NATIVE PLANT REVEGETATION & RESTORATION PROGRAM

The cumulative effects of urbanization have threatened water availability and water quality while many streams and fisheries enhancement programs are in jeopardy of cumulative pollution. There is tremendous pressure from developers and local government to urbanize more of the formerly rural areas with major housing and commercial developments planned to accommodate the growing influx of residents to this area.

The Nearshore Habitat Evaluation & Enhancement project sought to mitigate the adverse effects of development along critical areas and protect these waters by planting abundant vegetation with native plants in 7500 linear feet of shoreline along the east side and upper reaches of Liberty Bay.

Professional landscape designers, master gardeners, botanists, and other project volunteers worked with property owners, businesses, and local government to plan and design on a site-by-site basis. Planned vegetation, stormwater controls, and types of plants to be installed were considerations. Shoreline property owners have concerns not usually faced by other landowners, such as erosion, water quality, algae blooms, protecting fish and marine habitat. Revegetation of disturbed sites serves several important functions here.

Stabilizes shorelines: the roots of many native plants reinforce shorelines and minimize erosion from uncontrolled stormwater runoff, wind, wave action, boating wakes, currents and other forces of man and nature.

Provide habitat: Cover, food, nesting sites, and resting areas for fish, amphibians, invertebrates, birds, and mammals. Diverse native plants will attract more diverse native wildlife.

Providing shade: Protects smelt egg production, restricts algal growth to open areas where light is available, reduces water temperature, and allows more oxygen to dissolve in the water.

Reduces nutrients: Slows water movement along shorelines, causing nutrient-laden sediment to settle to the bottom, where it is less available to algae, and low dissolved oxygen occurrences.

There are many resources available for information and help in using native plants. The local conservation districts hold annual plant sales and plant salvage opportunities. For information on the Kitsap County Conservation District sale call (360) 337-7171. Although some native plants can be purchased from nurseries, often the only way to obtain them is from plant materials centers that furnish plants for large-scale restoration projects. The county conservation districts and master gardeners association can offer help and a list of suppliers for your project. Remember that many climatic and site factors influence plant characteristics. Shoreline trees and shrubs have much slower rates of growth than upland sites and heights vary considerably.

For more information, see links on the next page . Knowledge about native plants is still evolving, and we recommend taking careful notes to document your successes and failures. Record the planting dates and locations; times of leaf production, flowering, fruiting, seed production, and leaf-fall.

The plants we used were not necessarily the most valuable species possible for erosion control, wildlife, or aesthetics. They were readily available, easy to propagate, and common in this area. Phyllis Meyers, former Fisheries Biologist with the Suquamish Tribe, performed considerable research on native plant establishment and provided the project team with a refined list from her successful trials.

The key to maintaining a stable bluff, using vegetation to control erosion, and preventing polluted runoff, is to recognize the natural forces at work. Another important consideration is the frequency of care and watering it will receive in establishing. The largest, most continuous stretch of vegetated area in this project was along a narrow strip along a busy roadway with full sun and southern exposure. This was a particularly harsh environment - though extremely beneficial once plants were established successfully.

There is a lack of research on vegetation management for these sites and existing sources only provide generic native plant lists that may not survive in this environment.

The initial sites were selected based on the need for riparian replanting determined during shoreline surveys, as well as the willingness for cooperation by property owners. Shoreline riparian revegetation projects require a long-term commitment for watering and weed-control measures that go far beyond the initial replanting effort.

Plant Selection
The species of native plants used for the Liberty bay riparian revegetation effort are shown in Table 1 following. The relative rate of survival for each species was ranked high, moderate, low, or poor. The HIGH group survived better than 70%, the MODERATE less than 50%, the LOW at less than 25%, and the POOR did not survive at all in most cases.

 

 

Table 1

TREES, SHRUBS, GROUNDCOVERS and RELATIVE SUCCESS BY SPECIES
Trees:	HIGH	MODERATE	LOW	POOR
Douglas fir (P seudotsuga menziesii)	X
Shore pine (P inus contorta)	X
Western red cedar (T huja plicata)	X
Pacific Willow (Salix lasiandra)			X
Wild Crab Apple (Pyrus diversifolia)		X
Shrubs:
Nootka Rose (R ose nutkana)	X
Oregon Grape tall (M ahonia aquifolium)		X
Red flowering currant (Ribes sanguineum)	X
Red osier dogwood (C ornus stolonifera)	X
Vine maple (A cer circinatum)	X
Mock orange (P hiladelphus lewisii)	X
Black Twinberry (L onicera involucrata)	X
Common Snowberry (S ymphoricarpus albus)	X
Indian plum (O emleria cerasiformis)		X
Pacific ninebark (P hysocarpus capitatus)		X
Douglas spirea (Spiraea douglasii)		X
Cascara (Rhamnus purshiana)		X
Evergreen huckleberry (Vaccinium ovatum)			X
Douglas Spirea (Spirea douglasii)		X
Serviceberry (Amalanchier alnifolia)				X
Oceanspray (Holodiscus discolor)			X
Wax Myrtle (Myrica californica)				X
Salmonberry (Rubus spectabilis)				X
Sword Ferns (Polystichum minitum)				X
Ground covers:
Oregon Grape ( M ahonia nervosa )		X
Pink mountain heather (phyllodoce empetriforams)			X
Kinnikinnick (arctostaphylos uva-ursi)			X
Coastal strawberry (fragaria chiloensis)				X
Early blue violet (viola adunca)				X
Salal ( gaultheria shallon)			X

It must be noted that this was a 4 year effort and the plantings weathered 3 record drought seasons. Most affected were the groundcovers that withered in the harsh sun along the southern exposed bank of Lemolo Shore drive. Many of the conservation districts and restoration projects undertaken in this same period reported similar experiences (personal communication, Washington Conservation District Plant Materials Center). In retrospect, these plantings would likely have had a higher survival rate had the groundcovers been installed in the 3rd or 4th year. Planting should mimic nature - the pioneers come in first (conifers, larger shrubs, etc.) until they can provide shade for the understory (groundcovers).

For good color and great wildlife habitat Red osier dogwood, Red flowering currant, Indian plum, Twinberry, Snowberry and Oregon grape are great performers. These plants provide resting habitat for birds, food (the berries) for the birds, beautiful year round color and interest on the shoreline.

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