Transcript Riparian Plants of the Bear Creek Watershed

Riparian Plants
of the Bear Creek Watershed
December 2009
The Bear Creek Watershed Virtual Tours
were created with funds provided by the
Bear Creek Watershed Education Partners
through a grant from the
Oregon Watershed Enhancement Board
with additional funding from Oregon Trout’s Healthy Waters Institute.
THANKS TO:
•Terri Eubanks
•Brandon Goldman
•Tom Collette
Riparian Habitats
Riparian areas are the strip of
vegetation growing alongside
freshwater. This habitat is different
from habitats farther from the
stream (called uplands) and are
closely affected by the stream’s
presence. The soils in riparian
areas contain more moisture for
longer periods of time and changes
in the stream can affect the riparian
habitat.
Like other habitats, riparian
areas are made up of different plant
species such as trees, brush or
shrub species, and non-woody
plants like grasses and herbs.
Photo by Brandon Goldman
Trees
Common trees in the riparian area include:
• Black Cottonwood
• Willow species
• Oregon Ash
• Alder
• Big-leaf maple
• Vine Maple
Bear Cr. at Lazy Cr. confluence
Black Cottonwood is a very common and visible tall tree
in the riparian areas at the lower elevations
of the Bear Creek watershed.
Photos: Tom Collett
Photos: Tom Collett
There are many different species of willows
that grow in our watershed and all over the world.
In the Bear Creek watershed, willows can look like a shrub or a small tree.
How do these two species of willow look different?
Oregon Ash is a deciduous tree
with leaflets in groups of 5-7
Oregon Ash seeds
What is a deciduous tree? One that loses its leaves in winter.
Most broad leaf trees are deciduous.
Alder have long drooping catkin flowers in
spring and serrated leaf edges. The tree
produces what look like tiny “pine cones”
which contain the seeds.
Maples
Big-leaf maple and Vine maple are the two common native maple
species in Bear Creek riparian areas.
And guess what, Big-leaf maple has big leaves.
Maple seeds are familiar as the “helicopter seeds” that
spin as they fall and blow from maple trees.
How do these “wings” help the maple tree?
Big-leaf maple seeds
Riparian tree species are able to withstand
the changing stream conditions.
From raging floodwaters to dry summers,
riparian trees survive the dynamic system.
Photo by
Brandon
Goldman
Riparian plants are important
1. They protect stream banks by holding soil.
2. They shade stream waters, keeping streams cool and good
habitat for native fish and animals.
3. They filter pollutants running into the stream.
4. Healthy riparian areas improve stream flow by regulating
groundwater discharge.
5. Healthy riparian areas slow flood flows.
6. Healthy riparian areas are good habitat.
What would our streams look like without riparian areas?
How would they function?
Invasive Plants
Some plants are not native to the Bear
Creek area, meaning those plants did
not live here before western settlers
arrived and most were
introduced recently.
Himalayan blackberry
Scotch Broom
Invasive plants are a problem.
Plants that are not native can take
over habitats. Have you ever seen
large areas with only
blackberries growing?
Invasive plants crowd out native
plants and animals so the natives
do not have a place to live.
What did the riparian areas
of Bear Creek look like before
blackberries took over?
Purple Loosestrife
Puncture Vine is a low growing non-native ground cover that
produces very sharp spiny seeds in a unique shape which gives the
plant its other name of “Goathead”. This plant is commonly seen
along the Bear Creek Greenway path and other disturbed areas.
Bike riders
hate
Goathead.
Why?
Try to keep weeds from moving to new places
by not letting their seeds be hitchhikers on your
pets, clothing, or vehicles.
Riparian habitats in the Bear Creek
watershed are a valuable resource
to enjoy and protect.
Ashland
Creek in
Lithia
Park
Photo by
Brandon
Goldman
What plants do you know in the Bear Creek watershed?
Note to user:
• Objective of presentation: brief introduction to native and invasive plants
found in Bear Creek watershed riparian areas.
• Most appropriate for: Ages 6 and up
• How to integrate this presentation into other activities:
– Take a walk to a nearby wet area, stream, or irrigation canal and see if
any of these plants are observed. Record data on presence/absence,
ratio of native to non-native species. Compare different riparian areas.
– Bring in plant samples, identify, draw , categorize, or describe plant
characteristics and habitats. Discuss plant adaptations.