Early Postfire Revegetation 

 in a Western Montana 

 Douglas-fir Forest 



IVI. F. Crane 

 James R. Habeck 

 William C. Fischer 



INTRODUCTION 



The wildfire that burned peirt of Pattee Canyon (fig. 1) 

 on July 16 and 17, 1977, was a fast-spreading, intense 

 crown fire. It burned 1,200 acres (486 ha) of land con- 

 sisting mainly of Douglas-fir forest in the Pseudotsuga 

 menziesiilPhysocarpus malvaceus h.t. (PSME/PHMA; 

 Douglas-fir/ninebark) as described by Pfister and others 

 (1977). The Pattee Ccinyon burn presented an opportuni- 

 ty to study vegetative recovery following a severe 

 wildfire in the extensive, interior Douglas-fir forest of 

 western Montana. Such studies began in spring 1978. 



THE STUDY AREA 

 Location 



The Pattee Ctuiyon drainage is located in the north 

 end of the Sapphire Mountains in west-central Montana 

 just southeast of Missoula. Pattee Creek drains the area 

 and is fed by more than a dozen first- to third-order 

 tributaries draining the side ridges. During spring runoff 

 these small first- and second-order streams may flow 

 overland their entire length, but in summer they become 

 intermittent. 



The fire burned a portion of the north-facing slope of 

 the canyon lying below Mount Dean Stone (fig. 1). Land 

 holdings in the area are divided among private, State, 

 and Federal ownerships (fig. 1). 



Geology and Soils 



Bedrock in Pattee Canyon consists of quartzites and 

 argillites of the Belt Series. Pattee Canyon was not 

 glaciated during the Pleistocene ice ages. Glacial Lake 

 Missoula, however, extended into Pattee Canyon (Alden 

 1953). 



Soils in the study area are Tevis series with Mitten- 

 Tevis complex on some upper slopes (L. T. Stem, USDA 

 Soil Conservation Service, personal communication, 

 1980). These gravely loam inceptisols are colluvial soils 

 derived from argiUite and quartzite. The presence of an 

 andic layer differentiates soils of the Mitten-Tevis com- 

 plex from those of the Tevis series. 



Climate 



Climate in the Missoula area is strongly influenced by 

 the Pacific Ocean where most of the area's weather 

 originates. By the time the Pacific air masses reach 

 Missoula, however, much of the moisture has been 

 released. According to the National Weather Service, 

 Missoula receives an average of 12 to 15 inches (305 to 

 381 mm) precipitation annually. Most of the moisture in 

 Missoula and Pattee Canyon falls as snow during the 

 winter or as rain showers during May and June. Mid- 

 summers cire usually dry. 



Pattee Canyon receives more moisture than Missoula 

 itself. National Weather Service data from the Missoula 

 Airport station and from a climatological station located 

 on the north side of Pattee Canyon at about 3,740 feet 

 (1 140 m) elevation are summarized in table 1. This com- 

 parison indicates that precipitation amounts in Pattee 

 Canyon are generally higher than those recorded at the 

 Missoula Airport station. Based on these data, Pattee 

 Canyon gets an average of 85 percent greater precipita- 

 tion than Missoula in spring and about 30 to 40 percent 

 more during other seasons. 



Vegetation 



During a geographical study of Pattee Canyon (circa 

 1975) Bruce Bugbee (1981; personal communication) 

 described habitat types in terms of Pfister and others 

 (1972), preliminary forest habitat types of western Mon- 

 tana. The most widespread habitat type in the burned 

 area was a Pseudotsuga menziesiilPhysocarpus 

 malvaceus h.t., Physocarpus malvaceus phase 

 (PSME/PHMA-PHMA; Douglas-fir/ninebark, ninebark 

 phase). Pseudotsuga menziesiilPhysocarpus malvaceus 

 h.t., Calamagrostis rubescens phase (PSME/PHMA- 

 CARU; Douglas-fir/ninebark, pinegrass phase) occupied 

 drier slopes and Douglas-fir scree occurred on the driest 

 ridges. The upper slopes near the ridge were Pseudot- 

 suga menziesiilVaccinium globulare h.t., (PSME/VAGL; 

 Douglas-fir/blue huckleberry) and, extending down the 

 ravines, the coolest, moist areas were occupied by Abies 

 lasiocarpalLinnaea borealis h.t. (ABLA/LIBO; subalpine 

 fir/twinflower). 



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