CHCH

Chrysolepis chrysophylla

giant chinquapin

Fagaceae

The Basics

Giant chinkapin (Chrysolepis chrysophylla), also called golden chinkapin, giant evergreen-chinkapin, and goldenleaf chestnut, is an interesting hardwood species in a landscape dominated by coniferous forests. Over much of its range, giant chinkapin shows several growth forms; it grows in a wide variety of habitats but is rarely a dominant component of any stand. In certain portions of its range, it can be an undesirable competitor of commercial species during early stages of stand development. Ecologically and taxonomically, it remains a poorly understood species.

Pure stands of giant chinkapin are uncommon and rarely exceed 10 ha (25 acres). The species is a minor component in a wide range of forest communities and in its shrub form is a component of chaparral communities. Common tree associates in the Cascade Range are Douglas-fir (Pseudotsuga menziesii), incense-cedar (Calocedrus decurrens), sugar pine (Pinus lambertiana), western hemlock (Tsuga heterophylla), white fir (Abies concolor), ponderosa pine (Pinus ponderosa), Pacific madrone (Arbutus menziesii), and Shasta red fir (Abies magnifica var. shastensis). In southwestern Oregon, Douglas-fir, western white pine (Pinus monticola), incense-cedar, sugar pine, Pacific madrone, and ponderosa pine continue to be associates, with the additional species: tanoak (Lithocarpus densiflorus), California black oak (Quercus kelloggii), knobcone pine (Pinus attenuata), Port-Orford- cedar (Chamaecyparis lawsoniana), and canyon live oak (Quercus chrysolepis). Redwood (Sequoia sempervirens) is added to the list in north coastal California. (Silvics Manual)

Identification

Characteristic leaves are flat, leathery and lance-shaped; they are dark green adaxially and olive-yellow abaxially. Giant chinquapin produces spikes of white flowers and chestnut-like seeds. The tree form of C. chrysophylla can grow up to three feet in diameter, though often times it stays small and has relatively poor form. It branches extensively, forming a very dense habit. More often than not, giant chinquapin occurs as an understory shrub. Due to its ability to reproduce through sprouting, some individuals can live to be several hundred years old. (Silvics Manual)

Threats

Giant chinquapin had evolved to grow well in areas with frequent fire return intervals and is a hearty competitor. Consequently, some form of disturbance is necessary for it to remain competitive within the ecosystem. The shrub form is very shade tolerant, though the tree form is less so.

Not many insects or diseases seem to plague giant chinquapin. It is resistant to chestnut blight, even though it is closely related to chestnut. That said, it is susceptible to Phellinus igniarius, a heart-rotting fungi. Seed-infesting species (ie, filbertworm, Melissopus latiferreanus) do have a significantly negative impact local regeneration. Other foliage-damaging pests occasionally make giant chinquapin their host. (Silvics Manual)

Reproduction

Flowering and Fruiting- Giant chinkapin is monoecious, with unisexual staminate and pistillate flowers on the same plant. The staminate flowers form dense catkins 2.5 to 7.6 cm (1 to 3 in) long. One to three pistillate flowers are borne within an involucre at the base of the staminate catkin or separately along the stem. Pollination is adapted to wind, but bees frequent the flowers and probably aid in pollination, much to the dismay of beekeepers, for it imparts a bad taste to the honey in a mast year.

The fruit matures in the fall of the second growing season and contains one to three hard-shelled nuts within a very spiny golden brown bur 15 to 25 mm (0.6 to 1.0 in) broad, colloquially referred to as "porkypine eggs." The nuts are relatively large1,800 to 2,400/kg (830 to 1,100/lb).

The phenology of flowering, fruit ripening, and seed dispersal varies widely over the range of giant chinkapin: flowering (February to July), fruit ripening (August to October), seed dispersal (fall). Three years of phenological records at the H. J. Andrews Experimental Forest in Oregon show local phenology to be less varied: flowering (mid-June to mid-July), fruit ripening (mid-August to early September), and seed dispersal (peaking in late September, but prolonged into early December).

Seed Production and Dissemination- Vigorously growing giant chinkapin produce some seed every year with mast years occurring at 2- to 5-year intervals. Understory shrubs of the species flower infrequently. Sound seeds are produced by vigorous trees, apparently of seed origin, that are 40 to 50 years old, but the age of the first seed production is probably much less. Six-year-old stump sprouts have produced some sound seeds.

The production of sound seeds can be greatly reduced locally by insects. In a sample of seeds at three locations in the H. J. Andrews Experimental Forest, two sites had less than 15 percent of the seeds infested, but at the third site nearly 100 percent of the seeds had been attacked by insects.

The primary agents of dissemination of giant chinkapin seed are gravity, squirrels, and birds, not necessarily in that order of importance. Vertebrates are undoubtedly important vectors. Several species of birds feed on nuts, and clumps of young seedlings not originating from sprouts implicate squirrels in caching food.

Seedling Development- Reported germination ranges from 14 to 53 percent; one study found it to have the poorest rate of germination of all hardwoods in the Klamath Province of southwestern Oregon and northern California. Germination is hypogeal and takes place in 16 to 24 days. Although the rate of germination was not increased by cold stratification, which suggested that germination and establishment in the fall are possible, no such germination was observed during 3 years of study at the H. J. Andrews Experimental Forest. Natural seedlings of giant chinkapin which ranged from 15 to 45 cm (6 to 18 in) in height were found only in relatively open stand conditions in the Experimental Forest. The individuals appeared to have germinated under a light leaf mulch in partial shade. The tallest was 12 years old and the shortest 4, but the height-age relationship was poor. In the northern Coast Ranges of California, the best seedling establishment occurs on mesic sites without dense layers of understory vegetation.

Vegetative Reproduction- Giant chinkapin sprouts prolifically when cut or injured. Light understory fires cause vigorous basal sprouting. Even intense broadcast burns will not prevent basal sprouts from rapidly regrowing. Height growth of the sprouts can be rapid, outstripping young conifer growth for several years. Because of its aggressive sprouting ability, giant chinkapin is a problem for forest management on many sites.

The species is well adapted to a regime of frequent fires, which is reflected in the chaparral shrub form. Also, over much of the northern portion of the range of giant chinkapin, the tree form occupies ridgetop positions with other fire-adapted species. Its ability to exist with the potentially taller conifers may be the result of both its sprouting ability and relatively high fire frequency. (Silvics Manual)

Species Distribution

The natural range of giant chinkapin extends from San Luis Obispo County in California to Mason County in west-central Washington. In California, it grows primarily in the Coast Ranges, with a disjunct population in the Sierra Nevada in El Dorado County. In Oregon, it is found in the Coast Ranges as far north as Benton County, and throughout the Cascade Range. Giant chinkapin is represented in Washington by two disjunct populations in Mason and Skamania Counties. Shrub forms of the species are found throughout its range. The tree form is primarily distributed from Lane County, OR, south to Marin County, CA. It is found from near sea level in the Coast Ranges of Oregon and California to over 1525 m (5,000 ft) in elevation in the Cascades. Although giant chinkapin is generally thought of as a mid- to low-elevation species, the shrub form can be found along the crest of the Cascade Range in Oregon from 1525 to 1830 m (5,000 to 6,000 ft). (Silvics Manual)

Citation

USDA Plant Database http://plants.usda.gov/characteristics.html USDA, NRCS. 2016. The PLANTS Database (http://plants.usda.gov, 4 February 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA.

Flora of North America http://www.efloras.org/flora_page.aspx?flora_id=1 Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 19+ vols. New York and Oxford.

Silvics of North America Burns, R.M., and B.H. Honkala. 1990. Silvics of North America (Volume 1: Conifers, Volume 2: Hardwoods). USDA Forest Service Agricultural Handbook 654.

Intermountain Herbarium http://intermountainbiota.org/portal/collections/harvestparams.php Consortium of Intermountain Herbaria. 2016. http//:intermountainbiota.org/portal/index.php. Accessed on February 04.

Burke Museum Plant Image Collection The plant image collection at the Burke Museum, University of Washington.

Jepson Manual http://ucjeps.berkeley.edu/eflora/ The Jepson Manual: Vascular Plants of California. B.G. Baldwin, D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken [editors]. 2012. 2nd edition, thoroughly revised and expanded. University of California Press, Berkeley, CA., hardcover; 1600 pages. ISBN-13: 978-0520253124.

USGS Plant Species Range Maps http://esp.cr.usgs.gov/data/little/ Critchfield, W.B., and Little, E.L., Jr., 1966, Geographic distribution of the pines of the world: U.S. Department of Agriculture Miscellaneous Publication 991, p. 1-97. Little, E.L., Jr., 1971-1978, Atlas of United States trees, volume 1,3,13,17, conifers and important hardwoods: U.S. Department of Agriculture Miscellaneous Publications.