FIRE CASE STUDIES
SPECIES: Juncus balticus | Baltic Rush 



CASE NAME : 
Malheur National Wildlife Refuge, Oregon


REFERENCE : 
Young, R. P. 1986 [36]


SEASON/SEVERITY CLASSIFICATION : 
fall burn; information on severity unavailable


STUDY LOCATION : 
The fire was conducted on Malheur National Wildlife Refuge, 24 miles (40
km) south of Burns in southeastern Oregon.  The burn was located at
Martha Lake Field (T26S, R28E, S24 SE 1/4, & S25 NE 1/4).


PREFIRE VEGETATIVE COMMUNITY : 
The study sites consisted of five wetland habitats dominated by
monotypic communities of emergent macrophytes.  These sites ranged from
deep-water habitats to upland wet meadows.  All dominant species were
rhizomatous and included hardstem bulrush (Scirpus acutus), American
threesquare (S. americanus), alkalai bulrush (S. maritimus), common
cattail (Typha latifolia), burreed (Sparganium eurycarpum), awned sedge
(Carex atherodes), Nebraska sedge (C. nebraskencis), Baltic rush (J. b.
var. montanus), and common spikerush (Eleocharis palustris).


TARGET SPECIES PHENOLOGICAL STATE : 
dormant


SITE DESCRIPTION : 
Total area of the refuge is 178,456 acres (72,219 ha) and sits within a
basin which forms the northwestern part of the Basin and Range Province
of the western United States.  Two major rivers, the Silvies and the
Blitzen, flow through the refuge.  The climate is semiarid with moderate
to cold temperatures.  Annual precipitation averages between 10 and 12
inches (25 and 30 cm), the majority of which falls in winter and spring.
Growing seasons are shortened by cool springs, dry summers, and freezing
in late August or early September.


FIRE DESCRIPTION : 
The fire in the Baltic rush community was conducted on 20 October 1981.
Test fires were used to evaluate fire behavior before burning the main
unit.  Fires were started with drip torches on the downwind boundaries
of all plots.  Strip headfires were used after backing fires created a
wide line.  Firelines were constructed where natural breaks did not
occur.  Prefire fuels, and weather conditions at the time of the fire
were as follows:

        Prefire fuel loading:  591-1,104 gm2
        Fuel height:  29 cm
        Litter height:  12 cm
        Fuel moisture:  3.5 percent
        Temperature:  16-23 deg C
        Relative humidity:  13-17 percent
        Wind speed:  3-16 km/h

Fire behavior and effects on fuels during the prescribed fire were as
follows:
                                                   Postfire
Rate of Spread   Flame Length   Fire Intensity   resid. fuels
  (m min-1)           (m)           (kW m-1)       (g m-2)     Reduction
________________________________________________________________________
Headfire  50-60      3-6         10,131-18,924     mean=68       92%
Backfire  1-2        1.5            276-516


FIRE EFFECTS ON TARGET SPECIES : 
Fire effects were evaluated in terms of vegetative response, including
shoot height, density, weight, and growth rate; aboveground standing
crop; residual organic materials; and reproductive effort.  These
measurements were taken for 2 years following the fore.  Baltic rush
increased in aboveground standing crop and shoot densities.  Shoot
weights decreased, although not significantly.  Organic residues
increased the second postfire year.  All shoots of Baltic rush produced
flowers following the fire.  Shoot height and rate of height-growth
following burning and nonuse treatments for the first postfire growing
season are as follows:

                                Fall fire               Nonuse
                   Growth
                   period    Height   Growth rate   Height  Growth rate
   Date            (days)     (cm)      (cm/d)       (cm)     (cm/d)
------------------------------------------------------------------------
22 April 1982        --      7 (5)*      --          6 (4)      --
29 May   1982        37     17 (6)       0.3        15 (6)      0.3
 3 July  1982        35     68 (23)      1.5        62 (22)     1.4
29 July  1982        26     80 (26)      0.5        72 (18)     0.4
19 Aug   1982        21     82 (24)      0.1        69 (19)       0

* All shoot height values = mean + or - (standard deviation)
   


FIRE MANAGEMENT IMPLICATIONS : 
The purpose of this study was to provide information for wetland fire
management plans.  Fire can play an important role in rejuvenating these
emergent species; however, long-term effects and effects of repeated
burning need further investigation.

Related categories for Species: Juncus balticus | Baltic Rush