The ecology of Pacific Northwest coastal sand dunes

American east coast and Great Lakes
region. It seems ts~ have similar
ecological requi rements to those of
European beachgrass. Data from
North Carol ina ( Woodhouse et a1 .
---(P
1977) show that this specEs 1s
short lived (2 to 5 yrs) and higtlly
susceptible to at least one disease
and one insect. These problems may
be related to growth near the
southern 1 imit of its range (34 N).
European beachgrass has spread
along the west coast of North America
from 34" to 55"N latitude. In only
a very few locations has it not taken
over enti rely in the foredune zone
just above tile beach. These areas,
rnost notably parts of the north and
south spits of tiurnboldt Bay (Local ity
33), give a clue to the api~earance of
the vegetation of the foredune aorw
prior to the takeover by European
beachyrass . Even here, howevc I*, the
high bedchgrass rid ye is qradual ly
rep1 aci ng the 1 oosely aggregated
collection of relatively 7a.r hui~~rriocks
fo rrned by t!~e na 2; i ve speci es .
The biological effect of the
grass is to crowd out, through rapid
growth and dense cover, the native
hummock builders. In many places
where they once occurred commonly,
such species as American dunegrass,
sandverbena, si 1 ver bursage, beach
morning glory, and dune tansy occur
sparingly or are not seen at a1 1.
Since virtually a71 of the sand
blown off the beach is trapped by
European beachgrass foredunes or
hummock fields, there is concern
that "sand starvation" (discussed
earlier) could change the character
of the 'large moving dunes. Although
this is open to much specuf ation,
informal consideration has been
gi wen to trying to find a way to get
sand moving inland again. There is
na precedent since getting European
beachgrass es tab1 isked has his tori -
eally been of greater importance than
destroying it, Recent experiments
in northern Cal ifornia IS. VanHook,
Lanphere-Chris tensen Dunes Preserve,
Arcata, California; pers, corn. 19833
have involved sa't t, black polyvinyl
sheeting, digging and pulling, burning,
and herbicides to try .to control
the species. The best method thus
far has been burning (the grass burns
readily, but is not killed) followed
by an application of the herbicide
'"~oundup - Pulling young plants
is also effective, but requires
constant patrol 1 ing.
European beachgrass is permanently
established on the Pacific
Northwest coas ta1 dunes. Its
ultimate impact on nati we species
and dune morphologiy is not known.
Al though con si derabl e research on
its ecology and physiology has taken
place in Europe, very little has
been done in North America, or in
the numerous other places in the
world where it has been introduced.
Any possibil i ties at all of "managing"
this species along the northwest
coast will depend upon a
program of research that examines
both anatomical and physi 01 ogical
response to local conditions.
Endangered Species
A number of plant and animal
species that occur on the sand dunes
are on one or more state lists of
rare, sensitive, threatened, or endangered
species. Only one is protected
by Federal law as a threatened
or endangered species. These
1 ists are usually maintained by
state natural heritage programs, but
rmy originate with gruups such as
Glyphssate - a broad spectrum,
nonselective herbicide, readily
broken down in the soil to carbon
dioxide by r~ticrobial degradation
(Watson 1981).