moderate disturbance, such as a light ground fire, could 

 eliminate the present seedling crop. This would diminish 

 dramatically the relative success of lodgepole pine on the 

 burn. With a more constant seed source in the face of 

 moderate disturbance, other conifers could fare better in 

 the long run. Without any disturbance, lodgepole pine's 

 early maturity may allow it to increase in proportion to 

 other species in the developing postfire stand. 



Recovery of Individual Understory 

 Species 



This discussion of understory species attributes is 

 based on observation and data collected on the Pattee 

 Canyon site only. Species may behave differently on dif- 

 ferent habitats within the limits of their range. 



SHRUB RESPONSE 



Of all the shrubs considered, only ninebark, white 

 spirea, and huckleberry have at least 1 percent mean 

 cover on both upland and ravine sites. Thimbleberry, 

 Rocky Mountain maple, common snowberry, and service- 

 berry Eire important in the ravines while huckleberry has 

 little cover at present. Serviceberry has shown the most 

 damage from browsing by deer in the first years since 

 the fire. Postfire response of shrubs in Pattee Canyon is 

 shown in table 14. Increases in volume for the most 

 dominant ravine shrubs are shown in figure 14. 



Competitive abiUty in shrubs is frequently related to 

 their ability to spread from rhizomes. Those species that 

 spread from rhizomes tend to show clustered 

 (aggregated) distributions. On the Pattee Canyon burn, 

 patches of blue huckleberry, thimbleberry, and common 

 snowberry are conspicuous. Thimbleberry made a rapid 

 recovery in the first years and then gained volume more 

 slowly up to the fifth year; snowberry recovered more 

 slowly initially and has increased its volume very rapidly 

 in the third to fifth year interval. Spirea is more 

 uniformly distributed; it resprouted quickly, maintained 

 nearly the same cover during 1979 and 1980, but subse- 

 quently has declined in most areas. 



Resprouts of blue huckleberry were few in 1978, in- 

 creased somewhat in 1979, and then increased more by 

 1982 on upland sites. Miller (1977) states that the depth 

 of heat penetration controls the number of Vaccinium 

 globulare resprouts. Density increases if stems are killed 

 just below ground level, so that sprouts appear from 

 rhizomes; however, density decreases if heat kiUs the 

 shallow rhizomes and sprouting occurs from deeper 

 levels with fewer rhizomes. The Pattee Canyon fire was 

 severe in many areas and blue huckleberry's recovery 

 was slow. All plants sampled in ravine patches of 

 resprouting blue huckleberry during 1980 were sprouting 

 from lateral rhizomes located at depths of 3.5 to 6 inches 

 (9 to 15 cm). 



Table 14.— Postfire behavior of some Pattee Canyon shrubs 



Species 



Fire survival 



Seed production 



Expansion 

 potential 



Physocarpus malvaceus 



Acer glabrum 



Spiraea- betulifolia 



Symphoricarpos albus 



Vaccinium globulare 



Amelanchier ainifolia 

 Rubus parviflorus 



Root crowns 



Root crowns 



Rhizome 



Rhizome 



Both shallow 

 and deep 

 rhizomes 



Root crowns 



Rhizomes 



Occasional plants 

 flowered in 1980 

 most plants 

 flowered in 1981 



Did not set seed 

 in the 1st 3 post- 

 fire years. Did 

 have seeds by the 

 fifth summer 



Set seed the first 

 year following the 

 fire 



Some fruit the 

 first postfire 

 year 



Fruit the third 

 postfire year 



Fruit the second 

 postfire year 



Fruit the first 

 postfire year 



Appears to 

 be slow 



Has winged 

 samara 



Can spread 

 vegetatively 

 by rhizomes 

 and has early 

 seed production 



Vegetative 

 spread by 

 rhizomes; bird 

 carried seed 

 Vegetative 

 spread by 

 rhizomes; bird 

 carried seed 



Animal carried 

 seed 



Spreads vigor- 

 ously by rhizomes; 

 bird carried seed 



19 



