VALUE AND USE
SPECIES: Sorbus americana | American Mountain-Ash 



WOOD PRODUCTS VALUE : 
The wood of American mountain-ash is light, soft, weak, and close
grained.  The heartwood is pale brown; the sapwood is thick and lighter
in color [39].  The wood is not commercially important [21].


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
American mountain-ash is a preferred browse for moose and white-tailed
deer [22,43,46,48].  Moose will eat foliage, twigs, and bark.  Up to 80
percent of American mountain-ash stems were browsed by moose in control
plots adjacent to exclosures on Isle Royale [55].  Fishers, martens,
snowshoe hares, and ruffed grouse also browse American mountain-ash
[2,54].

The berries of American mountain-ash are eaten by numerous species of
birds and small mammals, including ruffed grouse, ptarmigans,
sharp-tailed grouse, blue grouse, American robins, other thrushes,
waxwings, jays, squirrels, and rodents [10,33,54].


PALATABILITY : 
Aldous [2] rates American mountain-ash as one of the most palatable
foods for deer.  Moose prefer American mountain-ash; it can comprise up
to 57 percent of their summer diet, depending on availability [26].


NUTRITIONAL VALUE : 
The berries of American mountain-ash were found to have the following
nutrient values [50]:

                        % of dry weight
crude protein             5.44
available protein         4.25
crude fiber               8.02
ether extract             4.66
Nitrogen-free extract    78.78
lignin                    9.57
cellulose                 6.87
tannin                    4.08

Stiles [48] found that the berries were 4.66 percent crude fat (by dry
weight), which is considered relatively low.

Twigs of American mountain-ash were analyzed by Hughes and Fahey [22]:

                % of dry weight      % of dry weight
                 in forest            in clearcut

crude protein      9-12                 10-20
cell solubles     62-80                 68-86
cellulose         10-12                  4-8
lignin             4-8                   2-6


COVER VALUE : 
American mountain-ash is rated fair for wildlife cover in North Dakota
[15].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
NO-ENTRY


OTHER USES AND VALUES : 
American mountain-ash is valued as an ornamental in many areas but is
not successful where there is insufficient moisture.  It is not well
adapted to warmer habitats [10,15,20].  American mountain-ash is also
planted for windbreaks [20].

The berries are edible for humans but are too acidic to be eaten raw
[6].  They can be cooked with meats or made into jelly [6,21].

The fruit and inner bark of American mountain-ash have been used for
medicinal purposes [21].


MANAGEMENT CONSIDERATIONS : 
American mountain-ash is preferentially browsed by moose and
white-tailed deer.  In a study of the effects of moose browsing on
American mountain-ash on Isle Royale, Michigan, a small to moderate
number of mature trees were reported on unbrowsed sites, but American
mountan-ash was nearly nonexistent on browsed sites.  The number of
seedlings and saplings were similar on browsed and unbrowsed sites; the
authors stated that stump sprouting has probably sustained stem
densities on these sites [46].  In long-term moose exclosures, American
mountain-ash declined in abundance, probably due to shading by other
trees.  There was an increase in abundance of American mountain-ash on
control plots adjacent to exclosures, but individuals were severely
retarded in vertical growth [43].  Krefting [26] reported that in some
areas of Isle Royale, American mountain-ash is sparse because of
browsing by moose.  Stunted and severely deformed plants may survive for
more than 50 years.  In general, browsing by moose may slow succession
[43].

American mountain-ash cannot withstand more than light use, and
productivity will decline under heavy browsing [2,26].  The availability
of American mountain-ash as food for white-tailed deer is often limited
due to excessive browsing.  Small plants are locally abundant, and are
kept small by constant browsing [2].  White-tailed deer have eliminated
American mountain-ash in some areas of Pennsylvania and New York [3].

American mountain-ash is rated as having good survival on exposed
cut-over areas [52].
 
In a study to obtain release of conifers after logging disturbance,
herbicide treatments (including 2,4-D, 2,4,5-T, triclopyr and
glyphosate) reduced the amount of cover of hardwoods, including American
mountain-ash, from 46 percent to 14 percent, with a concomitant increase
in growth of spruce (Picea spp.) and fir (Abies spp.).  The authors of
this study believe that this type of treatment approximately 5 to 7
years after logging is economical and safe and will help maintain
even-aged spruce-fir regeneration for 60-year rotations.  With this type
of management, over 30 percent of all age classes can remain in highly
desirable browse condition (browse species including American
mountain-ash) for most of the year [35].

American mountain-ash seeds can be sown unstratified in early fall or
winter.  Sowing in July or August for germination the following spring
is also satisfactory, since a warb treatment prior to chilling is
beneficial.  Seedlings are quite hardy and not readily susceptible to
insects or disease.  Unprotected seedlings may be nipped by deer [20].
Soil requirements for cultivation include a pH of 4.7 to 6.0, a minimum
of 1.7 percent organic matter and a minimum of 7 percent silt and clay
particles with ground water at 1.5 to 2.5 feet (0.5-0.8 m), and 15
percent silt and clay particles with ground water at 2.5 or more feet
(0.8 m or more) [52].

American mountain-ash is listed as a favored food for gypsy moth larvae
during all larval stages.  It may be subject to severe defoliation at
high levels of infestation [16].

Related categories for Species: Sorbus americana | American Mountain-Ash