Before going out to select a site, you will need some equipment:
Find an oak or ash. The drawings on pages 3 and 5 will show you what they look like. If you cannot find an oak or ash, some other kinds of trees may do. Old apple trees (not in a sprayed orchard!) work very well. Alder trees and most conifers, including Douglas fir, have totally different lichens and therefore cannot be used with this GUIDE.
If possible, select a tree standing in the open or, if you can only find trees standing in groups, select one on the side of the group which faces the wind.
Select five branches well up in the tree. When in doubt, select those branches which seem to have the most lichens. Cut the branches down, bend them down, or climb up to them. In any event, you will need to be able to examine them very closely.
On each of five branches find a segment that is five years old and a segment that is ten years old. Do this by starting at the terminal bud at the end of the branch and counting each year's growth back toward the trunk. (See drawling and explanation on page 7).
Compare the lichens you find on the twigs with the pictures and descriptions you find on pages 10 through 26 of this GUIDE. Start with the oldest twigs and the largest lichens. The drawings were made from mature specimens and show some features, such as apothecia, which are important for identification but which may not be present on young thalli. Once you have learned to recognize the mature form of a lichen you will find it easier to identify the young ones.
Note that in most cases the drawing is much larger than the lichen which it depicts and that the amount of enlargement differs from one drawing to the next. The amount of enlargement is indicated by a line with an accompanying measurement. If, for example, the measurement says "1 cm", but the line is actually five centimeters long, then the drawing is five times as large as the corresponding lichen.
Two different data sheets are included in the GUIDE. The one labeled Air Quality Evaluation Form #2 is designed to make it as easy as possible for you to evaluate air quality in your neighborhood. The other one, which is labeled Air Quality Evaluation Form #l and consists of two pages, is to be used if you wish to report your findings and have us include them in a master map of your area.
Once you have identified a lichen, you need a rough measure of its abundance. Examine the entire surface of each five-year-old or ten-year-old segment of twig and estimate how much of the total surface of each segment is 'covered by each species, if you use Form #2, record a zero ("0") if the lichen 'is absent or covers less than 5% of the total area; record a checkmark, if it covers 5% to 25% of the surface; and record a plus (+) if it covers more than 25% of the surface. If you use Form #l, record a zero (0 ) if the lichen is absent; record a 5 if it is barely present or covers up to 5% of the surface; record a 25 if it covers 5% to 25%; record a 50 if it covers 25% to 50%; a 75 if it covers 50% to 75.%; a 95-if it covers 75% to 95%; and a 100 if it covers 95% to 100% of the twig surface.
Form #l consists of two sides. Side A is used to record
the presence and abundance (% cover), or the absence, of each species of
lichen. Side B is used to describe the locality where the lichens
were found. If your sample is to be of use to others you must
fill out both sides as completely as possible.
Side A:
Number the ten segments (five five-year-old segments and five ten-year-old segments) one through ten. Beginning with segment number one, record its age. Then record the percent cover of each of the lichens on the list. Use the code at the bottom of the Form. If you do not find a particular lichen, leave the space blank. Few segments will have more than five or six lichens. When you have finished recording the first segment, continue to the second, and so on through all ten segments.
Side B:
Fill in your name, address, and the date you collected the sample.
Location of Sample Site: Fill in as much of the information called for as possible. It is important to be able to locate the site accurately and since street names or place names are often changed, it is helpful to have more than one point of reference. Most of the information required is easily found and self-explanatory, but the most useful information, the Universal Transverse Mercator (UTM) coordinates, require explanation. The UTM coordinates of a site are given by two numbers: 1) the distance east of a line which runs north and south; and 2) the distance north of a line which runs east and west. Both distances are measured in kilometers (km). The coordinates are found in the following manner:
Note that the UTM coordinates are not always printed on the map in exactly the same way. For example, they may be printed in black instead of blue, or may be found only beside selected tick marks. However, tick marks are always in blue and are always one kilometer (I km) apart.
Description of Sample Site: Fill in as much information as possible. It is particularly important to identify the kind (species) of tree and tell whether it stands alone or with others. The height and diameter may be estimated. The altitude and slope are important because they influence the movement of wind at low elevations; that is, at the heights at which wind strikes a tree.
When you have completed both Side A and Side B of Form #l, mail it to: LICHEN TECHNOLOGY, INC. Box 369. Corvallis, Oregon 97330. A new, blank copy of Form #l will be sent to you.
Instructions for using and interpreting Form #2 are printed on the form.