew.org/about-us/press-media/landscape-succession-plan
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​ARTICLES
Bouderbala, Sofia. (2024, November 25).
Phys.org, Science News Website
Beeches thrive in France’s Verdun in flight from climate change.
https://phys.org/news/2024-11-beeches-france-verdun-flight-climate.html​​​
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Chateau Capitoul Hotel Official Site. (2024).
Gardens & the Environment
https://www.chateaucapitoul.com/en/gardens-and-the-environment-chateau-hotel-south-of-france
Gauquelin, Thierry. (2025, July 22).
The Conversation.
Le cyprès de l’Atlas, unique au Maroc, en danger critique d’extinction. https://theconversation.com/le-cypres-de-latlas-unique-au-maroc-en-danger-critique-dextinction-257688
​Scape Design - Signature gardens by James Basson. (n.d.).
https://www.scapedesign.com/en/
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Fayolle, Pascal. (2025, May 9).
Le Lien Horticole.
Diaporama : une gamme végétale innovante pour des conditions totalement inédites !
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PROJECT GIONO
Office National Des Forêts. 2021.
Changement climatique : le projet Giono expérimente la migration assistée des arbres. (2021, November 9). https://www.onf.fr/vivre-la-foret/raconte-moi-la-foret/comprendre-la-foret/foret-et-changement-climatique/les-actions-des-forestiers/les-experimentations/+/2f9::projet-giono-en-images-le-grand-exode-climatique-des-arbres.html
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Office National Des Forêts. 2021.
Le grand exode climatique des arbres du projet Giono. (2021, November 9).
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Office National Des Forêts. 2025.
Changement climatique : des projets pour l’avenir des forêts. (2025, May 20).