Early successional components such as grasses, forbs, and some 

 brush increase following removal of community dominants (oaks) 

 and subsequent improvements of available sunlight and soil 

 moisture. Pipeline corridors lead to long-term changes in 

 community structure, composition, and biomass when the site is 

 converted from climax conditions to early successional stages. 

 Consumer species highly dependent on tree strata (for example, 

 fox squirrel, Rio Grande turkey, red-tailed hawk, great horned 

 owl, and numerous canopy-dependent songbirds such as the vireo, 

 chickadee, and titmouse ( Parus spp. ) experience immediate 

 long-term alterations. In addition to direct removal by con- 

 struction clearing, indirect alterations to the soil water- 

 oxygen regime can lead to replacement of woodland components by 

 more tolerant grasses and forbs. 



3.2 Grasslands 



Recovery of grasslands is generally completed within two yr 

 in easement corridors. Areal coverage of this type is 

 increased at the expense of other cover types, then artifi- 

 cially maintained by easement maintenance. Climax grassland 

 conditions can be reestablished easily with existing management 

 techniques. 



3.3 Brush-grass complex 



Recovery by the grassy components is relatively rapid, with 

 woody species requiring greater time for reestablishment. 

 Woody shrubs may be excluded permanently if fire occurs fre- 

 quently or if regular brush-control is practiced by the pipe- 

 line company. 



Disturbances associated with line installation typically cause 

 short-term displacement of sensitive wildlife species from 

 otherwise favorable nearby habitats. Following activity comple- 

 tion, these species reenter nearby sites if these remain essen- 

 tially unaltered. Short-term displacement may reoccur during 

 infrequent maintenance or repair sessions. 



4. Key attribute alterations 



Alterations associated with '.'-'e installation are a funci lOn of line 

 size, site location, and place,..-nt methodology. Tempora j' surface 

 lines, permanent overhead lines wi+^M road easements, and buried 

 utility lines and flowlines typicaiiy generate short-term impacts of 

 limited areal extent that are quickly reclaimed by the system and 

 generate little, if any, noticeable subsequent effects on consumer 



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