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CHAPTER 23 TERRESTRIAL BIODIVERSITY & FORESTRY
There is unrest in the forestThere is trouble with the treesFor the maples want more sunlighAnd the oaks ignore their pleasThe trouble with the maples(and theyre quite convinced theyre right)They say the oaks are just too loftyAnd they grab up all the lightBut the oaks cant help their feelingsIf they like the way theyre madeAnd they wonder why the maplesCant be happy in their shade? There is trouble in the forestAnd the creatures all have fledAs the maples scream `oppression!`And the oaks, just shake their headsSo the maples formed a unionAnd demanded equal rightsthe oaks are just too greedyWe will make them give us lightNow theres no more oak oppressionFor they passed a noble lawAnd the trees are all kept equalBy hatchet,Axe,And saw ... There is unrest in the forestThere is trouble with the treesFor the maples want more sunlighAnd the oaks ignore their pleasThe trouble with the maples(and theyre quite convinced theyre right)They say the oaks are just too loftyAnd they grab up all the lightBut the oaks cant help their feelingsIf they like the way theyre madeAnd they wonder why the maplesCant be happy in their shade? There is trouble in the forestAnd the creatures all have fledAs the maples scream `oppression!`And the oaks, just shake their headsSo the maples formed a unionAnd demanded equal rightsthe oaks are just too greedyWe will make them give us lightNow theres no more oak oppressionFor they passed a noble lawAnd the trees are all kept equalBy hatchet,Axe,And saw ... There is unrest in the forestThere is trouble with the treesFor the maples want more sunlightAnd the oaks ignore their pleas There is trouble in the forestAnd the creatures all have fledAs the maples scream `oppression!`And the oaks, just shake their heads The Trees So the maples formed a unionAnd demanded equal rightsthe oaks are just too greedyWe will make them give us lightNow theres no more oak oppressionFor they passed a noble lawAnd the trees are all kept equalBy hatchet,Axe,And saw ... The trouble with the maples(and theyre quite convinced theyre right)They say the oaks are just too loftyAnd they grab up all the lightBut the oaks cant help their feelingsIf they like the way theyre madeAnd they wonder why the maplesCant be happy in their shade?
Land Use In The United States • 1. PUBLIC LANDS - 35 % of land in the United States is designated as public and is managed by the Federal Government. - Classified as… A. Multiple-Use Lands B. Moderately Restricted-use Lands C. Restricted-use Lands
State and local 7% Federal 35% Native American 3% Private 55% U.S. Land Ownership
A. Multiple-Use Lands: - 155 Forests and 20 Grasslands of the National Forest System - Managed by the U.S. Forest Service & - National Resource Lands - Managed by the Bureau of Land Management
Uses for Multiple Use Land: • Logging • Mining • Livestock Grazing • Farming • Oil • Gas Extraction • Recreation • Sport Hunting and Fishing • Off-Road vehicles are restricted to certain areas
B. Moderately Restricted-Use Lands: National Wildlife Refuges - Managed by the U.S. Fish and Wildlife Service
Uses for Moderately Restricted Land • Sport Fishing and Hunting • Oil and Gas extraction • Mining • Logging • Grazing • Farming • Some Military Action
C. Restricted-Use Lands: National Park System - Managed by the National Park Service and - 630 road less areas of the National Wilderness Preservation System
Uses for Restricted Use Land: • Recreational activities • Camping • Non-motorized vehicles • Logging • Sport Hunting • Horseback riding • Grazing • Mining • No Commercial buildings permitted
National parks and preserves National forests National wildlife refuges
National wildlife refuges National parks and preserves National forests
I. Managing and Sustaining Forests Ecological -Support food webs -Act as sponge -Influence local climate -Habitat Economic -Fuel wood, 50% -Timber -Pulp -Medicines
1. MAJOR TYPES OF FORESTS - tropical, temperate, boreal A.OLD-GROWTH FOREST B.SECOND-GROWTH FOREST C. Tree Plantations (tree farms)
A. OLD-GROWTH FOREST • Undisturbed by humans and/or natural disasters • High biodiversity • Increased recycling of nutrients and good habitat Snag Bole Emergent Birds, invertebrates, bats Canopy Birds, reptiles, amphibians, lichens, mosses Understory Shade-tolerant plants, birds, squirrels, lizards, chipmunks Floor Rotting debris, worms, insects, bacteria Subsoil Nematodes, microrganisms
B.SECOND GROWTH FORESTS -Result from SECONDARY SUCCESSION -May result from clearcutting
C. Tree Plantations • Uniform ages of one species • Harvested by clear-cutting as soon as they become valuable • Replanted and clear-cut on regular cycles
MONOCULTURE: Grow only one type of specimen *An attempt to produce products more efficiently • Tries to hold back succession • Using DNA Technology to build in resistance and produce stronger trees Test Tube Tree
Characteristics of Monoculture forestry • Production of wood products in a predictable fashion • Even-aged management • Loss of soil nutrients • Does not increase biodiversity
2. WHAT IS HAPPENING TO THE WORLD’S FORESTS? • World-wide human activity has reduced the earth’s forest by 46% -In North America and Europe forests are on the upswing
More than 1% loss 0.5–1% loss 0–0.5 loss Annual Deforestation Rates Stable or increased forest No data
Long rotations Old-growth harvest (such as hardwoods for furniture) • 3. TYPES OF FOREST MANAGEMENT - The total volume of wood produced varies as it goes through different stages of growth and succession B Wood volume or wood biomass C Short rotation A Time
Weak trees removed Seedlings planted Clear cut 25 15 10 30 5 Years of growth
- Two basic forest management techniques… A. Even-Aged Management: - Also called INDUSTRIAL FORESTRY - Trees are kept as same size and age -Example: Tree farms *Extensive research in Germany has shown that soil had become depleted
PA Forest Management • Most of the forests are Even Aged • Average age of trees 80-120 years
Tree Diameter & Management • Important consideration of Even Aged Management • Trees of the same age may vary in diameter Factors that impact tree diameter: • Variation among species growth rates • Soil and Site conditions • Genetics • DBH (Diameter at Breast Height) can be measured with a Biltmore Stick
Using a Biltmore Stick - Diameter • Hold the stick at breast height (4.5 feet from the ground), 25" from your eye, with the back of the stick against the tree you are measuring. • Hold the stick at a right angle to the axis of the tree and keep your eyes level with the stick. • Adjust the stick so that the left or zero is in line of sight with the left side of the tree. • Without moving your head, shift the line of sight to the right hand side of the trunk. • 5. Read the diameter on the stick nearest the point at which the line of sight crosses it.
Using a Biltmore Stick - Height • 1. Total tree height is measured from the ground to the top of the tree. Merchantable tree height is measured from the stump height to the point at which the tree is no longer useable. • 2. Stand 66 feet from the tree you are going to measure. If the ground is not level, stand on a spot which has about the same elevation as the base of the tree. • 3. Hold the stick vertical, 25" from your eye, with the “Height of Tree” side facing toward you. • 4. Align the base of the stick at the ground (or at your estimated stump height for merchantable height). • 5. Without moving your head, shift your line of sight so you can read the height at the point where your line of sight and the top of the tree intersect (or merchantable height).
Using a Diameter Tape • Hold the tape at 4.5 Ft from the highest ground level at the base of the tree (Known as DBH) • Arrange the tape horizontally around the trunk. Any deviation from horizontal will cause you to overestimate dbh, and as dbh squared is used to calculate basal area, basal area can be very much overestimated in this way; and • Pull the tape as tightly as possible.
Classifying a Forest Based on Predominant Tree Size 3 Categories for describing tree diameter: 1.) Seedling-Sapling: DBH < 5” 2.) Mid-Size Tree: DBH 5-11” 3.) Large Tree: DBH > 11”
B. UnEven-Aged Management: - Trees are kept at a variety of ages and sizes -Goals are: • Biological diversity • Long-term sustainable production of timber • Moderate economical return • Multiple use of forests
4. HARVESTING TECHNIQUES A. Selective Cutting: - Mature trees are cut singly or in small groups -reduces crowding -encourages growth -protects against soil erosion -maintains uneven growth -Maintains habitat
HIGH GRADING • When only the largest and best species are used. • Problem: Remove the strongest species • REVERSE NATURAL SELECTION
B. Shelterwood Cutting: -Removes all mature trees in two/three cuttings over a period of 10 years. -allows natural seeding -keeps seedlings from crowding -reduces soil erosion -provides good habitat for wildlife
Cut 2 Cut 1 Shelterwood Cutting
C. Seedtree Cutting: -Harvests nearly all a stand’s trees in one cutting -Leave a few seed-producing trees behind to regenerate the area. -Leads to genetic improvement in new stands
D. Clear Cutting: -Removal of all trees from an area in a single cutting The area may be… • A whole stand • A strip • A series of patches.