In most ecosystems, there are three types of plants: native, introduced, and invasive. We have all three in Bridle Trails State Park, and you probably already know some of them!
Think about the list above and consider (or research) other native and invasive plants in our area. Are they good? Bad? Do we like them? Need them? What point of view are you thinking from?
How are invasive plants so good at invading?
Invasive plants can be damaging in many ways to native plants: by occupying space, changing the structure of the plant community, causing physical and chemical alterations of the soil or native plants, impacting animal and insect life, and covering and shading native plants. Most people try to dispose of invasive plants through volunteer work parties, so that they can try to restore the ecosystem. Letting invasive plants and animals continue to occupy our forests and other ecosystems can drastically impact the native plants upon which the native animals and insects depend on.
Essentially, invasive plants:
Are tough: hard to kill, hard to remove, can grow anywhere including polluted and disturbed areas such as parking lots and at the side of the road
Multiply quickly: they are fast and have unique or varied methods of reproducing such as cloning or making lots of seeds, often have more than one method of reproduction
Have no predators: they can spread without checks or balances because the native wildlife prefer native plants
“Blackberry is a great example of an invasive plant. It was introduced because its fruit is delicious. However, once planted it can take over and is hard to remove. Blackberry has thick, hardy roots that are hard to dig out and the thorny canes are really hard to chop down. Blackberry can spread by wildlife eating its fruit, via roots underground, or by overland vines/canes. Blackberry can also clone itself (grow new roots when branch has contact with soil). While some animals will eat the berries, blackberry only provides fruit for a couple months and if it has taken over an area, there will be limited food sources available to wildlife during the rest of the year. If a streamside forest gets replaced by blackberry, it will no longer have shade to keep it cool and the deep roots of the forest trees will be replaced by shallower roots that don’t filter as well.”
- Estuary Partnership
Another example you will see in our park is English ivy. Originally brought here as a decorative vine (and still sold in many hardware stores), ivy can grow up trees, digging under their bark until they suffocate and fall. Like blackberry, ivy can regrow from a small cutting left behind on the soil.
Native Plants in Bridle Trails:
On the bright side, we can do our part to restore the local ecosystem by removing invasive plants (safely) and planting natives in our own yards! Here are some native plants found in our state park.
Indian Plum
Indian plum is a native shrub that is abundant and obvious near the Bridle Trails parking lot, with dangling white blooms in early spring. The light green, lance-shaped leaves smell like watermelon rind or cucumber when crushed. While this plant does produce small fruits that look like plums and is edible to humans and animals, they are quite bitter.
Because it blooms and produces leaves early, it can begin warm weather growth before the overstory trees and is an early season food source for pollinators. The roots hold the soil together well and grow quickly, so it is used in many restoration projects in the area.
Salal
Salal is a predominant native evergreen shrub that can be found in most coastal forests as understory year-round. It has dark, leathery, shiny, deeply veined leaves and produces dark purple berries in the summer. These berries were an important food source for Coast Salish Native Americans and while they are more astringent than other berries, they are great for jams and jellies..
This plant is a great opportunity for learning more about native and invasive plants because while it is native here in the Pacific Northwest, it is considered invasive in Europe.
Yarrow
Yarrow is a medicinal plant that grows low to the ground with feathery fern-like leaves and small tightly-packed clusters of flowers in summer. Native Americans used it for many things, including anti-inflammation/pain relieving tea and insect bite ointment. Yarrow is interesting because while it is native, it grows rapidly and is considered native, introduced, and invasive depending on where you are in the U.S.
More information:
For more information about native plants in the PNW and a guide to deciding if you should “plant it or pull it,” check out this resource from the Lower Columbia Estuary Partnership.
For an education packet full of information and activities about invasive plants created by Nature Vision and Cascade Water Alliance, check out this page.
For a fun children’s activity book with coloring pages on native and invasive plants and animals in Washington, print this packet from the Washington State Department of Agriculture.
For wildflower and noxious weed coloring pages and books, visit this page on the U.S. Forest Service webpage.
Visit this page for a PNW forest coloring page.
For some information about native plants and animals, visit the Burke Museum Native Identification webpage.
For more information about invasive plants in King County, visit their noxious weeds page.
To be a part of science and report invasives you find, go here or check out this app!
Bridle Trails State Park plant overview and species list here.
Photo credits: King County, H. Rutherford, Wikimedia.