Appraisal Final Review Flashcards
Fixed Plot
Cruiser measures ALL of the trees that
fall within the boundary of a plot.
* Probability of a tree falling in a plot is
based entirely on location and this
probability is NOT affected by the tree’s
size
* Each sampled tree (or other resource)
represents the same, constant number
of trees per acre, regardless of the size
of the tree (or other resource).
What is a stand?
Definition: A Stand is an area of forest with common characteristics (e.g. tree species, age,
trees per acre). Once the common characteristics change, the new area is considered a
separate Stand.
Circular Fixed Area Plot
The key is the classic Area of Circle Formula:
* If we want to know what the radius of a
1/50th acre plot, we figure:
* 1/50th in decimal form is 0.02
* An Acre is always 43,560 square feet in size
* 0.02 x 43,560 = 871.2 sq ft
* 871.2 = 3.14 x ( r2 )
* (871.2 / 3.14) = ( r2 )
* 277.5 = ( r2 )
* 277.5 = r
* 16.7 ft. = r
*
16.7’
Tree Factor for Fixed Area Plots
- Always Constant for Fixed Area Plots
- Tree Factor for 1/50th Acre Plot is 50
- Tree Factor for a 1/100th Acre Plot is 100
- Tree Factor for 1/163rd Acre Plot is 163
- This means that whatever you found in your 1/163rd acre plot, there
are 163 of them per acre for every one instance you found them in
your plot. - Examples:
- If you found only one 51” DBH Cottonwood, your plot suggests you have 163
Cottonwood trees per acre in your forest that are 51” DBH in size - If you found only one bird nest, your plot suggests you have 163 bird nests per acre
- If you found two 51” DBH Cottonwoods, your plot suggests you have 326 Cottonwood
trees per acre in your forest that are 51” DBH in size. Since you found two instances on
your plot 2 x 163 = 326
Variable Area Plots
Many features are similar to fixed-area plot sampling
* number and location of sample points is similar
* establish a plot center
* measure DBH and height the same way
Basal Area of a Tree
The basal area of a tree is defined as the cross-sectional area (usually
in square feet) of a single tree at breast height, or 4.5 feet above
ground.
* The diameter of a tree at 4.5 feet above the ground is called diameter
at breast height (DBH).
* This cross-sectional area is calculated as follows
BA= DBH^2*0.005454
Basal Area per Acre
Basal area is the common term used to
describe the average amount of an area
(usually an acre) occupied by tree stems
* It is defined as the total cross-sectional area
of all stems in a stand measured at breast
height, and expressed as per unit of land area
(typically square feet per acre)
* Common metric for expressing stand
conditions
Variable Area Plot
To determine which trees are IN the
“plot,” stand at the sample point using
an instrument that projects a fixed
horizontal angle to “sight in” a diameter
for every tree at a fixed height, usually
taken to be breast height – trees thicker
than the angle are “IN”
* Relaskop
* Prism
Plot Radius Factor/Limiting Distance
You can also determine “in” and “out” trees by another method for
Variable Area Cruises. In fact, this method is the ultimate authority.
The other methods are sort of shortcuts.
* You can find out if a tree is “in” or “out” by multiplying it’s DBH by a
Plot Radius Factor (PRF). Each unique BAF has it’s own PRF. For a 40
BAF, the PRF is 1.375
* To use this, simply multiply the DBH of your tree by the PRF of 1.375 to get
your Limiting Distance. For a 51” Cottonwood Tree, this process would look
like this: 51” DBH x 1.375 PRF = 70.1 ft.
* So 70.1 ft is our Limiting Distance for this tree. If this tree is located within
70.1 feet of my plot center, it is considered an “in” tree. If it is further away
than 70.1, then it is an “out” tree.
Definition of PRF
Plot Radius Factor
Assess BA/Acre using varible area plots
EASY to assess Basal Area per Acre this way!
* Stand Basal Area estimates are found by multiplying the number of
tallied trees by the so-called Basal Area Factor, or BAF, which is
directly tied to the size angle that is projected – no measurements
needed !
* Example
* If I use a 40 BAF to cruise a plot and I find that only 2 trees are “in”, then I can
calculate my BA/Acre as follows: 2 x 40 = 80 sq ft
Tree Factor for Variable Area Plots
TF= BAF/BA
Tree Factor for
Variable Area Plots
So let’s dig into that. For a plot, let’s assume we have two Cottonwood
trees (each are 51” DBH), and our method of getting was a 40 BAF
Variable Area Plot.
* TF1 = 40 / (0.005454 x 512 )
* TF1 = 40 / 14.2
* TF1 = 2.8
* So our tree factor for ONE of these trees is 2.8. Since we found TWO
for these trees on our plot, our plot suggest we have a total of 5.4
Cottonwood trees per acre which are 51” DBH in size.
Random Sampling
There are two general types of sampling systems which are used in
association with fixed area plots: random and systematic. Random
sampling assumes that the location of each sampled area is randomly
determined. In these cases, you would need to randomly locate on a
map the places of the fixed area plots.
Systematic Sampling
Systematic sampling assumes that the location of the sampled areas is
dependent on the location of the first sampled area, and the density
of sampling areas required to meet the nominal (planned) sampling
intensity. Each fixed area plot is spaced apart from the others in a
regular pattern across the landscape (Figure C). The advantage of this
system is that it allows one to navigate much easier to each sample
location than when using randomly located plots.
Count plot
A plot in which only “in” trees are counted and recorded
by species. No measurements or grades are made.
Cruise plot
A plot in which “in” trees are counted and cruised
including DBH, form factor, bole height, grades and defect are
recorded. May be referred to as “measure plots” or “grade plots”.
Common Cruise Plot Measurements
“IN” & “OUT” Trees
* Tree Species
* DBH (Diameter @ 4.5’ above ground)
* Total Height (Total Height to Tree Top)
* Merchantable Height (total height of the stem of a tree from the ground to a minimum size top
diameter representing the customary log utilization.)
* Form Factor (The ratio of taper measured by diameter outside bark measured at the form
point (usually 16 feet above the stump) to the diameter at breast)
* Percent Live Crown (The percentage of tree covered by living branches)
* Log Defect (The amount of wood unsuitable for utilization as lumber or fiber. Usually
represented as a percentage of the gross volume)
* Log Segments (The number of logs within a tree)
* Log Grades (A classification of a log or log segment by standardized grading rules such as
the NW Log Rules Advisory group)
* Log Sort (A classification of a log or log segment by product utilization. Often defined by the
intended destination of the log. ie. Domestic Sawlog , Export Log, Pulp, Peeler/Veneer Mill,
Pole)
Form Point
The point at which the tree’s bole shape turns from
convex to concave. By convention this is set at 16 feet from the stump
height.
Form factor
The ratio of taper measured by diameter outside bark
measured at the form point (usually 16 feet above the stump) to the
diameter at breast
Horizontal Distance
The true geographical
distance two objects are from one another
independent of slope
Slope Distance
The distance between two
objects by following a sloped surface
Scribner Board Feet
(a Board Foot is 12” x 12” x 1”. Scribner Board
Feet is based on Log Diagrams that were converted to a chart).
Measurement Units in a Forestry
Cubic Feet/Meters
* Tons
* Cords (4’ wide x 4’ high x 8’ long)
How to Use a Scribner Chart
Scribner Tables always apply to the
smaller of the two log diameters aka
“small-end diameter”
- Determine you small-end diameter
- Determine your total log length
- Subtract any length deductions
assessed to your log for log defect
- Find the intersecting volume on the
Scribner Chart
- Example: For a 12” Douglas-fir log
with a total length of 40-feet length
deduction of 6-feet
- Find 12”
- Find 34’
- This log has a NET Volume of 170
Board Feet
- (It’s GROSS Volume is 200 Board Feet)
What is a scaling cylinder
an imaginary cylinder based on the smaller end of the logs
PRODUCT RECOVERY/ WHAT ARE THE VARIABLES?
OVERRUN/UNDERRUN?
Accuracy of the scaler.
* Saw kerf, Target Size.
* Products manufactured.
* Sawmill efficiency.
* Log size.
* Log Taper.
* Amount and type of defect in
logs.
Product recovery numbers based on measurement type
Board foot = 80-250% recovery for
lumber.
* CF = 40-70% recovery or 6.5-10 BFlum/CF
log (LRF).
* BF plywood recovery = 2.5-3.5 MSF/MBF
* CF plywood recovery = 1.5-2.0 MSF/CCF.
Preferred Lengths
The log lengths a given mill prefers. Generally
speaking, > 90% of logs delivered should be preferred lengths.
Log Trim
The extra amount of length to add to account for wood
loss through manufacturing. For example: A 40’ log with 12” of trim
would be a log that measures 41’ in length. This allow for up to a foot
of wood loss through the multiple cuts a log goes through in the mill
Max Butt
The largest diameter allowed by a mill on large-end
diameter. Logs with a large-end diameter exceeding this value will be
“no-pay” logs.
Sawlog
A log that is sawn into lumber
Chip’n’Saw
Typically a log that has a 5” small end diameter and can make one 4x4 of
lumber per length used and the rest is sawdust/pellets.
Pulp
Pulp is low quality or undersized timber with the principal use of making wood
pulp for paper production
Oversize
A log that is too big for a sawmill’s capacity. Measured on the Butt End.
Pole
A log that can serve as a large-scale pole. Often with little-to-no-defect. Taper
must be balanced (not too extreme in either direction). Douglas fir and Red Cedar are
the only common species in our region for this. Poles typically fetch the highest value
of sawlogs.
Peeler
A log that is cut with rotary milling technology into clear face-stock to be used
as the veneer for commercial wood products.
Common Domestic Log Grades –
Douglas Fir
Douglas Fir
* Peeler No. 1
* Peeler No. 2
* Peeler No,. 3
* Special Mill/Sawlog #1
* Sawlog #2
* Sawlog #3
* Sawlog #4
Outer Bark
The outer bark is the tree’s protection from the outside world. Continually renewed from within, it
helps keep out moisture in the rain, and prevents the tree from losing moisture when the air is dry. It insulates
against cold and heat and wards off insect enemies
Inner Bark
The inner bark, or “phloem”, is pipeline through which food is passed to the rest of the tree. It lives
for only a short time, then dies and turns to cork to become part of the protective outer bark
Cambium Layer
The cambium cell layer is the growing part of the trunk. It annually produces new bark and
new wood.
Sapwood
Sapwood is the tree’s pipeline for water moving up to the leaves. Sapwood is new wood. As newer
rings of sapwood are laid down, inner cells lose their vitality and turn to heartwood
Heartwood
Heartwood is the central, supporting pillar of the tree. Although dead, it will not decay or lose
strength while the outer layers are intact. A composite of hollow, needlelike cellulose fibers bound together by
a chemical glue called lignin, it is in many ways as strong as steel. A piece 12” long and 1” by 2” in cross
section set vertically can support a weight of twenty tons
Pith
Center of the tree. The original stem from which the tree grew
D.o.b. (Diameter outside bark)
the diameter outside the bark as
measured directly with a diameter tape or a Relaskop.
D.i.b. (Diameter inside bark)
The diameter inside the bark. Since all
logs are debarked at the mill, this the part of the log that is converted
to lumber.
Heartwood
vs Sapwood
Heartwood has different lumber qualities than sapwood. Not as
crucial for certain species like western hemlock, but it can be of
paramount importance for lumber grades for other species like
California Redwood.
Springwood
The first wood to grow
after budburst. The wood that grows
springtime. Typically a much lighter
color wood than Summerwood.
Product of a faster growth than
Summerwood, so the wood cells are
less dense, less strong. Aka
“earlywood”
Summerwood
The wood that grows
in the summer is typically growing in
hotter, drier conditions and is a much
denser wood. Noticeably darker than
springwood
Growth Rings
Tighter rings translates to denser
wood. Higher quality wood has
MORE growth rings per horizontal
inch measured. This is an attribute
of slower-growing wood
* Lower quality wood has LESS growth
rings per horizontal inch measured.
This is an attribute of faster-growing
trees.
Increment Borer
Used to determine age of tree
* Used to determine Annual Incremental
Growth.
* Annual Incremental Growth is the yearly
amount of additional wood a tree has put
on on average over a time-period of
interest.
* Increment Borer Parts:
* Handle
* Bit
* Extractor/Spoon
“Clear” Wood
Knot-free. Clear-grade wood is free from knots and blemishes, offering a
pristine and elegant appearance
Structural Lumber
It possesses the necessary structural integrity to withstand heavy loads
and is often employed in framing, beams, and other load-bearing element. Knots are
permitted in certain sizes, as long as they are sound, firm, tight, and well spaced. For
structural timber like Douglas Fir, it is important know how many growth rings per inch the
boards feature. Generally, you need boards with eight growth rings per inch or more, as this
is considered dense structural timber. Growth ring density is not a concern when
purchasing softer woods like Red Cedar or White Pine
Studs
A lower quality lumber, but still used in construction. Lumber of this grade has
strength and stiffness values that make it suitable for use as a vertical member of a wall.
MBF
This is a very common appraisal term. It is the abbreviation for “1000
Board Feet”
Station
This refers to 100’ of road
Whitewood
A northwest conifer species that is NOT Douglas-fir, Spruce or
Cedar. Examples: Western Hemlock, Noble Fir, Grand Fir, Subalpine Fir, Western
White Pine
Hardwood
Another term commonly used to describe deciduous trees.
Examples: Red Alder, Bigleaf Maple, Cottonwood.
Landing
The location where logs are yarded to. This is where they are
processed, decked, and loaded onto trucks.
Shovel Logging
Harvest System
where logs are
moved by using
machines (shovels)
that successively
move trees or
stems from one
pile to another in
the direction of
the landing.
Cable Logging
Taking the logs/trees from the stump area to the
landing area, using an overhead system of winch-driven cables to
which logs are attached with chokers
Choker
A piece of cable end that wraps around a log(s) to fasten the
log(s) to the yarding cables for transport to the landing
Chokersetter/Rigging Crew
The workers in the unit that wrap
chokers around the logs/trees
Feller-Buncher
Grabs hold of trees
and cuts them.
* While still holding
the cut tree it can
direct the tree to
fall where it wants
- falling only
Harvester
Grabs hold of tree the same
as a Feller-Buncher but can
also process the tree into logs
in the woods.
* Typically not as stout as a
feller-buncher, so slower
cutting
* Not as flexible as a processor,
so slower processing
* But a good middle ground if
you want a machine that can
do both. This is an ideal
machine for commercial
thinning
Processor
Cuts trees down into logs.
* Measures lengths and
diameters with sensors and
computer programs in the
cab that tell operator where
to cut to optimize the log
* This is a ‘dangle-head
processor’, and it is ideal for
grabbing lots of logs and
processing them quickly
Shovel
racked equipment with a
grapple on the end
* Used to yard/move logs or
trees from the forest to
the landing
* Also used to load log
trucks
* The key piece of
equipment for the logging
method known as ‘shovel
logging’
Tethered-Logging
A Feller-Buncher or a Shovel
is attached to a cable and
lowered down the mountain
* A anchoring machine is at
the top landing. It spools
out more cable as needed to
lower the Shovel/Feller-
Buncher down the mountain
* The cable keeps the machine
from sliding down the
mountain.
* This is used on steep slopes
Forwarder
typically used in
commercial thinning.
This machine walks
through the thinning
unit and picks up logs,
sets them in its bunks
and transports them
back to the landing
where it unloads them
and then repeats the
process.
Tower Yarder
Uses cables known as
‘guylines’ to anchor it in
place.
* Has one skyline that
hangs over the yarding
corridor and lowers and
pulls back the carriage
with logs attached
* Used for steep slope
logging
* Can yard logs from 2,000’
away
Swing Yarder
A much smaller cable yarding
system.
* As the carriage and logs get to the
landing, the machine turns
clockwise and lowers it’s cables to
set the log load down on the landing
* Used for much shorter distance
logging (100’ – 800’)
* Does not necessarily need guylines
to anchor it, so rig-up time is much
shorter. Trade off is that it doesn’t
get as high of clearance and also
cannot yard as much weight per
load.
* The term for the weight of a cable
yarding turn is “payload”
Yoder
Similar to a swing yarder,
but with a jointed boom.
More flexible but cannot
yard as much payload as a
swing yarder.
Short-Logger
Has a ‘truck’ (the logs on the
front part near the cab) and
a ‘pup’ (the trailer end)
* Capable of hauling short logs
(12’-24’)
* Not capable of hauling logs
greater than 24’
Long-Logger
Most common type of log
truck. Capable of hauling
~35 tons of logs.
* Hauls long logs (32’ – 44’)
Mule-Train
Hauls one end of
long logs (32’ -40’)
plus one pup trailer
of short logs (12’-
16’)
“Whole-Tree Yarding”
Wrapping the chokers around the entire cut
tree
“Fell & Buck”
After the tree is felled, the cutter uses a loggers tape
and specs to hand-cut logs (chainsaw) from the tree. These logs are
then yarded to the landing.
Stumpage Sale
Timber Sale awarded for the timber as it stands; uncut,
unyarded, unshipped. Up to the successful bidder to figure out how to
cut, yard, and ship wood to a mill.
Delivered Log Sale
The timber owner is paid by deliveries into the mill
Lump Sum
Bidder pays one sum for the rights to log the Stumpage Sale
‘By Scale’ / ‘Pay-As-Cut
sales are based on prices per unit volume. For
example For example, a buyer would agree to purchase all DF saw logs
for $500 per MBF, maple saw logs for $120 per MBF, and hardwood
pulpwood for $4 per ton. Prices are typically agreed on and paid by
volume and species regardless of quality
Forest inventory
The systematic collection of data and forest
information for assessment or analysis.
Sustained Yield Concept
Generally concerned with wood production over time
* Should provide a flow of products that is not diminished
over time by the management of the forest.
* Growth and removals are balanced over an extended time
horizon (several rotations)
Area method of regulation
* Dividing the forest into as many areas (units or
stands) of equally productive capacity as there
are years in the rotation and cut one each year
* If they are equal in area, but not productivity, the
annual yield will vary, but the forest will be
sustainable.
Volume method of regulation
Determine the allowable annual or periodic cut in
terms of volume with due regard for:
* Growing stock – current and desired
* Rates of growth – current and potential
Diameter Distribution of regulation
Similar to volume regulation, but is more
applicable to uneven-aged management
Growth Models
Forest and natural resource management decisions are often based on
information collected on past and present resource conditions.
* This information provides us with not only current details on the timber we
manage (e.g., volume, diameter distribution) but also allows us to track
changes in growth, mortality, and ingrowth over time.
* We use this information to make predictions of future growth and yield based
on our management objectives.
* Techniques for forecasting stand dynamics are collectively referred to as
growth and yield models.
* Growth and yield models are relationships between the amount of yield or
growth and the many different factors that explain or predict this growth
Describe Swiss needle cast.
A foliage disease that prevents the needles from photosynthesizing. Only found impacting Douglas fir growing near the ocean. Infections take place in late spring and early summer. Spores are spread via wind and splash.
Describe laminated root rot.
- Laminated root rot, caused by the fungus is responsible for an annual
estimated volume loss of 32 million cubic feet in the West Side
Douglas-fir type. Surveys indicate approximately 5% of the area of
highly susceptible host types in Oregon and Washington is out of
production because of this disease. - It causes growth loss, butt decay, uprooting, and tree mortality
- Highly susceptible-
- Douglas-fir
- Mountain hemlock
- Pacific silver fir, white fir, and grand fir
- Intermediately susceptible
- Spruces
- Larch
- Western hemlock,
- Red fir, noble fir, and subalpine fir
- Tolerant
- lodgepole, sugar, and western white pine;
- Resistant-
- ponderosa pine, western red and incense cedar-,
- Immune
- hardwoods.
- The fungus can survive for decades in large old stumps or roots;
- new hosts are infected when their roots contact old infected
material; tree to tree spread occurs across root grafts and contacts; - infection centers are generally small (less than 1 acre) and scattered
on West Side, large on East Side; - trees of all ages are affected; secondary attack by bark beetles is
common