Silviculture FNR 338/439 Exam 2

Not comprehensive

When are release treatments done?

early in the rotation before trees could be commercially harvested

Trees are selectively removed for four reasons

Too small, low quality, not enough merchantable material to justify harvesting them, and removal may damage everything else

Three mechanical ways to kill a tree and leave it standing

Axes (aka girdling), power brush saws, heavier equipment

Three chemical ways to kill a tree and leave it standing

stem applications/hypo hatchet, mist blowers, aerial applications

Cleanings

Cuttings made in an age class not past the sapling stage to get rid of the unfavorable trees of the same age class so they won’t overtop the favored trees

Species that you might clean

paper birch, white pine

Weedings

cuttings made in an age class not past the sapling stage to get rid of yuck vegetation regardless of crown position

Cleaning vs weeding

Cleanings are selective at the tree level, weedings aren’t. Cleanings release a small number of good crop trees, weedings eliminate an entire species in favor of another

Inverted cone concept of cleaning

Cut or kill only the trees whose crowns intersect the inverted cone of the crop trees on the chosen spacing

Liberation cutting

a release treatment made in a stand not past the sapling stage to free favored trees from older overtopping trees

5 times early release treatments are too early

trees are too small to respond, the new growing space will be reinvaded, crop trees haven’t shed to the right clear bole height, could induce attack by pests like blister rust, the method of release could damage stock (herbicides)

3 times early release treatments aren’t early enough

lcr of the crop trees is too low, treatment cost too high, treatment can be carried out by a commercial harvest

improvement cutting (AKA TSI)

cutting made in a stand pole-size or larger to improve composition and quality by removing less desirable trees of any species

microsite

immediate environment of the germinating seed and developing seedling

four variables that describe the environment and growth potential of the microsite

light, temperature, moisture, nutrient availability

PAR

photosynthetically active radiation; the wavelengths of light a plant can actually use

canopy gaps

all wavelengths available, lots of PAR

diffuse/open overstory

mostly blue light, some PAR

dense canopy

only green shade, no PAR

what microsite conditions cause PAR differences?

Type (deciduous/evergreen), light tolerance, density, phenology, height

what level of shade intercepts all available light?

low shade

what level of shade creates diffuse light conditions in the understory?

high shade

high vs low shade

living plants cast this shade; describes the distance of the plant to the seedling

dead shade

cast by non living materials and somewhat beneficial because it’s not competitive

dead shade is also

mulch

lethal microsite temp

50 celsius

how to keep microsite not too hot two ways

reflection with shade, conduct heat from surface

loose leaf litter as a microsite- two things

stable soil surface, good insulator

exposed mineral soil

high extremes if dry, conducts heat from surface if moist

loam soils

BEST for nutrients

clay soils

bind nutrients tightly

sandy soils

get leached of nutrients

5 kinds of dormancy

chilling, serotiny, scarification, buried seed, and tropical recalcitrants

natural regeneration will either be

produced after the disturbance by survivors or stored and survives disturbance

two kinds of natural regeneration that is stored on the site

serotiny or dormant seed

four kinds of regen produced on site

parents off site, parents on site, sprouting rootstocks, advance regen

regen method for parents off site

clearcutting

regen method for parents on site

seed tree or shelterwood

regen for serotiny

clearcut with slashed tops left

regen for dormant seed

clearcut or shelterwood

parents on site regen species

yellow poplar, paper birch, white spruce, aspen

parents on site regen species

oak, hickory, douglas fir, white pine

serotiny regen species

lodgepole, jack, pitch, table mountain

dormant regen species

yellow poplar white ash (limited) pin cherry raspberry (longer)

regen method for sprouting rootstocks

coppice

sprouting rootstock regen species

aspen, beech, oak, red maple

advance regen method

shelterwood or selection

advance regen species

balsam, red spruce, hemlock, sugar maple, oaks

density

absolute measure of stand occupancy per unit area

4 examples of density measurements

stems per unit area, basal area, merchantable volume, biomass

stocking

indication of growing space occupancy relative to a pre established standard

two kinds of stocking

optimal and absolute

optimal stocking

standard is based on some optimal condition

absolute stocking

standard is based on theoretical biological principle

percent stocking

measure of growing site occupancy

percent stocking equation

%stocking = TPA observed / TPA of A line with tree size (QMD) held constant

CCF

crown competition factor

CCF equation

((sum of all crown projection areas) / ground area ) x 100

Reineke’s stand density index (SDI) was the

first observation of a size-density relationship (1933)

SDI max is

max number of 10 inch trees observed

Reinke’s SDI equation

TPA (QMD/10) ^1.605

two kinds of DMDs

volume based and diameter based

relative density

a measure of the actual stand density compared to the max density that could occur for a given site and tree size

RD equation

TPA observed / TPA max size density line

neither sticking charts nor DMDs have what

an explicit temporal component

regeneration method

the cutting method by which a new age class is created

regeneration period

the time between the initial regeneration cutting and the successful re establishment of a new age class by natural or artificial means

four factors that distinguish among the different regeneration methods

origin of regeneration, seedling microenvironment, planned age structure, length of regen period

single cohort, aka

simple coppice

multi cohort, aka

coppice with standards, or compound coppice, or selection coppice

for multiple cohorts what is the name of the planned age structure

selection

what is the size of regeneration openings for 1 mature tree called

single tree selection

what is the size of regeneration openings for 2+ mature trees called

group or patch selection

height of regeneration when overstory is removed for seedlings is called what and is what length of regen period?

conventional, 1-5 yrs

height of regeneration when overstory is removed for saplings is called what and is what length of regen period?

extended, 10-20 yrs

height of regeneration when overstory is removed for large saplings, poles is called what and is what length of regen period?

irregular, 20+ yrs

high forests get what kind of reserves?

with reserves

low forests get what kind of reserves?

with standards

goal of preparatory cuttings

prepare for regeneration by developing good seed bearing trees and eliminating undesirable seed sources

when are preparatory cuttings optional

when regeneration will establish naturally without treatment

how many cuttings should you do with preparatory cuttings

one

whats another name for preparatory cuttings

midstory removal

goal of establishment cuttings

advance regen

establishment cuttings focus on

removing overstory and prepping seedbed

goal of overstory removal cuttings (OSR)

remove the overwood to promote the growth of the established regen

two kinds of OSR

complete and incomplete

complete OSR

all the overstory removed

incomplete OSR

only some of the overstory removed

OSR vs shelterwood

all OSRs are incomplete and mature trees are retained into the next

rotation, this is a shelterwood with reserves

only essential cut in shelterwood system

OSR

what is the regen period in a shelterwood

time between the establishment and final OSR

3 temporal variants

conventional, extended, irregular

conventional variant

Overwood removed as soon as seedlings are established. Used for intolerants. 3-5 yrs

Extended variant

Final removal cutting delayed until advance growth is sapling size (above bh). Often used for intermediates and tolerants. 10-25 yrs

Irregular variant

Some lower-stratum trees of the older cohort held over into the next rotation (often to pole-

size or larger); regeneration period extended indefinitely

3 spatial variants

uniform, group, strip

uniform

regeneration is uniform in stand by leaving uniform overwood in establishment cutting

group

separate patches within the stand are at different stages of the shelterwood sequence

strip

like group except that patches are linear

3 reasons to use group shelterwood

takes advantage of patchy advance regen, increase spatial diversity, keeps mature trees on site longer