VEGETATIVE RECOVERY ON RAVINE SITES 



Field methods and data analysis on ravine sites. Thir- 

 teen burned ravine stands were selected for study in ad- 

 dition to the unbumed ravine stand cited earlier. All 

 stands were sampled in August and September of 1978 

 and 1979, and eight of the stands were resampled in 

 1980. During August and September of 1982, all burned 

 ravine stands were resampled except for stands 10 and 

 14 which have been dropped from the study due to 

 postfire disturbance. 



The ravine study used the permanent nested plot 

 design as described by Stickney (1980). Grass 

 nomenclature follows Hitchcock and Chase (1950) other 

 vascular plant nomenclature follows Hitchcock and 

 Cronquist (1973). Data analysis was the same as describ- 

 ed for the upland study. Ravine stands are numbered 1 

 to 14. The physical features of these stands are listed in 

 table 4 and their locations are shown in figure 4. Appen- 

 dix A- 2 lists cover values for ravine species in individual 

 ravine stands each year the stand was sampled. 



Study results on ravine sites. Ravines are composi- 

 tionally far more heterogeneous than any of the upland 

 areas. Variation and shifts in vegetation are abrupt and 

 frequent, whereas on the open slopes shifts appear to be 

 more gradual. The most conspicuous source of this varia- 

 tion is the moisture gradient from the streambed itself 

 to the adjacent side slopes of the ravine. A generaliza- 

 tion of this gradient in a moist ravine is depicted in 

 figure 9. Some of the more common plants associated 

 with this gradient are listed in table 7. This moisture 

 gradient continues on up the side slopes to the ridgetop. 



Plot placement was subjective and generally attempt- 

 ed to parallel the axis of the ravine in either zone 2 or 



zone 3. In narrow ravine areas stream curvature may in- 

 troduce some elements of zone 1; examples are found in 

 stands 5 and 14. 



In higher dry ravines without summer overland flow 

 this gradient disappears. Plots in stands 8, 9, and 10 

 were placed in different areas of the same upper dry 

 ravine in order to represent some of the variation pres- 

 ent in those ravines. 



Table 8 contains cover and volume means for the serai 

 community Life-forms and some important species within 

 the ravine sites sampled in 1978, 1979, and 1982. 

 Recovery was generally more rapid than on upland sites 

 and, with the exception of the seeded grasses, most 

 species present in the initial stages of recovery 

 resprouted from root crowns or rhizomes. Growth of 

 these resprouts, both shrub and herbaceous, was rapid 

 and by the summer of 1978 the ravines as a whole had 

 77.4 percent vascular plant cover with 90 percent of that 

 cover resulting from native species. 



By 1982 shrub cover in the burned ravine stands was 

 77 percent of that in unbumed ravine stand 7. Service- 

 berry and Rocky Mountain maple in the unbumed stand 

 were very tall so that shrub volume in the bumed 

 stands was only 40 percent of the unbumed stand. 



Tree regeneration in the ravines has been minimal. 

 Mature larch and Douglas-fir survived the fire in stands 

 5, 11, and 12 and in the ravines above stands 6 and 14. 

 An inspection of the slopes near stand 5 in 1980 

 revealed larch seedlings, but no seedlings have been 

 observed in the ravine plots except for stand 6, which 

 had three Douglas-fir seedlings within the V2-m^ plots. 



The distribution of seeded grasses in the ravines ap- 

 pears to be related to bum severity, available moisture 

 and whether or not a given area received seed. In 



Figure 9.— Gradation across a Pattee Canyon 

 ravine. Some representative species from 

 each zone are listed in table 7. 



Table 7.— Species most frequently found in ravine zones identified in figure 9 



Zone 1 



Zone 2 



Zone 3 



Mimulus guttatus 



Acer glabrum 



Ptiysocarpus maivaceus 



Veronica americana 



Mitella stauropetala 



Acer glabrum 



Veronica serpy Hi folia 



Osmorhiza chilensis 



Calamagrostis rubescens 



Cardamine pensylvanica 



Galium triflorum 



Aster conspicuus 



Urtica dioica 



Urtica dioica 



Arnica cordifolia 



Cinna latifolia 



Cinna latifolia 



Smilacina stellata 



Giyceria grandis 



Giyceria grandis 



Anaphalis margaritacea 



Athyrium filix-femina 



Symptioricarpos albus 



Symptioricarpos albus 





Spiraea betulifolia 



Spiraea betulifolia 





Rubus parviflorus 



Rubus parviflorus 



12 



