• FIRE ECOLOGY OR ADAPTATIONS
• POSTFIRE REGENERATION STRATEGY

FIRE ECOLOGY OR ADAPTATIONS:

Pinegrass sprouts from rhizomes following fire [27,74,139,150]. Rhizomes are buried in the top 2 inches (5 cm) of mineral soil [18,72], allowing pinegrass to survive fires that do not completely consume the duff layer [34,50,114,128,150]. Pinegrass is seldom, if ever, eliminated from a site even after severe wildfires [141].  Throughout its range, repeated fires promote increased cover in pinegrass and often result in its early postfire dominance [17,27,30,91,130,155].

Pinegrass seedlings establish on burned sites from off-site sources, and pinegrass undergoes mass flowering in the years immediately following fire [34,72,114,142,151], allowing for rapid postfire colonization [72,74,150].

Historically, pinegrass stands have perpetuated surface fires that maintained open stands of ponderosa pine. Ponderosa pine is now being replaced by Douglas-fir, white fir, or grand fir in the Blue and Wallowa Mountains of Oregon, in central Idaho, and along the east side of the Cascade Range [61,62,134,152]. Pinegrass stands have also perpetuated low-intensity, high frequency fires in the interior Douglas-fir zone of British Columbia, maintaining an open stand structure [56]. Estimated fire return intervals for several pinegrass-dominated habitats follow:

Habitat type	Location	Estimated fire return interval
Ponderosa pine/pinegrass	Blue Mts., OR	10 yrs [73]
Douglas-fir/pinegrass	interior British Columbia	13 yrs [56]
Douglas-fir/pinegrass	Forest-grassland ecotones,  southwestern MT	22 yrs [8]
moist Douglas-fir/ pinegrass	Bitterroot NF, MT	28 yrs [6]
dry Douglas-fir/pinegrass	Lolo NF, MT	10 yrs [39]

Other habitat types in which pinegrass is named as a dominant understory species have been placed in "Fire Groups" in certain regions. Descriptions of these "Fire Groups", and the importance of pinegrass within them, along with fire history information and fire management considerations are available by region in the literature: eastern Idaho and western Wyoming [17]; northern Idaho [128]; central Idaho [32]; Utah [18]; Montana (east of the Continental Divide) [50]; and western Montana [39,49].

Estimated fire return intervals for some ecosystems and communities in which pinegrass occurs follow:

Community or Ecosystem	Dominant Species	Fire Return Interval Range in Years
silver fir-Douglas-fir	Abies amabilis-Pseudotsuga menziesii var. menziesii	> 200
grand fir	A. grandis	35-200
sagebrush steppe	Artemisia tridentata/Pseudoroegneria spicata	20-70
California montane chaparral	Ceanothus and/or Arctostaphylos spp.	50-100 [23]
curlleaf mountain-mahogany*	Cercocarpus ledifolius	13-1000 [9,121]
western juniper	Juniperus occidentalis	20-70
western larch	Larix occidentalis	25-100
Engelmann spruce-subalpine fir	Picea engelmannii-Abies lasiocarpa	35 to > 200
whitebark pine*	Pinus albicaulis	50-200 [23]
Rocky Mountain lodgepole pine*	P. contorta var. latifolia	25-300+ [7,117]
western white pine*	P. monticola	50-200
Pacific ponderosa pine*	P. ponderosa var. ponderosa	1-47
Rocky Mountain ponderosa pine*	P. ponderosa var. scopulorum	2-10 [23]
quaking aspen (west of the Great Plains)	Populus tremuloides	7-120 [23,57,99]
mountain grasslands	Pseudoroegneria spicata	3-40 (10)** [7]
Rocky Mountain Douglas-fir*	Pseudotsuga menziesii var. glauca	25-100 [23]
coastal Douglas-fir*	P. menziesii var. menziesii	40-240 [23,101,116]
western redcedar-western hemlock	Thuja plicata-Tsuga heterophylla	> 200
mountain hemlock*	T. mertensiana	35 to > 200 [23]

*fire return interval varies widely; trends in variation are noted in the species summary
**(mean)

POSTFIRE REGENERATION STRATEGY [139]:

Rhizomatous herb, rhizome in soil
Initial off-site colonizer (off-site, initial community)
Secondary colonizer - on-site seed

Related categories for SPECIES: Calamagrostis rubescens | Pinegrass