FIRE CASE STUDIES
SPECIES: Carex stricta | Tussock Sedge 



CASE NAME : 
Prescribed burning studies in trembling aspen woodlands in southern Ontario


REFERENCE : 
James, T. D. W.; Smith, D. W. 1977 [33]
Smith, D. W.; James, T. D. W. 1977 [23]
Smith, D. W.; James, T. D. W. 1977 [31]


SEASON/SEVERITY CLASSIFICATION : 
Spring/Low


STUDY LOCATION : 
The study was conducted at the Mullin Tract in West Luther Township,
Wellington County, Ontario.


PREFIRE VEGETATIVE COMMUNITY : 
The prefire vegetation was dominated by an open stand of trembling aspen
(Populus tremuloides) (164 stems/ha, average d.b.h. 14 cm) with
red-osier dogwood (Cornus sericea) in the shrub layer.  The herb layer
was codominated by tussock sedge (Carex stricta) and bluejoint reedgrass
(Calamagrostis canadensis).


TARGET SPECIES PHENOLOGICAL STATE : 
No specific information was given on the phenological state of tussock
sedge but it was probably in a preflowering condition during these
spring fires.  


SITE DESCRIPTION : 
The site is at an elevation of 1,221 feet (470 m).  Mean total
precipitation is 35.4 inches per year (885 mm/yr), the average length of
the growing season is 116 days, and the July mean daily temperture is 70
degrees Fahrenheit (21 deg C).  The study was located on poorly drained,
organic muck soils approximately 1 foot (3 m) in depth.  The area had
generally low relief but consisted of a mosiac of hummocks and hollows,
the latter filled with standing water in the early spring.


FIRE DESCRIPTION : 
Burn              Wind      Relative    Ambient    Dead fuel     Reaction   
plot   Date       speed     humidity      temp     combusted     intensity
                 (m/min)      (%)       (deg C)     (g/sq m)   (kw/sq m/min) 
                                                     
1      5/8/72     91.7        56         14         674.7           509
2      5/8/72     87.4        58         15         750.4           375
3      4/24/73    43.5        72         13         756.2           569 
4      4/24/73    68.7        43         15         651.1           489 

Standard deviations are reported for wind speed, fuel combustion, and
reaction intensity data [2].

Fuel moisture content was "generally high" on the treatment plots in
both 1972 and 1973 and evidently tended to reduce fire intensity.  The
pattern of burning in both years was heterogeneous.  This was related to
the uneven microtopography and patchy distribution of fuel prior to the
fires.  Areas dominated by tussock sedge had large amounts of surface
litter and standing dead material and consequently were the most
thoroughly burned.


FIRE EFFECTS ON TARGET SPECIES : 
Short-term postfire response of tussock sedge after light prescribed
surface fire in trembling aspen woodlands were as follows: 

               Percent abundance   Percent frequency
Burned 4/73          43.5                87.5
Burned 5/72          70.0                96.0
Control              54.0                83.5

Abundance of burned and control populations was not significantly
different (p=0.05) at postfire year 1.  Growth of the burned population
may have been affected by scorch or by increased competition from
bluejoint reedgrass.  Tussock sedge was substantially more abundant in
the plots measured 15 months following fire.


FIRE MANAGEMENT IMPLICATIONS : 
NO-ENTRY

Related categories for Species: Carex stricta | Tussock Sedge