The Cottonwood-Shrub complex is dominated by black cottonwood and often has a well-developed understorey composed of red-osier dogwood, black twinberry, red elderberry, black gooseberry, thimbleberry, Sitka alder, and mountain alder. This community is less widespread than other broadleaf communities in southern interior British Columbia, but is common in the IDF and ICH zones. It occurs to a lesser extent in the MS and PP zones. It characteristically occurs on floodplains, but is also found on moist upland sites. It is relatively rare in the Cariboo-Chilcotin area of the Southern Interior Forest Region, but may be found on floodplains in the ICH, IDF, and SBS zones, as well as very occassionally in the MS zone. The Cottonwood-Shrub complex is most common on rich sites because of the

high nutritional requirements of black cottonwood.

 

This community develops after logging from both seed and vigorous vegetative sprouting from the stumps of trees cut during logging. Logging disturbance or mechanical site preparation that exposes mineral soil promotes seeding in. Juvenile black cottonwood grows extremely quickly, and may reduce light availability to conifer seedlings soon after they are planted. The Cottonwood-Shrub complex occurs mainly on sites where moisture and nutrients are plentiful, so that competition for these resources is likely to be of minor importance.

An example of the Cottonwood-Shrub complex.