Interference to Hardwood Regeneration in
Northeastern North America: Pin Cherry and
Its Effects
ABSTRACT
Ralph D. Nyland, Amy L. Bashant, Eric F. Heitzman, and Jane M. Verostek
Pin cherry grows rapidly in a bright environment, overtopping most desirable hardwood species. Its rapid early development helps to reduce nutrient losses
from a site and provides a source of mast for wildlife. Some pin cherry trees live for up to 45–50 years, but their abundance usually decreases after 30 –35
years. Pin cherry begins producing abundant seeds at an early age, and high proportions of these remain viable in the forest floor for up to 6 –7 decades.
Germination has been linked to high availability of nitrogen (N) in the forest floor, either following fertilization or increased decomposition of the humus layer.
Heavy overstory cutting or natural disturbances that reduce stocking below 50 – 60 ft2/ac in stands ⬍90 years old will promote N release from the forest
floor, resulting in abundant pin cherry within the new cohort. When at high density, pin cherry interferes with the development of most other species, and
those of intermediate or low shade tolerance may die. Pin cherry may have a patchy distribution across a stand or form an almost complete canopy cover
when well distributed at high densities. Its arrangement may affect long-term stand composition and development. Where milacres have ⱖ3 pin cherry ⱖ3
ft tall, or ⬎1 of them ⬎5 ft in height, a release treatment may prove necessary to ensure good levels of stocking with desirable hardwoods of seedling origin.
Landowners should pay particular attention when they find a high pin cherry density across more than 30 – 40% of the stand area. These criteria may indicate
where a release treatment would improve the composition of young hardwood stands.
Keywords: pin cherry, hardwood regeneration, interfering plants, release treatment
P
in cherry (Prunus pensylvanica L.f.) often becomes a dominant
member of the new cohort among northern hardwood and
other temperate forest stands of northeastern North America
following clearcutting, shelterwood method seed cutting, and other
heavy overstory disturbances. Yet silviculturists and forest managers
have historically considered pin cherry fairly benign as a competitor
of hardwoods, and release treatments to remove it from young
stands are seldom considered necessary. Jensen (1943) and Longwood (1951) noted that due to its thin foliage, pin cherry does not
interfere with development of young sugar maple (Acer saccharum
Marsh.) trees. Leak (1988) also reported that few plots completely
lacked a commercial species in areas dominated by pin cherry and
considered striped maple (Acer pensylvanicum L.) and hobblebush
(Viburnum alnifolium Michx.) more severe competitors (see Nyland
et al. 2006a, 2006b). Even so, Safford and Filip (1974), Heitzman
and Nyland (1994), and Ristau and Horsley (1999, 2005) have
reported important reductions of at least mid- to shade-intolerant
species in areas dominated by pin cherry. Such contradictions suggest that pin cherry may actually interfere with the survival and
development of some species, but perhaps only at places where it
occurs above some critical threshold density across an appreciable
proportion of the stand area.
Several authors have provided detailed descriptions of silvical and
biological characteristics of pin cherry. This review summarizes key
information from those sources and other literature to describe the
reproduction, growth, and dynamics of pin cherry in northern hardwood forests. It also assesses the degree to which pin cherry interferes
with the development of other trees and the implications of that
interference.
Geographic Range, Habitat, and Ecological
Characteristics
Pin cherry has several other common names: fire cherry, bird
cherry, northern pin cherry, wild red cherry, pigeon cherry, western
fire cherry, and summer cherry (cerises d’été). It occurs northward to
the permafrost throughout Canada, at scattered locations in the
northern Rocky Mountains down to Colorado, throughout the
northern Great Plains, throughout the Great Lakes region and
Northeast, and south along the Appalachian Mountains to northern
Georgia (Fulton 1974, Graber 1980, Hall et al. 1981, Wendel 1990,
Borland 1994, Farrar 1995). Pin cherry often occurs only sparsely in
the matrix of intermediate-age and older cool northern forests, but
may become abundant in some stands after a heavy overstory disturbance or cutting. It will hybridize with bitter cherry (Prunus
emarginata Dougl.) where the ranges overlap (Hosie 1973, Borland
1994, Farrar 1995).
Pin cherry will form pure thickets or dominate the overstory of
some young stands, but it commonly occurs in mixture with other
Received March 24, 2005; accepted October 19, 2005.
Ralph D. Nyland (rnyland@mailbox.syr.edu), SUNY College of Environmental Science and Forestry, Syracuse, NY 13210. Amy L. Bashant, Clinton, NY 13323. Eric F. Heitzman,
Division of Forestry and Natural Resources, West Virginia University, Morgantown, WV. Jane M. Verostek, SUNY College of Environmental Science and Forestry, Syracuse, NY
13210. This paper is the fifth in a five-part series on Interference to Hardwood Regeneration in Northeastern North America. The first paper appeared in the March 2006 issue, the
second paper appeared in the June 2006 issue, the third paper appeared in the September 2006 issue, and the fourth paper appeared in the December 2006 issue.
Copyright © 2007 by the Society of American Foresters.
52
NORTH. J. APPL. FOR. 24(1) 2007
species that include quaking (Populus tremuloides Michx.) and bigtoothed aspen (Populus grandidentata Michx.); yellow (Betula alleghaniensis Britton), paper (Betula papyrifera Marsh.), and black
birch (Betula lenta L.); striped, red (Acer rubrum L.), and sugar
maple; American beech (Fagus grandifolia Ehrh.); black cherry
(Prunus serotina Ehrh.); balsam fir (Abies balsamea (L.) Mill.); and
red spruce (Picea rubens Sarg.) in northeastern forests (after Hay
1978, Graber 1980, Wendel 1990). Associated shrubs and woody
herbs in northeastern North America include Rubus spp., hobblebush, and American yew (Taxus canadensis Marsh.) (Wendel 1990).
Pin cherry grows in a wide range of soil conditions. These include
landslides, coal-spoil banks, infertile rocky sites, and soils that range
from sandy plains to moist and rich loams (Bramble and Ashley
1955, Flaccus 1959, Graber 1980, Wendel 1990). Considered a
shade-intolerant pioneer species, it becomes established at many
sites following major overstory disturbances related to fire, blowdown, and cutting (Chittenden 1905, Hough and Forbes 1943,
Wendel 1990, Leak 1991). It may regenerate along roadsides and in
old fields (Fulton 1974, Hall et al. 1981), but due to its low shade
tolerance (Baker 1945, Wendel 1990), pin cherry will not survive in
forest openings smaller than about 0.25 ac (Marks 1974). It grows
primarily at sites that previously supported forest cover at the time of
a disturbance (Marks 1974).
Pin cherry grows rapidly after establishment and commonly becomes a dominant and upper codominant tree. It generally does not
live more than 30 –35 years (Marks 1974, Wendel 1990, Leak
1991), and it reaches peak sizes of 8 –10 in. dbh and up to 50 ft tall
by age 25 (Fulton 1974, DeGraaf and Witman 1979, Hall et al.
1981, Wendel 1990, Farrar 1995). Individual trees have reached
85–90 ft and 22 in. dbh (Hay 1978). Pin cherry has a moderately
soft, porous wood of low strength and no commercial timber value
(Hosie 1973, Wendel 1990). It is used for landscaping in some parts
of western North America (Borland 1994). A variety of fungi attack
pin cherry. These include black knot (Apiosporina morbosa), brown
trunk rot (Phellinus pomaceus), Nectria galligena, and Leucostoma
persoonii. Other diseases include cherry leaf spot (Blumeriella jaapii),
powdery mildew (Podosphera clandestine and Podosphera tridactyla),
a rust (Tranzschelia pruni-spinosae), and leaf curl (Taphrina wiesneri). A brown rot may affect the flowers and fruits (Monolinia laxa
and M. fructicola) (Weiss 1952, Hepting 1971, Wall 1986, Farr et
al. 1989). Insect defoliators include uglynest caterpillar (Archips
cerasivoranus), cherry leaf beetle (Pyrrhalta cavicollis), and cherry
webspinning sawfly (Neurotoma fasciata) (Hall et al. 1981, Drooz
1985). Eastern tent caterpillar (Malacosoma americanum) only occasionally attacks pin cherry (Waage and Bergelson 1985).
Fruit Production and Persistence
Pin cherry may begin producing some viable seed at age 2 and
becomes sexually mature by age 4. It does not yield large quantities
of seed until a few years later, and then on 2–3 year cycles (Marks
1974, Wendel 1990). Most of them fall close to the parent tree.
Birds and mammals may move some seeds long distances from the
source (Ahlgren 1966, Marks 1974), but this is likely less important
than direct seedfall in eventually establishing new pin cherry trees
following a major overstory disturbance (Graber 1980). Existing pin
cherry trees also sprout vigorously from the stump if cut or killed by
a surface fire (Chittenden 1905, Jensen 1943, Stoeckler 1947,
Marks 1974, Wall 1983, Jobidon 1997b). Furthermore, they may
produce root suckers (Hall et al. 1981, Wendel 1990, Farrar 1995,
Jobidon 1997a). Yet vegetative sources come to play only in fairly
young stands that already have pin cherry trees or after it becomes
established from seed following a heavy overstory disturbance in
older communities.
Due to its prolific fruiting, the organic layer beneath developing
even-aged stands may contain large numbers of viable seed. Olmstead and Curtis (1947) found about 1.2 seeds/ft2 beneath a
50-year-old northern hardwood stand in Maine. Marks (1974) reported as many as 2.5–5.1 seeds/ft2 in New Hampshire northern
hardwoods. Graber and Thompson (1978) counted 10 seeds/ft2
beneath a 38-year-old stand, but only half as many underneath one
at 95 years old. For a Pennsylvania cherry-maple stand, Marquis
(1975) estimated the number at about 45 seeds/ft2. Tierney and
Fahey (1998) found 440 and 1,900 viable seeds per pin cherry stem,
respectively, in New Hampshire northern hardwood stands with
high and low densities of standing trees. The numbers beneath a
23-year-old stand increased by 76 for each additional pin cherry tree
in the overstory, indicating that the total bank of viable seed depends
on the density of seed-producing trees in an emerging cohort. The
amount remaining viable in the forest floor of older stands depends
on stand age as well.
Pin cherry seeds remain viable in the forest floor for 4 – 6 decades
(Marks 1974, Marquis 1975, Wendel 1990, Leak 1991, Peterson
and Carson 1996, Tierney and Fahey 1998). Viability declines after
that time (Peterson and Carson 1996). And although the ground
beneath even 95-year-old stands may contain abundant seeds (Graber and Thompson 1978), and some may germinate after more than
100 years (Olmstead and Curtis 1947, Marks 1971, Graber and
Thompson 1978, Wendel 1990, Peterson and Carson 1996), few
remain viable for more than about 60 –70 years (Graber and
Thompson 1978, Tierney and Fahey 1998). In fact, pin cherry does
not usually regenerate in abundance following disturbance of stands
older than 100 –120 years of age (Marks 1974, Peterson and Carson
1996, Tierney and Fahey 1998). Conversely, a management strategy using relatively short rotations (e.g., ⱕ50 – 60 years) and using
clearcutting to regenerate a stand will likely lead to relatively high
densities of pin cherry (Hough and Forbes 1943, Marks 1974, Graber and Thompson 1978, Hay 1978, Tierney and Fahey 1998).
Germination and Early Seedling Development
Although some pin cherry seed may germinate beneath a forest
canopy, major recruitment primarily follows some kind of heavy
overstory disturbance (Marks 1974, Marquis 1975, Auchmoody
1979, Bjorkbom and Walters 1986). The combination of forest
floor scarification, increased light and temperature at the surface,
and increased soluble nitrogen helps to stimulate seed germination
(Bjorkbom and Walters 1986). Appropriate stratification also seems
necessary, since the stony endocarp must age, breaking down inhibitors in the fleshy covering and/or making the hard shell more permeable (Marks 1974). Laboratory tests indicate that good rates of
new seed germination follow only after removal or scarification (e.g.,
by acid) of the stony endocarp (Schropmeyer 1974), or a combination of cold (90 days) and warm (60 days) stratification in a moist
medium (Schropmeyer 1974, Young and Young 1992).
Consistent with this, Marquis (1975) observed delayed germination of freshly collected pin cherry seeds sown at uncut, partially cut,
and clearcut sites, with the proportion of 1st-year germination decreasing with intensity of overstory disturbance. Drastic temperature fluctuations and high light intensity with no moisture stress
may improve the germination rate, but partial shade proves beneficial with a normal moisture regime (Marquis 1973, Laidlaw 1987).
NORTH. J. APPL. FOR. 24(1) 2007
53
Apparently, natural stratification for extended periods in the forest
floor adequately conditions the seed and makes germination likely
once nutrients, moisture, and temperature increase following overstory reduction (Marks 1974, Laidlaw 1987, Wendel 1990).
Nitrogen (N) seems to stimulate pin cherry seed germination.
Auchmoody (1979) observed that fertilizing with N (urea), N and
phosphorous (P), and N, P, and potassium (K) stimulated germination of naturally buried pin cherry seed beneath the closed canopy of
a 60-year-old stand, but not until the second season. So did application of urea, calcium nitrate, and ammonium sulfate. Safford and
Filip (1974) found that pin cherry germinated in abundance, but in
a clumped distribution, on unfertilized plots following clearcutting
in New Hampshire, accounting for 54% of the stems at the 4th year.
Plots fertilized with limestone and commercial NPK (15-10-10)
had 72% of the stems in pin cherry, indicating a stimulating effect of
the nitrogen.
Thurston et al. (1992) related the timing of pin cherry germination to the degree of ground surface scarification, and its effect on
the rate of nitrification. Scarified plots had high pin cherry germination during the 1st growing season, whereas the number at nonscarified sites peaked later. Both Thurston et al. (1992) and Mou et
al. (1993) also indicated that germination continued past the first
year, with average standwide pin cherry density increasing into the
2nd year following clearcutting in New Hampshire. Thereafter, pin
cherry stem density steadily declined. Among eight sites in Pennsylvania, average pin cherry stocking decreased by nearly 70% from 1st
to 3rd and 3rd to 5th years, and then by 57% between years 5 and 10
(Ristau and Horsley 1999). They did not indicate whether germination added seedlings beyond the 1st year. Other reports suggest
that field germination has been delayed by up to 4 years following
clearcutting, even though some 1st-year seedlings were noted (Ahlgren 1966, Marquis 1975, Graber and Thompson 1978, Bormann
and Likens 1979, Horsley and Marquis 1983, Lanteigne 1984,
Bjorkbom and Walters 1986, Wang 1990, Ristau and Horsley
1999). In one case, pin cherry recruitment lasted for 8 –9 years
following spruce-fir overstory disturbance associated with a budworm infestation (Osawa 1994).
Pin cherry may form pure thickets after a major overstory disturbance. High-end densities have reached 100,707, 61,974, and
4,648 trees/ac in 1-, 4-, and 14-year-old stands, respectively, in New
Hampshire (Marks 1974). Density reached 42,900 in year 1 and
dropped to 10,400 at year 5 in one Pennsylvania clearcut (Bjorkbom
and Walters 1986). Among eight other stands, stocking averaged
43,119 at year 1 and dropped to a mean of 3,932 by the 10th year.
Other observations indicate that stocking may range widely within
and between sites (Marquis 1965, Safford and Filip 1974), likely
linked to the abundance of viable seed in the forest floor at the time
of a disturbance (Marks 1974, Marquis 1975). Ristau and Horsley
(1999) found from 78 to 1,400 pin cherry/ac at 1 year after clearcutting in northwestern Pennsylvania. Wendel (1990) reported levels
between 1,000 and 3,000 trees/ac at 5 years following clearcutting of
40- to 70-year-old Appalachian hardwood stands. In New Hampshire, Marquis (1965) found 3-year pin cherry density of
4,700 –9,000 trees/ac following patch cutting in a former oldgrowth stand, and 11,400 –23,700 trees/ac in patches within a 70to 90-year-old even-aged stand. He observed the lowest level of
stocking beneath slash piles and on skid trails in the older stand, and
relatively small differences between disturbed and undisturbed seedbeds in either stand. Patches in the second-growth stand had appreciably fewer pin cherry beneath slash plies than elsewhere.
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NORTH. J. APPL. FOR. 24(1) 2007
Mou et al. (1993) found a range of 38,988 to 54,656 seedlings/ac
at 2 years following whole-tree harvesting in New Hampshire, with
the greatest density on scarified (though not severely disturbed)
seedbeds and the lowest numbers in the undisturbed forest floor.
The fastest growth for the first 5– 6 years occurred at scarified sites.
In another small clearcut, they observed 25 pin cherry/ft2 in undisturbed and 91 trees/ft2 in scarified soil. Wang and Nyland (1993)
reported that pin cherry accounted for 0, 3, 5, 32, and 36%, respectively, of the tallest trees on 2-m sample plots within five central
New York clearcuts. Stand ages ranged from 14 to 20 years, with no
relationship between pin cherry abundance and cohort age. Thurston et al. (1992) suggested that although surface scarification led to
increased stocking of pin cherry, heavy cover by coarse woody debris
resulted in lower pin cherry densities. Also, they speculated that
variation of seed availability across a stand affects pin cherry stocking
and that removal of the forest floor layer would remove buried seed
and reduce pin cherry stocking at those microsites following overstory disturbance.
Overstory density also affects pin cherry establishment. In Vermont, pin cherry became abundant after shelterwood seed cutting
reduced overstory cover to ⬍60% (Hannah 1991). Beneath a 75%
canopy cover (45–50 ft2/ac) in Pennsylvania, pin cherry seeds germinated, but no seedlings survived past year 4. Reducing overstory
cover to 50% (35 ft2/ac) resulted in pin cherry survival and development (Horsley and Marquis 1983). In New Hampshire, pin
cherry density has increased with intensity of overstory removal,
particularly to ⱕ60 ft2/ac. It succeeded in clearcut plots (30 –39%
of stems), but poorly (0 –9% of stems) where partial cutting left
ⱖ40 ft2/ac of residual trees (Leak and Solomon 1975). Pin cherry
accounted for approximately 1 to 8% of dominant stems at 8 years,
decreasing in abundance in stands ranging from clearcut to 38, 64,
83, and 95 ft2/ac of residual basal area (Leak 1988). In other trials in
Pennsylvania, pin cherry survived at clearcut sites, but few remained
through 5 year at the shelterwood (113 ft2/ac and 69% relative
density) or uncut sites (Bjorkbom and Walters 1986).
Growth and Persistence
The foliage, bark, and seeds of pin cherry contain hydrocyanic
acid, which is toxic to livestock, but at the lowest toxicity level of the
Prunus species (Meade et al. 1986). Yet a wide variety of birds and
mammals feed on its fruit (Martin et al. 1951, Marks 1974, Wendel
1990). Also, deer (Odocoileus virginianus) commonly browse on its
twigs, and may even eliminate pin cherry from emerging stands or
slow its development in heavily affected areas (Jordan 1967, Marquis 1974, 1981; Tilghman 1989, Smith and Ashton 1993, Shabel
and Peart 1994, Horsley et al. 2003). Black bears (Ursus americanus)
also damage pin cherry as they climb the trees and break the tops
when foraging for the fruits (Costello 1992, R. Cross, personal
communication, Maine Department of Inland Fisheries and Wildlife, February 2005). Yet when not severely affected by animals, pin
cherry develops rapidly during the first decade following germination. It has an indeterminate growth form, with an extended period
of shoot elongation each year and leaves that remain active into
autumn (Marks 1975, Bicknell 1982, Amthor et al. 1990). This
contributes to its rapid development. Even so, Bicknell (1982) reported that pin cherry initially develops slowly in height. Then the
rate increases annually, putting pin cherry into a dominant canopy
position by about 6 years.
Jensen (1943) reported that in 5-year-old clearcuts, pin cherry
stems ⬎4 ft tall outnumbered that of all other species. Pin cherry has
reached heights of 10 –12 ft and a dbh of ⬎1 in. in 3 years following
patch cutting (Marquis 1965, Crow and Metzger 1987). Ristau and
Horsley (1999) observed that pin cherry height exceeded 3 ft tall by
year 3 and reached nearly 40 ft by age 15. Bicknell (1982) observed
that average height growth increased from 20 in. in year 2 to 54 in.
in year 4 and then decreased to 38 in. in year 6. By age 7, trees had
also an average diameter of nearly 2 in. (even larger than striped
maple). Annual height growth in four New York clearcuts ranged
from 1.7 to 2.3 ft/year for a 17- to 20-year period, and annual
diameter growth averaged about 0.2 in. (Wang and Nyland 1993).
Mallik et al. (1997) measured average heights of 5 ft at year 6. Other
studies indicate that total heights may reach 10 –12 ft in 3 years, and
diameters may exceed 1 in. (Crow and Metzger 1987). Smalley
(1987) measured pin cherry heights at 9 –12 ft by year 9, with other
species ⬍5 ft. Most reports indicate that it overtops the Rubus spp.
and more shade-tolerant tree species by 3–5 years following overstory removal (Jensen 1943, Marquis 1965, 1967, Bicknell 1982,
Horsley and Marquis 1983).
Data show that pin cherry may persist for 30 – 45 years (Jensen
1943, Auchmoody 1979, Leak 1991, McClure and Lee 1993), but
Marquis (1967) noted that abundance declined from the 5th year
through the 30th year. Thurston et al. (1992) also reported a steady
decline in total stem density (all sizes) from year 2 to year 6. Those
ⱖ0.8 in. dbh first appeared at year 3, with their numbers increasing
through year 6, and then dropping only slightly during the next 8
years. Mou et al. (1993) observed a similar pattern for the change in
total pin cherry densities (all sizes) at undisturbed, scarified, and
severely disturbed seedbeds. Similarly, Mallik et al. (1997) found
1,440 pin cherry/ac at 5 years after clearcutting (with ground scarification) in a Canadian boreal forest, but they observed 64 and 49%
reductions in density during the 6th and 7th years, respectively.
In the longer term, Wang and Nyland (1996) observed that
during a 7-year period beginning with crown canopy closure, the
importance [(relative density ⫹ relative basal area)/2] of pin cherry
decreased (by 0.2%) in one stand having a relatively low pin cherry
density and increased in two others (by 1.3% with pin cherry at high
relative abundance, and 6.9% when at medium abundance). Ristau
and Horsley (1999) reported that pin cherry numbers ⬎5 ft tall
decreased by about 75% between years 3 and 15. Pin cherry died out
after 30 years when at a low density, but persisted for 40 – 45 years
when at high density. Liptzen and Ashton (1999) noted a 48 – 49%
reduction in pin cherry density between ages 19 and 28, with similar
rates of decrease on thin till and swale till. McClure and Lee (1993)
found pin cherry density positively related to opening sizes from
⬍0.23 to 0.6 ac among 24-, 34-, and 44-year-old openings. In all
cases, the species’ relative density decreased to a low level by the end
of that time period. Consistent with this, Merrens and Peart
(1992) found only dead pin cherry (34 trees/ac) in a 49-year-old
stand, and Leak and Smith (1997) observed no living pin cherry
in a 56-year-old stand. Some had persisted through at least age
35. In general, pin cherry has disappeared or dropped to low
levels by age 35– 45 (Longwood 1951, Auchmoody 1979, Wendel 1990, Leak and Smith 1997) and sometimes as early as 20 –30
years (Jensen 1943).
Ecologic Effects of Pin Cherry following Heavy
Overstory Disturbance
Rapid revegetation of a site following a major overstory disturbance (e.g., natural or after cutting) contributes importantly to ecosystem stability (Marks and Borman 1972, Marks 1974, Mou et al.
1993, Donoso and Nyland 2006). The new plants shade the surface
and transpire water, leading to conditions that slow decomposition
of the forest floor and reduce percolation of free water in the soil.
The vegetation also absorbs nutrients and fixes them in biomass.
These processes reduce nutrient losses from a site. In addition, the
new vegetation helps to stabilize the surface with their roots and by
adding litter to the ground surface. This helps to reduce erosion of
both mineral soil material and humus. As a rapidly developing tree,
pin cherry contributes to those processes.
Herbs, and particularly Rubus spp., usually spread rapidly across
a site and overtop new and other short trees, with pin cherry and
other fast-growing trees emerging into dominant positions after 4 –5
years. Some studies link the natural reduction of Rubus spp. with the
emergence of the new tree community (see Donoso and Nyland
2006), yet other research suggests that a reduction of nitrates (once
organic matter decomposition slows) may contribute to the decline
of Rubus spp. (e.g., Marks 1974, Whitney 1986, Fahey et al. 1998).
Truax et al. (1994) did find high levels of nitrate reductase activity in
3rd- and 4th-year Rubus spp. leaves, but limited amounts in young
pin cherry. Furthermore, only Rubus spp. responded to fertilizer
having a high amount of nitrate. They surmised that with the low
rate of nitrate reductase activity and the high accumulation of N in
the pin cherry tissues, ammonium could serve as a more important
source of N for its growth and development. Regardless, pin cherry
fixes and cycles important amounts of nutrients (including N). That
contributes to ecosystem stability following heavy overstory disturbances such as clearcutting (Marks and Bormann 1972, Truax et al.
1994).
This notion is further reinforced by data showing rates of biomass accumulation in emerging hardwood communities. Total biomass has reached 23,200 kg/ha in a dense 4-year-old stand where
pin cherry made up 96% of the biomass (Marks 1974). The amount
was only 12% as much where pin cherry accounted for only 41% of
the biomass (Marks 1974). Nutrient uptake among 4- to 6-year-old
stands of dense pin cherry was estimated at 50% higher than occurs
in an undisturbed mature forest (Marks and Bormann 1972). Furthermore, Mou et al. (1993) found that compared with other species
regenerating after clearcutting, pin cherry had the highest 1st-year
concentrations of N, P, and K. Differences decreased thereafter. The
rate of N concentration dropped sharply during the second season,
but less so in undisturbed than severely disturbed soil. The pin
cherry had proportionately low concentrations of calcium (Ca) and
magnesium (Mg), yet due to its great rate of biomass accumulation
during the early years of stand development, pin cherry became an
important nutrient sink for N, P, and K after clearcutting.
Safford and Filip (1974) noted that pin cherry accounted for
36% of the trees and 94% of the total biomass (21,165 kg/ha) at 4
years on clearcut and fertilized plots. This exceeded the 22 and 53%
levels, respectively, in unfertilized stands. Furthermore, pin cherry
in fertilized plots contained 86 – 89% of the total content of N, P, K,
and Ca there. Unfertilized stands had 32–39% in the pin cherry. For
Mg, the fertilized and unfertilized stands had 79 and 23%, respectively, in the pin cherry. Among plots in 2-year-old clearcuts in
western Maine, pin cherry on fertilized plots (10-10-10 NPK) had
twice as much aboveground biomass as those left unfertilized (Elliott
and White 1993). This, too, suggests a potential for high levels of
nutrient uptake by the pin cherry trees.
NORTH. J. APPL. FOR. 24(1) 2007
55
Interference with Desirable Hardwoods
Effects of pin cherry on species composition following clearcutting and other heavy overstory disturbances seems linked to its relative abundance in young hardwood stands (Marquis 1965, Marks
1974, Safford and Filip 1974, Heitzman and Nyland 1994, Ristau
and Horsley 1999). Where dense, the rapidly-developing pin cherry
will form a closed overstory layer above most other species, including black cherry, sugar and red maple, yellow and paper birch, white
ash (Fraxinus americana L.), and other long-lived hardwoods. In
stands having a lower density of pin cherry, trees of these same
species often grow into upper canopy positions between the pin
cherry, unless overtopped by some other fast-growing tree (e.g.,
quaking aspen or striped maple).
Some assessments indicate that pin cherry does not prevent the
regeneration and eventual development of shade-tolerant species, or
it may only slow their growth (Hough and Forbes 1943, Marks
1974, Leak 1988, Merrens and Peart 1992). This reportedly relates
to the thin foliage and the light shade cast by an individual pin
cherry tree (Jensen 1943, Longwood 1951) and the survival of
shade-tolerant species (e.g., sugar maple and beech) at low levels of
light (Marks 1974). Some findings indicate that even when interference by pin cherry reduces the abundance of other species, many
stands still have adequate numbers of desirable hardwoods (Leak
1988, Martin and Hornbeck 1990), likely for the reason noted
above. Other reports also indicate that pin cherry, as well as other
noncommercial hardwoods, has not prevented the regeneration of
balsam fir (Baskerville 1963, Wall 1983, Lanteigne 1984) but significantly reduced its growth and altered the rate of community
development in some cases (Lanteigne 1984). Abundant pin cherry
has also led to important reductions of other species, including sugar
maple and beech, where these did not occur as advance regeneration
(Marquis 1965). By contrast, in stands having abundant advance
regeneration of desirable species, fairly dense pin cherry (⬃8,200
trees/ac at year 5) did not prevent eventual dominance of aspen,
paper birch, white ash, beech, and sugar maple (Marquis 1967).
Elsewhere, pin cherry interfered with stand development despite
having desirable species present before overstory removal (Heitzman
and Nyland 1994, Ristau and Horsley 1999).
A few reports also describe negative effects on less shade-tolerant
species. Hannah (1991) concluded that where pin cherry becomes
abundant after heavy cutting, it will interfere with yellow birch
growth and development. Likewise, Marquis (1965, 1967) associated the limited success of yellow and paper birch with abundant
stocking of rapidly growing pin cherry following both block
clearcutting and patch cutting, and Leak (1988) associated a onethird reduction of yellow birch with the dominance of pin cherry in
heavily-cut stands. Similarly, Martin and Hornbeck (1990) observed more pin cherry in block than strip clearcuts and better
yellow birch development in the latter areas. Even so, both stands
had adequate numbers of desirable species. Safford and Filip (1974)
found fewer and smaller yellow and paper birch beneath pin cherry
thickets in fertilized stands at 4 years after clearcutting. Yet unfertilized stands had relatively few of these thickets, and more area of only
moderate-density pin cherry where the more desirable hardwood
species developed better. White and Elliott (1992) and Elliott and
White (1993) observed that interference by pin cherry significantly
slowed the growth and development of red pine (Pinus resinosa Ait.)
seedlings at both fertilized and unfertilized clearcut sites. Yet the
importance of that interference seemed related to multiple factors
56
NORTH. J. APPL. FOR. 24(1) 2007
(site and biologic) that led to differences in pin cherry biomass as
well as its abundance.
More recent studies implicate pin cherry density as a critical
factor for interference on mesic hardwood sites, even at relatively
low stem densities and in stands having abundant advance regeneration of desirable species. Source of the regeneration also contributes. To illustrate, Heitzman and Nyland (1994) compared 20-year
development of regeneration plots having high (ⱖ3 at least 3 ft
tall/milacre) and low densities of pin cherry at year 3 after complete
overstory removal in a northern hardwood stand in south-central
New York. All plots initially had at least one non–pin cherry seedling of intermediate or low shade tolerance. By 20 years, those with
a high pin cherry density at year 3 had significantly greater numbers
of total stems (due largely to the pin cherry), and that species accounted for 56% of the basal area. Among low-density plots, pin
cherry basal area averaged only 33%. Black cherry stem density
decreased from 53% of the total in year 1 to 9% at year 20 on plots
with a high density of pin cherry. Plots with a lower density of pin
cherry had more sugar maple, black cherry, and white ash. Those
with high pin cherry density averaged about 170 stems/ac of other
species in a dominant canopy position, whereas plots with a low
density of pin cherry had about 460 trees/ac. At the high-density
plots, trees of most desirable species (including sugar maple, black
cherry, and white ash) were shorter and had smaller diameters. Yet
pin cherry density did not interfere with height development of
beech, yellow birch, and aspen. On the other hand, areas with a high
density of pin cherry had limited numbers of desirable species in
dominant or codominant crown positions, and the ones that survived may not suffice to ensure full site utilization after the pin
cherry dies.
Ristau and Horsley (1999) also observed important negative interference by pin cherry in Allegheny hardwood stands of northwestern Pennsylvania. Historic records allowed them to evaluate
regeneration success at 19 sites following complete overstory removal from 15 through 77 years earlier. Low deer impact at the time
of cutting resulted in early pin cherry dominance where that species
regenerated, but at a range of stem densities from 0 to 710
stems/milacre. Findings indicate that high-density pin cherry reduced the 15th-year survival and development of seedling-origin
black cherry, red and sugar maple, white ash, and striped maple.
Those of black and yellow birch and of stump sprouts of other
species were not. By 25–38 years, plots with a high 3rd-year pin
cherry density had a lower mean diameter (among trees ⱖ6 in.) and
only about one-half as much standing board-foot volume (largely
due to the reduced stocking of black cherry). Differences persisted
through the 7th decade. They identified the critical 3rd-year threshold density as ⬎1 pin cherry ⬎5 ft tall/milacre. Stocking at that or
a higher level would interfere with the development of seedling-origin regeneration of most desirable species. Later, they recommended using a post cutting (3rd year) threshold of ⬎6 pin cherry
ⱖ5 ft tall on a 6-ft radius plot, and more than 30% of plots at or
above that pin cherry stocking, as a criteria for identifying Allegheny
hardwood stands needing remediation (Ristau and Horsley 2006).
Such stands would likely end up understocked with desirable species, except for black and yellow birch and other trees of stump
sprout origin.
Release Treatments and Their Effects
Newton et al. (1992) observed that pin cherry died from sprucefir stands by year 16, even if not removed by a release treatment.
Mallik et al. (1997) concluded that where short-lived species (e.g.,
pin cherry) cause interference and where potential crop trees occur
in comparable or better crown positions, release treatments may
prove unnecessary. Furthermore, Heitzman and Nyland (1994)
warned that managers could not likely justify a release treatment
among stands where prolonged interference by pin cherry had reduced the vigor and led to appreciable mortality of more desirable
species. Thus, they recommend early entry where a cleaning would
seem necessary, such as the situations identified by Ristau and Horsley (2006).
Heitzman and Nyland (1991) suggested, where it seems necessary, a crown-touching release (after Lamson and Smith 1987) limited to removing competitors from around the minimum number of
well-spaced and vigorous trees that would provide adequate site
utilization in the long run. Leak and Smith (1997) studied the
potential by examining effects of a cleaning at age 25 in northern
hardwoods having 600 pin cherry trees/ac, approximately 45–50
trees/ac each of striped maple and aspen, and about 1,200 trees/ac of
desirable species. Cutting all of the former three species, or only
removing them from around selected crop trees, had only a minor
long-term effect (56-year conditions) on overall stand development.
Similarly, Ostrom and Hough (1944) noted that although cleaning
in 13- and 18-year-old stands improved diameter growth among
crop trees, appreciable numbers of pin cherry began dying within
untreated plots within 5 years. That naturally stimulated the growth
of previously overtopped sugar maple and beech without any release
treatment. Later, although Church (1955) did not specifically discuss the influence of pin cherry, per se, he observed that by 16 years
after treatment, heavily released black cherry and sugar maple crop
trees had grown significantly more rapidly than ones given a light
release. Also, growth of the lightly released trees did not differ significantly from unreleased controls. Together, findings suggest that
managers can likely limit release treatments to stands having a relatively high density and widespread cover of overtopping pin cherry,
and they will realize the most gain from early entry to those stands
and making a heavy release around trees with the greatest height and
best crown development (Heitzman and Nyland 1991, 1994).
Biological control has been suggested as one alternative for mitigating effects of pin cherry on regeneration success. It might include early (year 2) inoculation of widely-spaced pin cherry trees
using black knot disease (Wall 1985, 1986). Within 5– 6 years, the
fungi should spread 30 – 65 ft around the points of entry, reducing
pin cherry height growth and causing mortality of infected trees.
Also, limiting the size of clearcuts ensures a nearby reservoir of
natural inoculum and may make intervention unnecessary where
black knot disease already exists.
Brush saws or basal spray treatments would likely prove most
cost-effective for crown-touching release of spaced crop trees. Cutting takes about 1 to 1.5 minute/tree (Nyland et al. 2005b). The
stumps often sprout (Longwood 1951, Jobidon 1997b), with the
most vigorous development from large and high stumps. Openings
created by the cutting also may stimulate germination and establishment of new pin cherry trees and will reduce competition-induced
mortality among the remaining ones in upper-canopy positions
(Longwood 1951). Whether rapidly developing stump sprouts will
once more overtop the released trees remains unclear. Wall (1990,
1997) and Jobidon (1998) found that inoculating pin cherry stumps
with the fungi Chondrostereum purpureum effectively controlled
sprouting. McCormack (1981) reported success from applying triclopyr amine (Garlon 4 in water at 2.2 and 4.5 kg/ha) to cut stumps.
Other work suggests that stem injection or applying a basal spray of
appropriate herbicides to the pin cherry and other interfering species
would also circumvent any concern about stump spouting.
“Cherry” shows a susceptibility or intermediate susceptibility to
a basal spray using triclopyr (Garlon 4) or imazapyr (Chopper) in oil
(Heiligmann and Krause 2002). The triclopyr allows considerable
flexibility in timing, but it must be applied to the entire stump, the
bark, and any exposed roots (Heiligmann 2004). For stem injection,
“cherry” shows a susceptibility or intermediate susceptibility to triclopyr (Garlon 4), picloram (Tordon and Pathway), imazapyr
(Chopper, Stalker, and Arsenal), and glyphosate (Accord, Roundup,
Rodeo, Glyphos, Glopro, and Glyphomax). Ammonium sulfamate
(AMMATE, AMICIDE) will also kill pin cherry (Hall et al. 1981).
However, imazapyr has caused flashback in nearby trees of several
species after both basal spray and stem injection treatments
(Kochenderfer et al. 2001, 2004; Mallet 2002) and requires caution
in its use.
For stands with particularly dense pin cherry in overtopping
positions, aerial application might provide an option for broadcast
treatment. Glyphosate (1.7, 2.2, and 3.3 kg/ha) has worked effectively in killing trees (McCormack and Newton 1980, Newton et al.
1992) and in reducing crown area by ⬎60% with rates ⱖ0.5 kg
a.e./ac. Higher rates of deposit are needed with progressively greater
levels of pin cherry crown area (Pitt et al. 1992). Sublethal doses
(0.04 – 0.5 kg/ha of glyphosate as Vision, applied with a handheld
sprayer at a droplet size of 250 ␮m) repeated twice over a 2-year
period reduced the development of pin cherry and its competitive
effects. At doses of 2.1 kg/ha, it killed the leaves (Stasiak et al. 1991).
Aerial application of triclopyr amine (Garlon 3A at 2.2 and 4.4
kg/ha) also controlled 7-year-old pin cherry (Newton et al. 1992).
Users should consult the source publications for details about
formulations and application methods outlined here. The Environmental Protection Agency web site and the Herbicide Handbook
(Vencill 2002) provide extensive information about currently available compounds, including those approved for use in forestry operations and conditions of their registration. State and local regulations and herbicide labels should serve as a final reference with
respect to any herbicide application.
Management Implications
Ambiguities about the degree of interference by pin cherry leaves
the judgment about release treatments to managers. Shade-tolerant
species sometimes survive in sufficient numbers to provide adequate
site occupancy, but early release treatments may increase the proportion of shade-intolerant and shade-intermediate ones (Marquis
1965, 1967; Safford and Filip 1974, Crow and Metzger 1987).
Likely, managers should wait until the 3rd year, noting the relative
abundance, extent of cover, and status of other species before making a decision. Direct action might include removing pin cherry
trees that overtop selected ones of a desirable species, freeing just
enough to ensure full long-term site utilization. That option likely
has merit in stands of patchy and/or moderate pin cherry cover.
Alternatively, broadcast treatments may prove more effective and
more cost efficient in stands having good numbers of desirable trees
of acceptable vigor, but where pin cherry occurs at high densities and
forms an almost complete canopy that protects the shorter trees of
desirable species.
Landowners may gain more by taking steps to reduce the numbers of pin cherry that become established following clearcutting
and other heavy overstory disturbances. Precutting fertilization with
NORTH. J. APPL. FOR. 24(1) 2007
57
nitrogen will trigger germination of pin cherry seed stored in the
forest floor (Auchmoody 1979), but the seedlings will die in the
heavy shade after only 2–3 years. Shelterwood seed cutting that
leaves ⬃70% canopy cover (or at least 70 –75 ft2/ac of basal area) in
upper-canopy trees will result in germination of pin cherry seed
from the forest floor (after Ristau and Horsley 1999, 2005). Yet the
seedlings will die after a few years because of the shade intolerance of
the species. The moderately heavy overstory cover may also dampen
development of even shade-tolerant species, so a second overstory
reduction must follow in a timely manner. To address this, managers might consider using a three-cut shelterwood method, delaying
the removal cutting until a new cohort of adequate size, density, and
composition forms beneath the seed trees. Landowners can also
minimize pin cherry abundance by extending rotations to at least
100 years. By that time limited amounts of viable pin cherry seed
remain in the forest floor. Shorter rotations, particularly those not
exceeding 60 –70 years, will more likely lead to greater pin cherry
stocking, based on the abundance of viable seed that likely remain in
the forest floor.
Although older reports suggest that desirable species will likely
survive beneath moderately dense pin cherry, more recent studies
have shown oppressive effects at local densities of even 3,000
trees/ac for pin cherry ⱖ3 ft tall, or ⬎1,000 of them ⬎5 ft tall. At
these levels, pin cherry has slowed the seedling development of
shade-tolerant species and triggered mortality of those with a low or
intermediate shade tolerance. Birches seem to persist in some cases,
but not in others. Perhaps due to their early rapid height growth,
yellow and paper birch (e.g., see Nyland et al. 2004) tend to emerge
into a free-to-grow or main canopy position by the 5th year after
clearcutting and heavy shelterwood seed cutting. Stump sprouts also
show few signs of oppression. Furthermore, for stands with a patchy
or uneven spatial distribution of pin cherry, average per-acre estimates of its density may fail to reflect the uneven interference that
occurs from one place to another in a stand. So although desirable
species may fail in some places, they become part of the main canopy
elsewhere. Yet recent findings indicate that when 3rd-year stocking
at a particular place exceeds the levels mentioned above, pin cherry
will likely interfere with the development of other species and may
trigger mortality of the less shade-tolerant ones. When a sufficient
proportion of the area has a high density of pin cherry, a standwide
failure seems probable.
In some cases, even sugar maple stocking has dropped through
time beneath a high density of pin cherry cover. In other stands, only
rapidly-growing stump sprouts have survived. Perhaps the ambiguities from past research stem from a difference in sampling
methodology—reporting general levels of stocking at wide spatial
scales without taking account of patchiness in pin cherry distribution versus observing the effect of interference around particular
points on the ground.
A difference of that kind suggests a potential methodology for
sampling pin cherry abundance following clearcutting and other
heavy overstory disturbances, perhaps mimicking that proposed by
Bohn and Nyland (2003) and Nyland et al. (2006b). First, managers should wait until the 3rd year, when pin cherry has become well
established. They then might use milacre or 6-ft-radius plots set out
along a grid to sample the width and length of a stand. They would
separate those plots into two groups (having either a low or a high
density of pin cherry). High-density milacres would have at least
three pin cherry ⱖ3 ft tall, or more than one ⬎5 ft tall (after
Heitzman and Nyland 1994, Ristau and Horsley 1999). High den58
NORTH. J. APPL. FOR. 24(1) 2007
sity 6-ft plots would have ⱖ7 at least 5 ft tall (Ristau and Horsley
2006). Presence of a vigorous stump sprout of desirable species
would put the milacre into the low category, despite the presence of
pin cherry at the threshold densities (after Ristau and Horsley
1999). After sampling, managers would calculate the proportion of
plots having high and low densities of pin cherry. That would indicate the proportion of stand area where interference might lead to
reduced stocking of desirable species and a risk of losing the species
of intermediate and low shade tolerance.
Based on this methodology, no single threshold level of highdensity pin cherry would signal the need for a release treatment.
Landowners would need to make their choice based on the management objectives and a landowner’s constraints about investing in
early tending operations. But as with other plants that interfere with
the development of desirable hardwoods (see Nyland et al. 2006b),
managers should seriously consider scheduling a release treatment
when ⬎30 – 40% of the area has a high threshold density of pin
cherry. Where the data indicate a patchy distribution (e.g.,
⬍50 – 60%), they might limit cleaning to the pin cherry patches,
using a crown-touching release to free vigorous trees of desirable
species at a fairly wide spacing (e.g., 15- to 20-ft intervals). For
stands with high-density pin cherry across greater proportions of a
stand, alternate approaches may prove necessary. Yet aerial application of herbicides (e.g., glyphosate or triclopy) would potentially
also affect the desirable species in cases where pin cherry does not
form a fairly complete overtopping layer. Such cases would require
careful planning with respect to formulation, dosage, and means of
delivery.
Literature Cited
AHLGREN, C.E. 1966. Small mammals and reforestation following prescribed
burning. J. For. 64(9):614 – 618.
AMTHOR, J.S., D.S. GILL, AND F.H. BORMANN. 1990. Autumnal leaf conductance
and apparent photosynthesis by saplings and sprouts in a recently disturbed
northern hardwood forest. Oecologia 84(1):93–98.
AUCHMOODY, L.R. 1979. Nitrogen fertilization stimulates germination of dormant
pin cherry seed. Can. J. For. Res. 9(4):514 –516.
BAKER, F.S. 1945. A revised tolerance table. J. For. 47(3):179 –181.
BASKERVILLE, G.L. 1963. White birch and pin cherry may not suppress young balsam fir.
Can. Dept. For., Res. Br. Mimeo Rep. 63-M-24.
BICKNELL, S.H. 1982. Development of canopy stratification during early succession
in northern hardwoods. For. Ecol. Manage. 4(1):41–51.
BOHN, K.K., AND R.D. NYLAND. 2003. Forecasting development of understory
American beech after partial cutting in uneven-aged northern hardwood stands.
For. Ecol. Manage. 180:453– 461.
BJORKBOM, J.C., AND R.S. WALTERS. 1986. Allegheny hardwood regeneration
response to even-age harvesting methods. USDA For. Serv. Northeast. For. Exp.
Stn. RP-NE-581. 13 p.
BORLAND, J. 1994. Field notes: Prunus pensylvanica. Am. Nurseryman 180(5):106.
BORMANN, F.H., AND G.E. LIKENS. 1979. Pattern and process in a forested ecosystem.
Springer-Verlag, New York. 253 p.
BRAMBLE, W.C., AND R.H. ASHLEY. 1955. Natural revegetation of spoil banks in
central Pennsylvania. Ecology 36(3):417– 423.
CHITTENDEN, A.K. 1905. Forest conditions of northern New Hampshire. USDA
Bur. For. Bull. 55.
CHURCH, T.W. JR. 1955. Weeding—An effective treatment for stimulating growth
of northern hardwoods. J. For. 53(10):717–719.
COSTELLO, C.M. 1992. Black bear habitat ecology in the Central Adirondacks as related
to food abundance and forest management. MSc thesis, SUNY College of
Environmental Science and Forestry, Syracuse, NY. 165 p.
CROW, T.R., AND F.T. METZGER. 1987. Regeneration under selection cutting. P.
81–94 in Managing northern hardwoods, Nyland, R.D. (ed.). SUNY College of
Environmental Science and Forestry, Fac. For. Misc. Publ. No. 13 (ESF 87-002).
(Soc. Am. For. Publ. No. 87-03). Syracuse, NY.
DEGRAAF, R.M., AND G.M. WITMAN. 1979. Trees, shrubs, and vines for attracting
birds. Univ. of Mass. Press, Amherst, MA. 194 p.
DONOSO, P.J., AND R.D. NYLAND. 2006. Interference to hardwood regeneration in
northeastern North America: The effects of raspberries (Rubus spp.) following
clearcutting and shelterwood methods. North. J. Appl. For. 23(4):288 –296.
DROOZ, A.T., ED. 1985. Insects of eastern forests. USDA For. Serv. Misc. Publ. 1426.
608 p.
ELLIOT, K.J., AND A.S. WHITE. 1993. Effects of competition from young northern
hardwoods on red pine seedling growth, nutrient use efficiency, and leaf
morphology. For. Ecol. Manage. 57:233–255.
FAHEY, T.J., J.J. BATTLES, AND G.F. WILSON. 1998. Responses of early successional
northern hardwood forests to changes in nutrient availability. Ecol. Monogr.
68(2):183–212.
FARR, D.F., G.F. BILLS, G.P. CHAMURIS, AND A.Y. ROSSMAN. 1989. Fungi on plants
and plant products in the United States. APS Press, St. Paul, MN. 1252 p.
FARRAR, J.L. 1995. Trees of the northern United States and Canada. Iowa State Univ.
Press, Ames, IA. 502 p.
FLACCUS, W. 1959. Revegetation of landslides in the White Mountains of New
Hampshire. Ecology 40(4):692–703.
FULTON, J.R. 1974. Pin cherry. P. 26 –27 in Shrubs and vines for northeastern wildlife,
Gill J.D. and W.M. Healy (eds.). USDA For. Serv. Gen. Tech. Rep. NE-9.
GRABER, R.E. 1980. Pin cherry type 17. P. 17–18 in Forest cover types of the United
States and Canada, Eyre, F.H. (ed.). Society of American Foresters, Washington,
DC.
GRABER, R.E., AND D.F. THOMPSON. 1978. Seeds in the organic layers and soil of
four beech-birch-maple stands. USDA For. Serv. Res. Pap. NE-401. 8 p.
HALL, I.V., C.O. GOURLEY, AND G.W. WOOD. 1981. Biology of Prunus pensylvanica
L.f. Proc. N.S. Inst. Sci. 31:101–108.
HANNAH, P.R. 1991. Regeneration of northern hardwoods in the northeast with the
shelterwood method. North. J. Appl. For. 8(3):99 –104.
HAY, R. 1978. Conditions for optimum growth of a species can be fragile and
fleeting, as this discovery proves. Am. For. 84(4):14, 62– 63.
HEITZMAN, E., AND R.D. NYLAND. 1991. Cleaning and early crop-tree release in
northern hardwood stands: A review. North. J. Appl. For. 8(3):111–115.
HEITZMAN, E., AND R.D. NYLAND. 1994. Influences of pin cherry (Prunus
pensylvanica L.f.) on growth and development of young even-aged northern
hardwoods. For. Ecol. Manage. 67:39 – 48.
HEILIGMANN, R.B. 2004. Controlling undesirable trees, shrubs, and vines in your woodland.
Ohio State Univ. Extension Sch. Nat. Resources. Available online at www. ohioline.
osu.edu/for-fact/0045.html; last accessed Feb. 6, 2007.
HEILIGMANN, R.B., AND D. KRAUSE. 2002. Relative effectiveness of herbicides
commonly used to control woody vegetation in forest stands. Ohio State Univ. Sch.
Nat. Resources, Extension Fact Sheet F-51-02. 4 p.
HEPTING, G.H. 1971. Diseases of forest and shade trees of the United States. USDA For.
Serv. Agric. Handbk. No. 386. 658 p.
HORSLEY, S.B., AND D.A. MARQUIS. 1983. Interference by weeds and deer with
Allegheny hardwood reproduction. Can. J. For. Res. 13(1):61– 69.
HORSLEY, S.B., S.L. STOUT, AND D.S. DECALESTA. 2003. White-tailed deer impact
on the vegetation dynamics of a northern hardwood forest. Ecol. Appl.
13(1):98 –118.
HOSIE, R.C. 1973. Native trees of Canada. Can. For. Serv., Dept. Environ., Ottawa,
Ont., Canada. 380 p.
HOUGH, A.F., AND R.D. FORBES. 1943. The ecology and silvics of forests in the high
plateaus of Pennsylvania. Ecol. Monogr. 13(3):299 –320.
JENSEN, V.S. 1943. Suggestions for the management of northern hardwood stands in
the northeast. J. For. 41(3):180 –185.
JOBIDON, R. 1997a. Pin cherry sucker regeneration after cutting. North. J. Appl. For.
14(3):117–119.
JOBIDON, R. 1997b. Stump height effects on sprouting of mountain maple, paper
birch and pin cherry-10 year results. For. Chron. 73(5):590 –595.
JOBIDON, R. 1998. Comparative efficacy of biological and chemical control of the
vegetative reproduction in Betula papyrifera and Prunus pensylvanica. Biol. Contr.
11(1):22–28.
JORDAN, J. 1967. Deer browsing in northern hardwoods after clearcutting. Effect on
height, density, and stocking of regeneration of commercial species. USDA For. Serv.
Res. Pap NE-57. 15 p.
KOCHENDERFER, J.D., S.M. ZEDAKER, J.E. JOHNSON, D.W. SMITH, AND G.W.
MILLER. 2001. Herbicide hardwood crop tree release in central West Virginia.
North. J. Appl. For. 18(2):46 –54.
KOCHENDERFER, J.D., J.N. KOCHENDERFER, D.A. WARNER, AND G.W. MILLER.
2004. Preharvest manual herbicide treatments for controlling American beech in
central West Virginia. North. J. Appl. For. 21(1):40 – 49.
LAIDLAW, T.F. 1987. Drastic temperature fluctuation—The key to efficient
germination of pin cherry. Tree Plant. Notes 38(3):30 –32.
LAMSON, N.I., AND H.C. SMITH. 1987. Response to crop tree release: Sugar maple, red
oak, black cherry, and yellow-poplar saplings in a 9-year-old stand. USDA For. Serv.
Res. Pap. NE-394. 8 p.
LANTEIGNE, L.J. 1984. The impact of cleaning with herbicide on successional
development and the growth of balsam fir after clearcutting a fir-spruce forest. MSc
For. thesis. Univ. New Brunswick, Fredericton, N.B., Canada. 106 p.
LEAK, W.B. 1988. Effects of weed species on northern hardwood regeneration in
New Hampshire. North. J. Appl. For. 5(4):235–237.
LEAK, W.B. 1991. Secondary forest succession in New Hampshire. For. Ecol.
Manage. 43(1):69 – 86.
LEAK, W.B., AND D.S. SOLOMON. 1975. Influence of residual stand density on
regeneration of northern hardwoods. USDA For. Serv. Res. Pap. NE-RP-310. 7 p.
LEAK, W.B., AND M.L. SMITH. 1997. Long-term species and structural changes after
cleaning young even aged northern hardwoods in New Hampshire, USA. For.
Ecol. Manage. 95(1):11–20.
LIPTZIN, D., AND P.M. ASHTON. 1999. Early-successional dynamics of single-aged
mixed hardwood stands in a southern New England forest, USA. For. Ecol.
Manage. 116:141–150.
LONGWOOD, F.R. 1951. Why release young maple from pin cherry? USDA For. Serv.
Tech. Note. LS-TN-360. 2 p.
MALLETT, A.L. 2002. Management of understory American beech by manual and
chemical control methods. MSc thesis. SUNY College of Environmental Science
and Forestry, Syracuse, NY. 152 p.
MALLIK, A.U., F.W. BELL, AND Y. GONG. 1997. Regeneration behavior of competing
plants after clear cutting: Implications for vegetation management. For. Ecol.
Manage. 95(1):1–10.
MARKS, P.L. 1971. The role of Prunus pensylvanica L. in the revegetation of disturbed
sites. PhD thesis. Yale Univ., New Haven, CT. 119 p.
MARKS, P.L. 1974. The role of pin cherry (Prunus pensylvanica L.) in the maintenance
of stability in northern hardwood ecosystems. Ecol. Monogr. 44(1):73– 88.
MARKS, P.L. 1975. On the relation between extension growth and successional status
of deciduous trees of the northeastern United States. Bull. Torrey Bot. Club.
102(4):172–177.
MARKS, P.L., AND F.H. BORMANN. 1972. Revegetation following forest cutting:
Mechanisms for return to steady-state nutrient cycling. Science
176(4037):914 –915.
MARQUIS, D.A. 1965. Regeneration of birch and associated hardwoods after patch
cutting. USDA For. Serv. Res. Pap. NE-32. 13 p.
MARQUIS, D.A. 1967. Clearcutting in northern hardwoods: Results after 30 years.
USDA For. Serv. Res. Pap. NE-085. 13 p.
MARQUIS, D.A. 1973. The effect of environmental factors on advance regeneration on
Allegheny hardwoods. PhD thesis. Yale University, New Haven, CT. 147 p.
MARQUIS, D.A. 1974. The impact of deer browsing on Allegheny hardwood regeneration.
USDA For. Serv. Res. Pap. NE-308.
MARQUIS, D.A. 1975. Seed storage and germination under northern hardwood
forests. Can. J. For. Res. 5(4):478 – 484.
MARQUIS, D.A. 1981. Effect of deer browsing on timber production in Allegheny
hardwood forests of northwestern Pennsylvania. USDA For. Serv. Res. Pap.
NE-475. 10 p.
MARTIN, A.C., H.S. ZIN, AND A.L. NELSON. 1951. American wildlife and plants: A
guide to wildlife food habits. Dover Publishing, New York. 500 p.
MARTIN, C.W., AND J.W. HORNBECK. 1990. Regeneration after strip cutting and
block clearcutting in northern hardwoods. North. J. Appl. For. 7(2):65– 68.
MCCLURE, J.W., AND T.D. LEE. 1993. Small-scale disturbance in a northern
hardwoods forest: Effects on tree species abundance and distribution. Can. J. For.
Res. 23(7):1347–1360.
MCCORMACK, M.L. JR. 1981. Chemical weed control in northeastern forests. Weed
control in forest management. P. 108 –115 in Proc. John S. Wright forestry
conference. Purdue Univ., Lafayette, IN.
MCCORMACK, M.L. JR., AND M. NEWTON. 1980. Aerial application of triclopyr,
phenoxies, picloram and glyphosate for conifer release in spruce-fir forests of
Maine. Proc. Weed Sci. Soc. Am.:47– 48
MEADE, J.A., R.L. WASHER, AND D.M. MOHR. 1986. Wild cherry and livestock. New
Jersey Coop. Ext. Serv., New Brunswick, NJ.
MERRENS, E.J., AND D.R. PEART. 1992. Effects of hurricane damage on individual
growth and stand structure in a hardwood forest in New Hampshire, USA. J.
Ecol. 80(4):787–795.
MOU, P., T.J. FAHEY, AND J.W. HUGHES. 1993. Effects of soil disturbance on
vegetation recovery and nutrient accumulation following whole-tree harvest of a
northern hardwood ecosystem. J. Appl. Ecol. 30(4):661– 675.
NEWTON, M., E.C. COLE, D.E. WHITE, AND M.L. MCCORMACK JR. 1992. Young
spruce-fir forests released by herbicides I. Response of hardwoods and shrubs.
North. J. Appl. For. 9(4):126 –130.
NYLAND, R.D., D.G. RAY, AND R.D. YANAI. 2004. Height development of
upper-canopy trees within even-aged Adirondack northern hardwood stands.
North. J. Appl. For. 21(3):117–122.
NYLAND, R.D., A.L. BASHANT, K.K. BOHN, AND J.M. VEROSTEK. 2006a.
Interference to hardwood regeneration in northeastern North America:
Ecological characteristics of American beech, striped maple and hobblebush.
North. J. Appl. For. 23(1):53– 61.
NYLAND, R.D., A.L. BASHANT, K.K. BOHN, AND J.M. VEROSTEK. 2006b.
Interference to hardwood regeneration in northeastern North America:
Controlling effects of American beech, striped maple, and hobblebush. North.
J. Appl. For. 23(2):122–132.
OLMSTEAD, N.W., AND J. CURTIS. 1947. Seeds of the forest floor. Ecology
28(1):49 –52.
NORTH. J. APPL. FOR. 24(1) 2007
59
OSAWA, A. 1994. Seedling responses to forest canopy disturbances following a spruce
budworm outbreak in Maine. Can. J. For. Res. 24(4):850 – 859.
OSTROM, C.E., AND A.F. HOUGH. 1944. Early weeding in northern hardwoods. J.
For. 42(2):138 –140.
PETERSON, C.J., AND W.P. CARSON. 1996. Generalizing forest regeneration models:
The dependence on disturbance history and stand size. Can. J. For. Res.
26(1):45–52.
PITT, D.G., R.A. FLEMING, AND D.G. THOMPSON. 1992. Glyphosate efficacy on
eastern Canadian forest weeds. Part II: Deposit-response relationships and crop
tolerance. Can. J. For. Res. 22(8):1160 –1171.
RISTAU, T.E., AND S.B. HORSLEY. 1999. Pin cherry effects on Allegheny hardwood
stand development. Can. J. For. Res. 29(1):73– 84.
RISTAU, T.E., AND S.B. HORSLEY. 2006. When is pin cherry (Prunus pensylvanica L.)
a problem in Allegheny hardwoods? North. J. Appl. For. 23(3):204 –210.
SAFFORD, L.O., AND S.M. FILIP. 1974. Biomass and nutrient content of 4-year-old
fertilized and unfertilized northern hardwood stands. Can. J. For. Res.
4(4):549 –554.
SCHROPMEYER, C.S. 1974. Seeds of woody plants in the United States. USDA For. Serv.
Agric. Handbk. No. 450. 833 p.
SHABEL, A.B., AND D.R. PEART. 1994. Effects of competition, herbivory and
substrate disturbance on growth and size structure in pin cherry (Prunus
pensylvanica L.) seedlings. Oecologia 98(2):150 –158.
SMALLEY, F.E. 1987. Regeneration hardwood stands in the Northeast. North. J. Appl.
For. 4(1):5– 6.
SMITH, D.M., AND P.M. ASHTON. 1993. Early dominance of pioneer hardwoods
after clearcutting and removal of advanced regeneration. North. J. Appl. For.
10(1):14 –19.
STASIAK, M.A., G. HOFSTRA, N.J. PAYNE, R. PRASAD, AND R.A. FLETCHER. 1991.
Alterations of growth and shikimic acid levels by sublethal glyphosate
applications on pin cherry and trembling aspen. Can. J. For. Res.
21(7):1086 –1090.
STOECKLER, J.H. 1947. When is plantation release most effective? J. For.
45(4):265–271.
THURSTON, S.W., M.E. KRASNY, C.W. MARTIN, AND T.J. FAHEY. 1992. Effect of site
characteristics and 1st- and 2nd- year seedling densities on forest development in
a northern hardwood forest. Can. J. For. Res. 22(12):1860 –1868.
TIERNEY, G.L., AND T.J. FAHEY. 1998. Soil seed bank dynamics of pin cherry in a
northern hardwood forest, New Hampshire, U.S.A. Can. J. For. Res.
28(10):1471–1480.
TILGHMAN, G. 1989. Impacts of white-tailed deer on forest regeneration in
northwestern Pennsylvania. J. Wildl. Manage. 53(3):524 –532.
60
NORTH. J. APPL. FOR. 24(1) 2007
TRUAX, B., D. GAGNON, F. LAMBERT, AND N. CHEVRIER. 1994. Nitrate assimilation
of raspberry and pin cherry in a recent clearcut. Can. J. Bot. 72(9):1343–1348.
US
ENVIRONMENTAL
PROTECTION
AGENCY.
Available
online
at
www.epa.gov.pesticides; last accessed Oct. 19, 2006.
VENCILL, W.K. (ED). 2002. Herbicide handbook, 8th Ed. Weed Sci. Soc. Am.,
Lawrence, KS. 493 p.
WAAGE, J.K., AND J.M. BERGELSON. 1985. Differential use of pin and black cherry by
eastern tent caterpillar Malacosoma americanum Fab. (Lepidoptera:
Lasiocampidae). Am. Mid. Nat. 113(1):5–55.
WALL, R.E. 1983. Early stand development after clearcutting on the Cape Breton
Highlands. Can. For. Serv., Maritime For. Res. Cent. Info. Rep. M-X-143.
WALL, R.E. 1985. The role of disease in removal of weed species from developing
forest stands. P. 673– 676 in Proc. VI international symp. on biological control of
weeds. August 19 –25, 1984. Delfosse, E.S. (ed.). Vancouver, Canada.
L’Agriculture Canadienne.
WALL, R.E. 1986. Effects of black knot disease on pin cherry. Can. J. Plant Pathol.
8(1):71–77.
WALL, R.E. 1990. The fungus Chondrostereum purpureum as a silvicide to control
stump sprouting in hardwoods. North. J. Appl. For. 7(1):17–19.
WALL, R.E. 1997. Fructification of Chondrostereum purpureum on hardwoods
inoculated for biological control. Can. J. Plant Pathol. 19:181–184.
WANG, Z. 1990. Effects of clearcutting on the species composition of second-growth
northern hardwood stands. MSc thesis. SUNY College of Environmental Science
and Forestry, Syracuse, NY. 118 p.
WANG Z., AND R.D. NYLAND. 1993. Tree species richness increased by clearcutting
of northern hardwoods in central New York. For. Ecol. Manage. 57(1):71– 84.
WANG Z., AND R.D. NYLAND. 1996. Changes in the condition and species
composition of developing even-aged northern hardwood stands in central New
York. North. J. Appl. For. 13(4):189 –194.
WEISS, F.A. 1952. Index of plant diseases in the United States. USDA, Beltsville, MD.
1,263 p.
WENDEL, G.W. 1990. Pin cherry (Prunus pensylvanica L.f.). P. 587–593 in Silvics of
North America, Vol. 2. Hardwoods. Burns, R.M., and B.H. Honkala (eds.) USDA
For. Serv. Available online at www.na.fs.fed.us/spfo/pubs/silvics_manual; last
accessed Feb. 5, 2007.
WHITE, A.S., AND K.J. ELLIOTT. 1992. Predicting the effects of hardwood
competition on red pine seedling growth. Can. J. For. Res. 22(10):1510 –1515.
WHITNEY, G.G. 1986. A demographic analysis of Rubus idaeus and Rubus pubescens.
Can. J. Bot. 64(12):2916 –2921.
YOUNG, J.A., AND C.G. YOUNG. 1992. Seeds of woody plants in North America.
Discorides Press, Portland, OR. 407 p.