BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Pinus washoensis | Washoe Pine 



GENERAL BOTANICAL CHARACTERISTICS : 
Washoe pine is a native conifer which grows up to 115 feet (35 m) tall
and 5 feet (1.5 m) in diameter.  It has a conic or flat-topped crown
[9].  The short, stout needles occur in bundles of three and are 4 to 6
inches (10-15 cm) long [4].  The seed cones are 2 to 3.2 inches (5-8 cm)
long and have short-winged seeds [4].  The bark is shallowly furrowed
[9].  The oldest Washoe pine is on Mount Rose, Nevada.  Its estimated
age in 1962 exceeded 300 years.  Several other trees in the area have
estimated ages of 100 to 250 years [4].
  


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Literature specific to Washoe pine regeneration is sparse.  In the Mount
Rose population, Washoe pine exhibits low seed production and has low
reproductive capacity [4,17].
   


SITE CHARACTERISTICS : 
Washoe pine is common on broad ridgetops and north-facing slopes
[18,20].  It may occur on other aspects; on volcanic ridges south of the
Warner Wilderness area, it comprises 50 to 75 percent of total stocking
on gentle west- and southwest-facing slopes [21].  Best growth occurs on
well-drained soils [9].  Washoe pine occurs from 5,500 to 8,500 feet
(1,650-2,550 m) elevation [4,9,10].  An isolated population in British
Columbia, Canada, occurs at 4,818 feet elevation (1,460 m) [4].



SUCCESSIONAL STATUS : 
Facultative Seral Species

Washoe pine is a long-lived seral species in white fir communities [20].
It is plentiful in the community, with cover often equaling or exceeding
white fir.  Fir reproduction usually exceeds that of Washoe pine,
however, unless fires are fairly frequent [20].  Washoe pine is dominant
at higher elevations [14,20].


SEASONAL DEVELOPMENT : 
Washoe pine pollen is shed from June 24 to July 4 on Mount Rose [4].
Cones mature in August and September and open in September throughout
its range [27].  

Natural seedling dormancy begins when soil temperature is below 50
degrees Fahrenheit (10 deg C) [11].

In the nursery, Washoe pine seedlings cease visible top growth by
mid-October and visible root growth by late November.  In January top
growth is evident.  The first traces of renewed root growth appear in
late February and bud swell begins in late March [11].

Related categories for Species: Pinus washoensis | Washoe Pine