Transcript Humansinbiosphere09

Adapting to a Changing
Planet
PLANT & ANIMAL
ADAPTATIONS/BEHAVIORS
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Nastic responses - reversible,
responsive movements of plants
(sunflowers, Venus fly-traps)
Tropism – response of a plant to
an environmental stimulus (+ & -)
Gravitropism – grow towards the
force of gravity
Phototropism – grow towards
light
Thigmotropism – response to
touch
Plant Hormones
– stimulates the lengthening of cells,
causes apical dominance, (plants grow
straight up with little branching) & inhibits
fruit dropping
 Gibberellins – cell elongation, cell division,
dwarf plants (lack gibberellins)
 Ethylene – gas – ripening of fruits
 Cytokinins – increase rate of growth
 Abscisic acid – slows growth (used in seed
dormancy – washed out when conditions
are favorable)
 Auxin
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Photoperiodism – response of plants to periods
of light & dark
Short-day plants – flower in winter, spring, or fall
Long-day plants – flower in the summer
Intermediate-day plants – equal amts. Of night &
day (equatorial plants)
Day-neutral plants – flower regardless of the
amount of dark/light
What adaptations have aquatic
plants made?
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Tissues with air-filled
spaces for oxygen to
diffuse, roots with air
spaces, cypress
knees, seeds that
float
What adaptations have salt-tolerant
plants made?
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Specialized cells that
pump salt out of the
plant tissues & onto
the leaf surfaces to be
washed away by rain
What adaptations have desert
plants have?
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Extensive roots,
reduced leaves, thick
stems that store
water, photosynthesis
at night
Why are some plants carnivorous?
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To obtain nitrogen
that they don’t get
from their poor soils
What are epiphytes?
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Plants that grow
directly on the bodies
of other plants – do
not harm the plant
What type of chemical defenses do
plants have?
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Poisons, insect
hormones that disrupt
life cycles & the
nervous systems of
animals
Behavior Terms
Stimulus – any kind of
detectable signal that carries
information
 Response – reaction to a
stimulus
 Innate Behavior – instinct –
consist of Fixed Action
Patterns (FAPs)
 Learned Behavior –
alterations in behavior that
result from experience
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Habituation – an animal decreases or stops its
response to a repetitive stimulus that neither
rewards nor harms the animal (Boy who cried Wolf)
 Classical Conditioning – animal makes mental
connection between stimulus and reward or
punishment (2 unrelated stimuli)
 Operant Conditioning – trial-and-error learning
(repeated practice)
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Insight Learning –
applying information
to a new situation
without trial & error
(reasoning)
 Imprinting – learning
based on early
experience (visual or
chemical signals) –
cannot be changed
once learned
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Why do birds migrate?
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To avoid predators &
to reach fertile
feeding grounds
Which animals are social? What
are the advantages?
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Primates, bees, ants,
termites, wasps,
dogs, wolves, whales,
meerkats, etc.
 Safety, food,
protection of young,
efficiency
How do animals communicate with
one another?
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Visual, sound, touch,
or chemical signals or
language
Humans have the greatest impact on the
environment of any living species on
Earth. The increase in our population over
the last few centuries has seriously &
dramatically changed the face of the
Earth.
4 Primary Factors that Have Contributed to
these Changes:
1)Availability of Clean Water
2)Sanitary Waste Disposal
3)Better Medical Care
4)Increase in Food Production
Ecological Footprint
An ecological footprint is used to describe
the environmental impact of a population.
It is the amount of the earth’s surface
that’s necessary to supply the needs of, &
dispose of the waste of, a particular
population. Americans have a 9.7 ha
ecological footprint while Indonesians
have a 1.1 ha footprint.
The Green Revolution
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The past 50 years have seen a huge
increase in world-wide ag productivity known
as the Green Revolution. 3 Primary factors
have led to this development:
 1) Mechanization of Farming
 2) Inorganic Fertilizers
 3) Pesticide Development
 Tragedy
of the
Commons – when
humans deplete a
renewable
resource to which
they have free &
unmanaged
access
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Renewable resources – resource that can be
replenished rapidly – trees, water, soil, wind
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Nonrenewable resources – resource that
exists in fixed amounts & takes hundreds –
billions of years to form – metals, fossil fuels
Sustainable Living
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Using resources at a
rate that does not
deplete them leads to
sustainable use.
This practice takes in
to account
economics &
ecology principles.
What human activities affect the
land?
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Farming, mining,
energy extraction,
construction, solid &
hazardous waste
disposal
Land Resources
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Soil is a renewable resource when used
properly. Soil mismanagement includes:
 1) Salinization - the soil becomes water-logged
& dries out with a salt layer on top
 2) Overgrazing - too many animals on too little
land
 3) Erosion - due to poor farming & construction
practices
Forest Resources
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Deforestation leads to severe erosion &
nutrient removal. Old-growth forests have
never been cut & have high biodiversity.
Second-growth forests are newer forests with
lower biodiversity. Sustainable forestry
practices such as alley cropping,
windbreaking, & selective cutting help to
preserve forestry & crop resources.
Hazardous Waste
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Hazardous wastes are disposed of in 3 main
ways:
 1) Injection wells - drill a hole in the ground
below the water table & inject the waste
 2) Surface impoundment - shallow, lined pools
- liquid wastes evaporate
 3) Landfills - layers of sand, liners, & clay
contain the waste in a giant holding facility
What human activities affect the
water?
 Farming, fishing,
Landscaping, air
pollution, sewage,
construction,
pesticides, thermal
pollution
 Eutrophication –
adding nutrients to
water – causes
excessive algae
growth, bacteria
overgrowth, death of
other organisms
Ocean Resources
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A fishery catches, processes, or sells fish, shellfish,
& aquatic animals. About 50% of all fisheries are
fully exploited. Methods of exploitation include:
1) Driftnets - dragged through the water - lots of
bycatch
2) Long lining - miles-long fishing lines that catch
numerous organisms
3) Bottom trawling - scrape the bottom floor with
heavy nets
Aquaculture (fish farming) is pursued as a method to
avoid fishery depletion.
What human activities affect the
air?
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Energy production,
burning fossil fuels,
cigarette smoking,
industry, agriculture,
using lead-based
materials
Air Pollution
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Primary pollutants are released directly
into the atmosphere in a toxic form
(carbon monoxide). Secondary
pollutants are formed by the combination
of primary pollutants (acid rain). Pointsource pollution describes a specific
location from which pollution is released
(a pipe, factory). Non-point pollution
comes from a number of sources (oil in
streams, methane in the air).
What causes ozone depletion?
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UV light combines with CFC’s & other ODC’s
to break O3 (ozone) into O2 & O
What causes global warming?
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When greenhouse
gases trap too much
heat in the earth’s
atmosphere (CO2,
methane, nitrous
oxides, CFCs, halons,
water)
What causes acid rain?
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Acid rain occurs as a result of pollution in
the atmosphere - usually when SO2 or
nitrogen oxides mix with water. It
leaches minerals, increases aluminum in
the soil, & damages, paints, rocks,
statues, & buildings.
Biodiversity – variety of
different species in an
area
 Species diversity - the #
of different species in the
biosphere
 Genetic diversity - the
gene pools available in
the biosphere
 The greater the
biodiversity of an area,
the greater the stability
of an ecosystem.
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The Importance of Biodiversity
 Instrumental
value (economic &
pharmaceutical worth)
 Ecological value (clean water, clean air,
intact ecosystems)
 Aesthetic value (for its beauty & worth in
itself)
Threats to Biodiversity
Habitat alteration – significantly
changing the living environment
of a species
 Habitat fragmentation –
breakup of a habitat into smaller
pieces – creates edge effects –
microecosystems with different
abiotic factors
 Overexploitation – excessive
use
 Pollution
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Threats to biodiversity
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Bioaccumulation the accumulation of a
toxic substance in
one organism
 Biomagnification the increase in
concentration of a
toxin in successively
higher trophic levels
in a food chain
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Introduced species
– species that migrate
or are brought to a
new area by humans
Conservation
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Strategies of conservation:
 1) Identify threatened & endangered species.
 2) Identify biodiversity “hot spots.”
 3) Emphasize ecosystem rather than species
conservation.
Methods of Protecting
Biodiversity
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Nature reserves
 2) Focus on “hot spots”
 3) Create conservation corridors – connect
smaller parcels of land
 4) Bioremediation – using living organisms
(plants, bacteria, fungi) to detoxify pollution
 5) Integrated Pest Management – reducing
chemicals used on crops