Olympic Habitat Development Study
US FOREST SERVICE

 

Station 3 -SKIPS


The skips are the densest parts of the VDT (variable-density thinning) areas. Tree growth in the interior of the skips (graph)Diameter growth of trees in skip interior compared to growth near the boundary with the thinned matrix. was the lowest (2.3 cm)0.9 inch in the VDT plot. There is an "edge" effect from having the skip located within the thinned matrix, and trees growing in the skip within 10 m33 feet of the thinned matrix grew the same as trees growing in the thinned areas. Since harvesting equipment was not allowed to enter the skips, some of the skid trails parallel the edge of the skips and provided a little more light than the thinning alone would have done (as additional trees were felled to make the trail). Skip areas were also "no entry" areas for equipment and logging personnel. This allowed us to leave tall snags and not worry about logger safety.


 

Skips allowed large snags to be retained.
Suppression mortality in an unthinned area at Clavicle (note the dead trees are mostly small). Skips allowed large snags to be retained. More light is available near the skid trails.
Skips allowed large snags to be retained.