BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Artemisia arbuscula ssp. thermopola | Hotsprings Sagebrush 



GENERAL BOTANICAL CHARACTERISTICS : 
Hotsprings sagebrush is a dwarf, spreading shrub reaching 12 inches (3
dm) in height, with a crown spread of 12 to 16 inches (30-40 cm) [2].
It closely resembles the more widespread subspecies gray low sagebrush
in morphology.  However, leaves are more finely divided than those of
gray low sagebrush and have three long, linear divisions [2,25].
Numerous vegetative branches are present.  Culms are 4 to 12 inches
(10-30 cm) long [2].  Hotsprings sagebrush is resistant to drought [26].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Hotsprings sagebrush reproduces only through light, wind-dispersed seed
[2].  Very little is known about germination rates or requirements.


SITE CHARACTERISTICS : 
Hotsprings sagebrush typically occurs on dry, shallow, infertile and
rocky ridgetops or benches [14,22].  It grows well in the cold, dry
mountain valleys of central and eastern Idaho, northern Utah, and
northeastern Wyoming [22,23].  Hotsprings sagebrush dominates extensive,
nearly uniform communities in many areas including parts of Yellowstone
and Grand Teton National Parks [3], but also grows in openings in
lodgepole pine (Pinus contorta) or ponderosa pine (P. ponderosa) forests
[2,30].

Many authorities believe that the distribution of low sagebrush is
largely related to soil conditions.  Hotsprings sagebrush generally
grows on poorly drained soils with a high clay content.  Soils are
generally less than 13 inches (33 cm) to an impermeable B horizon or, if
deeper, with 30 percent or more gravel and cobbles in the horizon [28].
Growth has been reported on volcanics, sediments, and granitics [22].  In
central Idaho hotsprings sagebrush grows on glacial outwash, dry
alluvium, terraces, or on poorly drained mountainous sites [22].  Soils
which support hotsprings sagebrush tend to be drier and rockier than
those which support big sagebrush (Artemisia tridentata) [3].
Hotsprings sagebrush typically grows on higher and cooler sites than the
closely related gray low sagebrush [14].  Hotsprings sagebrush sites are
characterized by large amounts of bare soil and exposed rock.

Hotsprings sagebrush grows on all aspects on slopes of 10 to 15 percent
or less [22].  Hotsprings sagebrush typically grows above 6,000 feet
(1,829 m) [23].  Elevational ranges are as follows [2,22,30]:

            from 6,000 to 9,800 ft (1,830 to 2,989 m) in ID
                 5,000 to 9,000 ft (1,524 to 2,743 m) in OR
                 6,000 to 7,000 ft (1,829 to 2,134 m) in WY


SUCCESSIONAL STATUS : 
Hotsprings sagebrush occurs with Idaho fescue in a number of low
sagebrush-bunchgrass climax communities [14,22].  Climax conditions in
these communities are generally attributable to edaphic factors.
Hotsprings sagebrush also occurs as a dominant in uniform, climax
populations in northwestern Wyoming and eastern Idaho and is also
represented in some early seral communities.


SEASONAL DEVELOPMENT : 
Seasonal development of hotsprings sagebrush is poorly known.  Some
researchers believe that its phenology is similar to that of gray low
sagebrush [2], while others maintain that hotsprings sagebrush exhibits
earlier phenological development [19].  Shultz [25] reports that
hotsprings sagebrush blooms in late summer and fall.  Seed matures from
late August through October, and ripens by October or November [2,30].

Related categories for Species: Artemisia arbuscula ssp. thermopola | Hotsprings Sagebrush