Vaccinium myrtilloides Michx.

More info for the terms: cover, density, prescribed fire

Season of burn: Response of velvetleaf blueberry is generally better
after early spring or fall burns than after late spring or summer burns.
Response by season of burn was documented as follows in forests of
eastern Canada [25]:

season of burn relative abundance (stem density for velvetleaf
blueberry in plot/stem dens. for all species
in plot) x 100

preburn 1 month 3 months 5 months

late spring (early July) --- --- --- 17 %
summer (July 20-22) --- --- --- 25 %
fall (September 15-17) --- --- 37% 30 %

Postfire recovery: Reestablishment of velvetleaf blueberry is often
fairly rapid where surviving portions of the plant sprout. Postfire
increases in cover and biomass were as follows in northeastern Minnesota
[62,63]:

year postfire percent cover (avg. of 7 sites)

1 0.6
2 0.2
3 1.1
4 0.7
5 1.1

postfire growing individual dry number of
season weight (gms) individuals

1971 .16 140
1972 .75 29
1973 .70 64
1974 1.43 84
1975 1.60 151

In northern Minnesota, comparative values from burned and unburned three
year old stands were as follows [76]:

unburned burned
stems/0.1 m sq. 2.3 2
flower buds/plant 6 8
stem length (cm) 22 24

The Research Project Summary Understory recovery after burning and reburning
quaking aspen stands in central Alberta provides information on prescribed
fire and postfire response of plant community species, including velvetleaf
blueberry, that was not available when this species review was originally written.

velvetleaf blueberry

Velvetleaf blueberry is tentatively listed by Washington as critically
imnperiled (S1?) in that state [103].

In Montana, velvetleaf blueberry has been found in only one location
near West Glacier. It is, however, widespread in neighboring Alberta
[55].

Velvetleaf blueberry was formerly believed to be extirpated from Ohio,
but several populations were found in 1984 [17].

More info for the terms: fruit, rhizome, shrub

Velvetleaf blueberry is a dwarf, deciduous shrub which grows from 4 to
35 inches (10-89 cm) in height [10,78,86,90]. This rhizomatous shrub
commonly forms small open colonies [88]. However, on favorable sites, a
single plant may reach 33 feet (10 m) in diameter [90]. Velvetleaf
blueberry typically develops an extensive network of roots and woody
rhizomes [76,90]. The numerous shallow roots are fibrous and
much-branched, with considerable lateral spread [5,77]. Roots average
0.004 to 0.02 inch (0.1-0.5 mm) in diameter [5]. Taproots may be absent
[77], although at some sites, taproots averaging 0.4 inch (10 mm) in
diameter have been reported at depths to 3 feet (91 cm) [29,53].
Elsewhere, researchers have observed maximum rooting depths of 4 to 6
inches (10-15 cm) [84]. Clonal variation in the number of shoots and
rhizomes, and in rhizome depth has been reported [77].

Branches are velvety pilose [76] and ascending [90]. Twigs are green or
brown [88] and the bark, a "dirty brown" or green [90]. Stem morphology
has been examined in detail [60]. The thin, alternate, entire leaves
are elliptic to sublanceolate and 0.8 to 1.6 inches (2-4 cm) in length
[10,78,90]. The leaf base is obtuse or cuneate and the apex acute
[78,86]. The upper leaf surface is bright green whereas the
undersurface is paler [86]. Leaves are variable [86] but, as the name
velvetleaf blueberry suggests, are usually pubescent on both sides [88].

White to greenish, pale pink or purple-tinged flowers [10,78,86] are
borne in terminal or lateral racemes [90]. Flowers are drooping,
urceolate, or broadly cylindric-campanulate in shape [68,86,90]. Floral
morphology has been examined in detail [65]. Velvetleaf blueberry is
cluster-fruited species [19]. Fruit is a bright, frosty blue to dark
blue, or, less commonly, white (as in the form chicococcum) berry which
averages 0.16 to 0.4 inch (4-10 mm) in diameter [78,86]. Berries are
generally glaucous [88] and contain several small seeds or nutlets 0.04
inch (1.0 mm) in length [88,90]. Berries contain an average of 16
viable seeds; 100 seeds weigh approximately 26 mg [90].

Velvetleaf blueberry grows from central Labrador across Canada to
British Columbia and the Northwest Territories [90]. In eastern North
America, it extends southward through the mountains of New England, New
York, and Pennsylvania to West Virginia and Virginia [78,80,86].
Disjunct populations have been reported in the uplands of the
Appalachian Mountains [88]. Velvetleaf blueberry is also common in the
upper Midwest and Lake States [80]. Evidence suggests that this now
transcontinental species [43], was formerly restricted to the central
Arctic at the end of the Tertiary [78].

More info for the terms: codominant, fire regime, forest, fruit, seed

Velvetleaf blueberry commonly sprouts from the stem base or rhizomes
after aboveground foliage is removed or damaged by fire [11,90]. Some
seed may be transported to burned sites by birds and mammals.

Velvetleaf blueberry appears to be well adapted to a regime of fairly
frequent fires. Although berry production may be much-reduced,
velvetleaf blueberry is apparently able to persist for years beneath a
closed canopy forest. Old clones decline in vigor, but periodic fires
initiate vigorous sprouting and regrowth. In the East, native Americans
and early European settlers used fire in wild berry fields containing
velvetleaf blueberry to enhance fruit production [76]. Evidence
suggests, however, that velvetleaf blueberry is less tolerant of annual
or biennial fires than its conspecific, low sweet blueberry [78].

Fire is a particularly common influence in northern boreal forests where
velvetleaf blueberry grows as an understory dominant or codominant [23].
Fire intervals in these areas vary, but often range from 27 to 54 years.
In parts of northern Minnesota, fire intervals have been estimated at 30
years [76], and in the jack pine woodlands of Alberta's Athabasca Plains,
patchy burns occur every 28 to 54 years [11]. Peak abundance of
velvetleaf blueberry evidently corresponds to these intervals. Peak
frequencies have been observed approximately 27 years after fire in
parts of Minnesota [73]. In parts of northern Ontario, increases in
velvetleaf blueberry have been observed approximately 50 years after
fire [78]. Fire intervals in many coniferous forests of eastern Canada
are somewhat longer than in boreal forests to the north. Flinn [23]
reported average fire intervals of approximately 370 years.

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".

More info for the terms: cover, fire suppression, forest, frequency, fruit, fuel, prescribed fire, rhizome, scarification, shrubs, tree

Wildlife: Evidence suggests that fire suppression may be having an
adverse impact on bear habitat in some areas [55,96]. Once-productive
berry fields are being invaded by conifers. Since plants beneath a
forest canopy generally produce few berries, fruit production has been
steadily declining in many areas [57]. Berry fields can be treated with
fire if maintenance or enhancement of berry crops is a prime management
objective. Logging treatments which include severe soil scarification
or slash burns may also reduce berry production. Even where timber
harvest favors berry production, lack of cover in early years can limit
bear use. Wildfires often create diverse habitat mosaics which
incorporate elements of hiding cover and favor bear use [96].

Prescribed fire: Prescribed fire has long been used to increase yields
in commercial low sweet blueberry fields of the East by naturally
pruning decadent shoots [23,42,57]. Flower buds generally tend to be
more numerous on new shoots and periodic removal of old shoots can
increase fruit yield as well as enhance overall vigor [57,75].
Prescribed fire has also proven effective in increasing fruit yield for
wildlife and recreationists in noncommercial forest stands of the Upper
Midwest [7]. In northern Minnesota, fruit production of blueberries
(Vaccinium spp.) was enhanced by the second growing season after fire
[7]. In addition to increased numbers of berries, fruit size was
noticeably larger than on adjacent unburned plots [7].

Spring burns, conducted when the soil is still moist, tend to be
effective in promoting fruit production. In the Great Lakes Region,
Kautz [42] recommends burning blueberry (Vaccinium spp.) stands with 4
to 5 years fuel accumulation during the early afternoon on warm, clear,
sunny days with average wind speeds of 5 to 10 miles per hour (6-8
km/hour). Fast-moving fire fronts, which burn aboveground parts but
leave underground regenerative structures intact, generally produce best
results. Therefore, when increased blueberry fruit production is a
primary management objective, head fires are preferable to backing
fires. It may be necessary to add fuels when burning blueberry stands
in the East. In the Great Lakes Region, areas to be burned should be
rotated over a 4- to 5- year interval to maintain adequate berry
production for recreationists and wildlife [42]. In the Great Lakes
region, blueberry stands are typically burned at 4 to 5 year intervals
rather than at the 1 to 2 year intervals common in the Northeast [76].

Many commercial stands made up of both low sweet blueberry and
velvetleaf blueberry, have been burned at two year intervals [88].
While burning at this interval is beneficial to low sweet blueberry,
velvetleaf blueberry generally decreases [30,88,90]. However, burning
at three year intervals appears to benefit woodlots made up of both
species [28]. Commercial berry fields are commonly burned in spring or
fall [5,76,78]. Moderate burns conducted during dormant periods are
generally most effective [78]. Flame throwers may be used [56] and hay
or straw spread at the rate of 1 ton per acre. Damage to underground
portions of the plant can be minimized by burning when the ground is
still frozen [5].

Timber harvest: Thinning by pulpwood cutting commonly produces vigorous
velvetleaf blueberry plants. However, clearcutting when followed by
burning within one year often causes shrubs to decline. Clearcutting
exposes small plants, often of poor vigor, to direct sunlight.
Presumably, when already weakened shrubs are burned, mortality can
occur. If plants are allowed to grow for several years after
clearcutting and attain good vigor, most generally survive subsequent
fires. Velvetleaf blueberry typically responds better if the tree
canopy is opened gradually, or if narrow strips are cut allowing
vigorous rhizome expansion from adjacent undisturbed areas. After
timber harvest in the fall of 1949 and an April 1951 burn in New
Brunswick, velvetleaf blueberry responded as follows [28]:

1949 1950 1951 1952
(plots sampled in June)

# of stems 45 44 71 77
frequency 8 9 7 2
percent cover 1.6 0.2 0.5 0.1

Biomass production of velvetleaf blueberry one year after timber harvest
and fire was as follows in northeastern Minnesota [63]:

dry g/m sq.

unlogged-unburned 0.12
logged-unburned 1.53
head fire-logged-burned --
back fire-logged-burned 0.09

Application of fertilizer and mulch: The effects of mulch and
fertilizer application on burned velvetleaf blueberry stands has been
examined in detail. Study results indicate that plants on burned sites
respond more favorably if fertilizer applications are delayed for one
year to allow plants additional time for regrowth [76].

More info on this topic.

More info for the term: phanerophyte

Phanerophyte

Velvetleaf blueberry is common in drier, relatively infertile conifer
types [90]. Velvetleaf blueberry also grows in forested portions of
bogs, in muskegs, peatlands, treeless mountain slopes, alpine meadows,
mountain meadows, barrens, headlands, boreal forests, and on rock
outcrops [10,68,88]. It commonly reaches greatest abundance on
disturbed sites such as in clearcuts or on recent burns [88,90].

Light regimes: Evidence suggests that conditions necessary for the
growth of velvetleaf blueberry differ in eastern and western North
America. On foggy, low elevation sites in New Brunswick, shade appears
to have a detrimental effect on the growth and development of velvetleaf
blueberry [77]. However, on dry, intensely sunny sites in Alberta,
shade enhances growth by aiding in water conservation [77]. Velvetleaf
blueberry is generally tolerant of shade and grows well in open woods
[30,33]. Hoefs and Shay [37] note that it prefers low light intensity
although some researchers report that berry production is enhanced in
sunny locations [86].

Climate: Velvetleaf blueberry grows across a wide range of climatic
conditions [90]. It grows in perhumid climates on the East Coast and in
dry subhumid or cool, temperate climates in the West [43,90]. In the
West, its abundance increases with greater continentality [43]. Growing
season length ranges from 60 to 200 days [53,90].

Soils: Most blueberries (Vaccinium spp.) require acidic soils and can
grow on infertile sites which have relatively small amounts of many
essential elements [44]. Velvetleaf blueberry grows on a wide variety
of soil types including well-drained coarse, or light-textured soils.
It occurs on fine sandy soils, loam, clay loam, till, and lacustrine
deposits [14,39,53]. Velvetleaf blueberry generally reaches greatest
abundance on moderate to light, often sandy, well-drained soils with
adequate soil moisture [77,90]. Soils are generally acidic, with pH
ranging from 3.0 to 5.9 [34,40]. Soils are commonly nitrogen-poor
[43,50] but may be rich in organic matter [34,43]. Organic content
ranges from 3 to 93 percent [90].

Elevation: Velvetleaf blueberry grows from sea level to 3,950 feet
(0-1,200 m) [90]. Generalized range by geographic location is as
follows [20,86]:

from 3,200 to 4,300 feet (975-1,311 m) in MT
> 2,950 feet (900 m) in VA

More info on this topic.

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

1 Jack pine
5 Balsam fir
12 Black spruce
13 Black spruce - tamarack
14 Northern pin oak
15 Red pine
16 Aspen
18 Paper birch
19 Gray birch - red maple
21 Eastern white pine
22 White pine - hemlock
23 Eastern hemlock
30 Red spruce - yellow birch
32 Red spruce
33 Red spruce - balsam fir
35 Paper birch - red spruce - balsam fir
37 Northern white cedar
38 Tamarack
107 White spruce
201 White spruce
202 White spruce - paper birch
204 Black spruce
206 Engelmann spruce - subalpine fire
218 Lodgepole pine
227 Western hemlock - western redcedar
251 White spruce - aspen
253 Black spruce - white spruce
254 Black spruce - paper birch

More info on this topic.

This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES10 White - red - jack pine
FRES11 Spruce - fir
FRES15 Oak - hickory
FRES18 Maple - beech - birch
FRES19 Aspen - birch
FRES23 Fir - spruce
FRES24 Hemlock - Sitka spruce
FRES26 Lodgepole pine
FRES44 Alpine

More info on this topic.

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the terms: bog, forest

K002 Cedar - hemlock - Douglas-fir
K015 Western spruce - fir forest
K093 Great Lakes spruce - fir forest
K094 Conifer bog
K095 Great Lakes pine forest
K096 Northeastern spruce - fir forest
K100 Oak - hickory forest
K106 Northern hardwoods
K107 Northern hardwoods - fir forest
K108 Northern hardwoods - spruce forest
K109 Transition between K104 and K106

More info for the terms: fire intensity, severity

Aboveground portions of velvetleaf blueberry are commonly killed by
fire, but underground rhizomes generally survive wildfires or controlled
burns [24,88,90]. Mortality typically increases with higher fire
intensity and severity [56,78], although in the West, some rhizomes
commonly survive even hot wildfires, as long as soil is sufficiently
deep to offer some protection [90]. Some plants may survive even after
lethal heat penetration to depths of 3.5 to 4.7 inches (9-12 cm) [23].
Rhizomes are typically most susceptible to heat damage during the period
of active growth [78].

Seed: Seeds of most Vacciniums are of short viability and are readily
killed by heat [55].

More info for the term: fruit

Browse: White-tailed deer and eastern cottontail browse the leaves and
twigs of velvetleaf blueberry [90]. In many parts of the East, deer
browse shoots or twigs during the fall and winter months [5,75].
Domestic sheep however, generally ignore velvetleaf blueberry [90].

Fruit: The wild turkey, gray catbird, band-tailed pigeon, ring-necked
pheasant, and quails, ptarmigans, towhees, spruce, ruffed, blue, and
sharp-tailed grouse all feed on Vaccinium fruit [54,88,91]. In central
Pennsylvania, grouse eat large numbers of velvetleaf blueberry flower
buds in winter [75]. The American robin, American crow, bluebirds, and
many other small birds consume velvetleaf blueberry fruit [5,76,90].

The white-tailed deer, black bear, red fox, porcupine, raccoon, mice,
and chipmunks all readily feed on the fruit of velvetleaf blueberry
[76,90]. Mammals such as the pika, white-footed mouse, gray fox, ground
squirrels, deer mice, squirrels, and skunks eat large quantities of
Vaccinium berries [54,91]. In parts of Minnesota and Wisconsin, the
reproductive success of black bears is reduced in years of Vaccinium
crop failure [70].

More info for the terms: bog, fern, forest, lichen, woodland

West: In the West, velvetleaf blueberry grows in submontane to subalpine
forests [43] dominated by lodgepole pine (Pinus contorta), spruce (Picea
spp.), jack pine (Pinus banksiana), western hemlock (Tsuga
heterophylla), or western redcedar (Thuja plicata) [90,97]. Velvetleaf
blueberry is a particularly common understory dominant on drier sites in
the sub-boreal spruce zone of British Columbia [93].

East: In the Great Lakes region, velvetleaf blueberry commonly grows in
xero-mesophytic pine woodlands [90] and bracken fern (Pteridium
aquilinum)-grasslands [16]. Stands may be dominated by jack pine, black
spruce (Picea mariana), eastern white pine (Pinus strobus), red pine (P.
resinosa), quaking aspen (Populus tremuloides), birch (Betula spp.), a
mixture of maple (Acer spp.)-aspen-birch (Betula spp.), eastern hemlock
(Tsuga canadensis), or tamarack (Larix laricina) [13,38,64,90]. In the
Maritime Provinces and northeastern United States, it grows in forests
made up of black spruce (Picea mariana), white spruce (P. glauca), red
spruce (P. rubens), and balsam fir (Abies balsamea) [23,90]. Further
south in Pennsylvania and the southern Appalachians, it grows in oak
(Quercus spp.)-hickory (Carya spp.) forests [75].

Velvetleaf blueberry grows abundantly with low sweet blueberry in
managed commercial blueberry stands in New England and the Maritimes
[33,59]. It is particularly common in recently cleared woodlots [5,30]
and is a common oldfield colonizer on farms which were abandoned during
the early part of the twentieth century [88].

Plant associates: In eastern forests, low sweet blueberry, bunchberry
(Cornus canadensis), bog birch (Betula glandulosa), kalmia (Kalmia
angustifolia), cloudberry (Rubus chamaemorus), bog Labrador tea (Ledum
glandulosum), creeping wintergreen (Gaultheria hispidula), wild
sarsaparilla (Aralia nudicaulis), red maple (Acer rubrum), bracken fern,
and Canada beadruby (Maianthemum canadense) are common associates
[23,28,68,85,90]. In the Great Lakes region and Upper Midwest, bracken
fern, low sweet blueberry, bunchberry, twinflower (Linnaea borealis),
bog Labrador tea, Canada beadruby, Cladonia spp. and various mosses
often occur with velvetleaf blueberry [14,39,90]. In western North
America, velvetleaf blueberry often grows with species such as
kinnikinnick (Arctostaphylos uva-ursi), dwarf huckleberry (Vaccinium
caespitosum), bunchberry, and Cladonia gracilis [90,93].

Published classifications listing velvetleaf blueberry an indicator of
community types or habitat types are presented below.

Jack pine - lichen woodland on sandy soils in northern Saskatchewan and
northern Alberta [11]
Field guide habitat classification system: For Upper Peninsula of
Michigan and northeast Wisconsin [13]
Forest community types of west-central Alberta in relation to selected
environmental factors [14]
Application of a forest habitat-type classification system in Michigan and
Wisconsin [45]
Field guide to forest habitat types of northern Wisconsin [46]
Habitat classification system for northern Wisconsin [47]
The Pinus contorta forests of Banff and Jasper National Parks: a study
in comparitive synecology and syntaxonomy [51]

More info for the term: shrub

Shrub

More info for the terms: cover, fire management, fruit, natural, seed, shrubs

Chemical control: Blueberries (Vaccinium spp.) exhibit variable
susceptibility to herbicides such as 2,4-D, 2,4,5-T, glyphosate,
karbutilate, and picloram [8]. Various herbicides, including
dichlorprop, picloram, 2,4-D, and glyphosate have been applied to
velvetleaf blueberry to facilitate conifer release [26,72]. Plants are
resistant to Asulam and Terbacil, although Dicamba and 2,4-D may reduce
shoot numbers during the year after treatment. However, rhizomes may be
undamaged by herbicides and often resume growth during the second year
after treatment [90]. The response of velvetleaf blueberry to various
herbicides has been documented [72,90].

Mechanical treatment: In northeastern Minnesota, mechanically clipped
velvetleaf blueberry plants produced flower bud numbers equal to those
on unpruned plants. Plants pruned mechanically, or by fire, exhibited
increases in stem numbers over unpruned controls. The effects of
fertilizer and mulch on pruned plants has been examined in detail.
Application of fertilizer may significantly increase flower bud numbers
on clipped individuals but typically reduces flower bud development on
unpruned plants. Unpruned plants generally exhibit increased stem
growth after fertilizer application, but fertilization has little effect
on mechanically pruned plants [76]. Mulch does not generally increase
flower bud numbers or vegetative growth of pruned plants. Its use
should be avoided on recently pruned velvetleaf blueberry [76].

Environmental considerations: In a number of recent studies, chemically
treated velvetleaf blueberry plants have been found to produce fruit
which exceeds permissible levels of herbicides [26,72]. In a
northeastern Ontario study, 50 percent of fruit tested was found to
exceed FDA safety standards. Much of the affected fruit grew in easily
accessible areas, such as along highway right-of-ways. Possible human
health risks are unknown, but approximately 0.3 percent of all wild
blueberries and red raspberries (Rubus idaeus) in Ontario are treated
annually with herbicides [26].

In many parts of the East, widespread use of insecticides has decimated
populations of wild bees which formerly pollinated blueberry fields. In
some locations, it is now necessary to supplement natural pollinators
with honey bees to ensure adequate fruit set in commercially managed
fields [58].

Velvetleaf blueberry is very sensitive to sulfur dioxide pollution and
may be a useful indicator for monitoring acid rain [90].

Commercial propagation: Numerous cultivation techniques have been
applied to commercially managed blueberry fields [76,98]. These include
applying mulch, fertilizer, or herbicides, and pruning with fire or
mechanical means [see FIRE MANAGEMENT CONSIDERATIONS]. Various
herbicides can be used to control plants such as kalmia (Kalmia
angustifolia) and little bluestem (Schizachyrium scoparium) which
commonly compete with velvetleaf blueberry in commercially managed berry
fields [30,95]. Disease and insects can greatly reduce fruit yields
under certain circumstances. Because clones differ genetically in their
resistance to disease, selective breeding has been used to develop
resistant strains [59]. In commercial blueberry fields containing both
velvetleaf and low sweet blueberry, yields are often lower than in
fields made up of only low sweet blueberry. Cross pollination
apparently results in reduced fruit set [1].

Berry production: Fruit production in velvetleaf blueberry fluctuates
annually according to the genetics of the individual clone, weather
conditions, and insect availability [5,94]. However, fruit production
is often good [16] and nearly all berries contain some viable seed [90].
Pollinators are required for good fruit set [94] and dry, warm weather
during flowering generally results in more active insect pollinators and
better fruit set. Late spring frosts can greatly reduce fruit
production [90]. In Newfoundland, reduced fruit production has been
correlated with heavy June precipitation and in Nova Scotia, warm
temperatures and ample sunlight enhanced fruit yields [31]. Fruit
production of velvetleaf blueberry typically declines as clones age
[75]. Production often peaks 10 to 20 years after fire, just prior to
canopy closure [90].

Damage: Plants may be damaged by cold winter temperatures. Shrubs are
often killed to ground level in the absence of a protective snow cover.
Spring frost damage reportedly occurs at 30 degrees F (-1 degree C) and
may be "complete" at 14 degrees F (-10 degrees C) [90].

Livestock: Ericaceous shrubs such as velvetleaf blueberry tend to
increase in response to heavy livestock grazing [28].

Wildlife considerations: Blueberries are an extremely important food
source for bears. In many areas, bear-human conflicts are most likely
to occur during years of Vaccinium berry crop failure [55,70]. Both
black and grizzly bears typically exploit areas with dense
concentrations of berries. The habitat value of blueberry shrubfields
to grizzly bears can be increased by permanent, or at least seasonal
road closures, by coordinating timber harvest dates to have minimal
impact on habitat use patterns, and by considering the cumulative
effects of habitat modification across a broad area. In general, site
preparation should include minimizing soil compaction, using cooler
broadcast burns rather than hot burns, or by eliminating site
preparation entirely wherever possible. Grizzly use is favored where
hiding cover is retained by treating small, irregular patches instead of
large contiguous areas, and by leaving stringers of timber within larger
cuts [96].

More info for the term: fruit

Browse: Blueberry (Vaccinium spp.) foliage is relatively high in
carotene, manganese, and energy content [18,35,90]. Nitrogen content of
velvetleaf blueberry generally declines through the growing season
whereas calcium and magnesium levels increase [90]. Plants accumulate
nitrogen for winter, but apparently do not store reserves of protein
[50]. Nutrient content of mature velvetleaf blueberry foliage is as
follows [90]:

element percent dry weight element micrograms/gram

N 1.5-2.00 Fe 20-192
P 0.09-0.21 Mn 202-2,177
K 0.24-0.52 B 16-54
Ca 0.38-0.67
Mg 0.10-0.31

Fruit: Blueberry fruits are sweet and contain high concentrations of
both mono- and di-saccharides [82]. Berries are rich in vitamin C,
carbohydrates, and energy content but low in fats [69,92]. The nutrient
value of Vaccinium berries from Pennsylvania is documented below [92].

crude ether crude total N-free avail. lignin
protein extract fiber ash extract protein

%dry wt. 4.19 3.80 9.67 1.44 80.90 2.75 13.85
% of fruit .63 .56 1.42 .21 11.88 .50 2.04

cellulose tannin Ca Mg P moisture

%dry wt. 7.97 1.28 0.4 .07 .07 -
% of fruit 1.17 .19 .01 .01 .01 85.3

Flowers: Nectar of velvetleaf blueberry flowers contains more sucrose
than do the flowers of low sweet blueberry [94].

CT DE ID IL IN IA ME MA MI MN
MT NH NY OH PA VT VA WA WV WI
AB BC LB MB NB NF NT ON PE PQ
SK YT

More info for the terms: fresh, fruit

The sweet, tart or "pleasantly acid" [76,86] fruit of velvetleaf
blueberry is eaten fresh or used in pies, pastries, jam, and ice cream
[5]. Large numbers of recreationists seek out and harvest these berries
throughout the Great Lakes Region [42,90]. During the 1970's,
approximately 20 percent of the total visitor hours were dedicated to
blueberry picking in several National Forests of northern Minnesota. By
1980, this amount had climbed to 30 percent in some locations [42].

Vaccinium berries were traditionally an important food source for many
native American peoples [76]. The Cree harvested velvetleaf blueberries
in parts of western North America [88].

Velvetleaf blueberry grows with low sweet blueberry in commercial
blueberry fields of the Northeast [1,59]. In some areas, velvetleaf
blueberry may represent a significant part of the commercial crop,
particularly in fields derived from woodlands [33,88]. However, it only
accounts for "commercially viable" quantities in New Brunswick and
Maine. More than 4,400,000 pounds (2 million kg) of blueberry fruit is
harvested annually in New Brunswick, of which 30 percent is velvetleaf
blueberry. Most commercially grown fruit is processed as pie filling or
is used in muffin mixes [90]. Lesser amounts are used to make wine,
juice, or freeze-dried products [5].

The cold-hardy velvetleaf blueberry may have potential for breeding
blueberry strains suited to northern climates [19]. Its affinity for
mineral soil also suggests that it may be useful for breeding plants
adapted to upland sites [22,44].

More info for the term: fruit

Velvetleaf blueberry fruit is highly palatable to a wide variety of
birds and mammals. Specific palatability of berries varies with the
clone [90]. Browse appears to be of relatively low palatability to most
big game species and to domestic livestock.

More info on this topic.

More info for the term: meristem

Phenological development of velvetleaf blueberry varies according to
weather conditions, geographic location, and the genetic complement of
the individual clone [5,90]. In eastern Ontario, vegetative buds begin
to swell in late April or early May, as night time temperature exceeds
42 degrees F (6 degrees C) for 4 or 5 days at a time. Leaves harden by
mid-June and turn red in early October or as early as July or August in
drought years [90]. Leaves generally abscise by late October.
Elongation of vegetative shoots ceases in June [5], and plants
overwinter without leaves. Phenological development in northeastern
Ontario has been documented as follows [78]:

phenological stage mean # of days

- budbreak in spring 23
- # of days from loss of bud scales and
swelling of flowerbuds until 50% of
flowers open 28
- # of days between vegetative budbreak
and death of apical meristem 28
- # of days between vegetative budbreak
and maturation of lateral buds 60

Flowering occurs the spring, either before or during shoot development.
Flower primordia form in late summer after annual vegetative growth is
complete [5,90]. Flower buds begin to swell in late April or May [90].
Berries generally ripen 49 to 68 days after flowering [90]. Ripening
time is greatly influenced by precipitation, temperature, and various
site characteristics. Annual variation in ripening is documented in the
following Ontario study [26]:

percent ripe
1979 August 22 80
August 30 100
September 5 overripe

percent ripe
1980 August 6 60
August 20, 25 100
September 2, 15 100
September 22 overripe

percent ripe
1981 August 12 20 20 --
August 17-19 40 40 45
August 24-25 50 50 60
September 1-2 70 70 85
September 9-10 90 85 100
September 14-15 100 100 --

Generalized seasonal development by geographic location is as follows
[5,74,78,86]:

location flowering fruiting

New England May 15-June 22 ----
c NY mid May ----
e ON mid to late May ----
ME, NB, NS, ne PQ, LB
n ON, n MB, SK, nAB, NT late May to early June ----
BC late May to late June ----
VA May-June July-August
s ME ---- late June
ON ---- July-September

More info for the terms: cover, fire intensity, fruit, rhizome, seed, severity, shrub, wildfire

Vegetative response: Velvetleaf blueberry typically sprouts from
underground rhizomes after aboveground portions of the plant are
consumed by fire [29,90]. Sprouting from latent buds located on the
stump or bole can occur where damage to the aboveground portions of the
plant is only partial [11,28,90]. Response depends on a number of
factors including season of burn, fire intensity and severity
[24,78,90], and subsequent weather conditions.

Seedling establishment: Seed banking does not appear to represent an
important regenerative strategy in the velvetleaf blueberry. However,
birds and mammals may transport some seed to burned sites.

Season of burn: Response of velvetleaf blueberry is generally best
after spring or fall burns [23,90]. Rapid regeneration or regrowth has
been noted after spring fires in northeastern Minnesota and in red
spruce-black spruce forests of eastern Canada [61,85]. Generally,
poorest response occurs after plants are burned in summer during periods
of most active growth [79]. Fires during dormant periods remove old
shoot growth and provide additional nutrients which result in greater
cover and enhanced productivity [78]. Good regrowth was noted after
fall burns in eastern Canada which occurred after storage of
photosynthate. Stored nutrients were presumably available for new
growth in spring after the burn [25]. In eastern Canada, plants burned
in mid-August exhibited reduced berry production by the end of the
second growing season. Plants burned in late August showed no increase
in berry production but did increase in cover [78]. Late October burns
produced increases in both fruit production and cover whereas, burns
conducted in late May reduced cover and did not increase berry
production [78].

Fire intensity and severity: Light to moderate fires presumably remove
decadent material and stimulate the growth of velvetleaf blueberry while
increasing nutrient availability [79]. Plants are commonly observed on
lightly burned plots in white spruce-paper birch-aspen communities [4]
and elsewhere [78]. However, cover and fruit production may be greatly
reduced after hot fires which result in greater heat penetration into
the soil [55,78,79]. In a northern Ontario study, largest increases in
cover and fruit production were noted after fires of 684 degrees F (362
degrees C) and 751 degrees F (417 degrees C) lasting 40 seconds per
meter square [78]. Fruit production was much reduced after hot fires of
1,296 to 1,513 degrees F (702-823 degrees C) with a duration of 80
seconds per meter square [78]. Recovery may be slow after hot fires
[61]. Ohmann and others [61] report that velvetleaf blueberry was more
common in mature forests than in areas burned by a severe wildfire 33
years earlier.

Soil: Soil characteristics may also influence the postfire response of
velvetleaf blueberry. Reductions in cover and production may be more
pronounced when the soil is dry [78]. The extent of lateral rhizome
development may be greatest where organic soil layers are relatively
thick [77]. Thus, the capacity to regenerate through rhizomes could be
reduced where a thin mantle of organic soil prevents the development of
an extensive rhizome network.

Postfire recovery: Recovery of velvetleaf blueberry is generally rapid
wherever portions of underground rhizomes survive [55,78]. This shrub
regained prominence within 2 to 3 years after fire in jack pine
communities of the East [83]. Relatively rapid increases in both cover
and biomass have also been documented [62,63]. Rapid increases in
biomass are often particularly dramatic during the first 2 years after
fire [63].

More info for the terms: caudex, root crown, seed

survivor species; on-site surviving root crown or caudex
survivor species; on-site surviving rhizomes
off-site colonizer; seed carried by animals or water; postfire yr 1&2

More info for the terms: competition, cover, fruit, organic soils, rhizome, seed, tree

Velvetleaf blueberry is capable of reproducing vegetatively or by seed.
However, regeneration after fire and other types of disturbance is
primarily vegetative [28].

Vegetative regeneration: Velvetleaf blueberry is characterized by an
extensive network of woody rhizomes. Rhizomes are generally
much-branched laterally, and give rise to many fibrous roots and shoots
[77,90]. Rhizomes usually grow rapidly in several directions once
plants reach 8 to 12 inches (20-30 cm) in diameter [90]. Depth, length,
and annual radial growth rates appear to be highly variable [77].
Rhizomes average approximately 0.15 inch (4 mm) in diameter and extend 3
to 46 feet (1-14 m) in length [29,77]. Rhizomes typically occur from
1.8 to 3.5 inches (4.5-9.0 cm) below the soil surface [53], although
depth depends on genetic factors and on site characteristics such as the
thickness of organic soil. Normal rhizome depth is apparently inversely
related to the thickness of organic soil. In eastern Canada, mean depth
of underground regenerative tissue in velvetleaf blueberry is 3.1 inches
(8 cm) [23,24]. In Alberta, shoots may occasionally develop from
rhizomes as deep as 4.3 inches (11 cm) [77]. Approximately 73 percent
of all shoots developed terminally on rhizomes, with 27.7 percent
developing from the middle [77]. Smith [77] reported rhizome length and
depth as follows in an Alberta study:

sites
1 2 3 4 5 6

average length (cm) 143.7 325.7 422.3 625.8 735.5 653.1
average depth (cm) 6.8 8.5 7.1 6.9 4.5 9.0
avg. # of sprouts/100 cm
of rhizome length 1.2 1.5 2.2 1.9 1.6 1.0
organic horizon 3 6 7 7 10 3
thickness (cm)
slope (degrees) 40 10 3 2 3 20
aspect NE S NE E NE S
tree cover (%) 81-100 41-60 81-100 81-100 21-40 0-20
# trees > 1 in. 27 12 32 28 5 4

Velvetleaf blueberry also sprouts from the bole, stump, or stem base
when disturbances such as fire destroy only portions of the aboveground
foliage [5,11,88].

Seed: Velvetleaf blueberry begins fruiting during the third growing
season [90]. It is generally considered to be self-sterile and requires
insect pollination for fruit set [1,58,90]. Bees are the most common
insect pollinators, with bumblebees the most effective [58,68]. Seeds
of velvetleaf blueberry can germinate on mineral or organic soils when
moisture and aeration are adequate [90].

Germination: Germination of velvetleaf blueberry has been described as
sporadic [87]. Germination rates have ranged from 20 to 30 percent in
carefully controlled laboratory experiments. Seeds typically germinate
from 18 to 82 days after planting; germination tends to be bimodal with
large numbers of seeds germinating early and late [90]. Seeds of most
blueberries (Vaccinium spp.) are not dormant and require no pretreatment
for germination [15]. Radicles first develop approximately 20 days
after seeds are sown, cotyledons emerge within 31 days, and the first
leaves unfold in 48 days [90].

Seed dispersal: Seeds of velvetleaf blueberry are readily dispersed by
various birds and mammals [58]. Evidence suggests that long-distance
seed dispersal by many birds and mammals can effectively increase
genetic diversity in the velvetleaf blueberry. The American robin is a
particularly effective dispersal agent. Fruit typically ripens just as
birds are preparing for seasonal migrations [90]. Vander Kloet and Hall
[90] report that viability is reduced by 10 percent after seed passes
through the digestive tracts of birds and mammals. However, Krefting
and Roe [48] suggest that digestive processes may actually enhance
germination. Seeds obtained from black bear scats apparently germinate
more readily than do those from uneaten fruit [71]. Composite samples
of velvetleaf and low sweet blueberry (50:50) were as follows [71]:
percent germination

uneaten fruit seed from feces
unrefrigerated 9 15
refrigerated 16 20

Seedling establishment: Initial growth is typically slow wherever
significant competition is present such as in oldfield communities [90].
Plants may require 5 years to reach 6 inches (15 cm) in diameter [.

More info on this topic.

More info for the terms: association, climax, fern, forest

Velvetleaf blueberry commonly reaches greatest abundance in young
postdisturbance communities [90]. In the East, velvetleaf blueberry
vigorously colonizes disturbed sites such as clearcuts, recently burned
pine forests, and oldfields [78,88,90]. Throughout New England and the
Maritime Provinces, it colonized old farms which were abandoned in the
early part of the twentieth century [88]. Velvetleaf blueberry often
forms dense stands during seral stages after clearcutting in balsam
fir-red spruce forests [90].

Residual velvetleaf blueberry plants commonly colonize burned sites in
northern boreal forests [78] and elsewhere. Reestablishment is often
rapid, particularly after light to moderate fires [see Plant Response to
Fire]. Velvetleaf blueberry can assume prominence within 2 to 3 years
after fire in jack pine woodlands [83]. In parts of parts of British
Columbia, velvetleaf blueberry commonly assumes dominance soon after
fire on dry to intermediately moist sites but is typically absent from
wet sites [36]. After hot fires in northern Ontario, velvetleaf
blueberry was initially replaced by more fire-tolerant species such as
Fremont sedge (Carex aenea), poverty oatgrass (Danthonia spicata), and
sweet fern (Comptonia peregrina) [71]. An extended period of moss and
grass dominance may occur prior to velvetleaf blueberry reestabishment
on severely burned sites [78]. In parts of eastern Canada, a
wintergreen (Gaultheria procumbens)-Canada beadruby-velvetleaf
blueberry-bunchberry association commonly develops under a regime of
frequent, light fires. However, a bunchberry-velvetleaf
blueberry-kalmia-bracken fern association is more typical where fire
intervals are longer and fires more severe [23]. In northern Quebec,
low sweet blueberry may gradually replace velvetleaf blueberry on burned
areas as velvetleaf blueberry becomes restricted to shady sites [53].

Velvetleaf blueberry can persist in a variety of mature or climax forest
stands. Limited evidence suggests that it is more tolerant of shade
than other sympatric species of Vacciniums. It can survive in closed
stands, including white spruce-balsam fir forests, but flowering is
generally limited to forest openings [90]. Flowering and fruiting is
typically much reduced or absent in dense shade in all community types
[99].

Vaccinium canadense
Vaccinium angustifolium var. integrifolium
Vaccinium pennsylvanicum var. myrtilloides
Vaccinium angustifolium var. myrtilloides
Cyanococcus canadensis

More info for the terms: fruit, natural

The currently accepted scientific name of velvetleaf blueberry is
Vaccinium myrtilloides Michx. (Ericaceae) [41]. The following forms,
distinguished primarily on the basis of fruit color, have been
identified [3,66,90]:

forma chicoccum (Deane) Fernald - (white fruit)
forma myrtilloides - (blue fruit with bloom)

Velvetleaf blueberry hybridizes with a number of species including sweet
hurts blueberry (V. boreale), hillside blueberry (V. pallidum), Darrow's
evergreen blueberry (V. darrowii), small cluster blueberry (V.
tenellum), downy blueberry (V. atrococcum), V. vacillans, and low sweet
blueberry (V. angustifolium) [1,10,22,32,78,87]. Naturally occurring
velvetleaf blueberry-sweet hurts blueberry hybrids are particularly
common and produce populations or "hybrid complexes" which exhibit
numerous intermediate characteristics [32,78]. In the past, much
taxonomic confusion has surrounded the relationship between velvetleaf
blueberry and low sweet blueberry. Velvetleaf blueberry was formerly
considered a variety of low sweet blueberry [90]. Plants of
intermediate characteristics, which were once delineated as Vaccinium
angustifolium var. integrifolium (synonym var. hypolasium), are now
considered natural hybrids produced from a velvetleaf blueberry-low
sweet blueberry cross [33,78,90].

More info for the terms: hardwood, seed

Species within the Vaccinium genus can be propagated from hardwood
cuttings or by seed. Blueberry (Vaccinium spp.) seedlings grown in the
greenhouse can be transplanted onto favorable sites 6 to 7 weeks after
emergence. Germination of velvetleaf blueberry is generally best in 1:1
sand-peat mixtures at a pH of 4.5 [90]. Seed collection and storage
techniques have been considered in detail [15].