Conservation & Research

Conservation & Research

Hoyt Arboretum and the Herbarium provide valuable exsiccate (dried) collections and rare living tree resources for research and study opportunities in systematics, phylogenetics, morphology, ecology, palynology, physiology, ecology, invasive species phytogeography, urban-nature interface, entomology, and ex situ conservation – the conservation of samples of living organisms outside their natural habitat.

Ex Situ Research

Hoyt helps protect 67 globally endangered species as listed by IUCN. We are in the process of expanding our ex situ conservation work to include regionally endangered species. This conservation work includes education about global and regional species protection and ecological system restoration.

Through ex situ conservation, Hoyt Arboretum protects priceless genetic lineages of North American and globally-endangered species. Ex situ conservation is an underused but important support system for in situ (on site) conservation. In no way does ex situ replace in situ conservation, as the ultimate goal is the restoration of original ecological systems.

In addition to genetic preservation, ex situ conservation is a powerful educational tool regarding habitat and ecosystem protection, directly reaching the public with powerful examples of “near extinct” and “extinct in the wild” species. Near extinct examples in our collection include Torreya taxifolia (Florida, USA) and Magnolia zenii (China). Extinct in the wild include Franklinia alatamaha (Georgia, USA).

Evolutionary Research

Systematics: Looks at the origins of both ancient diversity and new diversity, and the relationships through time of organisms. Systematics is a broader term used to include:

  • Taxonomy: This refers to the methods of plant classification, specifically naming and describing.
  • Biosystematics: The studies of the evolutionary process: how, when, where (ie hybridization and genetic drift).
  • Studies of Phylogeny: This is evolutionary history/relationships among and between groups based on cladistics and phylogenetics. Cladistics are methods of classification in which the relationships between organisms are based on selected shared characteristics assumed to have been derived from a common ancestor. Phylogenetics is the study of evolutionary relationships between and within taxonomic levels based on their implied evolutionary history.

Below are examples of the wide array of possible research projects utilizing our living collections and herbarium. For more information about Hoyt Arboretum’s Collections Policy or to request permission for research purposes contact Hoyt Arboretum Curator Martin Nicholson.

Community Science Research

Hoyt Arboretum staff and volunteer community scientists are conducting several research projects at the arboretum, including participation in the nationwide phylogeny project, Project Budburst, and research to identify invasive species of Rubus (blackberry) in the Portland metro area.

To see a list of research that has reference material from Hoyt Arboretum, go here.


I can’t emphasize enough how difficult it can be to access samples of fir trees that grow in such isolated and far-flung places as the Himalayas and Morocco.  Without places like the Hoyt, it would have taken me decades to find 40-50 fir species in their natural stands in North America, Europe, Asia, Africa, and Central America.

– Kevin Potter, North Carolina State University

The Hoyt has provided us with a source for stock plant material.  It also serves as a great example of adult plant morphology and species comparison.  We found many unique plants and were able to quickly see several similar species growing side by side for comparison.

– Frans Scholin, Xplant Laboratory

Dr. David S. Gernandt, Advisor, Universidad Nacional Autónoma de México, Departamento de Botanica, Instituto de Biologia
3er Circuito Exterior, Cd. Universitaria, A.P. 70-233, Mexico, D.F., MEXICO C.P. 04510
Larch and pine specimens from Hoyt Arboretum were included in the following papers.

Gernandt, D.S. and A. Liston. 1999. Internal transcribed spacer region evolution in Larix and Pseudotsuga (Pinaceae). American Journal of Botany 86: 711-723.
Larix decidua Mill. Hoyt Arboretum, Portland, Oregon, USA DSG001(a)/GBAN-AF041343(b)
L. gmelinii (Rupr.) Kuzen Hoyt Arboretum, Portland, Oregon, USA DSG002/none

Gernandt, D.S., Liston, A. y D. Piñero. 2001. Variation in the nrDNA ITS of Pinus subsection Cembroides: implications for molecular systematic studies of pine species complexes. Molecular Phylogenetics and Evolution 21: 449-467
Pinus aristata Engelm. AF037000 Hoyt Arboretum, OR, USA, Liston 980-2 (OSC)(c)
P. bungeana Zucc. AF036992 Hoyt Arboretum, OR, USA, Liston 1003 (OSC)
P. armandii Franch. AF036980 Hoyt Arboretum, OR, USA, Liston 986 (OSC)

Glenn Kohler, Forest Entomologist, Washington Department of Natural Resources.
Hemlock specimens from Hoyt Arboretum were included in the following research papers.

Ross, D.W., S.D. Gaimari, G.R. Kohler, K.F. Wallin and S.M. Grubin. 2011. Chamaemyiid predators of the hemlock woolly adelgid from the Pacific Northwest. In Reardon, R. & B. Onken (eds.), Implementation and Status of Biological Control of the Hemlock Woolly Adelgid. USDA Forest Service Publication FHTET-2011-04.

Kohler, G.R., V.L. Stiefel, K.F. Wallin, and D.W. Ross. 2008. Parasitoids reared from predators of hemlock woolly adelgid (Hemiptera: Adelgidae), and the hymenopterous parasitoid community on western hemlock in the Pacific Northwest. Environmental Entomology 37: 1477-1487.

Kohler, G.R., V.L. Stiefel, K.F. Wallin, and D.W. Ross. 2008. Predators Associated with the Hemlock Woolly Adelgid (Hemiptera: Adelgidae) in the Pacific Northwest. Environmental Entomology 37: 494-504.

Kohler, G.R. 2007. Predators Associated with Hemlock Woolly Adelgid (Hemiptera: Adelgidae) Infested Western Hemlock in the Pacific Northwest. M.S. thesis, Oregon State University, Corvallis, OR. 121 pp.

Dr. Aaron Liston, Professor, Director of Oregon State University Herbarium, Program Director Professional Science
Research Area: Plant systematics and evolution
Conifer specimens from Hoyt Arboretum were included in the following research papers.

Liston, A., W.A. Robinson, J.M. Oliphant, and E.R. Alvarez-Buylla.  1996.  Length variation in the nuclear ribosomal DNA internal transcribed spacer region of non-flowering seed plants.  Systematic Botany  21:109-120.

(a) David S. Gernandt voucher and collection
(b) The prefix GBAN has been added for linking the online version of American Journal of Botany to GenBank and is not part of the actual GenBank accession number.
(c) GenBank accession number

What is GenBank?
GenBank ® is the NIH genetic sequence database, an annotated collection of all publicly available DNA sequences ( Nucleic Acids Research, 2011 Jan;39(Database issue): D32-7 ). There are approximately 126,551,501,141 bases in 135,440,924 sequence records in the traditional GenBank divisions and 191,401,393,188 bases in 62,715,288 sequence records in the WGS division as of April 2011. (National Institutes of Health accessed 11/2012) (National Center for Biotechnology Information/GenBank accessed 11/2012)



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