Minnesota Forestry 101

Slide 1: MCC mid-year retreat, July 2006 Forestry 101 Eli Sagor esagor@umn.edu (612) 624-6948

Slide 2: Outline About forestry Forest types Silvicultural systems Combinations Q&A

Slide 3: About forestry

Slide 4: Outline About forestry Forest types Silvicultural systems Combinations Q&A

Slide 5: Sound forestry is… … production of a renewable resource … a $7 billion industry in Minnesota … beneficial to wildlife and water … conducted by professional foresters and loggers

Slide 6: Sound forestry is… … not necessarily timber-focused … a responsible way to make money from the land … a way to keep forest land forested … a way to restore lost habitat elements

Slide 10: Sound forestry is NOT… … clearing land to build shopping malls … a “cut & run” extractive industry

Slide 11: Some important concepts

Slide 12: Kraft Crown Classification Dominant crowns extending above main canopy receiving direct sunlight from above and from sides Codominant crowns at general level of crown cover receiving direct sunlight from above but little from the sides

Slide 13: Kraft Crown Classification Intermediate shorter but with crowns extending into the main canopy receiving direct sunlight from above but not from the sides Suppressed crowns entirely below the main canopy receiving no direct light from above or from the sides

Slide 15: Shade Tolerance A tree species’ ability to grow and thrive under low light conditions. Some trees need full sun, others can grow under a dense canopy.

Slide 16: Outline About forestry Forest types Silvicultural systems Combinations Q&A

Slide 17: Source: J. Tester, 1995. Fig. 1.6

Slide 18: Minnesota’s 3 biomes Northeast: Coniferous Central: Deciduous Southeast: Prairie Source: MN DNR

Slide 19: Source: J. Tester, 1995. Fig. 1.22

Slide 20: Common Forest types Photo by Firth Photo-Bank, Mpls, from Tester 1995

Slide 21: Aspen-birch Early successional Generalist Short-lived Excellent seed dispersal

Slide 22: Aspen-birch Natural disturbance that maintains this type: severe fire or extensive windthrow Transition to white-red pine or fir-spruce, depending on site

Slide 23: White & red pine Mid-successional Red, white, jack pine and birch Sticks around on drier, more fire prone sites Long-lived

Slide 24: White & red pine Natural disturbance that maintains this type: Severe fire / extensive windthrow

Slide 25: Black spruce Found on wet, low areas Not much competition… Dominant boreal forest type

Slide 26: Fir-spruce Late successional type Balsam fir, white spruce, birch, black spruce Can exist on many soil types but not driest Photo: UGA online photo library

Slide 27: Fir-spruce Natural disturbance that maintains this type: small or larger gaps from windthrow, insects, or tree death

Slide 28: Oaks Mid-successional type Fire dependent Likes drier, fire-prone sites Heavy seeds, seedlings and stump sprouts

Slide 29: Oaks Natural disturbance that maintains this forest type: Fire

Slide 30: Northern Hardwoods Late successional Yellow birch, red oak, maples, white pine, fir Rich, moist northern MN sites (cold) Long-lived type

Slide 31: Northern Hardwoods Natural disturbance that maintains this forest type: small gaps, windthrow

Slide 32: Maple-Basswood Climax type Moist, rich sites Doesn’t like disturbance Relatively heavy seeds, stump sprouts Likes low-intensity (gap) disturbance

Slide 33: Maple-Basswood Natural disturbance that maintains this forest type: small gaps from windthrow or tree death Small gap disturbance every 40-150 yrs Catastrophic disturbance 400-1000 yrs MN DNR

Slide 34: Outline About forestry Forest types Silvicultural systems Combinations Q&A

Slide 35: Silviculture The art and science of controlling the establishment, growth, composition, and health of forests and woodlands to meet the landowner’s objectives. (Modified from J. Helms 1998)

Slide 36: The toolbox Clearcut harvesting Protecting stands from damage from wildlife (deer!) “Selective” or partial harvesting Thinning at various times in the Prescribed burning: rotation to control understory Pruning: competition to improve log quality to prepare a cleared site for planting to reduce disease effects to favor natural regeneration Spraying herbicides or pesticides of desired species Cutting to reduce insect threats to reduce fuel loads Salvage cutting Planting of desired species and/or Fire suppression genetically improved stock And more…

Slide 37: Forest management systems Clearcutting Selection Group selection Single-tree selection Intermediate treatments

Slide 38: Clearcutting Clear all vegetation Prepare the site Plant trees (generally) Spray herbicide to control competition Thin (generally) Clearcut, and start over

Slide 39: (Wisconsin DNR image)

Slide 40: (Ontario Extension image)

Slide 43: Shelterwood Method Start with a mature stand Partial harvest New seedlings are established Remove canopy, “release the advance regeneration”

Slide 44: Shelterwood: mature hardwood stand before any treatment (Wisconsin DNR image)

Slide 45: Shelterwood: After first cut (Wisconsin DNR image)

Slide 46: Shelterwood: After first cut, 5 years later (Wisconsin DNR image)

Slide 47: Shelterwood: After overstory removal (Wisconsin DNR image)

Slide 48: (Ontario Extension image)

Slide 51: Selection System Start with mature stand Remove single trees or groups Repeat as needed

Slide 52: Group Selection Start with a mature stand Remove small groups of trees to create patches of regeneration Repeat periodically in different areas

Slide 53: Source: UGA Forestry Photo Gallery

Slide 54: Source: UGA Forestry Photo Gallery

Slide 55: Single tree selection: Before (Wisconsin DNR image)

Slide 56: Single tree selection: After (Wisconsin DNR image)

Slide 57: (Ontario Extension image)

Slide 58: Thinnings Improve the future growth of existing trees Row or selection thinnings Timber stand improvement

Slide 61: Outline About forestry Forest types Silvicultural systems Combinations Q&A

Slide 62: Forest Management 101 Favor the right species for the site Know and mimic natural disturbance regimes

Slide 63: Source: Tom McEvoy, 2000. Introduction to Forest Ecology and Silviculture. Second Edition. Copyright Natural Resource, Agriculture, and Engineering Service (NRAES).

Slide 64: Aspen-birch Early successional Generalist Short-lived Excellent seed dispersal

Slide 65: White & red pine Mid-successional Red, white, jack pine and birch Sticks around on drier, more fire prone sites Long-lived

Slide 66: Fir-spruce Late successional type Balsam fir, white spruce, birch, black spruce Can exist on many soil types but not driest Photo: UGA online photo library

Slide 67: Oaks Mid-successional type Fire dependent Likes drier, fire-prone sites Heavy seeds, seedlings and stump sprouts

Slide 68: Northern Hardwoods Late successional Yellow birch, red oak, maples, white pine, fir Rich, moist northern MN sites (cold) Long-lived type

Slide 69: Maple-Basswood Climax type Moist, rich sites Doesn’t like disturbance Relatively heavy seeds, stump sprouts Likes low-intensity (gap) disturbance

Slide 70: esagor@umn.edu