INTRODUCTION TO FOREST REGENERATION - SUNY ESF 05 Introduction to Forest... · 1 INTRODUCTION TO FOREST REGENERATION Ralph D. Nyland Distinguished Service Professor - Silviculture

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INTRODUCTION TO FOREST INTRODUCTION TO FOREST REGENERATIONREGENERATION

Ralph D. Nyland

Distinguished Service Professor - SilvicultureDepartment of Forest and Natural Resources Management

SUNY College of Environmental and Forestry

Syracuse, NY 13210

Nyland - 2010 All rights reservedUse of all or parts of this permission prohibited

without express consent of Ralph D. Nyland

Background reading:

Chapter 4, in Nyland, R.D. 2002. Silviculture: Concepts and Applications.Waveland Press. Long Grove, IL. 2ed.

Sources cited:

Harper, J.L. 1977. Population Dynamics. Academic Press. NY.

Maynard, CA., R.P. Overton, and L.D. Johnson. 1987. The silviculturist’s role in tree improvement in northern hardwoods. Pp. 35-46, in Managing Northern Hardwoods. R.D. Nyland (Ed.). SUNY Coll. Environ. Sci. and For.,Fac. For. Misc. Publ. No. 13 (ESF 87-002), Soc. Am. For. Publ. No. 87-03.

Nyland, R.D. 1998. Patterns of lodgepole pine regeneration following the 1988 Yellowstone fires. For. Ecol. & Manage. 111:23-33.

Roe, A.L., R.R. Alexander, and M.D. Andrews. 1970. Engelman spruce regeneration practices in theRocky Mountains. U.S. For. Serv. Prod. Res. Rpt. 115.

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Acting definitively to influence the future … Erkki Okasnen

WHAT SILVICULTURISTS DO:

CONTROL

ESTABLISHMENT

DENSITY

COMPOSITIONFACILITATE

HARVESTING

MANAGEMENT

USE

PROTECT

SITES

TREES

SALVAGE

DEAD & DISEASED TREES AND STANDS

POTENTIAL MORTALITY & EXCESS TREES

… in regenerationand tending

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... with plantations

At both large and small scales …

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Or natural regeneration …

Uneven-aged

Even-aged

… one stand at a time

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… gradually having a cumulative effect through time across a landscape

To promote regeneration …

1. Influence TIME when establishment occursand the PLACE

- schedule carefully the timing & nature of cuttings

- create new stands by seeding or planting if necessary

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… with the time, place, and method that best satisfies a landowner’s objectives

To promote regeneration …

2. Influence COMPOSITION of new stands

- alter or create favorable seedbeds & stand environment

- create new stands of wanted species, or enrich othersby artificial means

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... by regulating the intensity of cutting

... by influencing the character of seedbeds

... by scheduling the time and placement of cuttings

... by seeding and planting where deemed useful

To promote regeneration …

3) SUPPLEMENT naturally occurring regeneration,or REPLACE it

- enrichment- substitution- fortification

… by artificial means

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... by planting or seedingJ.D. Irving, LTD - 2000

... to make forests more valuable

... for an owner

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The role of cutting (e.g., timber harvesting)...

... implement the reproduction methodreproduction method

Create voids

when wanted ...

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… to initiatethe regeneration

process

At other times ...

... we keep stands DENSER

… when we don’t want regeneration

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... particularly among immature stands

So that all the growth potential

“goes” on the existing trees …

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Throughout the regeneration process you must:

- know the objectivesknow the objectives

- deliberately identifydeliberately identify the potential obstacles to success

- select an appropriate speciesselect an appropriate species for the site and objectives

- plan and implementplan and implement the necessary preparatorytreatments and anti-risk counter-measures

- identify a stocking and arrangementidentify a stocking and arrangement to enhance the use, tending, and harvest that will eventually follow

- implement the planimplement the plan using cost-effective methods

All to insure that the outcomeprovides appropriate rewardsprovides appropriate rewardsto the landowner …

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... and no surprises

So we insist upon seed or planting stock from origins:

- fitted to the needs- of desirable phenotypes- with a capacity to survive and grow successfully on

the site- at least as good in sought-after qualities as the old stand, or that natural regeneration would provide

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Appropriate species …… good seed source

... at adequate stocking

We seek to satisfy these objectives bygaining controlcontrol over forest stand regeneration …

… and the environmental conditions at the time when regeneration occurs

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We identifyidentify and managemanage the risk of being

overwhelmed by forces of disaster

Managing the risks …

Roe et al. 1970

… by integrative thinking

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… with a high chance of failure IFIF

one leg of the regeneration triangle

not suitable or gets out of control

We cannot entirelycontrol these

BUT BUT ……

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– EXTERNALEXTERNAL forces like …

• animal feeding

• disease

• insect attack

• fire

… we try to protect against these

Two groups of environmental factors …

… guarding against this

Glenwood Springs, CO -- June 2002

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– INTERNALINTERNAL site factors like…

• temperature• moisture• nutrients• light

… we want neither too much or too little

Two groups of environmental factors …

… controlling conditions by even unusual means

Like using shade to reduce transpirationfrom young and sensitive seedlings …

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By actively managing the risk that these present …

… and turning risk into OPPORTUNITYOPPORTUNITY

... and regeneration success

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SOURCES OF REGENERATION

– seed– seedlings

SEX

UA

L

… seeds carry the genetic traits of their parent treesNissen 2002

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… so do the seedlings that come from them

… most seed falls close to the parent tree

... especially in closed stands

And seed dispersal counts too …

Nyland 1998

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Then what happens to the seeds …

A reproduction methodprovides the stimulus …

… to get good numbers of well-distributed seedlings of desired species

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… to initiate and establish a new age class

… by leaving adequate seed-producingtrees in natural stands

… so we also need to controlcontrol seed dispersal and storageto insure regeneration success

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… or delivering it to a site by planting or seeding

Georgia Pacific, Maine

– sprouts / shoots / cuttings / suckers

– graftings

– plantlets from tissue cultureVE

GE

TA

TIV

E

Another source …

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… beech root sucker

… or with coppice methodof natural regeneration

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… originating as root suckers following clearfelling of aspen

How different sources fit into different regeneration programs …

Natural regeneration

seed advance seedlingssprouts / suckers / shoots

Artificial regeneration

seed nursery seedlings cuttings (vegetative)plantletsgraftings

Mostly for treeimprovement programs

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... in this case by tissue cultureMaynard 1985

Or like ArborGen southern pine plantlets for production use …

ArborGen 2007

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• NATURAL– least costly (though not without costs)

– species adapted to the site (though not necessarily the most valuable ones)

ADVANTAGES OF EACH

… though not without cost

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ADVANTAGES OF EACH

• ARTIFICIAL (CONTROLCONTROL)

– direct controlcontrol over genotypes, species, and placement

– complete controlcontrol over timing– can repeat if necessary

… with high costs togain “total” control

J.D. Irving, LTD - 2000

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ADVANTAGES OF EACH

• MIXED

– cost intermediate ifif done correctly–– somesome influence over genotypes, species, and

placement– excellent in salvaging a hopeless situation

… so take it all into account

Perhaps like this …

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DISADVANTAGES OF EACH

• NATURAL– get variation in stocking, species, and time– only existing genotypes and species regenerate– at mercy of natural forces

... we work hard to control these– must wait for adequate seed crops

… unless properly controlledcontrolled, it may give poor results

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DISADVANTAGES OF EACH

• ARTIFICIAL

–– expensiveexpensive (must repay with interest)

– impractical in remote areas…except for broadcast seeding

– major logistical effort

… balancing the costs against the gains

Great Northern Paper Co.

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DISADVANTAGES OF EACH

• MIXED– often must control naturally occurring plants

… interference– if need to reinforce, may find unsuitable

environment

But often beneficial if done correctly …

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... artificial

... naturalSo what to do …

Selecting between natural and artificial methods often means assessing …

AvailabilityAvailability of adequate seed of a suitable species and of good genetic quality

AssuranceAssurance of a suitable and reliable means for seed dispersal, or spread of vegetative parts

PotentialsPotentials for having a suitable seedbed at the appropriate time

Likelihood Likelihood of having available conditions essential to support initial post-establishment growth for the new seedlings

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… and how to best serve a landowner’s objectives

And don’t forget your genes ...

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BASE-LEVEL TREE IMPROVEMENT PROGRAMS

Base leveltree improvement

… practical silviculture fits in here

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BASE-LEVEL TREE IMPROVEMENT PROGRAMS …

- careful selection of seed sources

- artificial regeneration to establish an age class (including

enriching and supplementing natural regeneration)

- timber stand improvement (in tending)

- integrated pest management to safeguard the growing stock

- skillful use of appropriate reproduction methods

... ways that foresters influence the genetic constitutionof forest stands dailydaily

… by favoring and regenerating good phenotypes

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But always remember ...

Artificial regeneration commits a landowner to a long-term investment of considerable magnitude …

…so landowners MUSTMUST have assurance thatthe new stand will develop well under localconditions

So we insist on seed or planting stock from origins:

- fitted to the needs- of desirable phenotypes- with a capacity to survive and grow successful on

the site- at least as good in sought-after qualities as the old stand, or that natural regeneration would provide

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… at least as good

… and hopefully better

… to get the desired responseSilviculture manages all these factors …

Nissen 2010