Midterm Study Guide Flashcards
ROAD MAP
refer diagram
Primary reason we measure forest stands?
to establish value ($/m3)of timber before harvesting
Operational factors that contribute to determining timber value
access(road building, road reconstruction, maintenance) harvest system(cable, conventional, heli) distance markets silviculture obligations forest development
Stand factors that contribute to determining timber value
relate to the individual stand of timber -species -forest health, wood quality,decay -volume -piece size
Tree species symbols
refer page
Revenue implications assoc. with incorrect timber cruise measurements
species info: Decay %, LRF, stud log % tree to truck info: slope %, volume per hectare, blowdown %, wet/dry belt coding
Define LRF
what is it based on?
amount of lumber recovery per cubic meter of merchantable volume (cruise lumber recovery factor) Based on decay %, volume, log length, wet belt/dry belt (BEC) designation
define stud log %
a log whose top diameter is less than 20%
IMPLICATIONS: DECAY %
higher decay % = lower stumpage rates decay % affects LRF points improperly called decay indicators directly affect stumpage rates
IMPLICATIONS: LRF
Improperly called decay indicators impact LRF which impacts stumpage rates high decay %=low LRF=lower stumpage rate low decay %=high LRF=Higher stumpage rate stud % changes impact LRF therefore impacting stumpage rates improper tree heights impact number of log pieces which impacts stud %
IMPLICATIONS: STUD LOG%
driven by log length (stand height) overestimated stand height = increased stud % and LRF=increased stumpage rate underestimated stand height = decrease in stud % and LRF=decreased stumpage rate
IMPLICATIONS: VOLUME/HA (rounding errors)
every m3/ha = approx. $.01/m3 depending on rounding or truncating this could be interpreted as 234m3/ha or 253 m3/ha on 100, 000 m3 = $1000 REVENUE IMPLICATIONS EXTREMELY HIGH
IMPLICATIONS: SLOPE
higher slope % = lower stumpage lower slope % = higher stumpage Generally, slope is incorrectly measured
IMPLICATIONS: blowdown %
improperly called blowdown codes in the field impact stumpage rates high blowdown = lower stumpage low blowdown = higher stumpage
IMPLICATIONS: WETBELT/DRYBELT (IDF)
based on BEC zone dry belt fir stumpage rates are lower than wet belt fir stumpage rates improprerly coded cruise compliations severely impacts stumpage rate and revenue
decay indicators impact…
volume, decay %, LRF
Damage codes impact…
volume, decay %, LRF
Tree Heights impact…
of log pieces, which impacts volume, LRF, stude %
Slope impacts….
tree to truck
rounding/truncating impacts…
volume/ha
wet/dry belt impacts
LRF
PHF
per hectare factor area of ha/area of plot per hectare value = phf x plot value **see examples
variable radius sampling and its advantages
each tree assumed to have its own plot, size of plot determined by size of tree sample angle/critical angle aimed at DBH to determine “in” trees (tree plot includes plot center) ADVANTAGES: no plot boundaries to establish fewer trees to measure mainly larger, more valuable trees measured
define line intercept sampling example of how its used
only measuring in 2D. Distances intercepted along line can be used to determine area occupied by vegetation classes, ground classes, or individual plant species eg)run line 15 m, calculate 3m covered by clint uni = 3/15 = 33% used to measure ground cover for vegetation
define line intersect sampling example of how its used
object measured at point it is intersected by line to measure volumbe of wood on ground, run lines through area..diameter of log/tree measured at point it crosses the log…traverse length average volume/ha can be obtained knowing diameters of all intersected pieces. eg)CWD, waste/residue survey used to determine value of CWD
% live crown, why is it important?
used to evaluate potential tree growth when selecting crop/leave trees top%-crown bottom% / total tree% x 100
ht/dbh ratio and why its important
evaluates stability/suitability of tree for leave/crop tree tall skinny less stable than short, fat Should be <.75 for stable tree *important for windfirmness (high number means poor windfirmness)
General provisions for a cruise:
cruiser’s signature easily referenced tie point
what is measured at each plot once BAF decided?
species, dbh, path remarks, quality
why should changing BAFs within a timber type be avoided?
could intro a bias in terms of summary stand statistics and lead to more errors
how to determine if measure tree is “in”
determine HD from plot center to face of tree at DBH Add 1/2 dbh to HD to get total HD Determine PRF Multiply PRF by dbh to get CD if CD is greater than HD, tree is IN
leaning/down trees-how to measure HD
regardless of direction of lean or position on ground, have to measure HD measured from center of top side of tree at dbh to plot center to determine if tree is “in” or “out”
when is tree considered leaning?
if lower third of stem is more than 10 degrees vertical
how to decide if hidden trees are “in”
move baf away from plot center, keep it at same distance away from tree if tree is “in” above dbh, then it’s in may have to measure it
marking trees
paint or tag has to be put at dbh on tree facing plot center, marked as in or ‘x’ for measured trees that are out
how to estimate broken tree top tree heights
use adjacent trees and comparable tree heights
forked below dbh
2 trees fork 1 for each tree estimate dbh for each tree second tree is counted if it meets timber merchantability requirements
forked above dbh
1 tree fork in 1 measure dbh
no forking (pith intersects below point of germination)
2 trees
no fork in either tree
estimate DBH for each tree
when is path recorded?
when found on bole or merchantable secondary leader.
exception: P. schweinitzii, found at base of tree within 2m
