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Chapter 18
Conservation of Biodiversity
The
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th
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Mass Extinction
Extinction- when there are no longer any of the
species in the world.
Mass Extinction- an extinction event with a
great loss of biodiversity over a relatively short
period time
We are currently losing approximately 50,000
species per year.
Genetic
Diversity
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Higher genetic
diversity = higher rate
of survival for a species
facing environmental
changes
As a species shrinks,
inbreeding occurs.
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Inbreeding: when
individuals with similar
genotypes, generally
relatives, breed with
each other; decreasing
diversity
More inbreeding = less
likely to survive
Categories of
Endangerment
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Extinct- no known
species exist today
Threatened- high risk of
extinction
Near-threatened- likely
to become threatened
Least concern- species
are widespread and
abundant
HIPCO – Factors that Contribute
to the Destruction of Biodiversity
H- Habitat Loss
 I- Invasive Species
 P- Pollution
 C- Climate Change
 O- Overharvested
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Habitat Loss
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For most species the greatest cause of decline and
extinction is habitat loss.
Most habitat loss is due to human development
Forest Cover Map
Global changes in forest
cover from 1980-2000
Habitat Loss: Agriculture
Conversion to Agricultural Land
• About 40% of world’s land surface converted to
cropland and permanent pasture.
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Pressures to modify the environment are
greatest in areas with high population density
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Habitat Loss: Aquatic Ecosystems
When fish are harvested in shallow parts of the
ocean, trawls & nets drag along the bottom.
– Skim off decomposing debris (nutrients)
– Decrease oxygen in water
– Alter space and shelter for marine animals
– Uproot marine plants
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Habitat Loss: Aquatic Ecosystems
• Freshwater systems are often modified for
navigation, irrigation, flood control, or power
production.
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Invasive Species
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Native species- a species that still lives in its
historical range
Alien species (exotic species)- species that live
outside their historical range.
Invasive species- when alien species spread rapidly
across large areas.
Ex- Kudzu Vine, Zebra Mussel, Silver Carp
Exotic/Invasive Species
• No natural predators, parasites, etc.
• Rapid reproduction, adaptable to new
environments, and mature early
• Aggressive growth and spread
• Native species frequently out-competed
Cane Toads: An Unnatural History Part 5 (9 minutes)
Pollution
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Threats to biodiversity can come from toxic
contaminants such as pesticides, heavy metals,
acids, and oil spills
Climate Change
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The concern is how climate change will affect
temperature and precipitation around the world,
and how this will impact biodiversity.
Overharvesting
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When individuals of a species are removed at a rate
faster than the population can replace them.
Ex- dodo, American bison, passenger pigeon.
Overexploitation: Pet Trade
World Wildlife Fund estimates illegal trade in wild animals globally
produces $2 - $35 billion annually.
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Overexploitation: Fisheries
• U.N. estimates 70% of world’s marine fisheries are overexploited or are in danger of being fully exploited.
Lake Trout
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Conservation Efforts
1. Single species approach 2. Ecosystem approach
• Captive breeding
• Nature Preserves
• Gene Zoos
• Regulations
• Regulations
Lacey Act
One of the earliest laws in the U.S. to control
the trade of wildlife.
 First passed in 1900, the act prohibited the
transport of illegally harvested game animals,
primarily birds and mammals, across state
lines.
 Amended in 2008 to prohibit sale and import
of illegally logged woods and products made
from them.
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International Union for the
Conservation of Nature (1948)
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IUCN’s vision is a just world that values and
conserves nature.
The IUCN keeps a list of threatened species,
known as the red list.
Red List
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The IUCN keeps a list of threatened species,
known as the red list.
IUCN =
International Union for Conservation of Nature
Each country has its own way to monitor and
regulate the import and export of animals on the
list.
Conservation Legislation
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Marine Mammal Protection Act- (1972)
prohibits the killing of all marine mammals in
the U.S. and prohibits the import or export of
any marine mammal body parts
CITES
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Convention on International Trade in
Endangered Species of Wild Fauna and Flora
Developed in 1973 to control the international
trade of threatened plants and animals.
Today, CITES is an international agreement
between 175 countries of the world.
Endangered Species Act
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Endangered Species Act –
(1973) authorizes the U.S. Fish
and Wildlife Service to
determine which species can
be listed as threatened or
endangered and prohibits the
harming of these species.
Trading these species is also
illegal.
The act also authorizes the
government to purchase
habitat that is critical to the
species.
Convention on Biological Diversity
• In 1992, nations came together and made a treaty
to protect biodiversity.
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1.
2.
3.
The treaty had three objectives:
Conserve biodiversity
Sustainably use biodiversity
Equitably share the benefits that emerge from the
commercial use of genetic resources such as
pharmaceutical drugs
Conserving Ecosystem Biodiversity
• Habitat Analysis and Management
– Animals have highly specific habitat
requirements that change throughout the year.
Habitat Suitability Index
(HSI) describes the
suitability of a given habitat
by combining the
interactions of all key
environmental variables on
a species’ vital rates and
ultimately, survival.
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Size, Shape and Connectedness
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When designing and managing protected areas we must
consider how close to another area they should be, how large
the area is, and the amount of edge habitat the area contains.
Edge habitat - the area where two different communities come
together, typically forming an abrupt transition. Ex. A grassy
field meeting a forest.
Biosphere Reserves
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Protected
areas
consisting of
zones that
vary in the
amount of
permissible
human
impact.
Review Questions
• 1. Explain how genetic diversity loss is a positive
feedback loop.
• 2. What are the 4 categories of endangerment?
• 3. Explain how each of the 5 factors (HIPCO)
contribute to biodiversity loss.
• 4. Describe the Lacey Act and CITES.
• 5. Explain the purpose of the ICUN Red List and the
Endangered Species Act.
• 6. What are edge effects and why are they
important in designing preserves?
Conserving Ecosystem Biodiversity
Wildlife Management – application of ecological
knowledge to populations of vertebrate animals
and their plant and animal associates in a manner
that strikes a balance between the needs of those
populations and the needs of people. (Robinson &
Bolen 1999)
Conserving Biodiversity
• Animal species are often researched & managed
to assess population sizes and to document life
histories.
– Fin clips
– Radio collars
– Banding
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Conserving Biodiversity
• Wildlife management often involves harvesting for sport
and meat.
– Hunting regulation is crucial.
• Seasons usually occur in the fall to take advantage
of surplus animals.
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Conserving Biodiversity
Migratory birds
can travel
thousands of
kilometers.
• North in Spring
to reproduce.
• South in Fall to
escape cold
temperatures &
to find food.
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Preserving Biodiversity
• International agreements necessary to maintain
appropriate habitat.
– Canada
– United States
– Mexico
– International Crane Foundation
– http://www.savingcranes.org/
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Biodiversity Hotspots Poster
www.conservation.org/hotspots