Corylus americana, American hazelnut
Coladonato, Milo. 1993. Corylus americana, American hazelnut. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: https://research.fs.usda.gov/feis/species-reviews/corame
| Abbreviation | Common Name | Scientific Name | Classification | Status |
|---|---|---|---|---|
| Plants | ||||
| CORAME | American hazelnut | Corylus americana | Life Form: Plants/Shrub Kingdom: Plantae Class: Dicot Order: Fagales Family: Betulaceae Genus: Corylus | Fed. Protected: No Nativity: Native Invasiveness: Noninvasive |
Taxonomy
The currently accepted scientific name for American hazelnut is Corylus americana Walt. [17,31]. Two subspecific taxa based on morphological differences are found in southwestern Missouri and southeastern Kansas: C. a. var. indehiscens Palm. & Steyerm. and C. a. forma missouriensis (A. DC.) Fern. [18].
Synonyms
No entry.
Other Common Names
American hazel, American filbert
General Distribution
American hazelnut occurs from Maine west to Saskatchewan, south to eastern Oklahoma, east to Georgia, and north through New England [5,17,31].
States and Provinces
- United States: AL AR GA IL IN IA KS KY LA ME MD MA MI MN MS MO NH NJ NY NC ND OH OK PA RI SC SD TN VT VA WV WI
- Canada: MB ON PQ SK
Site Characteristics
American hazelnut occurs along streams, hedgerows, meadows, woodlands, roadsides, and forest margins. It grows best on rich, moist, well-drained soils [20,31,34]
Common understory associates of American hazelnut include shagbark hickory (Carya ovata), raspberry (Rubus spp.), smooth sumac (Rhus glabra), chokecherry (Prunus virginiana), arrowwood (Viburnum rafinesquianum), eastern hophornbeam (Ostrya virginiana), and dogwood (Cornus spp.) [1,2,10].
Plant Communities
American hazelnut is a dominant or codominant shrub in maple-basswood (Acer-Tilia) forests of Wisconsin and Minnesota [12]. In Nebraska, American hazelnut is a dominant shrub in the ecotone of forest and prairie [1,33]. It is a dominant understory species in jack pine (Pinus banksiana), paper birch (Betula papyrifera), trembling aspen (Populus tremuloides), and northern pin oak (Quercus ellipsoidalis) communities of northern Wisconsin [4].
Botanical Description
American hazelnut.
American hazelnut is a large, deciduous, rhizomatous shrub from 3 to 10 feet (1-3 m) tall [5,9]. It has a straight trunk with spreading, ascending branches, and can form dense thickets. The leaves are 3 to 5 inches (8-12 cm) long. The male catkins are 8 inches (20 cm) long, straight, slender, and regularly spaced along the upper stem. The female flowers are tiny, almost completely enclosed by bracts, and near the end of the twigs. The nuts are enclosed in two leafy bracts [20,28]. The roots are typically in the upper 6 inches (15 cm) of soil [6]. Some of the smaller roots run vertically toward the surface and branch profusely into very fine laterals [34].
Raunkiaer Life Form (Raunkiaer 1934)
- Phanerophyte
Seasonal Development
The flowers of American hazelnut are formed in the summer and open the following spring, before the leaves emerge. By late summer or early fall, the fertilized flowers develop into fruits [5].
Regeneration Processes
American hazelnut flowers.
American hazelnut reproduces both sexually and asexually. It begins producing seed after the first year, and produces good seed crops every 2 to 3 years. Seed dispersal is chiefly by mammals or birds [5].
Vegetative Reproduction: The most important mode of reproduction of American hazelnut is from rhizomes [6]. The large, woody rhizomes are 4 to 6 inches (10-15 cm) below the surface. Rhizomes give rise to new shoots 1 to 2 feet (30-60 cm) from the parent plant [34].
Successional Status
American hazelnut is shade tolerant [33]. It can grow under a light intensity of 15 percent or less; even as low as 1 percent [1]. It is a mid-seral species, and is usually absent in old-growth forest communities [2].
Immediate Fire Effects
The aerial portions of American hazelnut are easily top-killed by spring and summer fires [7].
Postfire Regeneration Strategy (Stickney 1989)
- Rhizomatous shrub, rhizome in soil
- Secondary colonizer - off-site seed
Fire Adaptations
Low- to moderate-severity fires top-kill American hazelnut [7]. It survives fire by sprouting from rhizomes [7,10].
The underground roots and rhizomes can survive low- to moderate-severity fires when the humus is moist. They are relatively shallow, however, and are vulnerable to fire when the humus is dry and combustible [6].
Plant Response to Fire
American hazelnut sprouts from rhizomes following fire [6].
Annual burning can help control American hazelnut. On oak woodland sites in Minnesota, a series of annual fires reduced the American hazelnut frequency to 39 percent on burned plots compared to 65 percent on unburned plots. Although annual burning increased the density of hazelnut stems, stems on burned sites were shorter and smaller than stems on unburned sites, so total American hazelnut biomass was less on burned sites [3]. See Fire Case Studies for more information on this study.
A volume equation for determining biomass, growth response, and woody density for American hazelnut following fire has been developed [8].
Fire Regimes
For fire regime information, search FEIS for this species by entering the species name on the Advanced Search page and selecting “Fire Regime” as the publication type.
Fire Management Considerations
In areas where fire has been excluded, a heavy density of American hazelnut has developed, suppressing desirable tree species and contributing to fuel buildup [10,21].
Repeated summer fires inhibit the ability of American hazelnut to sprout by exposing and damaging underground stems and roots and exhausting stored food reserves. Single fires may eliminate American hazelnut if humus is sufficiently dry to be completely consumed [6].
Effects of repeated prescribed fires at Cedar Creek Natural History Area, Minnesota
Source
Unless otherwise indicated, the information in this Fire Case Study comes from the following paper:
Axelrod, A. N.; Irving, F. D. 1978. Some effects of prescribed fire at Cedar Creek Natural History Area. Journal of the Minnesota Academy of Science. 44(2): 9-11. [3].
Season/Severity Classification
- Spring/low and moderate severity
- Summer/moderate severity
Study Location
Prescribed burning was conducted on the Cedar Creek Natural History Area in Anoka and Isanti counties, Minnesota.
Prefire Vegetative Community
Cedar Creek Natural History Area contains bur oak-northern pin oak-quaking aspen (Quercus macrocarpa-Q. ellipsoidalis-Populus tremuloides) woodlands [35], marshlands, and old fields. The study sites were on the oak woodlands. American hazelnut clones dominated the understory, and there was an herbaceous ground layer. Based on the unburned control plots, prefire American hazelnut density was approximately 11 stems/milacre [3].
Study sites are classified in the following plant community and likely experienced the historic fire regime described below:
| Vegetation community (Potential Natural Vegetation Group) | Fire severity* | % of fires | Mean interval (years) | Minimum interval (years) | Maximum interval (years) |
|---|---|---|---|---|---|
| Northern oak savanna | Replacement | 4 | 110 | 50 | 500 |
| Mixed | 9 | 50 | 15 | 150 | |
| Surface or low | 87 | 5 | 1 | 20 | |
| *Fire Severities: Replacement = Any fire that causes greater than 75% top removal of a vegetation-fuel type, resulting in general replacement of existing vegetation; may or may not cause a lethal effect on the plants. Surface or low = Any fire that causes less than 25% upper layer replacement and/or removal in a vegetation-fuel class but burns 5% or more of the area. Mixed = Any fire burning more than 5% of an area that does not qualify as a replacement, surface, or low-severity fire; includes mosaic and other fires that are intermediate in effects [36,37]. | |||||
Target Species Phenological State
American hazelnut phenology was not described. American hazelnut was probably rapidly elongating its stems during the spring fires and flowering during the summer fires.
Site Description
The study sites are on Anoka sand plain upland soils, with fine sands in the Sartell and Zimmerman series. Topography is generally level [3].
Fire Description
Fire Management Objective: Various repeat prescribed fire treatments were conducted to open stand structure in Cedar Creek's oak woodland. Prescribed burning was conducted over an 8-year period. The specific management objective was to reduce American hazelnut presence in the understory.
Fire prescription and behavior: Four fire treatment sites and an unburned control were selected for this study. Prescribed burning was conducted annually or on fire-and-rest cycles. A total of 19 prescribed fires were conducted on the 4 burn units. Seventeen of the fires were conducted in spring, with the earliest fire on 11 April 1969 and the latest on 16 May 1972. Surface fuels were oak litter and grasses (Poaceae). Fires on spring-burned sites were conducted before green-up, when surface fuels were mostly or completely cured. The majority of the prescribed fires were of moderate severity and fairly continuous; however, Site 3 experienced 2 low-severity, patchy summer fires before the moderate-severity April 1969 fire gave satisfactory fire continuity. April and May fires were ignited in the late afternoon, usually after 5:00 p.m., 3 to 10 days after measurable precipitation. Strip head fires were used.
| Stocking and treatment dates of prescribed-burn sites on Cedar Creek, MN | ||||
|---|---|---|---|---|
| Site | Treatment | Area (acres) | 1972 basal area (ft?) | Rx fire date |
| Site 1 | 7 burns in 8 years | 27 | 70 | 4 May 1965, 25 April 1966, 11 April 1967, 26 April 1968, 12 May 1969, 12 April 1971, 16 May 1972 |
| Site 2 | 8 burns in 8 years | 25 | 42 | 4 May 1965, 13 April 1966, 5 May 1967, 26 April 1968, 12 May 1969, 4 May 1970, 3 May 1971, 25 April 1972 |
| Site 3 | 3 burns in 7 years | 10 | 64 | 30 August 1966, 6 September 1967, 23 April 1969 |
| Site 4 | 1 burn in 5 years | 27 | 61 | 14 May 1969 |
| Site 5 | unburned control | not provided | 60 | no recent fires |
Weather conditions on days of burning ranged as follows:
| Weather conditions and fire behavior for the Cedar Creek burns | ||||||
|---|---|---|---|---|---|---|
| Air temperature | Relative humidity | Windspeed | Rate of spread | Fuel consumption | Flame height* | Depth of flame front* |
| 56-91 °F | 26%-72% | 1-20 mph | 8-15 ft/min | 917-6,500 lbs/acre | ~2 in-3 ft | <1ft in grass fuels ~3 feet in thick oak litter |
| *Flame height and flame front measures are for spring fires only. These measures were not provided for the summer fire on Site 3. | ||||||
Green-up had begun on some sites burned in late spring, so herbaceous surface fuels were only partially cured. These late spring fires burned at lower severities, had slower rates of spread, and produced more smoke than the other spring fires.
Fire Effects on Target Species
All the spring fires top-killed American hazelnut clones. Duration of flame contact with American hazelnut stems was usually less than 1 minute, which was enough to kill the cambium of aboveground stems. American hazelnut stems on sites with heavy concentrations of fallen branches and other downed woody debris from wind-damaged oaks remained in direct contact with flames for as long as 10 minutes. Effects of this longer-burning woody debris on American hazelnut's underground system were not noted. Effects of the fires on stand structure and American hazelnut growth are shown below.
| Overstory density and American hazelnut density, height, and biomass on study plots in the 4th postfire growing season. Data are means (SD). | ||||
|---|---|---|---|---|
| Treatment | Oak overstory basal area (ft/acre) | American hazelnut basal area (stems/0.001 acre) | Stem height* (inches) | Stem biomass (g) |
| Site 1 (7 burns in 8 years) | 70 (46) | 19.2 (4.6) | 16 (6.1) | 16.3 (3.6) |
| Site 2 (8 burns in 8 years) | 42 (68) | 19.9 (8.4) | 18 (6.1) | 30.6 (16.4) |
| Site 3 (3 burns in 7 years) | 64 (39) | 8.0 (2.7) | 34 (14) | 117 (92.2) |
| Site 4 (1 burn in 5 years) | 61 (51) | 10.0 (6.2) | 30 (9.4) | 92.1 (49.4) |
| Site 5 (unburned control) | 60 (44) | 11.0 (4.6) | 33 (14.2) | 150.4 (85.3) |
| *For American hazelnut stem height, data are the means of the longest stem on each of 218 plots. | ||||
Statistical analyses showed no significant differences (P=0.05 for all study measures) between either American hazelnut density or stem height on Sites 1 and 2, the annual burn treatments. Similarly, there were no significant differences in stem density or stem height between Sites 3 and 4, the treatments with rest years between fire treatments. Data for the 2 annual fire treatments were therefore pooled and compared to pooled data for the 2 fire-and-rest treatments. American hazelnut stocking was significantly denser on annually burned plots (Sites 1 and 2) compared to fire-and-rest plots (Sites 3 and 4), and American hazelnut stems were significantly taller on fire-and-rest plots (Sites 3 and 4) compared to annually burned plots. The authors attribute these differences to age variation in American hazelnut stems. Annually burned plots had only even-aged, 1-year-old stems. As time since fire increased on fire-and-rest plots, even-aged stems from the first postfire growing season were augmented with younger, shorter stems.
Both annual fire and fire-and-rest treatments initially reduced American hazelnut stem density and height compared to the control; however, by fourth growing season following 1 to 3 fires, there were no significant differences between American hazelnut density, stem height, or biomass on fire-and-rest plots compared to unburned plots. However, the series of annual fires approximately doubled American hazelnut density and reduced mean stem height to about one-half that of American hazelnut stems on unburned plots. Stems on unburned plots were older and larger than stems on burned plots, so biomass of unburned stems was approximately 4 times more than biomass of stems on annually burned plots.
Fire Management Implications
Fire management objective: The series of annual fires successfully controlled American hazelnut. Although density increased, the proportion of the understory occupied by American hazelnut was less due to reductions in height and biomass. Fire-and-rest treatments did not control American hazelnut.
Statistical analyses of the effects of the various fire treatments on the oak overstory were not provided. Based on overstory oak basal area, overstory stand structures were similar on fire-and-rest plots and control plots. The Site 1 annual burn plots had greater oak density than the fire-and-rest and control plots, while overstory density on the Site 2 annual burn plots was less than fire-and-rest and control plots. Further burning treatments on Cedar Creek and restoration fires on similar oak woodland/American hazelnut sites may help explain discrepancies in these study results.
Fire control of American hazelnut: The authors recommend repeated burning on a regular schedule to restore and maintain oak savannas. Field observations by the authors suggested that grass and forb cover increased where American hazelnut height and biomass were reduced by annual burning. The effect of repeated fires on American hazelnut was temporary, however. In this study, American hazelnut regained most of its prefire biomass by the fourth postfire growing season on fire-and-rest sites. Axelrod and Irving [3] predict that if burning is conducted at less than 7-year intervals, American hazelnut will completely regain its prefire height and biomass. The results of this study suggest that a schedule of annual or nearly annual fires provides optimal American hazelnut control.
Federal Status
None
Other Status
None
Importance to Wildlife and Livestock
The leaves, twigs, and catkins of American hazelnut are browsed by deer and moose [11,24]. The nuts are eaten by small mammals, northern bobwhite, ruffed grouse and other large birds, and deer [19.20]. Beaver eat the bark [20].
Palatability and Nutritional Value
American hazelnut has a fairly high protein and energy value. Percentage composition (dry weight) of the nuts is as follows [32]:
| Nutrient | Dry weight (%) |
|---|---|
| Crude protein | 25.1 |
| Crude fiber | 2.10 |
| Available protein | 23.25 |
| Calcium | 0.28 |
| Phosphorus | 0.39 |
Cover Value
No entry.
Value for Rehabilitation or Restoration of Disturbed Sites
No entry.
Other Uses
American hazelnut has been cultivated as an ornamental since 1798. It is also commercially cultivated for nut production. The sweet nuts may be eaten raw or ground and made into a cakelike bread [31]. The nuts were used by Native Americans to flavor soups [16].
Other Management Considerations
American hazelnut often competes with hardwoods and pines for light and moisture [25,27]. Because of shading and aggressive growth, it has long been recognized as a major deterrent to the successful regeneration of upland conifers [6]. American and beaked hazelnut (C. cornuta) are responsible for much of the failure of red pine (Pinus resinosa) regeneration in Minnesota [13].
American hazelnut can be controlled with herbicides [22,25].
Table A1— Forest and range ecosystems, Bureau of Land Management (BLM) physiographic regions, Kuchler plant associations, Society for American Foresters (SAF) forest cover types, and Society for Rangeland Management (SRM) rangeland cover types in which this species occurs.
Forest and Range Ecosystems (Garrison et al. 1977)
- FRES10 White - red - jack pine
- FRES11 Spruce – fir
- FRES14 Oak – pine
- FRES15 Oak – hickory
- FRES17 Elm - ash – cottonwood
- FRES18 Maple - beech – birch
- FRES19 Aspen - birch
BLM Physiographic Regions (Bernard and Brown 1977)
- 14 Great Plains
Kuchler Plant Associations (Kuchler 1964)
- K081 Oak savanna
- K093 Great Lakes spruce - fir forest
- K095 Great Lakes pine forest
- K099 Maple - basswood forest
- K100 Oak - hickory forest
- K101 Elm - ash forest
- K103 Mixed mesophytic forest
- K104 Appalachian oak forest
- K106 Northern hardwoods
- K108 Northern hardwoods - spruce forest
- K100 Oak - hickory forest
- K111 Oak - hickory - pine forest
- K112 Southern mixed forest
SAF Cover Types (Eyre 1980)
- 1 Jack pine
- 5 Balsam fir
- 12 Black spruce
- 13 Black spruce – tamarack
- 14 Northern pin oak
- 15 Red pine
- 16 Aspen
- 17 Pin cherry
- 18 Paper birch
- 20 White pine - northern red oak - red maple
- 21 Eastern white pine
- 22 White pine – hemlock
- 23 Eastern hemlock
- 24 Hemlock - yellow birch
- 25 Sugar maple - beech - yellow birch
- 26 Sugar maple – basswood
- 27 Sugar maple
- 30 Red spruce - yellow birch
- 31 Red spruce - sugar maple – beech
- 32 Red spruce
- 35 Paper birch - red spruce - balsam fir
- 39 Black ash - American elm - red maple
- 40 Post oak - blackjack oak
- 42 Bur oak
- 43 Bear oak
- 44 Chestnut oak
- 51 White pine - chestnut oak
- 52 White oak - black oak - northern red oak
- 53 White oak
- 55 Northern red oak
- 57 Yellow-poplar
- 58 Yellow-poplar - eastern hemlock
- 59 Yellow-poplar - white oak - northern red oak
- 60 Beech - sugar maple
- 62 Silver maple - American elm
- 76 Shortleaf pine – oak
- 78 Virginia pine – oak
- 108 Red maple
- 110 Black oak
SRM Rangeland Cover Types (Shiflet 1994)
No entry.
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