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How we measure forests David W. MacFarlane Dept. of Forestry MSU
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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?
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Basic tree measurements dbh = stem diameter at breast height 4.5 ft. (1.3 m) ? Digital caliper slope
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Measuring dbh C = π d d 4.5 ft. Logger’s tape
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Measuring height of standing trees (Trigonometry is useful) D= Distance from tree θUθU θLθL θ L = Angle from eye to tree bottom θ U = Angle from eye to tree top H 1 = D*TAN θ U Height = H 1 + H 2 H1H1 H2H2 Use a hypsometer
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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 Count # of trees to per sample unit area (= density) Project to larger area = 13.5 billion trees on forest lands (+ or - ?)
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Year = 2000 From US Forest Service, Forest Inventory & Analysis (FIA) Program
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dbh = 2” dbh = 6”7.6 billion trees 1.4 billion trees On Michigan Forest Lands in 2000
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Species groups # Trees Other white oaks1.28E+05 Yellow-poplar5.09E+06 Black walnut5.29E+06 Tupelo and blackgum5.39E+06 Other eastern hard hardwoods4.20E+07 Hickory4.54E+07 Other yellow pines4.89E+07 Other red oaks1.23E+08 Basswood1.28E+08 Eastern hemlock1.39E+08 Select white oaks1.55E+08 Yellow birch1.74E+08 Beech1.94E+08 Select red oaks2.61E+08 Jack pine3.39E+08 Eastern white and red pine6.36E+08 Eastern noncommercial hardwoods7.25E+08 Ash8.20E+08 Other eastern soft hardwoods1.01E+09 Other eastern softwoods1.20E+09 Sugar Maple (+hard)1.41E+09 Red Maple (+soft)1.67E+09 Cottonwood and aspen1.80E+09 Spruce and balsam fir2.59E+09 Total1.35E+10
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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 Contains spp. A, B and C Richness = 3 AB C RichnessRelative Dominance A A A A A A A A A A AA A A A A B C B B C C C C Relative Density
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Dominance vs. Density Area defined Density A = 2 per area Density B = 20 per area = spp. B = spp. A Area dominated
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Merchantable Volume ($$$) (Wood products are important!) Scaling Cylinder Volume of a cylinder = V = Area*Length r Area = π r 2 d L = log Length r = d/2 How many Boards per unit volume?
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Species group Board feet Other white oaks1.01E+07 Tupelo and blackgum2.52E+07 Other eastern hard hardwoods5.96E+07 Black walnut1.05E+08 Yellow-poplar2.87E+08 Other yellow pines4.23E+08 Hickory5.23E+08 Jack pine1.16E+09 Beech1.45E+09 Yellow birch1.66E+09 Other red oaks2.26E+09 Select white oaks2.29E+09 Basswood2.35E+09 Ash2.81E+09 Other eastern soft hardwoods3.07E+09 Eastern hemlock3.42E+09 Spruce and balsam fir3.53E+09 Select red oaks5.41E+09 Cottonwood and aspen7.54E+09 Other eastern softwoods8.00E+09 Red Maple (+soft)8.35E+09 Sugar maple (+hard)1.00E+10 Eastern white and red pine1.36E+10 Total7.83E+10 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 1Year 2Year 3
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Remote Sensing of Forest Dynamics October 19, 2000April 13, 2001July 2, 2001 Landsat Satellite Images in Area of Traverse City, MI
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