Specifications include, but are not limited to: Selection of leave trees or crop trees will be made by the Contractor according to the following specifications as well as those found in the Unit Description table (Section II-A). Two contrasting thinning procedures are recognized. The particular method to be used is designated for each unit on the Unit Description Table. These are Simple Spacing Thinning and Diameter Limit Thinning. A. Simple Spacing Thinning When thinning on a spacing basis, Contractor will select and leave uncut the largest live conifer trees of good form and vigor that will maintain the average spacing designated in the Unit Description Table. To maintain average spacing, Contractor may not need to cut as many trees immediately adjacent to gaps. B. Diameter Limit Thinning When thinning on a diameter limit basis, Contractor shall cut trees smaller than the diameter limit, specified in the Unit Description, and will leave uncut the largest live conifer trees of good form and vigor that will maintain the spacing designated in the Unit Description.