Record Details
Field | Value |
---|---|
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 |