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Humans in the
Biosphere
PFHS Biology – Chapter 6
Things Change
 Hunting and gathering
 Hunted, fished,
gathered fruits, nuts,
berries, seeds, etc
 Nomadic
 Few demands upon the
environment and
allowed resupply
Things Change
 Agriculture
 Domesticated plants and
animals and grew supplies
 Stayed in 1 place
 Stable/predictable food
supply
 Larger stable settlements
 Elements of civilization
 Government, laws
 writing
Things Change
 Green revolution
 Equipment/machinery
 Improved seed and
techniques
 Fertilizers and pesticides
 Doubled food production
in 50 years
 Less manpower = death
of rural areas
Things Change
 Industrial Revolution
 Mechanization and
factories
 Urbanization to provide
workforce
 Reliance on fossil fuels
 Overcrowding/ Pollution
 Demands on the
environment
 Evils of society ?
Resources
 Renewable –
regenerated or
replenished faster
than used
 Water, wood fiber,
cattle, windpower
Resources
 Non-renewable –
cannot be
replenished by
natural processes or
is so slow as to
eliminate it as usable
 Fossil fuels,
minerals, metals
Sustainable Development
 Human activities can affect the quality
and supply of renewable resources such
as land, forests, fisheries, air, and fresh
water
 Development must provide for our needs
while maintaining ecosystem goods and
services that are renewable
Land Resources




Space for communities
Raw materials for industry
Soil for agriculture
Dangers
 Erosion
 desertification
Forest Resources
 Important products – lumber, paper,
furniture, fuel, food, etc.
 Oxygen/carbon balance
 Diversity of habitats
 Moderate climate
 Limit soil erosion
 Protect fresh water supplies
Forest Resources
 Management
 Sustainable management practices
 Plant/grow/harvest/grow/harvest/plant cycles
 Dangers
 Deforestation – removing forest permanently
for other uses (or no use at all)
 Fire – destruction of uses, may lead to
deforestation
 See previous page
The most
forested of the
Rocky Mt. states
Fishery Resources
 Invaluable food
source
 Overfishing/pollution
has damaged it
 Commercial use has
developed limits
 Aquaculture is
becoming popular,
but has its own
problems/dangers
Air Resources
 Do we actually have
to discuss the
importance of this
resource?
Air Resources
 Dangers
 Pollutant – a substance where it doesn’t
belong
 Natural
 Man made
 Smog – smoke+fog, a polluting haze
 Acid rain – pollutants dissolved into the
atmospheric water vapor, falls, DAMAGES
 The list of pollution types is endless
Freshwater Resources
 Another one that
really needs no
explanation
Water Uses
Biodiversity
 Variety in living things
 One of our greatest natural resources
 Foods, industrial products, medicines provided
by a variety of organisms
 Some future life-saving substances may come
from organisms that have not been discovered
yet
 Watch the video “The Medicine Man” with Elaine
Bracco and Sean Connery
Threats to Biodiversity
 Extinction – permanent disappearance of
a species
 Endangered species – declining in a way
that extinction is a definite possibility
 Threatened species – suffering a
dangerous decline in numbers
 Human activity is a major threat
 Hunting, fishing, pollution, introduction of
foreign species, and alteration of habitat
Introduced species
 Little known threat
 Become invasive species that reproduce
rapidly because they no longer have their
“natural controls” from their original
environment
 Successfully outcompete the native
species
Conserving Biodiversity
 Today, conservation efforts focus on
protecting entire ecosystems as well as
single species. That ensuresthat the
natural habitats and the interactions of
many different species are preserved at
the same time.
 The biggest challenge – time and $$$
Biggest Concerns
 Ozone depletion – leading to more UV
exposure…..which leads to skin cancers,
eye damage, plant damage, and reduced
resistance to disease
 Can we make the switch to non-CFC
substances?
 Will the ozone repair itself?
Biggest Concerns
 Global Warming – a rise in the Earth’s
average temperature
 It is both natural and manmade:
 Natural cycles of sun and earth
 Enhanced greenhouse effect from man’s
activities
The End……… of
this presentation