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The frequency of occurrence of corticolous lichens on Quercus garryana in the Willamette Valley

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Title The frequency of occurrence of corticolous lichens on Quercus garryana in the Willamette Valley
Names Saxton, Robert Howard (creator)
Beer, Frank M. (advisor)
Date Issued 1965-07-30 (iso8601)
Note Graduation date: 1966
Abstract This study was made to present any evidence as to differences
in the frequency of occurrence of corticolous lichens from east to
west in the Willamette Valley on a bark substrate of Quercus Garryana.
Twenty-four species of lichens were observed to be present
within the grid area of the 100 trees used in the study, i.e., ten
trees in each of ten stands of White Oak. At the western base of
the Cascades the total number of species present was 15. This number
diminished to a total of three species at the eastern base of the
Coast Range.
Only two lichens, Arthopyrenia punctiformis and Pertusaria
multipuncta, occurred throughout the ten stands in some frequency.
Among the stands nine species of lichens were found in one stand out
of ten. Variations in the frequency of occurrence were found to exist
among the other 14 species, and in many cases not necessarily in direct relationship to their habitats. This was especially true of
Lobaria pulmonaria which occurred most frequently in stand IV, but
in stand I, which was environmentally similar in all respects to stand
IV, it did not occur at all.
Certain species of corticolous lichens have a greater tendency
to appear on the north or south side of the trunk, while others appear
in approximately equal frequency on the north or south sides of the
trunks.
The grid method, applied to determine the frequency of occurrence,
was successful for all three forms of lichens: crustose, fruticose
and foliose. This made possible a quantitative approach to the
study of lichen relationships.
The corticolous lichens studied do occur at different frequencies
from east to west. In addition, the number of species and kinds of species
are different.
Genre Thesis/Dissertation
Topic Lichens -- Oregon -- Willamette River Valley
Identifier http://hdl.handle.net/1957/47734

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