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SILVICULTURE - Coggle Diagram
SILVICULTURE
OBJECTIVES OF
SILVICULTURAL PRACTICES
control
composition
restrict composition
no. of spp < that of forest
stand density
unoccupied space
unproductive for sparsely spaced
trees too branching
excessively dense
cant grow at optimum rate
maintain enough trees
stock areas at each stage
rotation length
ROTATION
period of yrs
required to grow a crop of timber
specified condition
economic maturity
natural maturity
optimum size & age for timber
shorten rotation by regulating stand density
crop grow earlier
restock
unproductive areas
protection & salvage
protection
modification
silvicultural techniques
proper control
damaging agencies
facilitate harvesting, mgmt, & use of forest
plan
stand growth
consider
location
composition
age classes
protection of site and indirect benefits
also for wildlife & grazing animals
aesthetic beauty
managed forest is more productive
than unmanaged forest
SILVICULTURE
art
produce & tend
forest
apply silvics knowledge
forest treatment
imitation of nature
forester
ecology
plant physio
entomology
social science
combination
improvement upon
limitation of natural process
forest growth
DEFINITIONS
STAND
contiguous group of trees
uniform in species
composition
arrangement of age classes
homogenous & distinguishable unit
FOREST
collection of stands
administered as an integrated unit
INTENSITY
amt. of effort
expended
treatment & care of stands
DEGREE OF
INTENSITY
amt of money
invested
cultural treatment
frequency
severity of cutting during the rotation
JUVENILE WOOD
low utility
rapid growth
found in central core
most coniferous stem
SILVICULTURAL SYSTEMS
planned program of treatment
whole life of stand
achieve objectives
stand structure
treatment
integrate
harvesting
regeneration
stand tending methods
predictable benefit yield
REPRODUCTION/REGENERATION
mode
HIGH FOREST
from seeds
reproduction methods
CLEAR CUTTING
all trees removed
larger/smaller
reproduction through
artificial regeneration
natural regeneration
applicability
spp that can be established thru full exposure
stands
thoroughly mature/overmature
if partial cutting is more costly
SEED TREE METHOD
clear cut except some trees
seed trees
left singly
distributed in groups
B. Pine
1 more item...
characteristics
3 more items...
SHELTERWOOD
series of gradual cutting
toward the end of rotation
kinds of cut (sequence)
PREPARATORY CUTTING
light partial cut
1 more item...
SEED CUTTING
to favor regeneration
1 more item...
REMOVAL CUTTING/ FINAL CUT
free the establishment of seedlings
SELECTION METHOD
uneven aged
regeneration are always protected
older age classes are around
mature timber removed
singly scattered trees
small groups
short intervals
modifications
SINGLE TREE SELECTION
individual trees removed
1 more item...
GROUP SELECTION
small groups of trees are cut
2 more items...
LOW FOREST
from vegetative part
PROCESS/CONSEQUENCES OF CUTTING
opening
canopy
ground
PARTS OF SILVICULTURAL
PRACTICE
A. Method of Reproduction
Reproduction/Regeneration
act of replacing old trees
naturally
artificially
MODE
HIGH FOREST
from seeds
METHODS
CLEAR CUTTING
SEED TREE METHOD
SHELTERWOOD
SELECTION METHOD
MODIFICATION
SINGLE TREE SELECTION
GROUP SELECTION
LOW FOREST
use of vegetative part
ADVANCED REPRODUCTION/REGENERATION
appear b4 any special
measures are undertaken
to establish a new growth
ex
reproduction/regeneration
cuttings
made w/ 2 purposes
remove old trees
create envi condition favorable
establishment of reproduction
B. Intermediate Cuttings
THINNING
OBJECTIVES
redistribute growth potential
optimum advantage
utilize all merchantable materials
during rotation
BASIS OF SELECTION
relative condition & position of the crown
health of the tree
condition & quality of bole
in mixed species
choice of species affects selection
EFFECT ON TREE DEVT
regulate amt. of growing space
↑ moisture & nutrient supply
more rapid lateral root expansion
↑ degree of taper
coz of dia. growth
↑ height growth
v. dense,, cause ↓ height coz of
branch & lower bole growth
halt natural pruning
stimulate devt of large branches
TYPES
LOW THINNING
Thinning from Below
lower crown classes
smaller trees are removed
difficult to profit from
leave dominant & co-dominant
German Thinning
Ordinary Thinning
CROWN THINNING
has immediate cash return
stimulate growth of selected crop trees
French Method
Thinning From Above
High Thinning
dominant & interfering dominant are removed
best
mixed stands
pure stand of tolerant spp.
SELECTION THINNING
dominant trees are removed
stimulate growth of the trees at lower crown class
conifers
eliminate dominants
rough
poorly formed
release least vigorous trees
better form
not suitable for even-aged
MECHANICAL THINNING
trees to be removed are selected
predetermined spacing/pattern
2 PATTERN
SPACING THINNING
distances chosen
for retention
1 more item...
ROW THINNING
trees are cut in
lines/ narrow strips
fixed intervals
done in stands
young
densely crowded
often followed in
pre-commercial thinning
investment in future growth
commercial thinning
all/part of felled trees
are extracted
useful products
if enough to cover
operation cost
FREE THINNING
w/o regard
form
position in crown canopy
used in:
eliminate scattered undesirable dominant
release crop trees
salvage
all overtopped undesirable trees
thinned well-stock portion
done in irregular
age
density
composition
applied in
1st thinning
untreated stands
MAIN CONSIDERATIONS
method of thinning to be used
each stage of rotation
timing of 1st and subsequent thinnings
1st thinning
when crowns/root
closed and intervene
criteria
live crown ratio
subsequent thinning
criteria
rate of growth of crop trees
young stands
frequently
close up rapidly
done once every profit
15 yrs to elapse b4 next thinning
determine approx. how much growing stock will be left
after each thinning
control stand growth
adjust stand density
stimulate growth of trees that remain
increase total yield of useful mat. in stand
Convenient parameters of
Stand Density
basal area
most common
parameter
sum of square of dia. of tree
relationship bet.
heigh/dia & spacing
volume per acre
functions of stand density
(normal stocking)
RELEASE CUTTINGS
OBJECTIVES
have enough light & growing space
2 KINDS
CLEANING
cutting in stand
not past the sapling stage
free the best trees
undesirable individuals
same age
overtop or will likely overtop
remove trees w/
poor form
WEEDING
remove all plants
competing w/ crop spp
regardless of crown
above/below/beside
applied to
new stands
after establishment
LIBERATION CUTTING
free a young stand
competition
older
overtopping individuals
not past sapling stage
METHODS
CUTTING
GIRDLING
severe bark, cambium
sometimes sapwood
carbohydate thru
phloem
1 more item...
best time
during most active growth at their lowest ebbs
exhausted food reserves
root die
APPLICATION
young crop/trees/stand
potentially good trees
overtopped
2 more items...
reap benefits
release young & vigorous seedlings
to overtake much older saplings
regulate stand composition by spp
improve quality of v. young stands
LETHAL EFFECT
surrest & most direct
way to kill plants
tear it bodily
out of the soil
IMPROVEMENT CUTTINGS
eliminate poor trees
in favor of good stems
poor trees:
inferior trees
crooked, leaning, badly formed, extremely limlbey
overmature individuals
seriously injured
biotic factors
atmospheric agencies
same purpose as
release cuttings
made in stands past
the sapling stage
improve composition
& quality
remove trees of
undesirable
species
form
condition
main canopy
older
good trees
PRUNING
TYPES
NATURAL/SELF-PRUNING
elimination of branches
physical factors
biotic facctors
OBJECTIVES
prevent loose knot formation
loose knot
knot in wood which is not firmly in place and may fall out
production of clear material on rotation shorter
ARTIFICIAL PRUNING
removal of branches
chosen stem portion
to increase the quality & value of crop ultimately harvested
STEPS
A. KILLING
B. SHREDDING OF BRANCHES
C. OCCLUSION OR HEALING
depends on dia. growth of bole
FOR LUMBER PRODUCTION
young stands dense enough
lower branches
dont grow larger than 1 - 1 1/2 in diameter
EFFECTS
ON TREE
injury to the bole
eliminate too much on live crown
bark & pitch pockets
pitch pocket
cavity in lumber that contains or has contained resin.
bark pocket
An opening between tree annual rings which contains bark.
OF LIVE PRUNING
ON GROWTH
serious retardation on growth
suppression of pruned by adjacent pruned trees
CHAR. OF TREES
best trees
those that will be harvested soon
no. of trees to be pruned
depends on space that each will occupy
end of rotation
START & HEIGHT
commence in youth
when lower branches start to die
when adequate differentiation into crown classes has taken place
1st operation
pruning branches
reached by standing person
continued upto
topmost of dead branches
below the living crown
up to 17 feet
bases 16 ft log
cutting or branches
cuttings
during devt from
reproduction stage to maturity
regulate growth
improve existing stands
provisions of early financial returns
C. Protection
SALVAGE CUTTING
remove trees
have been/ abt to be
killed/ damaged
injurious agencies
OBJECTIVES
utilize injured trees
minimize financial loss
PRE-SALVAGE CUTTING
anticipate damage
remove highly vulnerable trees
OBJECTIVES
harvest trees
vulnerable to loss
protect technical structure of trees and their position in stand
if vulnerable to climatic agencies
SANITATION CUTTING
eliminate trees
attacked
prevent spread
COMPONENTS FOR
SUSTAINED MGMT
REGENERATION
NATURAL
ARTIFICIAL
seeding
DEPENDS ON TYPE
OF HARVEST METHOD
THAT WILL BE USED
planting
TENDING
RELEASE TREATMENTS
PRUNING
THINNING
INTERMEDIATE TREATMENTS
treatment during that
portion of the rotation
not included in the regeneration period
types
THINNING
to control growth
adjustments in stand density
RELEASE CUTTINGS
to regulate stand composition by spp
improve quality of v. young stands
IMPROVEMENT CUTTINGS
made in older stands
to release cuttings
PRUNING
cutting of branches
HARVEST
CLEARCUTTING METHOD
SHELTERWOOD METHOD
SELECTION METHOD
SEED-TREE METHOD
OTHER PARTIAL CUTS
TWO-AGED METHODS
SILVICS
branch of ecology
treats
life of trees
forest
studies
life history
gen. characteristics
forest trees
stands
environmental factors
growth & devt
single trees
forest
biological unit
foundation of silviculture
PURPOSE
timber production
ensure permanent productivity
goods & benefits
WASTE & DESTRUCTION
materials left
tops
failure to utilize
trunk up to minimum merchantable height
unnecessarily in high stumps
partially unmerchantable trees
wind fall trees
dead trees
damage to soil
log transportation
EFFECT OF CUTTING ON
THE STAND STRUCTURE
2 TYPES OF STAND
AGE/STRUCTURE
EVEN-AGED STAND
same age classes
at least 20% period
bet. oldest & youngest
UNEVEN-AGED STAND
2 CLASSES
BALANCED UNEVEN-AGED STAND
3 or more diff. age classes
each class occupy approx equal areas
age classes spaced @
uniform intervals
from newly established reproduction
to trees near rotation age
IRREGULAR UNEVEN-AGED STAND
dont contain all the age classes
no assurance that will have trees at
rotation age @ short internals indefinitely
ex
uneven aged virgin stands
stands culled out w/o plan