Name _____________________________
Period ______________
Date ___________________
Unit 6: Biodiversity & Conservation (Ch.7)
Biodiversity
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Describes the __________________ across all levels of _______________ organization
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Includes three types:
1) Genetic diversity: Differences in ___________________________________________
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Within a species, organisms have genetic differences
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In general, species with more genetic diversity have better chances of survival
2) Species diversity: Variety of _____________ in a given ________
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Easiest to visualize & ________________________________
3) Ecosystem diversity: Variety of ____________, ___________________, or communities
in an area
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Ex. A seashore with rocky and sandy beaches, forested cliffs and ocean water
has more biodiversity than the same area of farmland
_______________________
_____________________________
_____________________
Species Diversity – Classification
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Taxonomists classify species based on physical ________________ , ___________ makeup and
ability to mate and produce ______________ offspring.
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Organisms are placed into a hierarchy of taxonomic groups:
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Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
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The more taxonomic levels two organisms have in
common, the ___________________________ they
are
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Taxonomic groups reflect _______________
relationships among species.
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Below the species level, organisms may fall
into________________—populations with genetically
based characteristics that differ area to area.
Biodiversity Distribution
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Species are ____________ distributed among taxonomic groups.
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Even though _________ are small in size, there are ________ known species of insect than any
other group.
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Scientists have identified and described ________________ species but estimate there are
between ________________ species on Earth.
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Why?
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________________________________________________
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________________________________________________
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________________________________________________
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Species are not evenly distributed ___________
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Latitudinal Gradient - there is an increase in species richness towards the ___________.
Benefits of Biodiversity
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_______________________ - valuable processes provided by intact ecosystems.
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Biodiversity enables services such as:
1) ___________________________________________
2) ___________________________________________
3) ___________________________________________
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High ________________ increases ____________ of communities and ecosystems, enabling
them to perform services.
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Stable ecosystems are resistant and resilient.
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Resistant: Resist environmental change without ____________ function
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Resilient: Affected by change, but ______________________ and regain function
Agriculture
1) Wild strains are _____________ with related crops to transfer beneficial traits.
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Ex. Corn that is disease resistant is cross-bred with normal corn to make a disease resistant
hybrid (___________ diversity)
2) New plants are constantly being ______________ that have the potential for widespread use.
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Ex. Babassu palm used for vegetable oil (_____________ diversity)
Medicine
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Organisms contain compounds that are useful for ____________________.
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Of the 150 most prescribed drugs in the United States,
_______ originated in __________.
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Ex. Yew tree, an original source of Taxol, a cancer-fighting drug
Ecotourism
__________________________________ tourism is a source of income for many nations.
Extinction
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Extinction – occurs when the _____________________of a species on the ____________ dies
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Extirpation – disappearance of a species from a particular __________ but
___________________________ globally
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Background extinctions: Naturally occurring extinctions, occurring _______ species at a time
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Mass extinctions: Events when extinction rates _____________ the normal background rate
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There have been ______ mass extinctions in Earth’s history
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Each time more than ______ of all species have gone extinct
Biodiversity at Risk
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The current extinction rate is ____________ times greater than the natural background rate.
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In 2009, 1321 species in the U.S. were classified as endangered or threatened.
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Endangered: At serious risk of _______________
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Threatened: Likely to become __________________ soon
through all or part of its range
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Living Planet Index: Summarizes ______________________ trends for
certain terrestrial, freshwater, and marine species
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The Living Planet Index fell by almost 30% between 1975 and 2005.
Causes of Biodiversity Loss
4 Primary Causes of Population Decline and Species Extinction:
1) __________________
2) __________________
3) __________________
4) __________________
Habitat Loss and Change
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___________ cause of biodiversity loss
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Organisms, ______________________________, decline in population when
the habitat changes.
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Ex. Clearing forests for logging or construction
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Habitat ___________________: Patches of _____________ habitat
surrounded by ________________ habitat
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In general, _________ habitat fragments can support _________________
biodiversity than smaller fragments.
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Habitat change or destruction is the primary cause of population decline in
more than ________ of threatened birds and mammals.
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A few species can benefit from human induced habitat changes.
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These species tend to be ______________ and can become _______.
Ex. ___________, __________________ & _____________.
Invasive Species
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Invasive species can ____________________________ native species.
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Increase rapidly, spread and displace native species.
Pollution
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Harmful chemicals and materials that make their way into habitats can __________ people and
wildlife.
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Ex. Heavy metals, fertilizers, pesticides and _____________.
Overharvesting
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Occasionally, species can be driven toward extinction when humans _________, ____________
or ___________ a species faster than it can replenish its population.
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Poaching (____________________________) is one reason that the Siberian tiger is at risk for
extinction.
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The parts from one tiger can be sold in the black market for approximately ____________.
Climate Change
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____________ becoming a factor in biodiversity loss
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Unlike the other factors, climate change will have a _______________________ effect on
biodiversity.
Protecting Biodiversity
The Endangered Species Act
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__________ that protects biodiversity, passed in 1973
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Has 3 major parts:
1) Forbids _________________ and ____________ from harming listed species and habitats
2) Forbids _____________________ made from listed species
3) Requires U.S. Fish and Wildlife Service to maintain an ________________of endangered and
threatened species, and to develop a __________________ for each listed species
Benefits
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Birds which were affected by ________ are no longer endangered
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Some species are still endangered but have stopped _______________ (40% of are now stable)
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Costs
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While trying to save the northern spotted owl, many __________________________because
timber harvesting was prohibited in their area.
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Landowners worry that use of _________________ might be restricted to protect an
endangered species.
International Cooperation
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Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES, 1975):
Bans ___________________ trade in _________________of endangered species.
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Convention on Biological Diversity (1992): International treaty to conserve biodiversity
and ensure its responsible _______________________
Single-Species Approaches to Conservation
1) Captive breeding programs: Raising and breeding organisms in controlled conditions, such as
______________________________
2) Species Survival Plan (SSP): Program to save individual species, includes:
________________________________________________
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Ex. Golden Lion Tamarins
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In the early 1970’s habitat fragmentation had decreased the number to ~______.
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Now there are nearly _____ in captivity & more than _____ have been released
back into the wild.
3) Cloning: Inserting _______ from an endangered species into a cultured egg cell with its nucleus
removed then implanting eggs into mothers of closely ____________________
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Most scientists __________________that this will prevent biodiversity loss since it does nothing
to fix the issues such as ______________.
Ecosystem and Habitat Approaches
1) “Hotspot Approach” - focuses attention on areas where the __________________________________
can be protected with the ___________________.
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A Biodiversity Hotspot is an area that both supports an especially ________________of endemic
species and in rapidly ______________________.
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Endemic – found ________________ in the world.
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Hotspots have:
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At least ________ plant species found nowhere else in the world
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Already lost ______ of their habitat as a result of __________ activity
The 34 biodiversity hotspots are home to 50% of Earth’s plant species and 42% of terrestrial
vertebrate species.
2) Economic Approaches - Many conservation efforts today attempt to balance
__________________________________ with the __________________________________________:
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Debt-for-nature swap:
Conservation organizations raise money to pay off a ______________________in return
for improved __________________________.
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Conservation concession: Conservation organizations
_________________________________________, instead of
_______________________.
3) Wildlife Corridors-Connect _____________________ enabling once-isolated populations to
interbreed
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Interbreeding increases ____________________.
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There is a current proposal to complete a
pieces of tiger habitat.
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Conservation biologists hope that a planned 250-km (150 mile) long corridor in Australia will
enable the endangered southern _________________ to recover from population declines
5000 mile long corridor in southeast Asia to rejoin
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