• IMMEDIATE FIRE EFFECT ON PLANT
• DISCUSSION AND QUALIFICATION OF FIRE EFFECT
• PLANT RESPONSE TO FIRE
• DISCUSSION AND QUALIFICATION OF PLANT RESPONSE
• FIRE MANAGEMENT CONSIDERATIONS

IMMEDIATE FIRE EFFECT ON PLANT:

Prairie Junegrass is usually top-killed or killed by fire. Fast-moving, low-intensity fires will consume above ground vegetation without damaging the plant's crown [101]. In general, late-spring burns are more damaging to prairie Junegrass than early-spring, late-summer, fall, or winter burns [113].

DISCUSSION AND QUALIFICATION OF FIRE EFFECT

The rootcrown of prairie Junegrass may sustain immediate damage depending upon amount of heat transferred through the soil [36]. Meristimatic tissue of most grasses is found at the ground surface in the rootcrown [101]. A study [36] in the southwest United States evaluated patterns of plant growth in relation to soil heating from wildfire in chaparral systems. Prairie Junegrass was found to have a strong negative correlation between heat load and resprouts.

PLANT RESPONSE TO FIRE:

Positive postfire vegetational responses are common for prairie Junegrass. Increased seedhead presence and height-of-inflorescence have been documented [41]. Annual burning of a native grassland in the aspen parkland of central Alberta caused a 40% increase in seedhead presence compared to unburned areas [5].

DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:

Prairie Junegrass shows positive responses to fire. Fall and early-spring burns produce better responses than summer burns [4,62]. A summation on the effect of burn seasonality in eastern Oregon is given below [126]:

Burn Season	Change in Basal Area	Mortality
Mid-May	-32%	20%
Mid-June (Post-seed-out)	-18%	0%
Mid-October	approx. -18%	0%

Observations of prairie Junegrass populations two years after a spring burn were conducted in Galena Gulch within the Deer Lodge National Forest in western Montana. Burned sites experienced a 40% increase in prairie Junegrass occurrence [6]. Percent coverage of prairie Junegrass was evaluated in burned and unburned sites after a June fire in western Montana. Coverage was greater in the burned areas two years after the burn populations decreased, but maintained levels above the control stands [6].

	Autumn 1977		Spring 1978		Summer 1978
	Unburned	Burned	Unburned	Burned	Unburned	Burned
	1.6	1.5	1.4	2.4	1.5	3.0

An experiment was initiated in 1926 on a bluestem pasture in eastern Kansas to record effects of fire upon several ecological parameters. Fires were set the same times each year beginning in 1926: early-spring (March 20), medium-spring (April 10), late-spring (May 5) and late-fall (December 1). The response of prairie Junegrass to the burns from late June, 1928, to early July, 1933, are summarized below [4]:

Number of plants/year within 2 rods square - observed late June and early July

Year Observed

Burn date	1928	1929	1930	1931	1932	1933	Mean
Fall	1,210	1,864	2,114	2,283	1,783	1,080	1,722
Early-spring	1,296	1,402	1,465	1,340	1,002	482	1,165
Medium-spring	574	555	756	1,031	767	523	701
Late-spring	1,058	1,052	1,571	1,818	1,068	447	1169
Check plot	619	1,084	1,052	992	627	181	759

Prairie Junegrass density on all burn treatments except medium-spring, exceeded density on the 1928 check plot until 1933, when densities were low on early-spring and late-spring treatment sites as well [4].

FIRE MANAGEMENT CONSIDERATIONS:

Burning, in general, has a positive influence on prairie Junegrass populations when conducted in early-spring and fall and followed by mean or above average annual precipitation [113]. Water availability after a burn is important for maintaining healthy postfire populations of prairie Junegrass. A fall burn and above average precipitation increased postfire prairie Junegrass density in a southwestern ponderosa pine (Pinus ponderosa) forest [86]. The opposite was seen at a fall burn in North Dakota, but burned areas possessed a lower moisture content than unburned areas [11].

Related categories for SPECIES: Koeleria macrantha | Prairie Junegrass