Transcript Activity: Biodiversity Review - Life Sciences Outreach Program

Summer 2010 Workshop
in Biology and Multimedia
for High School Teachers
“Finds tongues in trees, books in the running brooks, sermons in
stone, and good in every thing.”
William Shakespeare
http://upload.wikimedia.org/wikipedia/commons/4/40/Large_leaved_linden.png
David Eatough
Revere High School
Understanding Biodiversity
“We need an expedition to planet
Earth, where probably fewer than 10
percent of the life forms are known to
science, and fewer than 1 percent of
those have been studied beyond a
simple anatomical description…”
E. O. Wilson 2006 “The Creation”
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
How much do we truly know about life on earth?
Objectives:
• To better understand what humanity knows about life on earth
• To understand the value of biodiversity to earth and ourselves
• To better understand the methods used by science to explore and measure
biodiversity
• To understand how humanity has altered biodiversity
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
What is biodiversity?
Biodiversity is:
• the variety or richness of life at all structural
levels (molecular/genetic, species, ecosystem).
• an essential renewable resource.
• exploited and depleted by human activities
The current rate of biodiversity loss is comparable
to previous extinction events.
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
http://en.wikipedia.org/wiki/File:Undiscovered_species_chart.png
How are known species
distributed into groups?
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Why is maintaining earth’s
biodiversity important to survival?
Life Sciences - HHMI Outreach. Copyright 2010
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Biodiversity provides:
•
Natural Resources such as:
food, water, wood, energy, and
medicines
•
Natural (Ecosystem) Services including:
air and water purification, soil
fertility,
waste disposal, biological pest control
•
Aesthetic pleasure
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
http://en.wikipedia.org/wiki/File:MEAConservationStrategies.jpg
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
“The only way to save the diversity of life and come to peace with nature
is through a widely shared knowledge of biology and what the findings of
that science imply for the human condition.”
E. O. Wilson 2006 “The Creation”
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
How is biodiversity measured?
• Richness is the number of unique taxa (species / organisms)
• Abundance or relative abundance is the number of individuals present in
each taxonomic group relative to the total number of individuals
• Frequency is the percentage of times a species is observed
• Community Dominance Index measures the proportion of the two most
abundant species in a community. Higher Community Dominance Index
values are generally found in ecologically degraded areas.
• The Shannon-Wiener Index measures how evenly species (species
evenness) within a community are distributed on a logarithmic scale.
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http://en.wikipedia.org/wiki/File:Siberischer_tiger_de_edit02.jpg
What causes changes in biodiversity?
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“Animal and vegetable life is too complicated a problem for human
intelligence to solve, and we can never know how wide a circle of
disturbance we produce in the harmonies of nature when we throw the
smallest pebble into the ocean of organic life.”
George Perkins Marsh
Life Sciences - HHMI Outreach. Copyright 2010
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Brainstorm: Factors that affect your life
Grandfather
Mom
Art
Dad
Food
Siblings
Nature
Ocean
Skiing
ME
Colleagues
Books
Teachers
Order factors according to
impact each has had on your
life and create a graphical
representation.
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
Friends
“The decline of Earth’s biodiversity is an unintended consequence
of multiple factors that have been enhanced by human activity.
They can be summarized by the acronym HIPPO, with the order of
the letters corresponding to their rank in destructiveness.”
E. O. Wilson, The Creation
H
Habitat loss, including that caused by human-induced
climate change.
I
Invasive species harmful aliens, including predators, diseases,
and competitors that displace native species
P
Pollution Oil spills, human agricultural waste, fertilization,
pesticides, acid deposition, greenhouse gases etc
P
Population, Human overpopulation to be exact, a root cause
of the other four factors
O
Overharvesting, Overuse hunting, fishing, gathering
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
Human
Population
Increase
Land use change
(Habitat loss)
Increasing
Economic
Activity
Increasing
Economic
Activity
Increased use
of technology
Increased use
of technology
Social, political
and cultural
factors
Social, political
and cultural
factors
Indirect
(Underlying
causes)
Direct
causes
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
Declining
Biological
Diversity
Habitat loss is the greatest reason
for biodiversity loss.
http://en.wikipedia.org/wiki/File:Lacanja_burn.JPG
Habitat loss is due to:
• Conversion of natural areas to farms,
houses, etc
• Fragmentation of ecosystems by human
activities, housing, transportation,
agriculture etc.
• Simplification of genetic diversity and
complex ecosystems by planting/selecting
monocultures.
Life Sciences - HHMI Outreach. Copyright
2010 President and Fellows of Harvard
College
What are invasive species?
Invasive Species cause major environmental and economical damage
Invasive species, non-native species, invasive exotics, are introduced
usually by human activities. Invasive species are generally thought to
cause economic or environmental harm.
http://en.wikipedia.org/wiki/File:Brown_tree_snake_Boiga_irregularis_2_USGS_Photograph.jpg
Life Sciences - HHMI Outreach. Copyright
2010 President and Fellows of Harvard
College
How are invasive species spread?
Aquatic species may be transported in the ballast of ships or attach to the ship’s hull.
Invasive species travel in the cargo of ships, planes, trains …
The pet trade accidentally or intentionally spreads invasive species
Many invasive species are released intentionally
http://upload.wikimedia.org/wikipedia/commons/3/35/Zebra_mussel_GLERL_1.jpg
•
•
•
•
Life Sciences - HHMI Outreach. Copyright
2010 President and Fellows of Harvard
College
What are the characteristics of
invasive species?
•
•
•
•
•
•
•
Grow rapidly
Have high reproductive rates
Disperse easily
Tolerate a wide range of environmental conditions
Flexible diet
Limited naturally occurring predators
Genetic and phenotypic variability
http://en.wikipedia.org/wiki/File:LythrumSalicariaBig.jpg
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What are the environmental
costs of invasive species?
• Invasive species are primarily responsible for 42% of species on the threatened or
endangered species list.
• Invasive species prey on native species (brown tree snake eating bird)
• Nutrient cycles may be altered by invasive species making habitat less suitable to
native species
• Invasive species outcompete native species for resources (nutrients and space)
• Loss of native species due to invasive species disrupts trophic relationships
http://en.wikipedia.org/wiki/File:Birdsinging03182006.JPG
Life Sciences - HHMI Outreach. Copyright 2010
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What are the economic costs
of invasive species?
• Estimates for damage and the cost of controlling
invasive species in the United States exceeds $138
billion annually
• Estimates do not include loss of biodiversity and
ecosystem services provided by natural habitats
http://en.wikipedia.org/wiki/File:One_US_dollar_1917.jpg
Life Sciences - HHMI Outreach. Copyright 2010
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Are all invasive/introduced species harmful?
•
•
•
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Most introduced species are beneficial to society.
Introduced species provide food, shelter, medicine, and aesthetic pleasure.
Introduced species provide more than 98% of the United States food system
Some organisms are introduced to control the populations of invasive species.
http://en.wikipedia.org/wiki/File:Rice_p1160004.jpg
Life Sciences - HHMI Outreach. Copyright 2010
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Population
The expansion of human population (7 billion and counting) and
affluence, especially in the developing world harms natural ecosystems.
http://en.wikipedia.org/wiki/File:Population_curve.svg
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Pollution
http://en.wikipedia.org/wiki/File:AlfedPalmersmokestacks.jpg
Pollution is the release of harmful substances
into the environment. Pollution may include
chemical substances, noise, heat, or light.
Pollutants may be naturally occurring and
harmful when they exceed natural levels.
Life Sciences - HHMI Outreach. Copyright 2010
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Overexploitation / Overharvesting
http://en.wikipedia.org/wiki/File:Bluefin-big.jpg
Overexploitation refers to unsustainable harvesting of a
renewable resource which can lead to the collapse of the
population. This can result in extirpation and extinction.
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College
http://upload.wikimedia.org/wikipedia/en/thumb/b/bc/Atlantic-Cod-Stocks.jpg/773px-Atlantic-Cod-Stocks.jpg
References:
Carroll, David M. (1999) Swampwalker’s journal: a wetlands year, Mariner Books, New York
Jones, T. and and Laughlin, T. (2009) Learning to measure biodiversity: two agent-based models that
simulate sampling methods & provide data for calculating diversity indices, The American Biology
Teacher September 2009 vol 71 no 7
Miller Jr. G. Tyler (2007) Living in the environment: principals, connections, and solutions15th edition,
Brooks/Cole California
Raven, P., Berg, L., Hassenzahl, D. (2008) Environment 6/e, John Wiley & sons, New Jersey
Wilson, Edward O. (1992) The diversity of life, W. W. Norton & Company, New York
Wilson, Edward O. (1996) In search of nature, Island Press, Washington D.C.
Wilson, Edward O. (2006) The creation: an appeal to save life on earth, W. W. Norton & Company, New
York
Life Sciences - HHMI Outreach. Copyright 2010
President and Fellows of Harvard College