FNR 439 Exam 2

What influences the microsite?

- aspect, slope, climate, soil texture, latitude, veg., soil

Density

Exact measure of stand occupancy per unit area

Stocking

Relative measure of stand occupancy; indication of growing space occupancy relative to pre-established standard

Examples of density measurements

- stems/acre

- basal area (ft^2/ac)

- merchantable volume

- biomass

Optimal stocking

Standard based on some optimal condition

Absolute stocking

Standard based on theoretical biological principle

Density Trends Over Time - TPA

overall decrease in TPA

- tolerant species higher than intolerant

Density Trends Over Time - BA

BA increases over time

- hardwood > softwood

- tolerant > intolerant

Stocking charts

Graphical representation of stand density

Diameter isolines

Combinations of basal area and stems per unit area with the same quadratic mean diameter

A-line

Stand that has never been managed; overstocked

C-line

Stand that will grow to the B-line in 10 years; understocked

B-line

Stand that is just dense enough to achieve crown closure; fully stocked

Percent stocking

Measure of growing site occupancy; used to correct estimates from yield tables

Percent Stocking Equation

TPA(observed)/TPA(a-line)

Crown competition factor (CCF)

Measure of crown projection areas relative to ground area

CCF Equation

(sum of crown projection areas/ground area)*100

Optimal standards

Density standards based on some optimal condition; CCF = b-line, normal stocking = a-line

Absolute standards

Density standards based on theoretical maximum density

Reineke's Stand Density Index (SDI)

Measure of stand density based on number of trees per unit area and quadratic mean diameter; varies by species and location; higher SDI = more shade tolerant

-3/2 Self-Thinning Law

Relationship between tree size and density in a stand; larger trees in less dense areas

-3/2 Self-Thinning Law Equation

aN^-1.5

Relative density

Measure of actual stand density compared to the maximum density

Volume Based DMD (ft2/tree)

- More common

- Need volume conversion to DBH for practical use

Diameter Based DMD (QMD, SDI)

- Easier to use in field

- Less robust as DBH-volume relationship changes with density

Relative Density Equation

TPA(observed)/TPA(max stand density line)

Stocking Charts vs. DMDs

- stocking chart: even aged stands, hardwood species, developed from crown width relationships (built up from B)

- DMD: even aged stands, commercial conifer species, based on ecological theory, display non-timber factors (built down from max SD line)

Stocking Chart Graph

- x: TPA

- y: BA/acre

- QMD at top of chart

- a, b, c lines

CCF Stocking Chart

- x: TPA

- y: BA/acre

- QMD at top of chart

- CCF levels

DMD Chart

- x: TPA

- y: avg volume

- right side: QMD

- lines for height

- crown closure line down the middle

In a pole-size stand, I removed all undesirable species by girdling and felling individual stems. Trees were left in situ. What treatment did I do?

Improvement cut

Describe the inverted cone concept for cleaning.

- used when 4 sided thinning isn't enough (small trees)

- cut trees whose crowns touch inverted cone of crop trees

- usually 45 degrees; wider angle = heavier release

In a sapling-sized oak stand, I removed large, much older trees that were left after a harvest of a prior stand because they were interfering with the growth and development of my crop trees. What treatment did I do?

liberation cut

What side of a 0.5 ac regeneration opening is going to receive the most cumulative sunlight over the course of a growing season in Indiana?

north

List the four "ways" regeneration is stored on the site to survive a natural disturbance or a harvest.

- unopened serotinous cones- dormant seed in forest floor- sprouting rootstocks- advance regeneration

Please put the following stages of the natural regeneration process in the correct order from earliest to latest: Seed supply, Flowering, Seed dispersal, Germination, Succulent stage, Establishment and growth, Dormancy

1. flowering

2. seed supply

3. seed dispersal

4. dormancy

5. germination

6. succulent stage

7. establishment and growth

List 3 reasons why reserves and standards should be incorporated into most regeneration methods.

- to ensure structural diversity

- to provide future coarse woody debris

- to increase value of reserve trees (ie. leaving financially immature trees)

Within a loblolly pine plantation, removal of 5 adjacent rows every 20 rows for sawtimber and telephone poles. Harvested rows are replanted soon after.

strip clearcut

Removal of all trees of commercial size (>6" dbh) in a mixed hardwood stand

commercial clearcut

Uniform removal of most of the overstory in a western larch stand, leaving scattered individuals for a seed source.

seed tree

Harvest of all aspen stems from an aspen stand with scattered white pine (10 tpa). The white pine is kept for another aspen rotation

coppice w/ standards

Removal of 50% of overstory stems in small localized areas in an oak stand, with intent to remove remaining oaks when resulting oak regeneration is at least 6' in height. At that time, another localized area will have 50% of overstory stems removed.

extended shelterwood

Cleaning

Cuttings made while saplings to free favored trees from lower quality competition in the same age class; similar to crown thinning; selective - releases crop trees

Weeding

Cuttings made while saplings that eliminates or suppresses

undesirable vegetation regardless of crown position; nonselective - removes species

Release Treatments

- kills trees where they stand

- mechanical or chemical removal

- done before commercial harvest

Mechanical Removal Examples

- axes

- chainsaws or brushsaws

- heavy equipment

Chemical Removal Examples

- stem applications

- mist blowers

- aerial applications

Reasons to remove trees in release treatments

- too small

- low quality

- not harvestable

- mechanized removal would damage residual stand

Trainers

trees left to shade the bole of crop trees

Importance of cleaning in oaks

- release saves 40% of I, 80-90% of D/C

Liberation Cut

Cutting made while samplings in order to free the

favored trees from competition of older, overtopping trees.

What's too early for release treatments?

- trees too small to respond

- vacated space will be occupied by vegetation

- crop trees not yet shed branches off bole

- could induce pest attacks

- method of release could damage stock

What's too late for release treatments?

- LCR of crop trees is too low

- treatment cost prohibitive

- treatment can be carried out soon by commercial harvest

Improvement Cutting (aka TSI)

Cutting made in a stand pole-sized/larger primarily to improve composition and quality by removing less desirable trees of any species.

When to use TSI?

- stands of poor quality timber, but with good potential

Why to peel/girdle trees?

- leaves wildlife habitat

- prevents sprouting

What factors create the microsite?

- describe: light, temperature, moisture, nutrient availability

- control: aspect, slope, climate, soil texture, latitude, veg., soil

Common microsite light conditions

- canopy gaps: all wavelengths available, lots of PAR

- open overstory: mostly blue light, some PAR

- dense canopy: green shade, no PAR

What causes differences in PAR?

- type of tree (deciduous/coniferous)

- light tolerance

- density

- phenology

- height

Types of Shade

- high shade: cast by living veg, affects understory

- low shade: cast by living veg, canopy

- dead shade: cast by non-living materials; doesn't filter PAR

Temperature of Soil

- leaf litter: insulator, stable at soil surface

- mineral soil: extremes if dry, conducts heat if moist

Water

- balance between transpiration and respiration

Nutrient Availability

- loamy soils are best (clay = binding, sand = leaching)

Flowering

- stand must contain sexually mature individuals

- environmental conditions determine seed set

Seed Supply

- cyclical patterns of masting (ie. high mast years)

- dominant trees produce most seeds

Seed Dispersal

- wind, gravity, water, mammals

- can affect regen method

Storage/Dormancy

- prevents seeds from germinating in wrong conditions

- chilling, serotiny, scarification, buried seed

Germination

- depends on moisture, oxygen, heat

Succulent Stage

- ends when bark tissues form

- heat injury possible in dry mineral soil

- damping off fungi possible in cool/wet conditions

Establishment & Growth

- roots have to keep pace w/ drying of soil

- light is limiting factor once roots reach water

Natural Regeneration

- produced after disturbance by surviving trees

- stored on site and survives disturbance

Examples of regen produced after disturbance

- parents located off site (clearcutting)

- parents surviving trees (shelterwood, seed-tree)

Examples of regen stored on site

- unopened serotinous cones (clearcut w/ chopped tops)

- seed bank (shelterwood, clearcut)

- sprouting rootstock (coppice)

- advanced regen (shelterwood, selection)

Barriers to oak regen

- thick leaf litter/duff layer

- dense canopy cover

- predation by animals

Regeneration Method

A cutting method by which a new age class is created.

Regeneration Period

time between the initial regeneration

cutting and the successful re-establishment of

a new age class by natural or artificial means

Factors b/w Regen Methods

- origin of regeneration

- seedling microenvironment

- planned age structure

- regen height at overstory removal (length of regen pd)

Low Forest

- regen from vegetation (coppice)

- root/stump sprouts, layering, cuttings

High Forest

seed origin

Simple Coppice

- single cohort, regen from vegetation

Coppice w/ standards

- multiple cohorts, regen from vegetation

Selection

- multiple cohorts

- 1 tree opening: single selection

- 2+ tree opening: group/patch selection (less shade tol.)

Even or Two-Aged Structure

- area based control

Clearcut

- seed from adjacent stands, buried seed, harvested trees

Seed Tree

- seed from tree left standing on site

Shelterwood

- partial shade, before overstory is removed

Conventional Method

1-5 yr regen period

- seedlings

Extended Method

10-20 yr regen period

- saplings

Irregular Method

20+ yr regen period

- extends into next rotation

Strip

- conducted in linear groups adjacent to each other

Group

- conducted in small areas of stand

Patch

- conducted in larger areas of stand

Reserve Trees

- leaving trees behind for reasons other than regen:

- reserves for high forest

- standards for low forest

Why leave reserves?

- financially immature

- enhance biodiversity/structure

- aesthetics

- conserve rare species

- provide future CWD

- reduce density of younger cohorts

Clearcutting as Logging Practice

- clearing most/all merchantable timber

- complete: removes everything

- commercial: removes valuable trees (highgrading)

Clearcutting as Silvicultural Practice

- removes all overstory & understory vegetation

- includes site prep

What are the cuttings in a shelterwood?

- prepatory

- establishment

- overstory removal

Prepatory Cuttings (aka Midstory Removal)

Prepare for regeneration by developing good seed-bearing trees and eliminating undesirable seed sources.

- often skipped if previously thinned

- optional if regen will occur naturally

Establishment Cuttings

Establish advance regeneration; resembles low thinning

- one cutting: overstory removal & seedbed prep.

- optional if regen can occur under canopy (tolerant spp.)

- leave best seedbearing trees

-synchronize w/ good seed year (or need mech removal)

When are oak seedlings competitive?

4.5-5ft; base of seedling is > thumb