Download Sustaining Biodiversity – The Species Approach

Learning Objectives
• Identify the role human play in the loss of species and
ecosystem services.
• Explain why we should care about sustaining species and
the ecosystem services they provide.
• Describe how humans accelerate species extinction and
degradation of ecosystem services.
Agenda
• Notes
Sustaining Biodiversity –
The Species Approach
CHAPTER 9
Homework
•
•
•
•
•
Population Ecology QUIZ Thurs/Fri
Pop Ecology Lab due Fri 10/16
ES Project due Mon 10/19
Unit 3 Reading Assignment due on Sun 10/25
Unit 3 Current Event article due on Sun 10/25
What is Biodiversity?
• Sum total of all organisms in an area
Why is Biodiversity Important?
• Ecological value - biodiversity provides
free ecosystem services
− Provides food, shelter, fuel
− Purifies air and water, and detoxifies wastes
− Stabilizes climate, moderates floods, droughts, wind,
temperature
− Generates and renews soil fertility and cycles
nutrients
− Pollinates plants and controls pests and disease
− Maintains genetic resources
− Provides cultural and aesthetic benefits
− Allows us to adapt to change
1
Why is Biodiversity Important?
• Economic value
− Genetic diversity within crops is
enormously valuable
− Ecotourism
• Wildlife tourism
• Generates between $950,000 and $1.8
million per minute in tourist expenditures
worldwide
Human Impacts on
Biodiversity
• We have
depleted and
degraded some
of the earth’s
biodiversity
and these
threats are
expected to
increase
We know how populations survive
and reproduce, but what happens
when something goes wrong?
Errrr! Humans! What effect do we
have?
• Biologists estimate that
we have a huge impact!
• Species are becoming
extinct 100 to 1,000
times faster than they
were before modern
humans arrived on the
earth
• This equals about .01-1%
a year.
Percentage of various
species types threatened
with premature extinction
from human activities.
2
Endangered & Threatened
What does it all mean?
• Organisms headed toward biological
extinctions can be considered:
− Endangered: numbers of individuals so
low that it may become extinct in part or
all of its natural range
Species Extinction
• Some species have
characteristics that
make them vulnerable
to ecological and
biological extinction
− Threatened: still relatively abundant in
number, but declining numbers suggest
that it is headed toward being
endangered
Blame HIPPCO
•
•
•
•
•
•
Habitat destruction
Invasive species
Population growth
Pollution
Climate Change
Overharvesting
Habitat Loss is the greatest
threat!
• Deforestation, destruction
of wetlands/coral reefs,
plowing of grasslands
− Endemic species: found
nowhere else on the
earth
• Habitat islands (those
surrounded by different
ones like national parks)
are at risk of the P and the
I
3
Habitat fragmentation
threatens species
Invasive Species
• Many nonnative species provide us
with food, medicine, and other
benefits but a few can wipe out
native species, disrupt ecosystems,
and cause large economic losses
• Habitat fragmentation
can:
− divide populations
− increase the effects of
disease
− storms
− fires
− predators
− restrict the movement
of genes
─ 50,000 invasive species in US; 1 in 7
are harmful
Kudzu vine was
introduced in the
southeastern U.S. to
control erosion. It has
taken over native
species habitats.
• They have no natural predators,
competitors, parasites, or pathogens
to control numbers in their new
habitat
• Invasives threaten 1,260
endangered and threatened species
with 95% of those in Hawaii
Invasive Species
• Prevention is the
best way to
reduce threats
from invasive
species, because
once they arrive it
is almost
impossible to slow
their spread
Fig. 9-12, p. 202
4