BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Salix lanata ssp. richardsonii | Richardson Willow 



GENERAL BOTANICAL CHARACTERISTICS : 
Richardson willow is an erect, much-branched shrub usually forming dense
clumps 3 to 6 feet (1-2 m) tall, sometimes to 15 feet (4.5 m) [5,35].
Young twigs are stout and densely hairy; older twigs are glabrous.  The
bark of Richardson willow is smooth [35].  Shrubs are composed of light
wood that becomes brittle with age; a single trunk rarely survives 60
years [2].  In silty loam containing much organic matter, the roots of
Richardson willow are numerous in the top 7.5 inches (19 cm) of soil,
but become less abundant at 9 inches (23 cm).  In frozen ground, roots
of Richardson willow do not exceed 9 inches (23 cm), but as the ground
thaws roots will grow up to 17 inches (43 cm) deep [12].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Sexual reproduction:  Richardson willow is dioecious.  The fruit of
these plants is contained in a capsule that splits in half to release
many seeds that are then dispersed by wind or water [11,33].  Optimum
seed production occurs between 2 and 10 years [11].  Bees are the chief
pollinating agents [11].  The seeds of Richardson willow are
short-lived, germinating immediately on moist surfaces [21].  Seed
germination occurs over a broad temperature range, 41 to 77 degrees
Fahrenheit (5-25 degrees C).  This appears to be a compensatory
mechanism due to the short seed life [6].  Germination of Richardson
willow seeds occurs best in moist, exposed mineral substrates that
receive direct sunlight [11].
 
Vegetative reproduction:  Richardson willow will sprout from the root
crown or basal stem [11].  It will root readily from stem cuttings or
from root and stem fragments buried in moist soil.  Damaged and cut
stems produce prolific sprouts from the stembase or root collar [11].
  


SITE CHARACTERISTICS : 
In Alaska and northern Canada, Richardson willow is found in wet areas
such as heaths, riverbeds, and streams; it is also found in the open
tundra, in pingos, and in mountains to at least 5,578 feet (1,700 m)
[14,39].  In interior Alaska, Richardson willow occurs in glacial drift,
outwash deposition areas, and on old river floodplains with considerable
variation in habitat conditions [4].

Soils:  Richardson willow grows best in moist, alluvial bottomlands but
is also found in well-drained sandy or gravelly substrates.  The general
pH range for willows is 5.5 to 7.5 [11].  Growth of Richardson willow is
severely reduced when water levels are maintained at or above the root
crown for extended periods [11].

Plant associates:  Richardson willow is commonly associated with the
following species:  quaking aspen, white spruce (Picea glauca), black
spruce (P. mariana), Alaska paper birch (Betula resinifera), feltleaf
willow (Salix alaxensis), diamondleaf willow (S. pulchra), netleaf
willow (S. reticulata), American green alder (Alnus crispa), Sitka alder
(A. fruticosa), bog birch (Betula glandulosa), lichens (Ericaceae spp.),
huckleberry (Vaccinium spp.), bluejoint grass (Calamagrostis
canadensis), bluegrass (Poa spp.), sedges (Carex spp.), and mosses
(Polytrichum spp.) [12,27].
  


SUCCESSIONAL STATUS : 
Obligate Initial Community Species

Richardson willow is an early successional species on moist sites and,
once established, may persist in areas with frequent disturbances such
as fires or flooding [7,8].  It also becomes important in the later
stages of riparian succession.  Successional studies have shown that
once silt accumulates, Richardson willow will become established quickly
[6].  Richardson willow was the first shrub to invade flood meadows,
after grasses and horsetail, on sandy alluvium in the tundra [3].
Richardson willow has low shade tolerance and therefore loses dominance
on sites that are heavily forested or succeeded by more shade-tolerant
species [38].
  


SEASONAL DEVELOPMENT : 
Richardson willow flowers from May through July or August [6,20].  The
fruit ripens soon after flowering, followed by seed dispersal in early
to midsummer [11]. 
 

Related categories for Species: Salix lanata ssp. richardsonii | Richardson Willow