FIRE EFFECTS
SPECIES: Pinus rigida | Pitch Pine 



IMMEDIATE FIRE EFFECT ON PLANT : 
Pitch pine is flammable and easily top-killed by fire [21].  Seedlings
up to 5 feet (1.5 m) in height will almost always be top-killed.  A hot
fire during a dry season can kill an individual, but following most
fires, dormant buds will sprout even if most of the tree is destroyed
[1,21].  Crown fires are the prevailing fire type in the Pine Plains and
result in high stem mortality [41]

Pitch pine needles were killed instantly when immersed in 147 degree F
(64 degree C) water, but withstood immersion in 136 degree F (58 degree
C) water for 1.5 minutes.  The study showed that pitch pine needles are
more tolerant of heat than the needles of other eastern pine species
(Pinus palustris, P. echinata, and P. taeda) [1].



DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
If fire exposes the mineral soil necessary for pitch pine regeneration,
seeds released from serotinous cones will germinate and seedlings will
establish during the first postfire growing season [22].  Established
trees will sprout vigorously from dormant buds along the bole following
fire.  Sprout production will continue at a relatively high but
declining rate for 15 years after the fire [5].  Little or no needle
scorch will result in no growth loss in pitch pine [21].

Seedlings that are top-killed will also sprout.  Seventy percent of
shade-grown seedlings sprouted after a prescribed burn if they were
vigorous and had well-developed basal crooks or were greater than 3/16
inch (0.5 cm) in diameter at the root collar [27].



DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
No seedlings were observed 1 year after a fire in the Pine Plains of New
Jersey.  Buchholz [3] attributed the lack of seedlings to the high seed
predation by eastern towhees and the prolific postfire sprouting that
characterizes the dwarfed pitch pines of this region.  The mean stem
density of the Pine Plains is 10,100 stems per acre (24,900 stems/ha).
Saplings and seedlings account for less than 1 percent of the stems [5].
The abundant sprout production results in a high wood surface area and
may contribute to the development and maintenance of the dwarfed
stature, and high fire frequency and intensity characteristic of these
Pine Plains communities [3].

Low-intensity surface fires selectively kill basal sprouts over larger
canopy stems.  Canopy stems continue to grow and discourage basal
sprouts from becoming established in the canopy and thus result in a
lower canopy stem density [41].


FIRE MANAGEMENT CONSIDERATIONS : 
Prescribed fire is an important management tool in eastern upland pitch
pine forests.  Pitch pine is fire dependent and most of its successional
competitors are not [15,21].  Recommendations for prescribed fire
intervals vary.  Based on bark thickness and its ability to protect the
tree from low-intensity fires, Harmon [16] suggests the fire interval be
no less than 15 years to have 50 percent survival of pitch pine as the
dominant crown class.  To suppress hardwoods, Little and Moore [26]
recommend burning at 5-year intervals after pines are old enough to
resist fire injury.  Prescibed fires are risky if stands are less than
12 feet (3.7 m) tall [27].  Short fire intervals kill sprouts, but allow
saplings to survive [7].  Barden and Woods [1] suggest that only a crown
fire will encourage pine reproduction and discontinue hardwood
succession.  A crown-burning program at 5- to 20-year intervals in
restricted areas is recommended for maintaining the unique Pine Plains
ecosystem [41].

In the early part of the twentieth century, fire frequency in the New
Jersey Pine Barrens was 20 years; today it is 65 years.  The decrease in
fire frequency has resulted in a loss of fire-adapted species and
continued fire suppression will probably result in complete changes from
mixed pine-hardwood forests to closed canopy hardwood forests
[11,33,37].  Frequent burns favor pine over oak, but the occasional
prescribed winter burn actually may accelerate succession toward oak
dominance.  A winter prescibed burn in the Pine Barrens of New Jersey
stimulated growth in oaks (Quercus alba and Q. prinus) more than in
pitch pine and did not improve soil fertility [2].

Related categories for Species: Pinus rigida | Pitch Pine