Olympic Habitat Development Study
US FOREST SERVICE

 

Station 1 - CONTROL

We start in the control stand to give you an idea of what the area looked like before the study began -- and what the area looks like now without management. Cover of both shrubs herbaceous plants (non-woody plants such as annuals or grasses) was <5%.

The Fresca stand was generally quite dense in overstory tree cover (see the Tree Tour for details) and thus had very little cover of understory species when we first started our surveys. The most common species were: deer fern (Blechnum spicant), wood sorrel (Oxalis oregana) and false lily-of-the-valley (more information on this species is available on the Natural History Tour) (Maianthemum dilatatum). Some shrub species were present (vine maple, salmonberry, red and blue huckleberry, salal) but were not very common. Bracken fern and cascara buckthorn (a small tree) were present in some existing openings.

We expected very little change in understory cover in the control area as no management activities were planned and stand development would probably not change much in that time period. However, we did see bigger changes than we anticipated, particularly in herbaceous plants at year 7 (graph).Chart of cover of herbs and shrubs over 10 years in the control. We think the increase in herbaceous cover was due to the stand being opened up thru breakage of branches in some severe ice storms. The species that responded the most -- false lily-of-the-valley and wood sorrel -- were perennial species present prior to this natural disturbance and were able to rapidly respond to changing conditions. Due to the sharp decline in cover from year 7 to year 10 and the subsequent slow increase, we suspect that the cover of these species will probably continue to change only slowly unless future disturbances occur. There was very little change in shrub cover in the control during the first 17 years of the study.


 

Understory view at the Control area
Vine maple (Acer circinatum) at Fresca.  Its wood is hard and flexible and its traditional uses include snowshoes, drum frames and utensils. Understory view at the Control area. Salal (Gaultheria shallon) is one of the most common shrubs in the Pacific Northwest.
Understory view at the Control area