Thanks for Coming - Your participation and thoughtful questions will make our presentation more applicable for you and the rest of the group.

- SAF Continuing Forestry Education Credit.- sign in and take a certificate of attendance.

Program Outline

- Morning discussion, afternoon outside

- Please understand if we may need to cut something short to stay on task.

- Can re-start truncated discussions during the afternoon field session.

- The program is arranged as many loosely related topics. Bear with us. We will attempt to pull them together in the end.

Goals for the Day

Dave and Lou’s Goals; 1. Brief overview of 9-week silvicultural training, 2. Translate to the practice of silviculture in Vermont, 3. Facilitate discussion within the forestry community.

We hope your goals are to; 1. Learn something,

2. Tailor presentation to suit your interests,3. Refresh memories from Undergrad and Grad School,4. Take part in a larger discussion of Vermont silviculture.

National Advanced Silviculture Program

Program Background

The goal is to prepare silviculturists to design prescriptions that meet the Minimum National Standards for Silviculture Certification.

4 National Modules

1 Local Module For Region 9 this has been in Michigan

Project Development and Defense

Ecological Systems

Inventory/ Monitoring and Decision Support

Landscape Ecology in Theory and Practice: Application to the Study and Management of Public Lands

Advanced SilvicultureIn Southern Hardwoods

National Advanced Silviculture Program

A great deal of informationSome direct application to Vermont,

but not all

Definitions

Concepts

Discussion

Silviculture (D.M. Smith)

• The art of producing and tending a forest.

• The application of knowledge of silvics in the treatment of a forest.

• The theory and practice of controlling forest establishment, composition, structure and growth.

Vermont Silviculture

The theory and practice of influencing the establishment, composition, quality, structure and growth of forests.

Some have said there should be a clear statement of responsibility to maintain

ecosystem health

• So what about this definition of silviculture?

• Silviculture is the theory and practice of influencing the establishment, composition, quality, structure and growth of forests, while maintaining or enhancing ecological function.

• Your thoughts?

Silviculture -- Clatterbuck

• Is not cookbook• Infinite variation• Must be able to think and assess situations

and be able to improvise and apply knowledge to complicated situations that are encountered in the field

Stages of Stand Development (Oliver & Larson)

Stem Exclusion

Understory Reinitiation

Old Growth

Stand Initiation

Silvicultural Implications

• Site preparation to favor a certain species• Shade tolerance can alter future species composition• Regeneration mechanism advantage – (sprouts, heavy seed, wind blown seeds, seed bank…)• Timing of harvest can influence regeneration• Density ---- too many or too few

Natural Systems

• Follows major disturbances (wind, fire, wide spread insect outbreaks…)• Regeneration of open space from seed, sprouts & advance regeneration• One cohort or age class• Stage ends when canopy becomes continuous and trees begin to compete with each other for light and canopy space.

Stand Initiation

Silvicultural Implications

• Few if any additional trees will grow into the canopy• All growing space is occupied with a chance of stagnation• Harvests can shape the desired condition and composition of the stand• Density/ spacing influences growth rates• Canopy gaps small enough to preclude establishment of understory regeneration

Stem Exclusion

Natural Systems

• Closed canopy precludes understory regeneration• Canopy continues to have one cohort• Stems compete for space and “self-thinning” occurs (density dependant mortality)• Species composition is influenced by:

growth rates of tree species, initial crown position, persistence/ tolerance

Understory Reinitiation

Silvicultural Implications

• Typically the stand has reached economic maturity• Understory regeneration will likely become a major component of the next stand following disturbance. •The length of this stage can be altered by silvicultural actions• Shade tolerance should be considered when trying to establish regeneration. - great time for shade tolerant and mid-tolerant species regeneration establishment

Natural Systems

• Reproduction occurs under the parent stand• Crowns are large enough that canopy gaps are not filled by neighboring overstory trees following mortality• Allows space for understory trees to grow into the canopy • More light reaches the forest floor

Silvicultural Implications

• Transition from even aged system to and uneven aged condition• Length of time in this or any stage is influenced by:

species composition, site quality, duration between stand replacing disturbances, silvicultural treatments• Most old growth stands are complex but many complex stands are NOT Old Growth!

Old Growth

DEFINED --- Natural mortality of large overstory trees produces irregular canopy gaps and accelerates the recruitment of reproduction and sub canopy trees into the overstory and main canopy.

Old Growth

Successional Theory

Relay Floristics vs. Initial Floristics

Relay Floristics

A model of succession in which species colonize sites in sequential waves. The first wave of colonizers is replaced by the second wave, and so on, until a climax community is established.

Example: Aspen, Paper Birch, Cherry, followed by Red Maple, White Ash, White Pine, followed by Sugar Maple, Beech, Hemlock.

Initial Floristics

Most species present in the late stages of stand development, are able to colonize the site soon after disturbance. Some species may take early advantage, or be slower to develop, or have different natural life spans, but they are all there at the beginning.

Successional PathwaySuccessional pathway is not pre-determined.

A “sugar maple site” could theoretically go to sugar maple in each successional model, but sugar maple is not guaranteed.

Beech could occupy that same site for an extended period, IF during stand initiation, sugar maple was not established, or if it was established, but was then suppressed (deer browse) and lost.

Current Thinking• Both relay floristics and initial floristics occur in

the development of a forest.• Initial floristics is considered the more common

pattern following disturbance.• Successional path is not pre-determined.

Multiple successional pathways are possible, depending on the timing, size and nature of the disturbance, and the presence/absence of established regeneration or seed to colonize the open growing space.

Natural Range of Variability

•Typical disturbance agents in New England--Wind, ice, insects, fungal pathogens, beaver, flooding, fire

• 1 -3% of northern hardwood forest were in the seedling/sapling stage historically

• Vermont was 80 – 90 % farm land at the turn of the last century

• 2001 FIA data shows seedling/sapling stage at 16% across the northeast (4% in MA to 25% in ME)

We are managing a forest that is outside its natural range of variability.

Wind Event Return Intervals

Tornados 1950 - 2003

New England Resources

Climate Change

• Higher CO2 results in more trapped heat throughout the system (greenhouse effect),

• Oceans are warming,• Polar ice is melting,• Sea levels are rising.• Climate is changing and this affects different

places in different ways.

• Some regions will receive more precipitation, some less, and it may come at different times of the year and in different forms.

• Much of our rain is expected to come in heavy downpours.

All regions will warm, but some will warm more rapidly than others.

Climate Change in Vermont• Less snow, more mixed precipitation

(rain/sleet/ice).• Shorter Winters, less extreme cold (snow as

climate switch).• More precipitation in Winter, Spring and Fall.• Less precipitation in Summer (drought).• More severe precipitation events.• Damaging winds more common.

Climate Change Impacts in Vermont

• Change is slow, but the rate of change is increasing, and the impacts are widespread.

• Changes in growing conditions result in changes to the competitive balance between species.

• Not all bad. Some species are “winners” even while others are “losers”.

Silvicultural Considerations of Climate Change

• Invasive Plants, Insects, Disease, Earthworms.• Regeneration difficulties with certain species

(sugar maple).• Decline of species results in more loss,

salvage, lower quality (balsam fir).• Operational difficulty. Warmer Winter, severe

storms, wet springs, more drainage measures required.

More to think about• Warmer temperatures result in a longer

growing season. • More CO2 results in “CO2 fertilization”.

Increased photosynthesis?• Photosynthesis: CO2 + Water => sugar + O2.• Sunlight, leaves and Co2 plentiful, but lack of

available water may limit the ability of trees to fully utilize the longer growing season.

What Impacts Available Water?• Total annual precipitation. Yes, but not the

whole story.• How and when moisture enters the system

(gentle rain, snow melt, heavy rain) matters.• Soil O.M. (forest floor and humus).• Soil texture (sand, silt, clay).• Soil depth (storage, aeration, rooting depth).

Soil Organic Matter

• Forest Floor – Contains nutrients.– Moderates temperature (reduces evaporation)– Reduces soil compaction (pore space holds water and O2)– Slows runoff from heavy rains and thus results in greater percolation

into soil, and longer water residence time.• Soil Humus - holds water and nutrients. • O.M. is important to the retention of available water.• All O.M. eventually decomposes, cycles through other organisms

and ultimately returns to the atmosphere as Co2. • O.M. cycle. We influence inputs (snags, logging debris) and

outputs (size, temperature affect decomposition rates).

Forest Type Shift

Year 2000 Year 2100

http://www.fs.fed.us/nrs/atlas/

Spruce Fir Forest

Spruce Fir Forest ?

Balsam FirYear 2000

http://www.fs.fed.us/nrs/atlas/

Year 2100

Sugar MapleYear 2000

http://www.fs.fed.us/nrs/atlas/

Year 2100

Northern Red OakYear 2000

Year 2100

http://www.fs.fed.us/nrs/atlas/

Photosynthate Prioritization

• Maintenance respiration• Foliage and fine root growth• Primary growth (height, lateral crown)• Secondary growth (diameter)• Reproduction *• Protection *

* The order of reproduction and protection may change based on environmental factors

Silvicultural Systems

Broad: Even-Age ManagementNarrow: Even-Age Management of Northern Hardwoods in the Northeast

A program for treating a type of stand through a full rotation, or other management cycle.

Expressions of a person’s or persons’ silvicultural vision.

They are sets of recommendations. Guides.

They can and should evolve over time.

There is plenty of room for personal or regional variation.

Silvicultural Systems

- The stand is the management unit, rather than individual trees.

- Stands are grown to their “rotation” age.

- intermediate thinning, and regeneration systems that include shelterwood, seed tree and clearcutting with many variants.

Even-aged Management in

Vermont (one or two age classes)

- Simple to implement. The principal problem with this system is that forests are generally not simple.

- Most effective in stands with uniform growing conditions and few species

Even-aged Management in

Vermont (one or two age classes)

Uneven-aged System: A planned sequence of treatments designed to

maintain and regenerate a stand with three or more age classes.

(The Dictionary of Forestry)

Uneven-age Managementmay be “Balanced” or “Irregular”

Balanced Uneven-age Management• Reverse-J diameter distribution is generally assumed to

approximate the natural condition of uneven-age stands. (incorrect assumption)

• “Balanced” means that each diameter class consists of the same portion (BA) of the stand.

• Q-value is the logarithmic slope of the TPA in successive diameter classes. Slope is assumed to be constant across all diameter classes.

• Diameter distribution and current q-value are determined from point sampling data.

• Desired q-value is subjective.• Higher q-value means fewer large trees.• BDq method.

Balanced Uneven-age Management Continued• Group selection, 1/20 to 2 acres in size (NE-603).• Regeneration is often a goal at each entry.• Mixing of “size” and “age”. Diameter classes assumed

to be equivalent to age classes.• Sampling intensity: is approx. a point every 5 acres for

small UVA ownerships. Lower (much lower?) sampling intensity on large, industrial, State or Federal ownerships.

• Does our data provide us the information to practice balanced uneven-aged management?

• Why would we want to?

Irregular Uneven-age management

• Must maintain three or more age classes.• Not necessary to balance diameter classes. • Flexible diameter distribution, with greater

emphasis on growing individual trees.• Maximum group size is flexible.• Regeneration not considered necessary at

each entry. Only when necessary to maintain three or more age classes.

Management Units

Even-age mgt: the Stand (Age Class)Balanced uneven-age mgt: Diameter ClassesIrregular uneven-age mgt: Individual Trees

Multi-Age Crop Tree Management

• Must maintain two or more age classes.• Not necessary to balance diameter classes. • Emphasis is on growing individual crop trees to full

term.• Maintain complexity of forest structure.• Regeneration matters but is not considered

necessary at each entry. Only necessary to maintain full stocking with two or more age classes.

• BDSQ method.

• Grow large diameter sawlogs and veneer• Maintain growth in two size classes• More structurally diverse• Maintain seed source on site to “life boat”

desirable species

Two – Aged Systems andDeferment Harvests

Two – Aged Systems andDeferment Harvests

Considerations:• Loss of initial revenue from traditional

clearcut• Overstory still influences the regeneration • Expected life span of overstory trees• Ease of operations at next entry• Silvicultural goals being met?

Two – Aged Systems andDeferment Harvests

How To:• Following regeneration establishment remove overstory trees to 10 -15 ft2/acre• Retain long lived species with good crowns and vigor • Pay attention to microsites to avoid wind throw and

other disturbances• Protect reserved trees during harvesting operations!• Let them grow for another rotation!

What really matters?

• Model the managed system after the natural system as much as possible.

• Manage for quality rather than quantity.• Manage for a healthy forest rather than solely for a

single species, product, age or diameter distribution.• Manage for complexity rather than simplicity, but

define complexity in simple terms.• That is, strive for forest complexity, not

management complexity.

Regeneration

A silvicultural issue in most regions of the country.

Tennessee/Kentucky – want to regenerate oaks, but have problems with

more shade tolerant competition.

Oak Regeneration Method

“Shelterwood” MethodMid-story removal near the rotation end.20% reduction with little canopy break.Enough diffuse light to keep established oak growing.When sufficient advance regeneration is present, release with partial or full OSR.

Sugar Maple Regeneration Method• Do we have one?• Here is a possibility.• Maintain high enough early stocking to inhibit the establishment of

competing regeneration while still maintaining growth of the dominant trees. Maybe 80 sq.ft./acre.

• When the understory begins to re-initiate, and it is composed of more tolerant competitors, treat them. (Jeff Springer)

• When we must break the canopy in order to maintain growth of our best crop trees, reduce stocking to 60-70 sq.ft./ac. to release a wave of established sugar maple.

• When desirable regeneration is established, do subsequent harvesting to release and advance the regeneration. Winter only.

• At the junction of desired diameter and vigorous, advance regeneration, implement group selection.

Common Theme

• Oak/Sugar Maple• Maintain high early stocking to inhibit any

regeneration.• Control more tolerant regeneration.• When it is time to regenerate, establish the light

conditions that most favor the target species.• Protect the regeneration and keep it growing.• Ultimately release it when the mature overstory is

harvested.

Crop Tree Release

• Common practice in other regions• 76% of stand value in best 30 T/A (upland

hardwoods, U.Tenn.).• 98% of stand value in best 60 T/A (upland

hardwoods, U.Tenn.).• 25% of harvest value in 4% of harvest volume

(Vermont: Paganelli)

Principles of Release• Early release is preferable to late release• Release may occur in stages• Strive for eventual, full release, where

possible.• S, W, E release is more effective than N• Growth lag results from late release

– Partly crown-building– Partly leaf replacement as sun leaves replace

shade leaves

Crown/Diameter/Quality

• Crown size is strongly correlated with available growing space.

• Diameter growth is strongly correlated with crown size (photosynthate prioritization).

• Proportion sapwood is very strongly correlated with crown size. When crown begins to recede, heart wood expands.

• Particularly important to remember with sugar maple.

Pruning Theory• Pruning is most effective in young, fast-growing trees

with small branches.• Bottom third of the crown more for insurance against

top breakage than growth.• Lower branches are so inefficient that pruning

sometimes provides a growth response.• Branch collar wounding increases size of pruning

wound, but also results in faster occlusion.• Pruning closer to the trunk (not flush cut) increases

the amount of clear wood, with no evidence of additional decay.

More on Pruning

• Most rapid diameter growth occurs at the base of the live crown.

• Form class improves as the crown moves up the tree.

• Prune softwoods to 17 feet.• Prune hardwoods to 12-14 feet.

Hardwood Release & Pruning Multi-Stage Technique

• Early release in stages. Age 20-30. Two to three release cuts 3-5 years apart.

• Early corrective pruning (low, narrow forks)• Prune trunks to 12-14 feet (veneer (8-12)target).• Follow to pick up any epicormic branches.• 60-80 T/A on roughly 20-30 feet spacing.• Minimize equipment entries. Girdling, cut/leave.• Target is rapid diameter growth on high-quality first

log.

Potential?

• 60 veneer logs/acre.• Mix of 10-feet and 12-feet logs, 18-inch dib,

one log/tree.• 150 bf/log.• 9 mbf/acre veneer.• $5,000/mbf mill price.• $4,500/mbf stumpage price.• $36,000/acre, plus associated logs/pulp.

Take Home Messages

We have the option to develop local silvicultural systems, and we should.

Climate change and invasive species will change our forests and change how we

practice forestry.

Pruning Practices should be re-evaluated.

There is significant potential for value growth associated with localized intensive

management.