by Denny Olson
Invasive plant species have been described as a slow-motion nuclear bomb going off. While this sounds like hyperbole, we have to remember that the this “bomb” can affect entire bioregions, and invasives can reduce tree cover, cause increased erosion and reduce water quality, increase fire risk, have noxious effects on humans and other animals, and even chemically inhibit the growth of native plants. But the greatest effects of invasives are broad and systemic.
Biodiversity is the gold standard, the byword, of healthy systems. A broad array of native plants, with a long established set of relationships with other plants, leads to a broad array of native insects and their larvae – all very specific to an individual plant species or two. Because of the timing of native insect reproduction, tuned to the timing of plant flowering and growth, birds have evolved migration and nesting timings over the past 150 million years, tuned to the native plants and insects. (When the timing chain on a car slips just one cog, the entire car quits running.) Birds, bugs, and other wildlife have no such relationships with exotic species from “across the ponds”. The depressing recent news about losing one quarter (300 billion) of our North American birds in the last 50 years, plus the new ‘birds and climate change’ projections for Montana by National Audubon, puts habitat restoration at an absolute premium.
That’s why, in order to keep our (Owen Sowerwine) “natural area” natural, we have been monitoring and attempting to control the spread of herbaceous invasives in the understory (houndstongue, Canada thistle, Oxeye daisy) small shrubs (Daphne mezereum, barberry) and large shrubs that grow into trees and form a low canopy (highbush cranberry). Our intrepid volunteer botanist, Pat Jaquith, also found a small area with poison ivy, which we have hopefully eradicated.
Two years ago, we cut down a lot of large cranberry shrubs forming a low canopy over the seasonally flooded old river channels. The really good news is that native red-osier dogwood and cottonwood seedlings have jumped at the chance to replace the invasive shrubs in the main trail area. Maybe coincidentally, I have also noticed many more Red-eyed vireos and White-breasted nuthatches this summer.
But, on August 25th, the scope of our invasives issues changed dramatically. If you have been either off-trail, or just walking in the shaded area near Greenridge entrance, you have noticed a lot of shrubs grown up into trees, forming a dense canopy. Either through poor observation or wishful thinking on my part (or both), I tentatively identified the shrub-trees as false buckthorn, native to the wet Northwest. Pat J. encouraged me to take a second look (at 40-power with hand lens), and it turns out that this canopy, covering much of the OSNA Mainland Area, is composed mostly of either native chokecherry “trees”, or common buckthorn, an exotic scourge in the eastern half of the U.S., very difficult to eradicate. In some places, it has completely taken over, and it has been there, based on the size of the trunks, for many, many years. So, our Natural Area is less natural than we thought …
After some obligatory depression of a few hours, I starting scheming about how this news can fit into our future student education plans. As OSNA Important Bird Area caretakers, we really don’t have much choice but to deal with the invasive problem. Leaving it alone, especially in a habitat as rare and sensitive as river bottom, is the worst of all choices.
First things first, we have to complete our lease/license arrangements with DNRC as OSNA managers. From there, we intend to get our Education and OSNA Committee members together, along with interested and affected landowners adjacent to OSNA, and restoration experts from FWP and other state agencies, and come up with a long range plan. This plan will likely combine our student botany and bird diversity research with extensive removal and restoration efforts. Hopefully, we will be turning buckthorn lemons into restoration lemonade – and increasing the naturalness and bird diversity in the process. And, true to our mission, kids will be monitoring and studying that process.
We will need help! We are a volunteer organization, and the numbers of helpers we have now will be dwarfed by the scope of this problem. Remember, your own efforts will not be for Flathead Audubon. It will be for the birds, the kids, and the land. Contact us!