How we measure forests

1
How we measure forests

• David W. MacFarlane
• Dept. of Forestry
• MSU

2
Why measure the forest?

• We want to know the current status of the forest.
• Size of trees, density and area covered by
  forests
• Species Composition Biodiversity
• Value of forest products (wood and non-wood)
• Age, health and vigor of trees
• Etc..
• How is the forest changing over time?

3
Basic tree measurements

• dbh stem diameter at breast height

?
4.5 ft. (1.3 m)
Digital caliper
slope
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Measuring dbh
Loggers tape
C p d
d
4.5 ft.
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Measuring height of standing trees(Trigonometry
is useful)
Height H1 H2
H1
?U Angle from eye to tree top
H1 DTAN ?U
?U
D Distance from tree
Use a hypsometer
H2
?L
?L Angle from eye to tree bottom
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(No Transcript)
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Lidar Measuring canopy height remotely
Aircraft mounted laser
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How many trees in Michigan?
Michigan 36.4 million acres 19.4 million acres
of forested land Census?
We usually express number of trees as Tree
Density trees / unit area (e.g., 400 trees
per acre)
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Sampling
Select smaller areas to sample
13.5 billion trees on forest lands ( or - ?)
Count of trees to per sample unit area (
density)
Project to larger area
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Year 2000
From US Forest Service, Forest Inventory
Analysis (FIA) Program
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On Michigan Forest Lands in 2000
dbh 2
dbh 6
7.6 billion trees
1.4 billion trees
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Species groups Trees
Other white oaks 1.28E05
Yellow-poplar 5.09E06
Black walnut 5.29E06
Tupelo and blackgum 5.39E06
Other eastern hard hardwoods 4.20E07
Hickory 4.54E07
Other yellow pines 4.89E07
Other red oaks 1.23E08
Basswood 1.28E08
Eastern hemlock 1.39E08
Select white oaks 1.55E08
Yellow birch 1.74E08
Beech 1.94E08
Select red oaks 2.61E08
Jack pine 3.39E08
Eastern white and red pine 6.36E08
Eastern noncommercial hardwoods 7.25E08
Ash 8.20E08
Other eastern soft hardwoods 1.01E09
Other eastern softwoods 1.20E09
Sugar Maple (hard) 1.41E09
Red Maple (soft) 1.67E09
Cottonwood and aspen 1.80E09
Spruce and balsam fir 2.59E09
Total 1.35E10
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What kind of tree is it?

• Problem 1 How can we identify tree species?

Take FOR 204 Forest Vegetation!
Reproduced from National Arbor Day Foundation
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Measuring Biodiversity

• Richness spp. in an area
• Relative Density (density of spp.) / (density
  of all species) abundance
• Relative Dominance (area covered spp.) / (total
  area.) area covered

C
Contains spp. A, B and C Richness 3
A
A
A
A
A
A
A
B
B
B
C
A
A
A
A
A
A
A
A
C
A
C
C
B
C
A
Richness
Relative Dominance
Relative Density
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Dominance vs. Density
spp. A
spp. B
Density A 2 per area Density B 20 per area
Area defined
Area dominated
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Merchantable Volume ()(Wood products are
important!)
Volume of a cylinder V AreaLength
Scaling Cylinder
d
L log Length
r
How many Boards per unit volume?
Area p r2
r d/2
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Species group Board feet
Other white oaks 1.01E07
Tupelo and blackgum 2.52E07
Other eastern hard hardwoods 5.96E07
Black walnut 1.05E08
Yellow-poplar 2.87E08
Other yellow pines 4.23E08
Hickory 5.23E08
Jack pine 1.16E09
Beech 1.45E09
Yellow birch 1.66E09
Other red oaks 2.26E09
Select white oaks 2.29E09
Basswood 2.35E09
Ash 2.81E09
Other eastern soft hardwoods 3.07E09
Eastern hemlock 3.42E09
Spruce and balsam fir 3.53E09
Select red oaks 5.41E09
Cottonwood and aspen 7.54E09
Other eastern softwoods 8.00E09
Red Maple (soft) 8.35E09
Sugar maple (hard) 1.00E10
Eastern white and red pine 1.36E10
Total 7.83E10
78 Billion Board feet on forested lands in MI, in
2000
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Michigan forest statistics for 2000
13.5 Billion trees / 19.4 million acres 696
trees per acre on forested land in Michigan 78
Billion Board feet / 19.4 million acres of forest
land 4,020 Bd. ft. per acre on forested land in
Michigan 0.10 to 3.00 per Bd. ft. 78 Billion
board feet / 132 million feet around the Earth
Make a 590 feet wide ring around the Earth!
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Measuring change over time
CFI Continuous Forest Inventory USDA Forest
Service (Forest Inventory and Analysis
(FIA) USDA Forest Service (Forest Health
Monitoring (FHM) State Forest Inventories /
Health Monitoring Programs University
Researchers / Scientific Foundations Private
Forestland Inventories (e.g., Mead-WestVaco)
Year 1
Year 2
Year 3
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Remote Sensing of Forest Dynamics
Landsat Satellite Images in Area of Traverse
City, MI
October 19, 2000
April 13, 2001
July 2, 2001