Thalictrum fendleri, Lupinus argenteus, and Geranium 

 viscosissimum. The dominant S. oreophilus in the shrub 

 layer is frequently accompanied by Rosa woodsii and 

 Berberis repens. 



We believe that this type is essentially a climax com- 

 munity type representing a fairly broad POTR/SYOR/ 

 CAGE habitat type. The occasional presence of 

 Pseudotsuga menziesii or Abies lasiocarpa and 

 associated species suggests that it may also be consid- 

 ered a serai community within either of those coniferous 

 forest series, possibly the P. menziesii/S. oreophilus, 

 P. menziesii/B. repens, or A. lasiocarpa/B. repens habitat 

 types (Mauk and Henderson 1984; Youngblood and 

 Mauk 1985). Overgrazing within the POTR/SYOR/ 

 CAGE c.t. probably shifts community composition 

 toward greater abundance of Poa pratensis, Sitanion 

 hystrix. Astragalus miser. Taraxacum officinale, and 

 Achillea millefolium. 



This type has a fairly high potential for wood produc- 

 tion, yet only moderate potential for the production of 

 undergrowth. Tree basal area on 14 sampled stands 

 ranged from 74 to 292 ft^/acre (16.9 to 67.0 m-'/ha) and 

 averaged 165 ft^/acre (37.8 m^/ha). Virtually all of this 

 consisted of aspen. Site index at 80 years for aspen 

 ranged from 35 to 75 ft (10.7 to 22.9 m) and averaged a 

 moderate 50 ft (15.3 m). Aspen suckers averaged a 

 moderate 1,700/acre (4 100/ha), slightly over half of 

 which were in the 1- to 4.6-ft (0.3- to 1.4-m) size class. 



Annual production of undergrowth ranged from 331 to 

 1,990 lb/acre (372 to 2 234 kg/ha), and averaged a moder- 

 ate 1,071 lb/acre (1 202 kg/ha). This production was 

 divided among major vegetation classes as follows: 23 

 percent shrubs, 44 percent forbs, and 33 percent grami- 

 noids. Over 50 percent of the vegetation fell into the 

 desirable forage suitabiUty class, and less than 10 per- 

 cent was in the least desirable class. The type is rela- 

 tively good livestock summer range, perhaps more suited 

 to cattle than to sheep. The lack of a tall shrub stratum 

 reduces structural diversity and consequently somewhat 

 diminishes the value of the type as wildlife habitat. 



Aspen communities similar to this type have been 

 observed elsewhere. Schlatterer (1972) identified a 

 P. tremuloides/S. oreophilus-C. geyeri habitat type in the 

 Sawtooth area of south-central Idaho. A similar 

 P. tremuloides/S. oreophilus-Calamagrostis rubescens 

 community type, with C. rubescens replacing C. geyeri 

 as the principal graminoid, occurs in southeastern Idaho 

 (Mueggler and Campbell 1982). Some of the stands 

 occurring in the generalized P. tremuloides/S. oreophilus 

 habitat type in northwestern Colorado (Hoffman and 

 Alexander 1983) resemble those in our 

 POTR/SYOR/SESE c.t. 



Populus tremuloides/Symphoricarpos 

 oreophilus/Festuca thurberi Community 

 Type (POTR/SYOR/FETH c.t.) 



This minor type, sampled by only seven stands, is re- 

 stricted to central and southern Utah. Three stands were 

 encountered on the Fishlake Plateau and four on the 

 Aquarius Plateau. These stands were at elevations 

 between 8,600 and 9,400 ft (2 620 and 2 870 m) and on 



soils derived either from volcanic or granitic parent 

 materials. 



The type is cheiracterized by a distinct shrub layer 

 dominated by Symphoricarpos oreophilus and a rather 

 simple herbaceous layer in which Festuca thurberi is a 

 conspicuous dominant. Although conifers are not abun- 

 dant, Pseudotsuga menziesii frequently will be found in 

 this type. The shrub stratum often contains appreciable 

 amounts of Berberis repens and Rosa woodsii. Grasses 

 that may be abundantly associated with F. thurberi 

 include Bromus anomalus and Stipa occidentalis. Forbs 

 are ordinarily sparse; those most Likely to form a sub- 

 stantial part of the undergrowth are Lathyrus spp., 

 Vicia americana, Taraxacum officinale, and Thalictrum 

 fendleri. 



The few stands sampled in the POTR/SYOR/FETH 

 c.t. appeared to reflect considerable past grazing pres- 

 sure, judging from the abundance of T. officinale, 

 V. americana, and Lathyrus spp. The type appears to 

 represent primarily a POTR/SYOR/FETH habitat type, 

 but with appreciably altered species composition. The 

 amount of P. menziesii occurring in some stands sug- 

 gests that they may be serai within the P. menziesii for- 

 est series. 



Only two stands within this type were sampled to 

 assess productivity. This limited sample suggests that 

 wood fiber production is relatively high. Tree basal area 

 was 160 and 178 ft^/acre (36.8 and 40.9 m^/ha), and the 

 80-year site index for aspen was 52 and 63 ft (15.8 and 

 19.2 m). Virtually all of the basal area was aspen. 

 Reproduction of aspen in these mature stands was very 

 low, averaging less than 180 suckers/acre (450/ha). 



Undergrowth production was a relatively low 405 and 

 774 lb/acre (455 and 869 kg/ha). A high proportion of 

 this, an average 56 percent, consisted of shrubs, 27 per- 

 cent was forbs, and 17 percent was graminoids. A high 

 proportion of the undergrowth consisted of vegetation in 

 the desirable and intermediate forage suitability categor- 

 ies. Thus, although the type appears to produce high 

 quality livestock forage, the quantity is relatively low. 

 The absence of a tall shrub layer somewhat reduces the 

 value of this type as wildlife habitat. 



Langenheim (1962) reported aspen stands with the tus- 

 sock F. thurberi as a major grass component in the 

 undergrowth in only one other location, the Crested 

 Butte area of west-central Colorado. Some of the commu- 

 nities she described contained a low shrub stratum domi- 

 nated by S. oreophilus and an herbaceous layer with 

 appreciable amounts of F. thurberi. 



Populus tremuloides/Juniperus communis/ 

 Carex geyeri Community Type 

 (POTR/JUCO/CAGE c.t.) 



The POTR/JUCO/CAGE type was encountered prin- 

 cipally on the Wasatch-Cache and Ashley National 

 Forests where 70 stands were sampled. Over three- 

 fourths of the occurrences were in the Uinta Mountains 

 of northeastern Utah. The type was occasionally encoun- 

 tered in central and southern Utah on the Fishlake and 

 Aquarius Plateaus and in the Tushar Mountains. Carex 

 rossii and Stipa occidentalis were the equivalent indica- 



18 



