3.3 Brush-grass complex 



Recovery in the brush-grass complex is slower than in grass- 

 lands, and most likely the site will initially reestablish with 

 grasses. The proportion of brush depends upon land management 

 practices, fire regime, and vigor of surrounding grasslands. 

 Consumer groups are probably not noticeably affected unless a 

 large area is altered. 



Disturbance factors should be recognized as an important consid- 

 eration because they extend the project impacts beyond the 

 boundaries of the immediate site. 



4. Key attribute alterations 



The primary alteration is the complete or partial removal of vegeta- 

 tive components resulting from the cleanup procedure. Removal 

 produces community disruptions which require reestablishment of new 

 equilibrium conditions through competitive biotic processes. Domi- 

 nating influences on soil moisture and solar energy are reordered 

 such that resource availability is increased, at least temporarily, 

 allowing suppressed flora or earlier serai stages to appear. 

 Consumer response varies by species, size of the area affected, and 

 the extent of the floristic change. Clean up methodology determines 

 site alterations that occur and whether subsequent biotic changes 

 are temporary or long term. 



The existing data are insufficient to evaluate whether greater 

 detrimental effects result from the introduction of petrochemicals 

 into upland systems or from the cleanup efforts (cutting, burning, 

 soil extraction) directed at their removal. 



Site shutdown and restoration. 



1. Activity sequence 



Completion of pipeline installation and trench backfilling, removal 

 of production facilities, or road abandonment usually signals initia- 

 tion of the shutdown and site restoration phase. Structures, equip- 

 ment, concrete foundations, pipes, well casings, drilling mud, and 

 other artifacts of oil production are removed if they possess salvage 

 or reuse value. Otherwise, only as much attention is paid to resto- 

 ration procedures as is required by Federal and state regulations, 

 lease stipulations, and general company policy. Typically, restora- 

 tion includes removing or burying toxic substances, refilling all 

 pits, knocking down earthen levees, and generally leveling the site. 



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