Battle to eliminate invasive plants starts with seedlings
By Timm Nawrocki
Special to the Turnagain Times
As the season grows colder and snow begins to dust the mountaintops, many plants are losing their leaves, wilting, or dying. Alaskans often associate autumn with leaves changing colors on trees and smaller plants dying, rather than with growth or rejuvenation.
Yet at this time of year many plants are releasing their seeds into the surrounding soils, which will contribute to next spring's bounty of new growth.
Unfortunately, invasive plant species are also releasing plenty of seeds at this time of the year. The release of invasive plant seeds compounds the already existing problems associated with invasive plants. Even the seeding of beautiful plants, such as Orange Hawkweed, can have serious negative impacts on the ecosystem.
Those of you who have seen the bright flowers of Orange Hawkweed growing along the side and in the medians of the Seward Highway just Northeast of Turnagain Pass can attest to the thick, uniform mats that this plant has the potential to produce. These mats impede the growth of native grasses, which reduces the amount of food available to many grazing animals. The released seeds increase the density of the invasive species in the infested area.
Invasive plant seeds also pose problems because many can survive in soil for long periods of time, even if all the parent plants are dug up. The seeds of the invasive Reed Canarygrass can survive in soil for five years, impeding efforts to eradicate patches. Because Reed Canarygrass grows in water along streams and in wetlands, the plant has the potential to adversely affect the habitat of salmon and other important wildlife. The worst potential of invasive plant seeds, however, is to create new infestations, sometimes far off from the parent plant.
Many environmental and biological factors contribute to the movement of plant seeds, native and invasive alike, and sometimes it is easy to forget that we are biological vectors ourselves. Humans can unwittingly move invasive plant seeds from the roadsides and trailheads where these plants are established into areas that are currently occupied only by native species.
The Forest Service has seen some success in efforts to curb the growth of certain invasive plants. A generous grant from the US Fish and Wildlife Service's Coastal Conservation Program has gone far to help control invasive plant species in Girdwood. Despite these efforts, however, the eradication of invasive species can be costly and time consuming, and the movement of seeds by people further complicates efforts to control their growth. Prevention of new infestations is the easiest, cheapest, and most effective method for controlling invasive plants.
As the trees change colors and you, your families, and your friends head out to enjoy the autumn, there are a few simple things you can do to help prevent the transportation of invasive seeds. Try not to walk through patches of invasive plants before heading up trails. If you do walk through patches of invasive plants, brush the seeds off of you and any pets that may be with you.
Don't pick invasive flowers or seeds and carry them along with you. Drive on established roads to avoid rolling through patches of invasive plants. Avoid camping or resting in invasive plant patches.
Take the time to learn some of the commonly found invasive plants that grow along roads and in disturbed areas in Southcentral Alaska. Your efforts will help preserve the natural beauty, diversity, and productivity of the Chugach Mountains.
You can learn more about invasive species online at:
http://www.fs.fed.us/wildflowers/invasives/index.shtml
http://www.fs.fed.us/invasivespecies/
Timm Nawrocki is a biological technician for the US Forest Service.
