|Abstract or Summary
- Distribution of lichens was studied at seven coastal dune sites in
Oregon. Lichens were sampled in the dry stable, dry meadow,
meadow, rush meadow, marsh, shrub and forest deflation plain communities.
Observations were made of the standing water in the marsh
community. Quantitative measurements were made of the percent
organic matter of the surface soil in the dry stable, dry meadow,
meadow and rush meadow communities and of the light intensity in a
Pinus contorta forest.
In the moss stage of the dry stable community, only the lichens
Cladonia alpestris and Cladonia verticillata were found. Peltigera
polydactyla and several species of Cladonia were in the meadow and
rush meadow communities. No lichens were found in either the dry
meadow or marsh communities.
Driftwood logs were found in the herbaceous communities.
Twenty-one species of lichens were found on the logs, more species
than on any other single type of habitat. Parmelia sulcata, crustose
and Cladonia spp. were the most common. Six species were recorded
only on these logs.
In the shrub community, crustose lichens had the highest percent
frequency. Lichens were present only on the older branches and
stems of the shrubs, with no lichens being found on newer growth.
Lichens were studied on one-third meter bands circumscribing
tree trunks and on the lower branches of Pinus contorta in a forest
community. Transects were taken into the stand from several directions
and light readings taken at a tree every ten paces. As light
intensity decreased, percent cover of lichens on tree trunks also
decreased, Lichens on the branches showed a less pronounced tendency
to decrease in proportion to light intensity. Hypogymnia
enteromorpha predominated in this community with many crustose
lichens also present.
Trees and shrubs in a pine-cedar bog, a specialized forest
type, were also observed for lichens. Crustose, Hypogymnia
enteromorpha and Menegazzia terebrata were the more frequent
species with Platismatia herrei being abundant only on Pinus contorta.
Sphaerophorus globosus was found only in this environment.
Menegazzia terebrata was recorded only once outside the pine-cedar
bog forest. This one observation was in a wet shrub area on Salix hookeriana. Both species may require a constantly wet habitat which
is not found in the Pinus contorta forest of the deflation plains.
Calculating percent organic matter of soil samples from the
herbaceous communities not seasonally inundated revealed that generally,
areas with more than three percent organic matter had lichens
while areas with less than three percent organic matter had no lichens.
The dry meadow had loose sand and little organic matter. Since
lichens grow slowly, they are unable to establish themselves where
the sand is unstable.
Most lichens cannot tolerate long periods of inundation. Standing
water for up to nine months of the year in the marsh community
may explain absence of lichens from this vegetation type.