Olympic Habitat Development Study


Station 1 - CONTROL

We start in the control stand. To the casual eye, the Fresca control stand has not changed in the 15 years since the study started. It is still a dense stand with very few trees in the understory or midstory. But of course, there are always changes going on in forest stands. Some trees grow, others die and new ones become established.

•  Basal area (basal area = the cross-sectional area of all trees measured at 1.3m (4.5 feet) above ground) increased from 41 m2/ha to 54 m2/ha179 ft2/ac to 235 ft2/ac if all trees (live and dead) were counted. However, several trees died in that time period so the basal area in live trees only was 44 m2/ha.192 ft2/ac

•  This type of stand (fairly uniform conditions) can be modeled with available regional growth models such as FVS, ORGANON or TASS (more discussion of modeling at Station 5).

•  Although this is primarily a conifer stand with mostly western hemlock and Sitka spruce trees in the main canopy, there are some established hardwood trees - primarily red alder and cascara buckthorn and also a few big-leaf maple and willow. But we found no hardwood seedlings (plants <1.3 m<4.3 feet tall) or small saplings <5 cm<2 inches in diameter) in the control stand in our most recent survey.

•  Western hemlock (Learn more about western hemlock on the Natural History Tour) is a prolific seed producer and many seeds are produced and will germinate even in a dense stand. There were 19,000 small seedlings and 2000 small saplings per ha7,700 small seedlings and 800 small saplings per acre in the control stand. Although these may seem like large numbers, this is much less than in the thinned area and almost all of these seedlings and saplings will die in the future.

•  There were 500 seedlings and 1 sapling per ha200 seedlings per acre and 1 sapling every 2 or 3 acres of Sitka spruce in the control stand.

•  On average, about 5 trees per ha12 trees per acre blew down during the first few years (Detailed information on windthrow at 4 sites in the study has been published (See Info/Publications for a link).after thinning. In 1994, this stand had a relatively high ratio of overstory tree height to diameter (70 as measured in meters of height to meters of stem diameter). Thus, more trees may blow down in future years.


There are many trees in the unthinned control plot at Fresca.
Mushroom grows on a decaying log. There are many trees in the unthinned control plot at Fresca. Many snags are present in the control plot at Fresca.
There are many trees in the unthinned control plot at Fresca.