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Mosses hang thick on the Big Leaf Maple trees forming a tunnel over the Yaquina River. As the morning sun breaks across the stream, steam rises in slender columns from the moss, soaking every square inch of tree in moisture. Up the bank, Highway 20 runs to Newport through a similar tunnel of maple and fir. The road cuts a thin line through the dark green forest that covers this landscape. From sword ferns and salal to pitcher plants and giant spruce trees, Oregon's north coast is thick with a diversity of plant life that rivals tropical ecosystems for diversity and biomass.

Salt Marshes

Salt marshes are transitional areas between land and water, occurring along the intertidal shore of estuaries and sounds where salinity (salt content) ranges from near ocean strength to near fresh in upriver marshes.

Salt marsh plants, such as pickleweed (Salicornia spp.) and saltgrass (Distichlis spicata), are uniquely adapted to the fluctuating coastal salt marsh environment, where their roots take a twice-daily bath in ocean water at high tides. As these plants die and break down, their stored nutrients enter the food web and provide a continual source of food for clams, crabs, and fish. Most animal life in the salt marsh is not easily seen, but a closer look might reveal tracks left by a raccoon or black-tailed deer visiting for a low tide snack.

Salt marsh plants are important because their matted roots stabilize the shoreline and are a buffer for pollution from runoff. As rain and debris from strong winter storms courses downstream, the salt marsh acts as a sponge, where bacteria trap and break down excess nutrients, heavy metals and other chemicals from polluted runoff water. This helps protect the water quality of the bay.

Coastal Strand

These plant communities are occurring both on beaches above high tide and on sand dunes behind the foredune.

Since the establishment and subsequent naturalization of European beachgrass, this habitat has decreased as the width and height of the foredune has increased. The physical conditions of these habitats are adverse and have high substrate instability, nutrient-poor soils, a high exposure to salt spray and "sandblasting" (caused by daily northwesterly winds) which leads to a shifting, sandy substrate.

Vegetation on beaches is generally low in species richness and plant cover. On most beaches typically only 2-3 species (such as Cakile ssp., beach bursage, and yellow sand-verbena) are present on the ocean side of the foredune. These species are typically herbaceous perennials (the exception is Cakile) which are evergreen, succulent, and prostrate. Many of these species are early colonizers which begin sand stabilization. Seed production is typically low as the majority of these species disperse by rhizomes or stolons. Seed dispersal is primarily by wind and possibly by tides. Yellow sand-verbena fruits have small wings which aid in dispersal along the beach. In some cases (although undocumented) long-distance dispersal may be caused by seeds being swept into the tide and being deposited on another beach.

Historically, (pre-European beachgrass) beaches had a low foredune, which rose gradually from the beach. The foredune consisted of rounded mounds caused by the native sand stabilizing plant species. The dominant species included American dune grass (Leymus mollis ssp. mollis), yellow sand-verbena and beach bursage. This pattern resulted in a series of dunes alternating with swales which were oriented perpendicular to the coast (that is, aligned with the prevailing onshore winds). Very few of these low, mounded foredunes remain along this section of coast, with the exception at river mouths. With the establishment of European beachgrass, these rounded dunes have been replaced by a steep foredune and inland dunes oriented parallel to the coast. European beachgrass may reduce native species richness by up to one half. This decline has resulted in many of these plant communities being threatened (although most of the plant species are relatively common).

European beachgrass deserves special attention due to its impact on vegetation along the Pacific Coast. It was first introduced to North America in 1869 at San Francisco. Extensive plantings occurred on the Oregon coast from the 1930s to 1950s. It now occurs from the Queen Charlotte Islands south to southern California. European beachgrass grows best in areas where sand accretion is greatest (windward side of dunes). When established, the plants develop a vigorous rhizome system, both horizontal and vertical. Under conditions of heavy sand accretion many new shoots arise from the nodes of the vertical rhizomes, thus creating hummocks. Although the plants produce numerous seeds, very few of these survive. It appears that conditions along the Oregon coast, such as strong onshore winds, moderate year round temperatures, ample rainfall and an abundant sand supply favor the growth of European beachgrass. Many efforts have been made in recent years to control European beachgrass in certain areas, all with little success. Methods have included herbicides, burning, tilling, salt-water irrigation, and manual removal. It appears the best method may be a combination of two or more of these methods over a long period of time.

As a result of dune stabilization, many of the plant species occurring on the dunes are introduced species. These include; sweet vernalgrass (Anthoxanthum odoratum), ripgut brome (Bromus diandrus), hairy cat's-ear (Hypochaeris radicata), and in this area, gorse (Ulex europaea). These and other exotic species make up a large proportion of the vegetation on most of the sand dunes in the area.

Deflation Plain

Behind the foredune is the deflation plain, which is formed when sand is eroded away to the water table. Since the establishment of European beachgrass the deflation plain has steadily increased in width. Species present in these communities include many species of sedges (Carex ssp.), rushes (Juncus ssp.) and spike rushes (Eleochaeris ssp.).

Coastal Headlands

Coastal headlands are dominated by evergreen shrubs, usually less than 2 meters tall, and wind pruned tress. Species include coyote brush (Baccharis pilularis), salal, black crowberry (Empetrum nigrum), common juniper (Juniperus communis), hazel nut (Corylus cornuta), black twinberry (Lonicera involucrata), and wax myrtle (Myrica californica). Herbaceous species include reed grass (Calamagrostis nutkaensis), frosted paintbrush (Castilleja affinis var. littoralis), and Bolander's sneezeweed (Helenium bolanderi). These plant communities endure very harsh environmental conditions including, strong winds, year round salt spray, and fog.

Coniferous Forests

Coniferous forests in this region occur on soils ranging from stabilized sand to soils on old marine terraces. These forests are primarily composed of shore pine, Sitka spruce (Picea sitchensis) and, in more protected areas, Douglas-fir (Pseudotsuga menziesii var. menziesii) and western hemlock (Tsuga heterophylla). These coastal forests have a dense understory composed of many shrubs such as rhododendron (Rhododendron macrophyllum), salmonberry (Rubus spectabilis), black twinberry, and wax myrtle. Aerial photographs from the 1940s and 1990s show that these forests have become more abundant on sand dunes. This is probably a result of the establishment of European beachgrass which has caused secondary succession to occur more rapidly by removing the historical disturbance factor (moving sand).

Freshwater Wetlands

These habitats include deflation plain wetlands, sphagnum bogs, and lakes formed by small creeks that have been blocked by moving sand dunes. Sphagnum bogs typically occur in depressions and in coastal headlands with Blacklock soils where water is "perched." Species present in these communities include pitcher-plant (Darlingtonia), russet cottongrass (Eriophorum chamissonis), yellow pond-lily (Nuphar luteum ssp. polysepalum), and bladderwort (Utricularia vulgaris).

Culturally Significant Plant – the Douglas Fir

The Douglas-fir is the state tree of Oregon for good reason. No other tree is more widespread throughout the Cascade and Coast Range mountains. Douglas-fir timberlands are the most productive softwood timberlands in the U.S. in terms of volume per acre. More softwood lumber is produced in Oregon than in any other state due in large part to the predominance of Douglas-fir in its coastal forests.

Douglas-fir was originally named after the Scottish botanist David Douglas who was sent by the Royal Horticultural Society to study the tree in the late 1700s. In 1867, Douglas-fir was given its own genus Pseudotsuga, which means false (pseudo) hemlock (tsuga), and is considered not to be a "true" fir.

Description of Species

Douglas-fir (Pseudotsuga menziesii) is a clear, straight-trunked tree, with a spire-like crown, and the capacity to grow over 300 feet tall. The upper branches of the tree point up and the lower branches droop down and recurve. Its bark is characterized as gray to reddish brown with deep, thick grooves, which form by the time it reaches maturity and serve as a defense mechanism against wildfires. Spreading needle covered branches consist of one inch needles, which are slightly pointed at the tip. Coast Douglas-fir (P. menziesii var. menziesii), have yellowish green needles, while Rocky Mountain or blue Douglas-fir (P. menziesii var. glauca), have bluish green needles both varieties having two white bands on the underside of the needle. Male flowers of Douglas-fir are bright red, female flowers are green and have prominent bracts. Mature seed cones are approximately 3 to 4 inches long, reddish brown in color, and have pitchfork-shaped bracts. The entire cone is shed in the fall, and the seed is a light brown color, approximately 5-6 mm long.

Douglas-fir ranks as the second tallest tree species in the world behind coastal redwood, and contains the largest trees in the entire Pinaceae family. The tallest known Douglas-fir is the Brummit Fir (located in Coos County, Oregon), which reaches the height 328 feet. In terms of thickness the Queets Fir, located in Olympic National Park, Washington, has a diameter at breast height of 14.3 feet. Most old-growth Douglas-fir range in height from 200 to 250 feet, and have a diameter of 5 to 8 feet. The oldest known Douglas-fir can be found on Vancouver Island in British Columbia, and is estimated to be between 1300 to 1400 years old.

Natural History

The seasonal growth of Douglas-fir begins during the spring (usually April) with the onset of vegetative bud growth. During the months of May and June the vegetative buds begin to burst forth. From July to November the lateral bud grows and we begin to see the initiation of the leaf and bract. Pollen development begins to occur around March and by April the cone buds burst or flower and pollination of the seed cones begins. In May and June fertilization is underway and the seed cones begin to enlarge at a rapid pace. From August to September embryo and seed development is in full swing and by late September cones have matured and begin to shed their seeds. The entire reproductive cycle of Douglas-fir extends over a 17-month period from early April to late September of the following year.

Evolutionary History

The fossil record of Pseudotsuga-like forms in North America begins in the early Tertiary period about 50 million years ago. The cones, seeds, and needles of the modern genus Pseudotsuga can scarcely be distinguished from those of its ancestors. Unfortunately, no concrete record of the genus exists in the pre-Cenozoic era, so we are forced to work with only a small portion of the evolutionary history. The earliest known occurrence of fossil cones, seeds, and leaves of Pseudotsuga in North America was found in the Eocene Copper Basin flora of northeastern Nevada. Although little is known about the range of Pseudotsuga during the early to middle Tertiary periods, fossil records indicate that its range was rather restricted. However, by the late Tertiary period its range had expanded considerably to as far north as Alaska, which lasted well into the middle to late Miocene about 20 million years ago.

During the Tertiary period, fossil records indicate that Pseudotsuga was a minor component of the forests of western North America. In the Pleistocene epoch Pseudotsuga began to develop into a vegetational unit of the forests located at mid-latitudes and mid-altitudes in the northwestern region of North America. Fossil pollen found in Quaternary deposits indicates that during the interglacial intervals, Douglas-fir (Pseudotsuga menziesii) became an important part of northwestern forests in North America. Its theorized that during glacial periods the repeated growth and waning of ice sheets caused large fluctuation in the range of Douglas-fir. During the post-glacial period Douglas-fir emerged as a dominant element in the coniferous forests of western North America. Beginning about 10,000 years ago, Douglas-fir began to migrate from glacial refugia into the range it occupies today.

Topography

Coast Douglas-fir typically grows in elevations that range from sea level to 5,500 feet above sea level along the coastal ranges and west of the mountain regions in the Pacific Northwest.

Other interesting issues

Fire has been a major component of Douglas-fir forests for thousands of years, and has helped to create almost pure stands of the species throughout the Pacific Northwest. Logging has eliminated much of the original old-growth forests in this region, and clear-cutting has fragmented the environment, especially for wildlife. Timber companies often employ a method of burning slash after a clear-cut, which helps Douglas-fir to regenerate faster, but by this time the overall quality of the forest ecosystem may have been damaged.

Invasive species are those plants, animals, and microbes not native to a region which, when introduced either accidentally or intentionally, out-compete native species for available resources, reproduce prolifically, and dominate regions and ecosystems. Because they often arrive in new areas unaccompanied by their native predators, invasive species can be difficult to control. Left unchecked, many invasives have the potential to transform entire ecosystems, as native species and those that depend on them for food, shelter, and habitat disappear.

Sources

Compiled by John Ame, Science Writer (2007)

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