21 



Ponderosa Pine Series 



This was the most diversified of the vegetation types with seven 

 subtypes. It was defined as all areas in which ponderosa pine 

 {Plnuii ponde.Ko6a] occurred. The subtypes were determined by 

 the dominant shrub in the understory. Edwards (1977) described 

 a Donderosa pine mosaic vegetation type with four subtypes based 

 on categories described by Pflster et al. (197^) in the Horse 

 Creek drainage west of Colstrlp. Martin (1980c) expanded that 

 to six ponderosa pine vegetation subtypes in the Sarpy Creek 

 drainage. 



(1) Ponderosa Pine Subtype 



This subtype (Figure 15) was defined as dense stands of 

 Donderosa pine with sparse understory and ground cover. Krenzke 

 (1976) referred to this subtype as "dog hair" thickets. 



(2) Snowberry Subtype 



This subtype occurred on meslc and north facing slopes (Figure I6). 

 It had fairly dense stands of ponderosa pine with a very dense 

 understory. Common snowberry {SymphoKX.ca.fipo 6 alba] and 

 Western snowberry (S. ccld(LntoitA,& ] were the dominant shrubs. 

 Other common species Included rose (Ro4a spp.), chokecherry 

 [?fianai> vA.figZnZana) , Oregon grape (8e.A.b&/^-c-6 ^epeni ) , green needle- 

 grass [Stipa \}lfildata] and Kentucky bluegrass [Voa pK.atzni>'i&] . 



(3) Juniper Subtype 



Rocky mountain Juniper [3anlpzfiu.i> &copatofiam] was the primary 

 understory species (Figure 17). The ponderosa pine overstory was 

 generally open. Ground cover species were variable but Included 

 bluebunch wheatgrass [kqiopyfion iplcatiim] and other forbs and 

 grasses. 



(4) Creeping Juniper Subtype 



The ponderosa pine overstory varied from dense to fairly open 

 canopy coverage (Figure I8). The understory was dominated by 

 creeping .juniper ( Jun-cpeA.u.4 hon.-izoYitat-i6] and bluebunch wheatgrass. 

 Needle-and-thread grass [Stipa. comata] is also present. Major 

 forbs include cudweed sagewort [Kfito^m-iitia tudov-LC'ian.a] , western 

 yarrow [Kdhittda mitZe,^oliam) , curly cup gumweed {Gfiindztia 

 AquafLfLO^a] , white penstemon {P&n6t&mon atbidui) and several 

 asters {A^tzH. spp.). 



(5) Sagebrush Subtype 



In this subtype, big sagebrush (Kfitzmi&la tfiide.ntata] was 

 the dominant understory shrub (Figure 19) in open stands of 

 ponderosa pine. It occurred on xerlc upland benches and plateaus. 

 Bluebunch wheatgrass, blue grama grass {Boatzloua gfLaclZiA) , 

 Japanese chess {EfLomui japoniau^] and broom snakeweed {Kanthoczpalum 

 AafLothfiae.) were common grasses and forbs. 



