Figure 5.— The infrequent 

 but broad-ranging Populus 

 tremuloides/Heracleum 

 lanatum c.t. is structurally 

 simple but is usually 

 productive. Heracleum 

 lanatum is a conspicuous 

 component of the 

 undergrowth. This stand 

 occupies a moist, easterly 

 exposure at 8,000 ft 

 (2 440 m) elevation near Mt. 

 Timpanogos on the Uinta 

 National Forest; 98 percent 

 of the undergrowth 

 production was forbs. 



Types similar to the POTR/HELA c.t. occur at least in 

 Wyoming and in Colorado. Youngblood and Mueggler 

 (1981) describe such a type in western Wyoming that is 

 virtually identical. A P. tremuloides/Heracleum 

 sphondylium habitat type was described for north- 

 western Colorado (Hoffman and Alexander 1980, 1983) 

 that is similar to our type. Dorn (1977) indicates that 

 H. sphondylium is synonymous with H. lanatum. 



Populus tremuIoides/Pteridium aquilinum 

 Community Type (POTR/PTAQ c.t.) 



This infrequent but distinct community type occurred 

 principally on the Wasatch Range in northern Utah, par- 

 ticularly on that portion between Salt Lake City and 

 Heber City. One stand was encountered as far south as 

 the Markagunt Plateau east of Cedar City. The 13 

 stands sampled within this type generally ranged in ele- 

 vation between 5,800 and 8,400 ft (1 770 and 2 560 m). 

 The stand in southern Utah was at 9,350 ft (2 850 m). 



These stands occupied soils of sedimentary as well as 

 granitic origin. They did not appear restricted by either 

 exposure or steepness of slope. 



The POTR/PTAQ c.t. is readily identified by the abun- 

 dance of Pteridium aquilinum in the undergrowth and 

 the absence of a pronounced shrub stratum (fig. 6). How- 

 ever, minor amounts of some shrubs, particularly 

 Symphoricarpos oreophilus and Sambucus racemosa, 

 may be present. Members of the tall forb group are 

 usually associated in the herbaceous layer with the con- 

 spicuously dominant P. aquilinum. The most frequent of 

 these are Rudbeckia occidentalis, Agastache urtici folia, 

 Senecio serra, and Aster engelmannii. Occasionally 

 Lathyrus spp. may be abundant. Graminoids, especially 

 Bromus carinatus and Elymus glaucus, are often present 

 in substantial amounts. Conifers are usually absent. 



The successional status of this type is uncertain. 

 Pteridium aquilinum is a native species sporadically dis- 

 tributed in Utah and elsewhere throughout the West. 

 Where it does occur, however, it is usually a dominant 



Figure 6.— The distinctive 

 Populus tremuloides/ 

 Pteridium aquilinum c.t., 

 though seldom encountered, 

 is widespread in the 

 Intermountain and Rocky 

 Mountain area. Pteridium 

 aquilinum overwhelmingly 

 dominates the undergrowth 

 in this stand found in the 

 Big Flat area of the Uinta 

 National Forest west of 

 Heber City. 



23 



