dissemination mechanism?

Kathleen Sayce ksayce@willapabay.org
Sat, 21 Sep 2013 09:37:56 PDT
I agree with Jane about shade tolerance. On Saddle Mtn in northwest Oregon, a storm in 2009 opened up a formerly densely shaded stand of Douglas-fir, and now the understory is coming into dense foliage cover and abundant flowers. Included in this formerly light-starved, tolerating the shade group are Lilium columbianum, Prosartes hookerii, P. smithii, Maianthemum racemosum and M. stellatum, and Trillium ovatum. Even the sedges are flowering more heavily, including Carex mertensiana and C. hendersonii. 

From observations made in other forests in the Pacific Northwest, Pacifica Iris persist in sometimes very dense shade for decades, waiting for light after wind throw or forest fires, to come into full growth and bloom. These include Iris tenax, innominata, douglasiana, thompsonii, and other species. On Saddle Mtn, Iris tenax grows at higher elevations in more open areas.  Lack of forest disturbance has shaded it out below 2400 ft, where this stand occurs, though if it appears in the next few years in this stand, it will be yet another site where irises persisted as seeds and vegetative clumps in dense shade. 

Pacific Northwest Coast, zone 8, mild wet winters, cool dryish summers

More information about the pbs mailing list