Transcript Power Point Version

Univ. of Phoenix
SCI/256
Week 4 Chapter 16,17,18
(Not chapter 1 & 24)
Species Diversity and
Preservation I
Chapter 16 pt1
Factors Affecting Biological
Resources
Natural Processes (e.g., fires)
Land Use (e.g., urban development)
Water Use (e.g., hydroelectric)
Climate Change (e.g., global warming)
(http://observer.guardian.co.uk/international/story/0,6903,1153513,00.html)
Nonindigenous Species
Environmental Contaminants (e.g., oil spills)
Harvest (e.g., overfishing)
Species Diversity Terrestrial
Species
Diversity
Definitions
Extinction: the irreversible loss or ‘death’ of a species.
Endangered species (ESA): a
species in imminent danger
of extinction throughout all
or a significant portion of its
range. (What is a species?)
Threatened species: a species
that is likely to become
endangered in all or a
significant portion of its
range.
Species Diversity
Characteristics of
Endangered Species
• Extremely small range - lily on single
hilltop near SF.
• Large territories - California condor. (+
issue of Minimum Viable Populations)
• Living on islands - endemics (living
nowhere else); evolved in isolation from
predators, disease, and competition.
• Low biotic potential - blue whales.
• Specialized breeding areas - green sea
turtles.
• Specialized feeding habitats - pandas and
bamboo.
Extinction
Mass Extinctions
Historic Period
Time (MYA)
Ordovician
Devonian
Permian
Triassic
Cre taceous
444
370
250
210
65
Quaternary
present
Effects
_
25% of all families extinct
19% of all families extinct
54% of famili es, 90% of s pecies extinct
23% of famili es, 50% of s pecies extinct
17% of famili es, 50% of s pecies extinct (including
dinosaurs but not mammals)
1/3 to 2/3 of all species extinct if present trends
continue
If extinction is a natural process, why should we be
concerned about extinction?
Human-based Extinction:
Human disturbance dominates many landscapes, making
the processes of many ecosystems human-dominated.
Species Diversity - Loss of
Ecosystems
Effects of
Human
Population
on Diversity
Human-based Extinction:
:We affect species through:
1.
2.
3.
4.
5.
6.
7.
Habitat Destruction
Hunting and Fishing
Predator Control
Pollution
Genetic Assimilation
Diseases
Exotic Species
Introductions
Species Diversity - Health of
Ecosystems
Species Diversity - Loss of
Ecosystems
Habitat Destruction: conversion of wilderness into
human-based habitat; mainly for farming, range use, and
forestry, but also for urban centers.
Iowa has lost much greater than 90% of its wetlands.
Fragmentation can cause forests (or
prairies) to slowly become small islands of
wooded area that can be too small to
maintain breeding populations.
Fragmentation eliminates the core
environment, expanding the amount of edge
available for weedy species to invade, and
eliminates the environment some species
need to survive.
Critical Size of an Ecosystem
Amazonia example:
Thomas Lovejoy
created patches of
various sizes (from 1 to
1000 ha and a 10,000 ha
'mainland'). A hectare
(ha) = 10,000 sq
kilometers or ~ 2.5
acres
Results from Lovejoy’s Amazonia
Studies
A guild of insectivorous birds (that feed on insects
fleeing swarming army ants) disappeared in 1, 10
hectare, and some 100 ha fragments plots.
Pollinators, euglossine bees, would not cross 100 m
cleared strips, so population biology of at least 30 plant
families dramatically affected.
Results from Lovejoy’s Amazonia
Studies
Rain forest fragments in central
Amazonia were experienced a
dramatic loss of above-ground tree
biomass that was not offset by
recruitment of new trees. These losses
were largest within 100 meters of
fragment edges, where tree mortality
was sharply increased by
microclimatic changes and elevated
wind turbulence. Permanent study
plots within 100 meters of edges lost
up to 36% of their biomass in the first
10 to 17 years after fragmentation.
Results from Lovejoy’s Amazonia
Studies
Dung and carrion feeding beetles responded similarly
to other insects, so the decomposition process slowed.
Much of the primate diversity went almost
immediately extinct in the isolated fragments.
Only 7 of 20 mammal species present in reserve areas
persisted in the first isolated fragments, and many of
those that persisted were those capable of surviving in
disturbed areas or secondary vegetation.
Minimum Viable Populations
Populations that are large enough that inbreeding does not
cause the species to go extinct.
If Minimum Viable Populations are not maintained, the
species cannot survive. (Plus, chance events have a greater
likelihood of eliminating a species that is already reduced in
numbers.)
Greater Prairie Chicken
Planned reserves on an ecosystem basis. For example, in
Yellowstone National Park (for watershed and wildlife
resources), more land would have to be added.
Protected Forests
Preservation and Park Usage in
the U.S.A.
Habitat destruction does not
Threats to Parks:
end just because land is placed
1. Islands of nature
surrounded by destructive into a reserve/preserve/park.
land use.
2. Roads, trails (especially
ATVs and off-road vehicles).
3. Visitor impact: Yosemite
National Park - 25,000
visitors for a 3-day weekend
(cars, laundries, concessions,
guest rooms, etc).
Corridors
Strips of habitat running between patches of habitat.
Used to allow movement of
species from one area to
another to help maintain
genetic exchange and prevent
extinction.
However, corridors can also
be a risk because they may act
as a corridor for disease,
invasive species, or as traps
for the species you are trying
to protect.
Hunting and Fishing
Consider the large Pleistocene mammals - extinctions
probably caused by human hunting - mammoths, mastadons
wooly rhinos, and ground sloths.
Hunting and Fishing
In the recent past, whales have been hunted to the brink of
extinction. Bison were once in the 10’s of millions, but
were reduced to less than 1000 individuals.
Passenger pigeons - now
extinct; once over 3 billion.
Predator/Pest Control
Involves top
predators
(keystone
species).
Wolves,
mountain lions,
gators.
American alligator:
top predator - keeps gar populations in check.
creates habitat diversity - islands created by nest mounds
gator trails - prevent marsh establishment
gator holes - provide habitat for other species in drought
Pollution
Amphibians as early
warning indicators. In
North America, and worldwide, amphibian
populations have drastically
declined and deformities
have increased.
Pollution
Environmental estrogens: (DDT, PCBs, Dioxins)
disrupt hormones; impact fish, reptilian, and
amphibian reproduction.
Acid precipitation: alters pH of water, thereby affecting
species.
Ozone depletion (due to CFCs): cause increased UV
light penetration and so cause higher mutation rates,
thereby affecting populations.
Global warming: temperature alterations can cause
population declines.
Species Diversity - Loss of
Ecosystems
Genetic Assimilation
Classic definition is that genes of species at low population
numbers are at risk of being swamped if they hybridize with
close relatives.
With the use of genetically modified (GM) species in
farming, for example, could include the assimilation of
native species into closely related GM species.
Genetic Assimilation
Red wolf: predator control
and destruction of mature
woodland caused a reduction
in range and population size.
By 1970s, the species had
dwindled to a single
population in eastern Texas,
and this population is
threatened by interbreeding
with the close relative, the
coyote (Canis latrans).
Disease
Dutch elm disease owes its name to
the fact that it was first identified in
the Netherlands in 1921.
Dutch elm disease was first found in the United States in
Ohio in 1930. It has now spread throughout North America
and has destroyed over half the elm trees in the northern
United States. Dutch elm disease is caused by the fungus
Ophiostoma ulmi which is transmitted by two species of
bark beetles or by root grafting.
Powdery Mildew on Dogwoods
(Dogwood Anthracnose)
Powdery mildew, which is caused by the fungus
Microsphaeria penicillata.
Probably introduced into the United
States near Connecticut and Washington
State simultaneously in the mid-1970s.
Although it entered the U.S.A. at two
separate points, genetic analysis has
shown that the causal organism is the
same. However, the origin of this
pathogen remains unknown, as it has yet
to be identified on any species of
dogwood occurring outside the U.S.
Disease
American chestnut trees were once 1/4th of all trees in the
Appalachian Mountains. Infection by a fungal blight
destroyed all chestnuts of reproductive size.
Introduced Species
The fungus that destroys
the American chestnut was
introduced with a
shipment of nursery stock
from China in 1904, so it
was in actuality an
introduced exotic species.
Introduced Species
Species Diversity and
Preservation II
Chapter 16 pt 2
Terminology
Alien species - refers to a species that is transported or
established outside of its native range. This transport
may or may not be intentional.
Introduced species - is an alien species that was
transported intentionally.
Invasive species - is an alien species that disrupts the
normal functioning and/or structure of an ecosystem.
A naturalized species is one that has become established
and is self-sustaining in a new area.
Invasive Species - USA
The current environmental, economic, and health costs of
invasive species could exceed $138 billion per year,
more than all other natural disasters combined.
West Nile virus and Purple loosestrife (northeast)
Kudzu, water hyacinth, nutria, and fire ants (southeast)
Zebra mussels and leafy spurge, (Midwest)
Salt cedar, Russian olive, and Africanized bees (southwest)
Yellow star thistle, Asian clams, and sudden oak death
(California)
Cheatgrass, knapweeds and thistles (Great Basin)
Whirling disease of salmonids (northwest)
Hundreds of species (microbes to mammals) (Hawaii)
Brown tree snake (Guam)
Factors that Contribute to
Community Vulnerability to
Invasion
Vacant niches
Escape from biotic constraints
Community species richness
Disturbance before or upon immigration
Exotic Species Introductions (Biotic
Pollution)
Other than habitat loss (and possibly exploitative
hunting/fishing practices), the introduction of exotic
species has caused the greatest threat to biodiversity.
Introduced competitors and predators have a greater
negative effect on local organisms than do native
competitors or predators because exotic species have not
coevolved with those native species. Therefore, the native
species have no adaptations to the introduced species.
Islands (e.g., Hawaii, Australia) are particularly susceptible
to introductions because predators are often rare on islands.
Introduced Species in Hawaii
With the arrival of Captain James Cook in 1778, the
environment of Hawaii began to change dramatically. These
first European settlers brought a number of new species
including; pigs, goats, sheep, and many ornamental and
horticultural plants.
It is now estimated that an
average of 20-50 new species
arrive annually in Hawaii.
The subsequent loss of native
species has decreased the
diversity and produced
economic problems.
Introduced
Species in the
Continental
USA
Kudzu: Introduced in the
southeastern U.S. in the
1930s as a control for
erosion. Has overgrown
everything in its path,
causing millions of dollars
in damage annually.
Introduced
Species in the
Continental USA
Purple loosestrife:
Cultivated for its beautiful
purple flowers, this wetland
plant escaped into New
England marshes a century
ago.
It now fills the wetlands
across much of the northern
U.S. and southern Canada,
reducing wetland
biodiversity.
Introduced
Species in the
Continental
USA
Japanese honeysuckle:
This aggressive vine
seriously alters or destroys
the understory and
herbaceous layers of
communities it invades,
including prairies, glades,
floodplains, and upland
forests.
Cane toads: Bufo
marinus is the
most introduced
amphibian in the
world. It
outcompetes native
amphibians and
also causes
predator declines
because they have
no natural
immunity to the
bufotoxin it
secretes.
Introduced
Species in the
Continental USA
Great
Lakes
Introducti
on of
Species
Zebra Mussels
Introduced from the ballast water of cargo ships from the
Caspian Sea. They glue themselves to any solid surface.
These mussels clog
intake pipes, cover the
bottom of lakes, and
invaded the Hudson
and Mississippi
Rivers. They cost
$400 million/year in
removal costs, and
exclude other, native
mussels.
Zebra Mussels
The estimated cost to industry,
shipping and sport fishing was
$5 billion in the Great Lake
region alone by the year 2000.
Each female can produce one million
eggs a year. Being colonial, as many as
500 000 mussels may be attached as a
solid mass on each square meter of
substance, encrusting and clogging
various utilities like the intake ducts
and pipes of power stations and
industries, drains, etc.
Lampreys
Lampreys
The impact of lamprey on commercial fishing in the
Great Lakes.
Protecting Species
Habitat Protection:
Placement of habitats into Preserves, Reserves, and
National Monuments, can protect both endangered
species, as well as provide ecosystem stability.
Risks:
Multiple use (recreation, timber extraction, grazing use,
mineral extraction) can often conflict with preservation of
a habitat.
“Paper” parks are often logged, farmed, mined, or
poached. Poaching is a common practice, even in U.S.
protected areas.
Protecting Species
Sometimes the
protection of a
specific habitat
(e.g., freshwater
river) involves
monitoring of
other
ecosystems
(e.g., riparian
environment).
Protecting Species
Debt for Nature Swaps:
The purchase of debt by organizations at a much lower
rate (10 cents on the dollar), and then forgiveness of that
debt in return for that countries efforts to make reserves
in certain areas.
The largest of the “debt for nature swap” organization is
the World Wildlife Fund (WWF). Since its inception in
1961, WWF has invested in over 13,100 projects in 157
countries. The annual budget is about $20 million,
almost all from private donations.
Examples of Non-governmental
Organizations (NGOs) Involved in
Defending Species and Habitats
Nature Conservancy
Conservation International
World Wildlife Fund
Environmental Defense Fund
Sierra Club
Greenpeace.
Protecting Species by Laws
Hunting and Fishing Laws - Limit number of animals that
can be ‘harvested’ on a yearly basis.
Usually animal populations are monitored so that hunting
pressures do not limit the populations.
For some animals, such as deer, management practices
favor them, so they may be even more abundant than
prior to settlement of the U.S.
In these cases, the species can be more of a problem for
habitat integrity than a species that needs protection.
Zoos, Botanical Gardens, Captive
Breeding Programs
Breeding of endangered animals
(Cheetahs, other big cats, rhinos,
other large game animals),
conservation of plant species
(sometimes through the storage
of seeds in banks), may provide
a haven from which to
reestablish very endangered
species.
Costs are prohibitive.
Restoration Ecology
Restoration Ecology means to bring back a habitat to a
former condition. When overexploited, ecosystems
degenerate and services decline. Ultimately we need
the capture of renewable resources while sustaining the
global ecosystems that convert sunlight into ecosystem
services.
Principles and Goals:
Need to consider several levels - genes, populations,
ecosystems at the same time. Ongoing research to
collect data on the restored site to monitor changes.
Curtis Prairie in
Wisconsin:
In 1934, seeds were
collected from
remnants along
railroad right-ofways and in pioneer
cemeteries and
cultivated in an old
field. Periodic fires
helped to establish
the prairie; it now
serves as a seed
source for other
prairies.
Restoration
Ecology
Restoration
Ecology
Guanacaste National Park (Tropical dry forest):
In an attempt to restore a tropical dry forest in Costa
Rica, used existing livestock to germinate seeds, fire
control to help establish forests, and intensive labor to
eliminate weedy plants.
Restoration
Ecology
Rivers - The Army Corp of Engineers straightened and
drained naturally occurring meanders in rivers. Now,
after realizing the value of wetlands along rivers as a
flood control (and for groundwater recharge), they are
trying to restore wetlands.
Endangered Species Act of 1973.
Regulate activities involving endangered species,
including taking, selling, or transporting any endangered
animal. Protecting these species often involves
preserving habitats that are also endangered, as well as
the other unidentified species using that habitat.
Recovery Plans: Several success stories,
1.
American Alligator, which was overhunted for
meat and skin
2.
Eagles, hawks, and falcons which were
decimated by DDT.
Definitions Resulting from
Endangered Species Act
Federal Endangered - animal or plant species,
subspecies or varieties in danger of extinction
throughout all or a significant portion of their range.
These are considered "Federally-listed" or "listed"
because a final rule was published in the Federal
Register.
Federal Threatened - species, subspecies or varieties
likely to become endangered within the foreseeable
future throughout all or a significant portion of their
range.
Population:
Policy Responses
Governments can help to
create the conditions
where having fewer
children will make sense,
and where people have
the means to reach their
desired fertility.
And if fertility can be reduced, there will usually be
environmental benefits.
Policy Responses
Consumption:
Realistic approach is to divert
consumption into channels with lower
environmental costs, while ensuring
that people still enjoy the end products
or services they need for dignity and
comfort.
The balance of taxes and subsidies can be shifted so as to
make environmental "bads" like excessive car or fossil-fuel
use less attractive to consumers, and environmental "goods"
such as energy-saving technology more attractive.
Policy Responses
Technology:
The heaviest burden will fall on the
technology element of the equation.
If, as is quite likely, the scale of the
world economy triples by 2050,
then technological changes will
have to reduce the environmental
impact of our activities by two
thirds - just to prevent the present
rate of damage from increasing.
Land and Food Resources I
Chapter 17/18 pt 1
The Tragedy of the
Commons
Giving it a try…
Ecosystem Services of Natural Areas:
1.
2.
3.
4.
5.
Wildlife habitat (protect species)
Flood and erosion control
Soil formation/maintenance
Groundwater recharge
Recycle wastes (nutrient cycles)
and break down pollutants
Pasture and Open Rangeland
Predominantly grasses
with a fibrous root
system. Rangelands
occupy about 26% of
the world’s land
surface.
Pasture and Open Rangeland
There is twice as much permanent grazing land as area
given to agricultural crops in the world. Much of the
western Great Plains and the Prairie provinces of
Canada fall in this category.
Pasture and Open Rangeland:
Carefully managed, grazing can be sustained in grasslands
(with the loss of a few grazing-intolerant plant species),
because most species are tolerant of being grazed.
For the U.S.,
rangeland/prairies have more
species of plants, and more
threatened species of plants,
than any other biome type.
Pasture and Open Rangeland:
Benefits of grazing include:
Hooves create seed-to-soil contact
Natural grazers break soil crusts that keep seeds from
growing
Grazers trample standing vegetation into mulch
Grazers act like living compost piles, turning vegetation
into high-quality fertilizer
By pruning stale growth, they keep forage plants at peak
production
Pasture and Open Rangeland:
Effects of overgrazing grazing
include:
Compacting soil thus
preventing seeds from
germinating and water from
seeping into soil.
Overfeeding on plants not
allowing them time to
recover and adequately root.
Overgrazing
Overgrazing is when plants are consumed such that the
plant community does not quickly recover.
1/3rd of the world’s
range is severely
degraded by
overgrazing, making it
the largest cause of soil
degradation.
Overgrazing
The first symptom of overgrazing is the loss of palatable
species of herbs and grasses. Continued overgrazing
compacts the soil, strips the ground bare, and leads to
erosion.
Desertification
Continued degradation leads to a fertile land becoming more
desert-like.
Without plants to
hold soil moisture,
surface runoff
increases, wells
dry, the
microclimate
becomes
inhospitable for
plants, and deserts
occur.
Desertification
In Africa, deserts have increased by 50 million hectares,
and humid or semiarid lands have decreased by that
amount. Is human activity responsible?
Remember the
Tragedy of the
Commons
Any commonly held
resource becomes degraded
or destroyed because the
narrow self-interests of
individuals tend to outweigh
the public interests.
U.S. Rangelands
Bureau of Land Management (BLM): 200 million acres
U.S. Forest Service (USFS): 50 million acres
60% of rangeland is privately owned.
55% of public rangelands are in poor condition (sage,
mesquite, cheatgrass, and cactus).
Grazing fees: grazing permits on BLM or USFS land was
$1.35 per animal. It costs them $3.21 per animal to
administer grazing. This equals a loss of of $32 million.
Few people hold most of these permits = welfare for rich
cattlemen.
Forests and Forest Products
The amount of fuel wood consumed by each person in
developing countries is roughly equal to that used as
paper products by each American.
Demand for fuel wood will be twice the available
supply in just 25 years.
The Rates of Deforestation Are Increasing
Consider Costa Rica, an environmental success story.
Lost 75% of its primary forests in the last 60 years due to
timber harvest, Del-Monte plantations, cattle grazing
(mostly for export).
Costa Rica (the “Green
Republic”)
Costa Rica contains more biological diversity than all
of North America combined.
Costa Rica encompasses only.03%
of the world’s landmass, but it
contains and supports 5-6% of the
entire world’s biodiversity.
Costa Rica Policies
Costa Rican Government has been a front runner in
conservation policy - 90% of its remaining forest is
protected, and it has the largest percentage of land
dedicated to national parks in the world.
Emphasis has been on sustainability.
Along with a strong conservation policy, the Costa
Rican Government has enacted incentive programs to
promote reforestation projects. These incentive
programs include such things as residency status and
various tax exemptions.
Causes of Tropical Rainforest Destruction
Commercial Logging: tropical forests harvested for
timber.
Subsistence agriculture: “slash and burn tactics” (also
called swidden or milpa agriculture).
Cattle ranching: After commercial harvesting or after
subsistence agriculture, or on its own.
“Slash and Burn” (Swidden or Milpa
Agriculture.
Farmers clear a small plot (2 acres), burn the dried plants
to provide a burst of nutrients (and ash is basic,
increasing the release of minerals from clay).
On field, they practice polyculture (using some
perennials). Banana/plantain, papayas, cassava and sweet
potato (root crops), beans (increase nitrogen), and maize
(plots hold the soil because there is a variety of roots).
In time, the plot is given over to encroaching forest
because the fertility has decreased, and the farm begins in
a new area.
Milpa Agriculture
Depends on land to rotate
through. If the farm remains
long term, the productivity
of the land declines.
Higher populations are
increasing the pressure on the
land and not allowing enough
time for recovery.
Cattle Ranching
Ranching often introduced after commercial harvesting or
after subsistence agriculture, or on its own.
Tropical soils are Oxisols and
ultisols - soils that are highly
leached and nutrient poor.
Minerals are locked up in the
vegetation; if vegetation is lost,
minerals are lost.
So, it is hard to go from a pasture
back to a forest again.
Logging in the
U.S.A.
Kinds of cutting:
Clear cutting: removal of all wood in a compartment.
Strip cutting: harvesting strips within a compartment on a
rotational basis.
Selective cutting: planned removal of individual trees or
small groups of trees within a forest stand.
Clear Cutting:
Cost effective because large machines can be used, making
it easier to fell, trim and skid logs.
But: 1. Eliminates almost all habitat
2. Increases soil erosion greatly
3. Favors early succession tree species and deer (game)
4. Increases soil and water temperatures.
Sometimes seed trees or nurse plants left
Clear Cutting:
Clear Cutting:
Strip Cutting
1. Reduces erosion compared to clear cutting
2. Provides seed sources for establishment,
But strip
cutting still
favors early
successional
tree species
and edge
animals.
Selective Cutting
• Favors the more shade-tolerant trees like red spruce,
sugar maple and hemlock because the shade is not
broken.
2. Provides a continuing supply of food and cover for
wildlife throughout the life of the forest.
3. An uneven-aged stand is particularly favorable to birds.
Selective Cutting
Need intensive skilled management to prevent degradation
of the remaining stand (genetically superior trees are likely
to be removed).
Management and skidding costs are likely to be higher,
road construction and maintenance must be more
extensive.
High grading - taking out
the few choice trees for
profit and leaving the rest.
Lowest impact, but
requires other skidding
techniques.
Land and Food Resources II
Chapter 17/18 pt 2
Review of Logging Methods
Menominee Forestlands as a
Model
Menominee tribal people once controlled about 1 million
acres of land in Northeast Wisconsin and Michigan's
Upper Peninsula; treaties in the 1850s confined the tribe
to their current Reservation lands, totaling 235,000 acres.
Longest running
operation for
sustained-yield
forestry in the
nation. Densest,
most diverse
forests in Great
Lakes.
Menominee Forestlands as a
Model
Tribe recognized that their future depended on the forest
and embarked on a course of sustained yield
management to avoid forest exploitation and preserve
Tribal existence.
In order to survive off of their limited land base, the
Tribe decided that it must harvest timber, but must
maintain and perpetuate the forest resources for future
generations.
Menominee Forestlands as a
Model
The basic concept used was to harvest timber from one
end of the reservation to the other in such a manner that
when done, the first areas cut would be ready for cutting
again.
Long-term yields:
1. Maintain the mix of
hardwoods (sugar maple,
beech, hemlock,
basswood).
2. Mimicking firesuccession.
3. Cutting the worst first.
Menominee Forestlands as a Model
Tribe considers itself a part of the ecosystem and the
Tribe's survival depends on managing and protecting the
forest ecosystem. The Tribe's land ethic and management
philosophy contain the 3 components of a sustainable
system.
1. It must be sustainable for future generations. Must cut
trees across the Reservation at a rate that there will always
be timber ready to cut.
2. The forest must be cared for properly to provide for the
needs of people. Must conserve the productive capacity of
the land in order to sustain the Tribe's economy.
3. Keep all the pieces of the forest. Must maintain diversity.
U.S. Forest Service (USFS)
USFS supplies cheap logs to the nations timber industry.
Charges for timber sales have not been enough to repay
management costs, cleanup of logging debris, and
replanting of forests.
In 1997, the net loss on U.S. Forest Service timber sales
was $1.2 billion. (This estimate includes road-building
costs.)
Of 104 National Forests, 83 lost money on timber sales.
U.S. Forest Service (USFS)
In the past 40 years, USFS has made 340,000 miles of roads
(10 times the interstate highway system).
Value of Road-less Areas:
1. Supply clean drinking water
2. Decreases habitat fragmentation (lynx, wolverines, and
marten, pygmy owls, trillium).
3. Provide habitat that is resistant to invasion by exotic
species.
4. Provides unique recreational opportunities.
National
Protected
Areas
Butterfly
Habitats
Butterfly
Habitats
Include Redwoods, Red Cedar,
Douglas fir, Hemlock, and Sitka
spruce.
Forests are complex and diverse.
Vaux’s swift and marbled
murrelet live nowhere else. Now,
less than 10% of the forest
remains, with 80% scheduled to
be cut.
Pacific
Northwest Temperate
Rainforest
In 1989 environmentalists sued, using the Endangered
Species Act and the Spotted Owl as their defense.
150,000 people in Pacific Northwest are employed because
of forest products.
Logging jobs are disappearing (recreation jobs may provide
more jobs). Loss mainly due to mechanization, shipping of
raw lumber to Japan mill, and harvested of 90% of forests.
Wetlands are
transitional areas
between terrestrial
and aquatic
ecosystems.
Wetlands provide not
only habitat for
wildlife but also aid
in the recharging of
the groundwater and
reducing the effects
of changes in river
level by providing
flood zones.
Wetlands
Wetlands and Forests
Wetlands - Economics
Wetlands are important from an economic standpoint.
It is estimated that the bottomland hardwood and
cypress swamps of the Southeastern part of the United
States are worth over $8 billion.
Waterfowl hunters spend over $600 million annually
in pursuit of wetland-dependent birds, with a large
percentage of this money going directly to wetland
habitat protection.
Wetlands – Flood Control
Wetlands play an important role in flood control. It is
estimated that storm and flood damage exceeds $1
billion annually in the United States. Wetlands
intercept storm waters, thereby moderating sharp
runoff peaks to slower discharges over longer periods
of time. Wetland vegetation serves to stabilize
landforms and protect development.
Wetlands – Water Quality
Wetlands have been shown to remove organic and
inorganic nutrients and toxic materials from the water
that flows across them.
Wetlands remove sediments, and remove or filter
excess nutrients. These wetlands improve water
quality just as a water treatment plant costing millions
of dollars to build.
Wetlands - Destruction
Wetlands are most endangered by agriculture, fossil fuel
exploration and exploitation, construction of energy
projects (e.g., dams), and development.
Wetlands are
shrinking in the
USA at about
117,000 acres per
year.
About 75% of
remaining USA
wetlands in private
ownership.
How is Land Distributed
Globally?
Not that long ago,
natural areas were
considered essentially
limitless. Now,
emphasis is on
preservation of natural
areas. How much of
that 37% is enough?
What Is To Be Done?
1. Encourage reassessment of taxes on private
agricultural land near urban centers.
2. Require thorough public review and planning of
land use. Review procedures of long-standing.
3. Balance interests in management of Federal lands.
Wise-use movement
Environmental movement
Food Crops and Biodiversity
Human beings have used about five thousand species of
plants as food, but only 150 or so have entered world
commerce.
Fifteen crops provide most of the world's food, and three
crops - wheat, rice, and maize - account for roughly 60
percent of the calories and 56 percent of the protein that
humans consume directly from plants.
Food Crops and Biodiversity
Forty percent of an estimated 2,300 species of cultivated
plants belong to just four families: Graminae (grasses),
Leguminosae (legumes), Rosaceae (apples, pear, etc.), and
Solanaceae (potatoes).
The grass family - including
such crops as wheat, rice,
maize, barley, sorghum,
millet, oats, and rye - provides
some 80 percent of calories
consumed by humans.
Origins of Major Food Crops
Many of the major food crops originated in regions that
are not particularly species rich. Crops were
domesticated in warm temperate and subtropical zones
and in tropical mountainous regions.
Wheat and barley were first grown in the steppes and
woodlands of southwestern Asia, and the origin of maize
has been traced to the seasonally dry central highlands of
Mexico. The highlands of Peru contributed the tomato
and potato (though the tomato was probably first
cultivated in Mexico).
Origins of Major Food Crops
Most important food crops appear to have originated
where seasons are pronounced. In part this is due to the
tendency of plants in seasonal environments to store
nutrients during the growing season. Often, these
reserves are what human eat.
Much of the
world's
agriculture is
based on
introduced
crops.
Origins of Major Food Crops
In developing countries in the Americas, only 32 percent
of production is of crops of American origin.
The comparable figure for African developing countries
is 30 percent of crop production is native plants.
Only in Asian developing countries is most production 70 percent - by native species.
Origins of Major Food Crops
Dependence on introduced species reaches its extreme in
Australia, the Mediterranean, northern Europe, northern
Asia, and the United States and Canada. In these
regions, more than 90 percent of production is derived
from introduced species. None of the world's fifteen
most important food crops are native to Australia or to
North America north of Mexico.
World Food Issues
Amounts (famine)
Distribution
Poverty
Types of food available (malnourishment
compared to undernourishment)
Grain
Production
Conclusion – at the
moment supply
keeping up with
population growth.
World
Production
Major Food
Crops
Regional Differences in Food
Production
Regional Differences in Food
Availability
Distribution of Food
Most of the 183 countries of the world are now to some
degree dependent on food imports. These imports come
from cereal surpluses produced in only a few countries
that have a relatively low population density and intensive
agriculture.
For instance, in the period 1989-1991, the United States,
Canada, Australia and Argentina provided about 81% of
net cereal export on the world market
Differences in Food Usage
Rice, which has origins in either India or China, is the
eighth most important crop in the developed world (by
weight).
However, rice is by
a factor of two the
leading crop in the
developing world,
and it is the most
important source of
calories in tropical
developing
countries.
Differences in Food Usage
Similarly to rice, cassava (manioc) - native to tropical
America - is not grown in developed countries but is the
fourth most important crop in the developing world (by
weight) and provides more than half of the caloric
requirements for over 420 million people in 26 tropical
countries.
Cassava is a highyield, starchy, low
protein (<1%)
staple.
Food Resources - Figures
Over the past 20 years World food production has
increased by 2.1% per year.
There is enough food globally to give everyone 2,700
calories per day. The minimum requirement is 2,100
calories per day and malnourishment is considered to
be anything lower than 1,800 calories per day.
In the developing countries of the world one in five
people do not have enough food to meet their daily
requirements.
Take Home Message
Global food production outstrips the population!!!!!
Yet, 800 million people are malnourished!!!!!
One person dies each and every
second from starvation and its related
diseases. Three-quarters of those are
children under the age of five. Three
children died in the time it took you
to read this short paragraph.
Number of Undernourished
People (1969-1997)
Undernourished people (millions)
1969-71 1979-81 1990-92 1995-97
Sub-Saharan Africa
89
126
164
180
Near East & North Africa
45
22
26
33
East & South-East Asia
504
406
283
241
South Asia
267
338
299
284
Latin America & Caribbean
54
46
59
53
Industrialized countries
n/a
n/a
9
8
Countries in transition
n/a
n/a
20
26
TOTALS
959
938
860
825
Source: FAO (1999)
Distribution of
Malnourishment
Farming
General Types of Agriculture
In highly developed countries the main type of agriculture
is high-input agriculture (i.e., lots of energy, fertilizers,
pesticides) which produces high yields.
In developing countries
practice subsistence
agriculture, which does
not produce enough
surplus crops to sell or to
store for later need.
USA Grain Yields
Types of Subsistence
Agriculture
Slash and burn (aka shifting agriculture)
Nomadic herding - mainly in the areas of
Northwest Asia, the Middle East, North Africa
and the Arctic Tundra.
Polyculture
Genetic Diversity in Food
Crops
Genetic diversity can enhance crop production. Several
varieties can be planted in the same field to minimize crop
failure, and new varieties can be bred to maximize
production or adapt to adverse or changing conditions
As important as genetic diversity is to increasing yields, it
is at least as important in maintaining existing productivity
because of factors like coevolution. Over 400 species of
pests now resist one or more pesticides, and the proportion
of U.S. crops lost to insects has approximately doubled - to
13 percent - since the 1940s, even though pesticide use has
increased.
History of Plant Breeding
An Assyrian relief
carving from 870 B.C.
showing artificial
pollination of date palms.
For several thousand years,
farmers have been altering
the genetic makeup of the
crops they grow. Human
selection for features such as
faster growth, larger seeds or
sweeter fruits has
dramatically changed
domesticated plant species
compared to their wild
relatives.
Genetically Modified (GM)
Crops
Most new genetic engineering techniques initially
involve single-gene modifications of species, and in
many cases such modifications are less useful than the
multiple-gene changes that result from traditional
breeding programs.
Maize
Maize genetically
modified to produce
Bt protein
Bt protein kills
the
corn borer insect
Biodiversity
of Food
Risks of High-Yielding Crop
Varieties
Whereas traditional mixed farming systems produce
modest but reliable yields, planting a single modern crop
variety over a large area can result in high yields but the
crop may be extremely vulnerable to pests, disease and
severe weather. The results may be substantial loss of
yield (e.g., the 1970 loss of more than 15% of corn crop
to a fungus).
Single crop agriculture has a history of producing
famines when an organism of opportunity destroys that
crop.
Loss of Crop Diversity
Problems with Genetic
Uniformity
Genetic diversity provides the variation within
species that allows populations to adapt to changes
in climate and other local environmental conditions.
Without a constant infusion of new hardy genes into
our crop species, pests and diseases could quickly
get out of hand. Already more than 400 species of
crop pests have developed resistance to one or more
of the pesticides used to control them.
National Plant Germplasm
System (NPGS)
NPGS is a cooperative effort by public (State and
Federal) and private organizations to preserve the
genetic diversity of plants.
The NPGS acquires, preserves and distributes crop
germplasm.
There is also a National Animal Germplasm Program
under development.
Sources of Food
Approximately 99% of the world food supply
is derived from terrestrial ecosystems with
the percentage from aquatic systems
shrinking.
The availability of arable land at world level
is less than 0.27 ha per capita, lower than it
has ever been in history, and much less than
the average of 0.7 ha per capita in the United
States. Note that 0.5 ha per capita has been
suggested as the minimum requirement for a
diverse diet of animal and plant food
products
Fisheries
Basic problem
with ocean
fisheries is the
issue of the
tragedy of the
commons. No
single nation
may legislate or
enforce policies.
Fish Farms (Aquaculture)
Are fresh water and marine water facilities.
Approximately 1/3 of the shrimp consumed globally are
from aquaculture sources.
More than 50% of salmon
consumed is raised on fish
farms.
Fish Farms (Aquaculture)
Farmed fish are frequently fed
on meal made from wild-caught
fish. In 2000, Goldburg coauthored a paper revealing that
1.9 kilograms of wild fish were
on average required to produce
every 1 kg of fish farmed in
1997.
Summary
Development must meet sustainability criteria
Earth has a carrying capacity
Earth’s productivity and resources limited
Renewable resources need sufficient protection
to be reusable
Resources are distributed unequally and the quality of
life is unequal
We are part of and dependent on the web of life and
must conserve diversity (ecosystem services enable us
to survive)
Summary
We must change our personal attitudes and practices to
produce the collective activities which will balance of
standard of living with sustainability
Success of society will depend upon personal activities,
economic costs, and political will.
Ultimately, global considerations will need to
supersede the interests of individual countries or
limited alliances
GET INVOLVED
You can make a difference!!!
Think before you consume or dispose of
wastes. What can I do to help cut down on
resource utilization and make sure we
efficiently utilize the resources necessary for
human survival.
Baby Steps!
the end
Now it’s your turn to highlight the things
that matter…