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

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?

Photos: Tom Collett

Oregon Ash is a deciduous tree with leaflets in groups of 5-7

What is a deciduous tree? One that loses its leaves in winter.Most broad leaf trees are deciduous.

Oregon Ash seeds

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.

MaplesBig-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.

Big-leaf maple seeds

How do these “wings” help the maple tree?

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 PlantsSome 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.

Scotch Broom

Himalayan blackberry

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

Invasive plants are a problem.

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.

Photo by Brandon Goldman

Ashland Creek in Lithia Park

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.