FIRE EFFECTS
SPECIES: Larix laricina | Tamarack 



IMMEDIATE FIRE EFFECT ON PLANT : 
Tamarack is easily killed by fire because it has thin bark and shallow
roots.  On peatlands it is usually killed by all but very light surface
fires [26].  Tamarack seeds have no endosperm to protect them from high
temperatures; therefore, seeds on the ground are usually destroyed by
fire.  Cones are not necessarily destroyed by summer fires, but immature
seeds will not ripen on fire-killed trees [52].  If summer fires kill
tamarack trees over extensive areas, no seed will be available to
revegetate the burned area.

Following a fire in a northern Wisconsin muskeg all tamaracks died
(trees were 1 to 5 inches [2.5-12.5 cm] d.b.h.) [50].  In interior
Alaska, all tamarack trees died following a low-intensity surface fire
that burned only 2 to 4 inches (5-10 cm) into the organic mat [20].
These trees were 49 to 79 years old and 1.5 to 3 inches (3-6 cm) in
diameter.


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Following fire, tamarack reestablishes via wind-dispersed seeds from
surviving trees in protected pockets or adjacent unburned areas.  Burned
organic surfaces favor seedling establishment.  Within a few years
tamarack reproduction is often localized and centered around areas of
surviving trees [37].

In northeastern British Columbia, tamarack seeded onto burned areas over
several years.  Most seedlings established within 10 years after fire,
but additional establishment continued until 20 years after fire [41].
Postfire tamarack seedlings grow rapidly.  Twenty-one years after a fire
in a tamarack-black spruce swamp in northeastern British Columbia,
tamarack seedlings were more than 2 times taller than black spruce
seedlings.  Tamarack seedlings that established soon after the fire
averaged 7.9 feet (2.4 m) tall, while black spruce seedlings that
established at the same time were only 3.6 feet (1.1 m) tall [40].

Tamarack seedlings were abundant 6 years after clearcutting and
broadcast burning in mixed black spruce-tamarack stands in northern
Minnesota.  Tamarack seedlings made up 43 percent of tree seedlings 66
feet (20 m) downwind from the uncut border, even though tamarack made up
only 27 percent of the seed trees (55 per acre [136/ha]).  On this site,
4,200 tamarack seedlings averaging 21 inches (53 cm) in height were
established per acre (10,400/ha).  On another cut where there were only
12 tamarack seed trees per acre (30/ha) at the uncut border, 4,400
seedlings averaging 39 inches in height (1 m) were established per acre
(10,900/ha) [24].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Tamarack establishes readily on sites where logging slash is burned but
poorly on sites where slash is untreated.  On peatlands in Minnesota,
tamarack seedlings were abundant 6 years following broadcast burning of
black spruce-tamarack slash in clearcuts [24].  However, pure tamarack
slash is difficult to broadcast burn.  Therefore, when cutting pure
tamarack stands, piling and burning slash is the option that best favors
tamarack reproduction [25].

In Wisconsin, prescribed burning has been conducted in conifer swamps
and muskegs to improve wildlife habitat.  Prescribed burning killed
tamarack and other conifers in swamps, and improved feeding and nesting
habitat for game birds by converting these areas to swamps dominated by
sedges (Carex spp) and ericaceous shrubs [50].

Related categories for Species: Larix laricina | Tamarack