Difference between revisions of "AY Honors/Forestry/Answer Key"

Revision as of 01:50, 20 November 2011

1. Prerequisite: Tree Honor

2. Learn the proper use of the following common forestry tools and practice using them on trees in a forest. Record the information for each tree giving also the common name of each tree:

For this requirement you will need access to a forest and permission from a land owner to bore into the trees.

You can go as a group, but each person in the group must take several measurements. In addition to the equipment listed below, each participant should bring a notebook and a pen for recording measurements and observations.

a. DBH (diameter at breast height) tape – measure the diameter of trees (or measure the tree circumference and calculate the diameter)

A DBH-tape is a form of dendrometer that consists of a cloth or metal tape that is mainly used to measure diameter at breast height (DBH). DBH is measured at a fixed height of 140cm above the ground, where it is most convenient to measure diameter. DBH is measured up high so to avoid measuring a tree's butt swell. Butt swell is where the base of the tree is unconventionally fatter than the rest of the tree. height and diameter are used to determine the volume of a given tree, measuring above the butt swell is required to provide the most accurate measurement.

Diameter is easily measured because the tape is calibrated in units of 3.14 ([math]\displaystyle{ \pi }[/math]) inches or centimeters. The tape is actually measuring the tree's circumference but since circumference and diameter are related by pi, the diameter can easily be obtained. The only problem with the diameter tape is that the measurements assume the tree's trunk cross-sections are perfectly circular. Thus the diameter tape just gives an approximation, regardless it is the most commonly used dendrometer for DBH.

b. Clinometer or Tangent height gauge – measure the height of trees

c. Increment borer – count the growth rings to determine age

d. Prism – estimate the basal area per acre or hectare

3. Use the information gathered in #2 to determine the board foot volume of the trees in the forest you measured.

4. Calculate the basal area of a tree from the diameter (dbh) or circumference measurement. What is basal area per acre or hectare?

5. Study five tree species important to forestry in your area and give the following information about each:
a. common and scientific name
b. range of tree
c. height and diameter of tree at maturity
d. common use and importance of tree
e. habitat of tree, forest zone, and elevation

6. List the benefits of forest to the environment, water quality, air quality, wildlife, and recreation.

7. List the uses of wood produced in the forests in your area, and which tree species are important for each use.

8. Discover & Discuss the following: How are forests managed to reduce the damage from insects and disease? What factors influence fire behavior? Considering that wildfires produce both benefits and destruction, what treatments could reduce wildfire severity?

9. Do one of the following in forest regeneration:

a. Tour a forest seedling nursery

b. Plant forest seedlings or forest seed

10. Explore the biblical stories in Genesis 1-3 and Revelation 22 that talk about the tree of life. In your discussion, discover the role of trees in God’s perfect environment, and our responsibility to take care of our environment.

References

@@ Line 1: / Line 1: @@
-[[Image:Clinometer commonly used by foresters.JPG|right|200px|thumb|A clinometer used in forestry]]
+{{honor_header|2|2008|Vocational|North American Division}}
-The '''clinometer''', known in many fields as an [[inclinometer]], is a common tool used in [[forestry]] to measure [[slope]], [[vertical (angles)|vertical angles]], and &ndash; in combination with distance measurements &ndash; elevation change or tree heights.
+==1. Prerequisite: Tree Honor==
+{{ay prerequisite|Nature|Trees}}
-==How it works==
+==2. Learn the proper use of the following common forestry tools and practice using them on trees in a forest. Record the information for each tree giving also the common name of each tree:==
-A forester using a clinometer makes use of basic [[trigonometry]].
+For this requirement you will need access to a forest and permission from a land owner to bore into the trees.
-First the observer measures a straight-line distance ''D'' from some observation point ''O'' to the object. Then, using the clinometer, the observer measures the angle ''a'' between ''O'' and the top of the object. Then the observer does the same for the angle ''b'' between ''O'' and the bottom of the object. Multiplying ''D'' by the  [[Trigonometric_functions#Right_triangle_definitions|tangent]] of ''a'' gives the height of the object above the observer, and by the tangent of ''b'' the depth of the object below the observer. Adding the two of course gives the total height (''H'') of the object, in the same units as ''D''.<ref>[http://mysite.du.edu/~jcalvert/astro/abney.htm Calvert, J.B. “The Clinometer.” 2003.]</ref>
+You can go as a group, but each person in the group must take several measurements.  In addition to the equipment listed below, each participant should bring a notebook and a pen for recording measurements and observations.
-Note that since multiplication is [[distributive]] it is equally valid to add the tangents of the angles and ''then'' multiply them by D:
+===a. DBH (diameter at breast height) tape – measure the diameter of trees (or measure the tree circumference and calculate the diameter)===
-:''A'' = tan ''a''
+A DBH-tape is a form of dendrometer that consists of a cloth or metal tape that is mainly used to measure diameter at breast height (DBH). DBH is measured at a fixed height of {{units|140cm|4.5 feet}} above the ground, where it is most convenient to measure diameter. DBH is measured up high so to avoid measuring a tree's butt swell. Butt swell is where the base of the tree is unconventionally fatter than the rest of the tree. height and diameter are used to determine the volume of a given tree, measuring above the butt swell is required to provide the most accurate measurement.
-:''B'' = tan ''b''
-:''H'' = (''A'' &times; ''D'') + (''B'' &times; ''D'') = (''A'' + B) &times; ''D''
-Note also that both angles should be [[positive number]]s (i.e. ignore any [[minus sign]] on the clinometer's scale).
+Diameter is easily measured because the tape is calibrated in units of 3.14 (<math>\pi</math>) inches or centimeters. The tape is actually measuring the tree's circumference but since circumference and diameter are related by pi, the diameter can easily be obtained.  The only problem with the diameter tape is that the measurements assume the tree's trunk cross-sections are perfectly circular. Thus the diameter tape just gives an approximation, regardless it is the most commonly used dendrometer for DBH.
-==Units of measure==
+===b. Clinometer or Tangent height gauge – measure the height of trees===
-There are typically three different units of measure that can be marked on a clinometer: [[degree (angle)|degrees]], [[percent]], and topo. When buying a clinometer it is important to make sure it is calibrated to units suitable for the intended use.
+===c. Increment borer – count the growth rings to determine age===
+===d. Prism – estimate the basal area per acre or hectare===
-==Tree height measurement==
-The [[forester]] stands at a fixed distance from the base of the [[tree]]. The most common distances in the [[United States]] are {{convert|50|ft|2}}, {{convert|66|ft|2}}, and {{convert|100|ft|2}}.<ref> Avery, T.E. and Burkhart, H.E. “Height Measurement Principles.” Forest Measurements 5th Edition. McGraw-Hill, 2002. 154.</ref> To obtain accurate readings it is best to use taped measured distance instead of [[Pacing (forestry)|paced distances]]. For the most accurate readings it is best to use a distance that is not less than the height of the tree being measured.<ref> Williams, M.S., Bechtold, M.A., and V.J. LaBau. 1994 five instruments for measuring tree heights: an evaluation. Southern Journal of Applied Forestry 18: 76-82</ref>, that is, that the clinometer will measure an angle less than 45° (100%).
-The observer sights to the top of tree, if total height is the desired measurement. If the desired measurement is merchantable height &ndash; that is, the height producing timber that can be sold &ndash; the observer sights to a point on the tree above which no more merchantable timber is found. The observer then measures to the bottom of the tree, takes the tangents and multiples them by the distance, and adds the two figures together. This will be the height of the tree.
-The observer must always measure a leaning tree so that the tree is leaning to the left or right. Measurements should never be taken with the tree leaning toward or away from the observer because this will affect their [[accuracy]] because of [[foreshortening]].
-==Slope measurement==
-[[Image:Measuring Slope With a Clinometer 2.JPG|right|200px|thumb|Measuring slope with a clinometer]]
-The clinometer is also commonly used by foresters to obtain the [[gradient|percent slope]] of terrain. This measurement is based on the same trigonometric principles described above. Slope measurements, however, require that both observer and target be a constant height above the ground; thus a range pole or height of measurement (HI) stick is often used in slope measurements.
-{{commonscat}}
-==Manufacturers==
-* [[Brunton, Inc.]]
-* [[Suunto]]
-* [[Haglöf]]
-* [[Silva compass]]
-==See also==
-*[[Inclinometer]]
+==3. Use the information gathered in #2 to determine the board foot volume of the trees in the forest you measured.==
+==4. Calculate the basal area of a tree from the diameter (dbh) or circumference measurement. What is basal area per acre or hectare?==
+==5. Study five tree species important to forestry in your area and give the following information about each: <br>a. common and scientific name<br> b. range of tree<br> c. height and diameter of tree at maturity<br> d. common use and importance of tree<br> e. habitat of tree, forest zone, and elevation==
+==6. List the benefits of forest to the environment, water quality, air quality, wildlife, and recreation.==
+==7. List the uses of wood produced in the forests in your area, and which tree species are important for each use.==
+==8. Discover & Discuss the following: How are forests managed to reduce the damage from insects and disease? What factors influence fire behavior?  Considering that wildfires produce both benefits and destruction, what treatments could reduce wildfire severity?==
+==9. Do one of the following in forest regeneration:==
+===a. Tour a forest seedling nursery===
+===b. Plant forest seedlings or forest seed===
+==10. Explore the biblical stories in Genesis 1-3 and Revelation 22 that talk about the tree of life. In your discussion, discover the role of trees in God’s perfect environment, and our responsibility to take care of our environment.==
 ==References==
-{{Reflist}}
-[[Category:Forest modelling]]
-[[Category:Dimensional instruments]]