What’s in Your Woodpile?

Gary Johnson

Urban and Community Forester

University of Minnesota

Approved Firewood Required on State- Owned Land

Obtained from firewood distribution facility on State-owned land

Obtained from a firewood dealer approved by the DNR commissioner

DNR commissioner approved firewood.

Penalties: After May 1, 2008 Confiscation of firewood, and

$100 penalty (purchaser), or

$100 penalty for each sale (dealer)

*Firewood: any wood intended for campfire.

Softwood versus Hardwood

Softwoods have Tracheids (fibers), No Vessels (pores). Many have Resin Canals.

Resin Canals

Softwoods versus Hardwoods

Hardwoods have Fibers and Pores

Pores

Ring Porous versus Diffuse Porous Large Pores in Earlywood and Small Pores

in Latewood = Ring Porous Hardwood

Large, obvious lines are Earlywood.

Smaller,darker heartwood or lighter sapwood lines are Latewood.

Ring Porous Wood: Black Ash

Ring Porous Wood: Bur Oak

Ring Porous Wood: American Elm

Semi Ring Porous: Black Walnut

Ring Porous versus Diffuse Porous Pores about same size and distributed

evenly throughout growth ring = Diffuse Porous.

Diffuse Porous Wood: Basswood

Diffuse Porous Wood: Boxelder

Diffuse Porous Wood: Big Toothed Aspen

“Other” Features: Elm Bark Cross-Section

Layered Bark of American and Rock Elm

“Other” Features: Long-Grain of Elm

“Other” Features of Oak: Rays

Rays

Versus, No Rays in Ash

Cracks or Checks, but not Rays

“Other” Features: Elm and Hackberry

Both Have Wavy (tiretrack) summerwood

“Other” Features: Elm and Hackberry

Hackberry has Corky Ridges on Bark, no Layered Cross-Section

“Other” Features: Red vs. White Oak

Sodium Nitrite turns White Oak Heart Wood Blue to Purple

“Other” Features: Black Walnut

Medium brown to dark chocolate heartwood.

Let’s Quiz the Log Splitter!

What is It?

0%

100%

0%

0%

0% 1. Hackberry

2. Chokecherry

3. Crabapple

4. River Birch

5. Chokeberry

What is it?

What is It?

What is it?

0%

0%

78%

22%

0% 1. Birch

2. Cottonwood

3. Big-Toothed Aspen

4. Silver Maple

5. Black Cherry

What is It?

What is it?

0%

22%

33%

44%

0% 1. Black Walnut

2. Buckthorn

3. Bur Oak

4. Boxelder

5. Ironwood

What is It?

What is it?

33%

44%

22%

0%

0% 1. White Oak

2. Hickory

3. Hackberry

4. Winged Euonymus

5. Bur Oak

What is It?

What Is It?

0%

11%

0%

22%

67% 1. Cottonwood

2. Green Ash

3. Hackberry

4. Elm

5. Linden

What is It?

11%

67%

0%

22%

0% 1. Elm

2. Boxelder

3. Silver Maple

4. Ironwood

5. Linden

What is it?

What is It?

11%

33%

0%

56%

0% 1. Black Pine

2. Black Cherry

3. Austrian Pine

4. Douglas Fir

5. White Cedar

What is it?

What is It?

11%

0%

11%

22%

56% 1. White Cedar

2. Sugar Maple

3. Ponderosa Pine

4. Black Cherry

5. Douglass Fir

What is it?

What is It?

What is it?

78%

0%

11%

11%

0% 1. Linden

2. Sugar Maple

3. Black Ash

4. Elm

5. Green Ash

Questions… Gary Johnson

UM Urban & Community Forester

University of Minnesota Extension Foresters: Angela Gupta, Rochester Mike Reichenbach, Cloquet Gary Wyatt, Mankato