Silviculture FNR 338/439 Exam 3

If there was a third exam, this would be it

removals are called

selection cuttings

time between cuttings is called the

cutting cycle

selection cuttings do what three things

harvest mature trees, tend immature cohorts, regenerate a new cohort

what is the application of single tree selection?

shade tolerant species that consistently regenerate

what is the application of group selection?

intermediate or intolerant species to mimic nature

hybrid selection

a combo of single tree with scattered groups used in mixed species forests of multiple shade tolerances

regulation

helps maintain an even flow of harvested timber from a large piece of land

area regulation

same area on average each year

structure based regulation

cut annual growth everywhere each year

two assumptions of structure based regulation

each age class occupies equal area, and cohorts differ by a consistent time interval

BDq method, define value B

B= target stand basal area

BDq method, define value D

max DBH

BDq method, define value q

Ratio of number of trees in adjacent 2 inch dbh classes

Pine forest q

1.1

sugar maple q

1.4

mixed hardwood q

1.9

3 variants of seed in clearcut

seed rain from adjacent uncut stands, seed in situ, artificial regen

seed rain use and size and details

wind dispersed seeds, 1-6 tree heights wide, seed catch must be immediate

seed rain species

douglas fir

why use progressive strip clearcutting

increase the size of the clearcut in relation to seed rain distances

where can seed be from in situ

seed bank or serotiny or crown

how to open serotiny or crown

lop and crush, fire, hot ground

seed bank serotiny example

lodgepole, oak

seedbank open species

yellow poplar, blach cherry, ash

2 reasons natural regen is risky

every step must succeed, no second chances (seed used up and competition)

artificial regen species

douglas fir and loblolly pine

3 seed tree system cuts

preparatory cut, seed tree cut, removal cut

preparatory cut

focused on improving seed tree vigor and windfirmness

seed tree cut

removal all but seed trees

removal cut

remove seed trees to release regen

4 seed tree characteristics

proper species, large crowns/high seed production, windfirm, phenotypically superior

stump sprout species

most hardwoods, coast redwood

root sucker species

aspen, beech, sweetgum, tulip poplar

when to thin sprout clumps?

Wait until sprouts have expressed dominance and residuals can be pruned (if needed) one lift

When to harvest coppice to maximize regen?

during dormant season

site prep

manipulation of site to enhance regen success

5 methods of site prep

rx fire, mechanical, herbicide, timber harvest, fertilization

6 mechanical methods

raking, shearing, chopping, mastication, scarification, bedding

3 things to know about using a disk for scarification

good for light to moderate litter and duff, site cannot be rugged, little midstory or saplings

3 things to know about using a dozer for scarification

needed for deeper litter and duff, site can be a bit more rugged, remove midstory at same time

if you’re gonna scarify an oak site

you need a lot of acorns

3 purposes of fertilization

increase NPK quality of site, amend soil for deficiencies, change pH

fertilization rates depend on four factors

targeted species, site properties, timing of year, tree age

mastication purpose

fuel reduction after harvest or for plantation prep

two kinds of divergence over time

gradual and abrupt

three stratification patterns

divergence, convergence, none

gradual divergence

continual divergence over time

gradual divergence species

NRO, RM, Black birch

abrupt divergence

rapid initial divergence then parallel growth

abrupt divergence species

aspen over white pine, red oak over hemlock

convergence

new intolerant cohorts gradually catch up with older and taller advance regen of tolerant species

where does no stratification occur

forests with high species diversity or species with similar growth characteristics. microsite more important

advantages of mixed species stratified stands

grows high quality crop trees at low density without drawbacks

monoculture

small crown, little differentiation, crowded B stratum

Mixed species stand

emergent crop trees have large crowns but boles are shaded by trainers from the lower stratum

what four things do you need to understand for each species in the mixture

height growth patterns, growth potential to respond to release (or not), life span (relative to others), markets and financial maturity

disease

harmful deviation from the normal structural or functional state of an organism

what causes a disease

pathogen

what is a sign of a disease

the physical appearance of a pathogen

what is a symptom of a disease

a change in form or function of an organism as caused by a pathogen

sign examples

fungal fruiting bodies, mycelial fans

symptom examples

chlorosis, early leaf abscission

four kinds of pathogens

obligate parasite, facultative saprophyte, facultative parasite, obligate saprophyte

obligate parasite

must have a living host

facultative saprophyte

may use dead material but is mostly a parasite

facultative parasite

may act as a parasite but is mostly a saprophyte

obligate saprophyte

only gains nutrients from dead organisms

predisposing factors

make stuff more susceptible

inciting factors

temporary stressors that make stuff more vulnerable

contributing factors

usually end in death

direct management

addresses the damaging agent

indirect management

manipulates the vegetation or hosts of agent

susceptibility

likelihood that a biotic pest will attack the host tree or species

vulnerability

likelihood that pest will cause damage if the pest attacks

sanitation cutting

remove trees or vegetation to prevent or slow the spread; proactive

pre salvage cutting

remove vulnerable trees before they are attack

salvage cutting

harvest dead or dying trees to recover value

2 abiotic damaging agents

fire and wind

two options to prevent fire problems

rx fire, PCT/CT with burning of slash

4 ways to stop wind damage

no hard edges, don’t do funnels, use appropriate species and treatments, keep HT:DBH ratios low

10 biotic damaging agents

bark beetles, gypsy moths, ash bore, thousand cankers, white pine blister rust, chestnut blight, dutch elm, laurel wilt, oak wilt, asian long horn beetle

bark beetles like

conifers

gypsy moth likes

oak