Cottonwood Ecology in Owen Sowerwine Natural Area 

presented by

Conrad Hedinger, Molly Adams, Sarah Randolph and Brandon Pyron

Cottonwood in Owen Sowerwine Natural Area Photo Credit: John WinnieJoin Flathead Audubon Society on Monday, November 13, 7:00 PM at the Gateway Community Center, US Hwy 2 West, Kalispell, for a look at the ongoing study of cottonwoods in Owen Sowerwine Natural Area (OSNA), a 442 acre river bottom managed by Flathead Audubon for educational purposes. OSNA appears to have high percentage of very old black cottonwood trees and very little recruitment of new cottonwoods in the “micro-upland” areas. Flathead High School students volunteered, through their Community Action Service Program, to get some hard data supporting the casual observations.

The Flathead Conservation District generously granted Flathead Audubon just over $2000 for the purchase of the tools needed for their study. For the last few months, FHS International Baccalaureate students Conrad Hedinger, Molly Adams, Sarah Randolph and Brandon Pyron have been coring and aging trees in a grid pattern throughout the mainland portion of OSNA, and aging all the cottonwood trees. Their next step will be to correlate the ages of the old trees to past major flood events, which have been shown to stimulate new growth.

Through this study, we hope to get a true picture of the present state of black cottonwood age diversity as a baseline for future studies on the effects of (1) micro-elevation changes of just a few feet, (2) the effects of browsing by white-tailed deer, (3) the effects of upstream changes on the historical frequency of flood events, (4) the plant succession patterns going on under the old cottonwoods, and (5) the effects of invasive plant species on succession patterns.

Since bird species diversity in riparian zones has been shown to correlate with cottonwood age classes diversity, it will be important for FAS to examine possible management options to increase both cottonwood age diversity and bird diversity.

Please join us on Monday, November 13.