Generally, prime movers such as wheeled skidders, forwarders, crawler tractors, or excavators are used. Special requirements of the site preparation implement include factors such as drawbar pull requirements, hydraulic requirements, weight and balance considerations, travel speed limitations, and special attachments to raise and lower implements for turning or travel between treatment areas. For further information on prime movers, see the Site Preparation chapter in the Silviculture Manual . Excavators undertake spot treatment of areas, generally concentrating on the portions of the block that pose the greatest difficulty to reforestation. Excavators are able to work in wet areas, creating mounds for planting in naturally wet areas, or where the water table has risen as a result of logging activities.
Excavators are also capable of working on relatively steep slopes.
Excavators are particularly effective where skidtrails or natural plateaus improve access. Excavators are also effective in rehabilitating tail-hold backspar trails, skid roads, skid trails, road deactivation, cleaning ditches and culverts, and returning drainage to its natural course across the setting. A wide variety of head attachments are available. Specially designed steep slope machinery Equipment such as the Kaiser Spider, has been developed for working on steep sidehills. While this equipment shows potential, it is very costly.