chapter 23
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CHAPTER 23. TERRESTRIAL BIODIVERSITY & FORESTRY. - PowerPoint PPT PresentationTRANSCRIPT
CHAPTER 23
TERRESTRIAL BIODIVERSITY &
FORESTRY
There is unrest in the forestThere is trouble with the treesFor the maples want more sunlightAnd the oaks ignore their pleas
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?
There is trouble in the forestAnd the creatures all have fledAs the maples scream `oppression!`And the oaks, just shake their heads
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 ...
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
U.S. Land Ownership
Federal35%
Private55%
Native American 3%
State and local 7%
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 MiningLivestock GrazingFarmingOilGas ExtractionRecreationSport Hunting and FishingOff-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 HuntingOil and Gas extractionMiningLoggingGrazingFarmingSome 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 activitiesCampingNon-motorized vehiclesLoggingSport HuntingHorseback ridingGrazingMiningNo Commercial buildings
permitted
Yellowstone
National parks and preserves National forests National wildlife refuges
National parks and preserves
National forests
National wildlife refuges
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 FORESTB. SECOND-GROWTH FORESTC. Tree Plantations (tree farms)
Emergent
Canopy
Understory
Floor
Subsoil
Birds, invertebrates,bats
Birds, reptiles,amphibians,lichens, mosses
Shade-tolerant plants, birds, squirrels,lizards, chipmunks
Rotting debris,worms, insects,bacteria
Nematodes,microrganisms
Bole
Snag
A. OLD-GROWTH FOREST
•Undisturbed by humans and/or natural disasters
•High biodiversity
• Increased recycling of nutrients and good habitat
B. SECOND GROWTH FORESTS
-Result from SECONDARY SUCCESSION
-May result from clearcutting
C. Tree PlantationsUniform ages of one speciesHarvested by clear-cutting as
soon as they become valuableReplanted 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
The Strange Side Effects of Trees on Steroids
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
Annual Deforestation Rates
More than 1% loss0.5–1% loss0–0.5 lossStable or increased forestNo data
3. TYPES OF FOREST MANAGEMENT
- The total volume of wood produced varies as it goes through different stages of growth and succession
Time
Short rotation
Woo
d vo
lum
e or
woo
d bi
omas
s
B
C
A
Long rotations
Old-growth harvest(such as hardwoodsfor furniture)
Years of growth
30
25 1510
5
Clear cut
Weak treesremoved
Seedlingsplanted
- 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 ManagementMost of the forests are Even AgedAverage 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
E. Measuring and Cutting Trees
1. 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.
2. Hold the stick at a right angle to the axis of the tree and keep your eyes level with the stick.
3. Adjust the stick so that the left or zero is in line of sight with the left side of the tree.
4. 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 - Diameter
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.
The Biltmore Stick
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: 1. Biological diversity 2. Long-term sustainable
production of timber 3. Moderate economical
return4. Multiple use of forests
4. HARVESTING TECHNIQUESA. Selective Cutting: - Mature trees are cut singly or in small groups
-reduces crowding -encourages growth -protects against soil erosion
-maintains uneven growth
-Maintains habitat
Selective Cutting
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
Shelterwood CuttingCut 1
Cut 2
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
Seed-Tree Cutting
D. Clear Cutting:
-Removal of all trees from an area in a single cutting
The area may be…A whole stand A stripA series of patches.
Clear-Cutting
Issues Concerning Clear Cutting
PROS- INCREASE
YIELD- LESS SKILL
NEEDED- INCREASED $- BEST WAY TO
HARVEST TREE FARMS
CONS- LEAVES LARGE
OPENINGS IN FOREST
- REDUCES BIO- DIVERSITY
- INCREASES SOIL EROSION
- FLOODING
E. Strip Cutting:
Type of Clear-cutting Removes a strip of trees along the contour of the land
Narrow enough to allow for natural regeneration
Strips are harvested every 30-40 years
Strip Cutting
Uncut Cut Cut Cut Uncut
6–10 years ago3–5 years ago 1 year ago
5. FOREST SUSTAINABILITY
-Longer rotation of timber growth (point C)
-Use anti-erosion techniques
-Assist Natural Regeneration
6. FOREST PESTS/DISEASEA. Parasitic Fungi:
Chestnut Blight (China)Dutch Elm (Europe)White Pine Blister (Europe)Beech Bark Disease
B. Parasitic Insects:
•Bark Beetles
•Gypsy Moth
•Hemlock woolly adelgid
Forest Pests of Pennsylvania
Hemlock Woolly Adelgid
Gypsy Moth- came from Europe
Eastern Tent Caterpillar
The ladybird beetle, Pseudoscymnus tsugae, is a known predator of the
hemlock woolly adelgid. P. tsugae is a native insect of Japan, where it is
observed to aggressively attack and control the hemlock woolly adelgid,
Adelges tsugae Annand. Beginning in 1992, extensive research efforts were
undertaken in the northeastern United States to breed and release this
ladybird beetle in an effort to combat the hemlock woolly adelgid. Mass rearing and release of P. tsugae in
Pennsylvania began in 1999. Efforts to establish this predator are continuing,
and, to date, more than 117,000 ladybird beetles have been released in
Pennsylvania.
Visit http://www.dcnr.state.pa.us/forestry/pests/index.aspx
to find out more about the Pests that Harm PA Forests
White Pine Weevil
Twolined Chestnut
Borer
The Newest Invasive Threats
Larvae of the beetle feed in the tissues under the bark of ash trees (Fraxinus spp.) causing the girdling and death of branches and entire trees. Adults of the species are active from mid-May until early August. Since its discovery in Michigan, the beetle has been detected in Ohio, Maryland, Virginia, Indiana and neighboring areas in Canada. In Michigan alone, over 7 million ash trees have been lost to this pest. Signs of emerald ash borer include upper crown dieback, woodpecker damage, sinuous galleries under the bark, and "D"-shaped emergence holes.
Girdled Tree by Emerald Ash
Borer
The Asian longhorned beetle was first identified in North America in New York in 1996. Larvae of the beetle feed in the stems and
branches of many hardwood tree species including maple, boxelder, alder, elm, birch, poplar, and willow. Continued feeding can lead to the death of branches and entire trees. Adults of the
species are active from mid-May until early August. Since its discovery in New York, it has become established in Illinois, New
Jersey, and Toronto, Ontario, where it is responsible for the destruction of over 8,000 trees. Recently a new infestation has
been discovered near Carteret, New Jersey.
Signs of Asian longhorned beetle infestation include dieback of the upper crown, sawdust around the tree, and dime-sized, round
emergence holes.
A disease-causing oak mortality was first discovered in California in 1995. Termed
sudden oak death, it was later determined that the causal agent was a newly described fungal
pathogen, Phytophthora ramorum.
Sudden oak death can be recognized by crown dieback, leaf discoloration, or the presence of black
or red ooze bleeding from cankers on the bark. Removal of diseased bark will reveal necrotic tissue surrounded by black zone lines. Homeowners can
help to stop the spread of sudden oak death by landscaping with native plants.
7. FOREST FIRESTypes of Forest Fires:
A. Surface Fires- Burn leaf litter and ground
clutterControlled & Not dangerous*cone bearing trees benefit*
http://activefiremaps.fs.fed.us/#
Surface fire Fig. 23.12a, p. 599
B. Crown Fires- •Burn in the treetops
Crown fire Fig. 23.12b, p. 599
C. Ground Fires- Underground and burn partially decayed leaves or peat
Common in peat bogs
FIRE
*Forest Fire Prevention:
-Controversial policy…
-Since 1972… -Let forest fires burn themselves out as long as not a danger to humans.
-Calls for change after fires of 1994 and 2000.
SHOW SMOKEY THE BEAR VIDEO
*Forest Fire Prevention Techniques:
-Education-Prescribed Burning-Presuppression-Suppression
http://kdka.com/national/texas.oklahoma.fires.2.981359.html
Salt is used as the red fire retardent
Pa Fires - 2002
II. Forest Resources/Management1. Today’s USA
Status:Since 1960, vast increase in the number of tree plantations
USA has set aside protected areas
Forest covers about 1/3 of the lower 48 United States.
Forest are generally bigger and healthier than in 1920.
Virgin forests, 1620
Virgin forests, 1998
National Forest ManagementTimber
Companies-Want to increase logging to satisfy demand…-Improvement of forest health…-Provides jobs…-Provide cheap timber
Environmentalists-Timber from national forest is small % of wood used-Timber from national forests does little to drop prices-Recreation should be the most important use of forest
2. Pennsylvania’s Forest Status
Pennsylvania’s ForestsIn the Past…1630 = 95% forest1907 = 30% forest2000 = 58% forestNo net loss of forestland statewide
in the past several years
Areas of Concern:South East and South Central PA
forests
2 Biggest Problems With PA Forests:
Urban Sprawl Greatest in Southeast White-tailed Deer Browsing- destruction of tree
seedlings
Black BirchBlack Cherry
Red Maple
What do We Do With the Wood?PA forests provide raw materials for:Fine Furniture, Cabinets, Hardwood floors
& Paper $5.5 billion in products 100,000 jobs
86 Billion Board Feet of Lumber
3. How To Reduce Tree Needs
- Increase the efficiency of wood use
- Increase paper recycling-Use alternative fibers
-EX: Kenaf (rapidly growing woody plant)
-Agricultural residue
14
12
10
8
6
4
2
01930 1940 1950 1960 1970 1980 1990 2000 2010
Year
Tim
ber c
ut (b
illio
ns o
f boa
rd fe
et)
Fig. 23.14a, p. 601
Ann
ual r
ecre
atio
nal v
isits
(mill
ions
)
350
300
250
200
150
100
50
01930 1940 1950 1960 1970 1980 1990 2000 2010
YearFig. 23.14b, p. 601
III. Ecological Restoration1. Restoration Ecology - Research and scientific study
devoted to restoring, repairing, and reconstructing damaged ecosystems
Done Through…
-Eliminating disruptive nonnative species
-Holding an ecosystem at a particular desirable stage of succession
-Speeding up natural ecological succession
-Using natural restoration
Forest Conservation
Diversity in Layers
How a Forest Forms