Index of Species Information

SPECIES:  Ostrya knowltonii


SPECIES: Ostrya knowltonii
AUTHORSHIP AND CITATION : Tesky, Julie L. 1994. Ostrya knowltonii. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].

ABBREVIATION : OSTKNO SYNONYMS : Ostrya baileyi Rose [9,23] SCS PLANT CODE : OSKN COMMON NAMES : Knowlton hophornbeam western hophornbeam woolly hophornbeam wolf hophornbeam ironwood TAXONOMY : The currently accepted scientific name for Knowlton hophornbeam is Ostrya knowltonii Coville [9,10,7,23]. There are no recognized subspecies, varieties, or forms. LIFE FORM : Tree FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


SPECIES: Ostrya knowltonii
GENERAL DISTRIBUTION : Knowlton hophornbeam is found in southeastern Utah, northern Arizona, southeastern New Mexico (in the Guadalupe and Sacramento mountains in Eddy County), and northern Trans-Pecos Texas. It is not a common tree and its occurrence is sporadic even in these areas [9,10,18,23]. ECOSYSTEMS : FRES21 Ponderosa pine FRES32 Texas savanna FRES35 Pinyon - juniper STATES : AZ NM UT TX BLM PHYSIOGRAPHIC REGIONS : 12 Colorado Plateau 13 Rocky Mountain Piedmont KUCHLER PLANT ASSOCIATIONS : K019 Arizona pine forest K023 Juniper - pinyon woodland K031 Oak - juniper woodlands K032 Transition between K031 and K037 K086 Juniper - oak savanna SAF COVER TYPES : 210 Interior Douglas-fir 237 Interior ponderosa pine 239 Pinyon - juniper 241 Western live oak SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Knowlton hophornbeam is commonly found in oak (Quercus spp.) woodlands, pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands, and lower ponderosa pine (Pinus ponderosa) forest zones [9]. In Texas it is a component of the gray oak (Quercus grisea)-true pinyon (Pinus edulis)-alligator juniper (Juniperus deppeana) association at 5,000 to 7,000 feet (1,524-2,133 m) and the ponderosa pine-Douglas fir (Pseudotsuga menziesii) association at 6,000 to 7,500 feet (1,828-2,286 m). In Texas it is also associated with Texas madrone (Arbutus texana), southwestern white pine (Pinus strobiformis), chinkapin oak (Q. muehlenbergii), and bigtooth maple (Acer grandidentatum) [18]. In deciduous canyon woodlands of Guadalupe Mountains National Park, Texas, Knowlton hophornbeam will increasingly replace wavyleaf oak (Q. undulata), alligator juniper, Riogrande cottonwood (Populus deltoides ssp. wislizenii) and little walnut (Juglans microcarpa) as the moisture gradient goes from xeric to mesic. Knowlton hophornbeam is replaced by bigtooth maple and chinkapin oak, especially on upper terraces, around springs and in canyonheads [6,13].


SPECIES: Ostrya knowltonii
WOOD PRODUCTS VALUE : Knowlton hophornbeam wood is thin, fine grained, hard, tough, and durable [4,23]. It is occasionally used for fuel or posts [23]. Because of its density the wood of hophornbeam (Ostrya spp.) can be used for tool handles, mallet heads, and other hard wooden objects [4]. IMPORTANCE TO LIVESTOCK AND WILDLIFE : Several species of breeding birds use canyonland habitats where Knowlton hophornbeam occurs [12]. PALATABILITY : NO-ENTRY NUTRITIONAL VALUE : NO-ENTRY COVER VALUE : NO-ENTRY VALUE FOR REHABILITATION OF DISTURBED SITES : NO-ENTRY OTHER USES AND VALUES : NO-ENTRY OTHER MANAGEMENT CONSIDERATIONS : Hophornbeam species (Ostrya spp.) suffer from few insect pests or diseases, and none of these are regarded to be of economic importance [4].


SPECIES: Ostrya knowltonii
GENERAL BOTANICAL CHARACTERISTICS : Knowlton hophornbeam is a native, deciduous, small tree 10 to 40 feet (3-12 m) tall with a 6- to 18-inch (15.2-45.7 cm) trunk diameter [9,23]. The trunk is usually short and divided into a number of slender, crooked branches to form a round-topped crown [23]. The leaves are 1 to 2.5 inches (2.5-6.3 cm) long and short-pointed or rounded at the apex [7,9,23]. The twigs are slender, tomentose at first to glabrous and lustrous later [l9,23]. The bark is 0.125 inch (0.31 cm) thick, shallowly furrowed and breaking into loose, small scales 1 to 2 inches (2.5-5 cm) long [23]. Male and female flowers are in catkins [9,23]. The staminate catkins form singly or in groups of two to three at the tips of the previous year's branches. They are slender, cylindrical, pendulous and 0.5 to 1.25 inch (1.3-3.2 cm) long [15,23]. The pistillate catkins are about 0.25 inch (0.6 cm) long, generally with two flowers in the axil of each bract [23]. The fruit is a compressed ovoid nutlet [4]. The nutlet is about 0.25 inch (0.6 cm) long, solitary, and sessile [23]. RAUNKIAER LIFE FORM : Phanerophyte REGENERATION PROCESSES : Knowlton hophornbeam reproduces by seed. The flowers are wind pollinated and the fruit is wind dispersed [14]. Germination is epigeal [4]. Unless seeds are sown soon after maturity or are stratified, they will not germinate until the second year [23]. No specific information was available on germination rates or viability of Knowlton hophornbeam seeds; however, information is available on eastern hophornbeam (Ostrya virginiana) [17]. Eastern hophornbeam seeds usually germinate in the spring the year after they are shed. Germination capacity of eastern hophornbeam seed is 27 to 65 percent [11]. Eastern hophornbeam trees do not produce seeds abundantly until they are about 25 years old [17]. Knowlton hophornbeam can be regenerated by grafting [23]. Other species of hophornbeam will sprout from the stump if cut or burned; however, no specific information was available regarding the ability of Knowlton hophornbeam to do so [11]. SITE CHARACTERISTICS : Knowlton hophornbeam is commonly found on sunny, dry, well-drained sites in mountains and canyons and at the bases of monoliths in sandstone areas [15,22,23,24]. Knowlton hophornbeam commonly occurs between 4,200 and 7,000 feet (1,280-2,133 m) in elevation [7,9,15,23,24]. SUCCESSIONAL STATUS : Specific information regarding Knowlton hophornbeam's successional status was not available in the literature. Eastern hophornbeam typically occurs in late seral to climax forests. It is shade tolerant and will reproduce well under full shade [11]. How closely this applies to Knowlton hophornbeam is unknown. SEASONAL DEVELOPMENT : Knowlton hophornbeam flowers are produced from March through May before or with the leaves [15,23]. The fruit of hophornbeam species matures and is dispersed during the same season as pollination. In most hophornbeam species, the staminate catkins are produced the growing season before anthesis and are exposed during the winter. The pistillate catkins develop in the spring with the new shoots, with anthesis occurring as the leaves are forming [4].


SPECIES: Ostrya knowltonii
FIRE ECOLOGY OR ADAPTATIONS : Specific information is not available regarding the fire ecology and adaptations of Knowlton hophornbeam. Knowlton hophornbeam may sprout after top-kill by fire, as do other species of hophornbeam [11]. Knowlton hophornbeam probably also colonizes burned sites via wind-dispersed seeds. Pinyon-juniper communities where Knowlton hophornbeam commonly occurs have historically burned every 10 to 30 years. Where livestock grazing has reduced grass cover and accelerated erosion, fire frequency has decreased [25]. POSTFIRE REGENERATION STRATEGY : NO-ENTRY


SPECIES: Ostrya knowltonii
IMMEDIATE FIRE EFFECT ON PLANT : Information is not available regarding the immediate effects of fire on Knowlton hophornbeam; however, this tree is probably top-killed or killed by most fires. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : NO-ENTRY DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS : NO-ENTRY


SPECIES: Ostrya knowltonii
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Washington, DC: U.S. Department of the Interior, National Park Service: 181-237. [16021] 13. Northington, David K.; Burgess, Tony L. 1979. Summary of the vegetative zones of the Guadalupe Mountains National Park, Texas. In: Genoways, Hugh H.; Baker, Robert J., eds. Biological investigations in the Guadalupe Mountains National Park: Proceedings of a symposium; 1975 April 4-5; Lubbock, TX. Proceedings and Transactions Series No. 4. Washington, DC: U.S. Department of the Interior, National Park Service: 51-57. [16017] 14. Pendleton, Rosemary L.; Pendleton, Burton K.; Harper, Kimball T. 1989. Breeding systems of woody plant species in Utah. In: Wallace, Arthur; McArthur, E. Durant; Haferkamp, Marshall R., compilers. Proceedings--symposium on shrub ecophysiology and biotechnology; 1987 June 30 - July 2; Logan, UT. Gen. Tech. Rep. INT-256. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 5-22. [5918] 15. Powell, A. Michael. 1988. 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Post-fire response of four plant communities in south-central New York state. Ecology. 51(6): 1074-1082. [3446] 21. U.S. Department of Agriculture, Soil Conservation Service. 1982. National list of scientific plant names. Vol. 1. List of plant names. SCS-TP-159. Washington, DC. 416 p. [11573] 22. Van Dersal, William R. 1938. Native woody plants of the United States, their erosion-control and wildlife values. Washington, DC: U.S. Department of Agriculture. 362 p. [4240] 23. Vines, Robert A. 1960. Trees, shrubs, and woody vines of the Southwest. Austin, TX: University of Texas Press. 1104 p. [7707] 24. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C., eds. 1987. A Utah flora. Great Basin Naturalist Memoir No. 9. Provo, UT: Brigham Young University. 894 p. [2944] 25. Wright, Henry A.; Bailey, Arthur W. 1982. Fire ecology: United States and southern Canada. New York: John Wiley & Sons. 501 p. [2620]

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