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Garry Oak Ecosystems --contextualizing biodiversity A nationally endangered ecosystem (under construction) |
| Cowichan Garry Oak Preserve, photo by Brian Klinkenberg, 2002 |
| Introduction | Identification of Garry oak | Research | Ecosystem classification |
| Links | Identification--photos | Keys | References |
| Acknowledgements | Ecosystem Photo Gallery |
Garry oak (Quercus garryana) is a species of restricted range in Canada and North America, with three varieties recognized in Flora North America (Q. garryana var. garryana, Q. garryana var. breweri, and Q. garryana var. semota). In British Columbia, Garry oak ecosystems (GOE) are red-listed ecosytems that support high numbers of blue- and red-listed species of flora and fauna. These ecosystems occur globally only along a narrow portion of the extreme western US and adjacent Canada. Distribution maps of Garry oak sites globally and in British Columbia and Canada are available. Throughout their range, these ecosystems are threatened by urban development and severe habitat loss. The recognition of the significant contribution of garry oak ecosystems to global, national and regional biodiversity has led to the development of a recovery team (GOERT) in Canada that aims to protect and, where possible, restore them.
Presently, GOERT, through a series of working groups, is working towards identifying and mapping Garry oak sites in BC, prioritizing them for conservation initiatives, initiating research, studying species at risk within Garry oak sites, etc. The Conservation and Planning Recovery Action Group, for example, has developed a set of criteria for assessing the relative quality of Garry oak sites. Through their work, the top ten garry oak sites will be targeted for protection initially. In addition to this, GOERT is working towards a standard classification system for Garry Oak ecosystems in BC. This system will draw on previous classifications of GOEs in BC and elsewhere.
Information on the Garry Oak Ecosystem is posted on the GOERT web site, and a variety of research projects have been initiated that aim to further our understanding of these ecosystems and their dynamics.
If you are interested in learning more about Garry Oak Ecosystems, the following topics and research areas will be of interest. The first step in this will be learning how to recognize Garry Oaks, and separating them from other planted and invasive oak species in our area, such as English Oak (Quercus robur). Visit the Garry oak photo gallery for a peek at these ecosystems.
Map Sources:
1 USDA Forest Service, web site: http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/quercus/garryana.htm
2 Map Source: GOERT (http://www.goert.ca/reference/map1.html)
Garry oak (Quercus garryana) is readily recognized, though it can be confused with introduced or naturalized plantings of English oak (Quercus robur). A detailed technical description is provided by Douglas et al. (1999), as follows:
| "Deciduous tree with heavy, craggy branches, up to 25 m tall but often smal, shrubby and as short as 1 m in dry, rocky habitats; trunks up to 1 m wide, bark light grey with thick scale ridges....Leaves alternate, deciduous...with 3 - 7 lobes, lobes entire or two to three- toothed., up to 12 cm long with stalks 1 - 2 cm long, the largest sinuses extending more than halfway to the midrib...bright shiny green above, paler below with reddish to yellow hairs, turning yellowish-brown in the fall. Acorns 1 seeded, maturing in one season, unstalked, egg-shaped to nearly round, 2 - 3 cm long, cups shallow, bumpy, hairy within. |
Key features from Douglas et al. (1999):
| Leaf stalks 5 - 15 mm long, leaves often deeply lobed, the largest clefts extending more than halfway to the midrib; acorns unstalked....................................................Quercus garryana
Leaf stalks 1 - 3 mm long; leaves shallowly lobed, the largest clefts extending much less than halfway to the midrib; acorns on long stalks................................................Quercus robur |
For some comparative photos between garry oak (Quercus garryana), English oak (Quercus robur) and sessile oak (Quercus petraea --a species which may also be planted in our area) -- click here.
Simon Fraser University
Amy Parachnowitsch:
Spring 2002, BISC 498: Variation in sex allocation among populations of Collinsia parviflora.
Summer 2002, NSERC undergrad award: Plant and pollinator diversity at the Cowichan Garry Oak Reserve.
University of British Columbia
Andrew MacDougall: Invasive Perennial Grasses in Quercus garryana Meadows of Southwestern British Columbia:
Emily Gonzales: exclosures in island garry oak communities
Richard Feldman: birds in Garry oak ecosystems
Consultants
Terry McIntosh (Yale Garry Oak community)
CLASSIFICATION OF GARRY OAK ECOSYSTEMS (GOERT)
Biogeoclimatic Ecosystem Classification assessment of Garry Oaks Ecosystems.
Historical Garry oak ecosystems of the Victoria area
Historical Garry oak ecosystems of the Cowichan Valley and Saltspring Island
Plant communities of Gary oak ecosystems
Higher-level physiognomic vegetation categories for Garry oak and surrounding ecosystems
Flora North America treatment for Oaks
US Federal database on Quercus garryana
New methods for evaluation of oaks
Garry Oak Ecology and Distribution
Oregon White Oak/Garry Oak
Oaks and oak hybrids in Oregon
Garry Oak Woodlands
A bibliography for Garry oak and other geographically and botanically related oaks
Quercus garryana DNA survey
Douglas, G. W., Del Medeinger and Jim Pojar. 1999. Illustrated Flora of British Columbia. Volume 3: Dicotyledons (Diapensiaceae through Onagraceae). Ministry of Environment, Lands and Parks, and Ministry of Forests, Victoria.
Jensen, R. J. 1990. Detecting shape variation in oak leaf morphology: a comparison of rotational-fit methods. Amer. J. Bot. 77: 1279-1293.
Jensen, R. J. 1992. Morphometric variation in acorns from two red oak communities in Land Between The Lakes:
hybridization or normal variation? pages 87-101. IN: Snyder, D. H. (ed.) Proceedings of the contributed paper sessions of the fourth annual symposium on the natural history of lower Tennessee and Cumberland river valleys. Center for Field Biology, Austin Peay State University, Clarksville,Tennessee.
Olsvig, L., Naveh, Z., Giskin, M.& Nevo, E. 1992 Microsite differentiation in a Mediterranean oak savanna. Journal of Vegetation Science 3(2): 209
McPherson, G.R. Effects of herbivory and herb interference on oak establishment in a semi-arid temperate savanna. Journal of Vegetation Science 4(5): 687
Thanks to Dr. Peter Ball, University of Toronto, Erindale College (TRTE), for information on oaks, including Quercus garryana (Garry oak), Q. robur (English oak) and Q. petraea (sessile oak). Thanks, too, to Ted Lea for providing great new links, and spotting broken links!