1. Humans in the Biosphere
Chapter 6
Humans in the Biosphere

2. A Changing Landscape “Earth is an Island”
All organisms- including humans -that live on Earth share limited resources & depend of them for their survival.
Natural ecological processes sustain these resources (water, carbon, nitrogen cycles)
To protect these resources – we must understand how humans interact with the Earth

3. Humans and the Biosphere
We as humans depend on chemical cycles (H20, C, N) to provide:
a. breathable air
b. drinkable water
c. fertile soil
d. storage & recycling of nutrients
We must understand how human activity affects these cycles

4. Human Activities that Affect the Biosphere
Hunting & gathering
Agriculture
Industry
Urban development
Human activity has become the most important source of environmental change on the planet.
We do not fully understand how these activities affect our ecosystems

5. Human Activities Hunting and gathering Agriculture Industrial growth
that have changed the biosphere include
Hunting and
gathering
Agriculture
Industrial
growth
Urban
development
may have once caused
often relies on the methods of the
have resulted in
Extinctions of
large animals
Green
revolution
High standard
of living
Increased
pollution
which increased
Food supply
Pesticide use
Monoculture
use

6. Renewable Resources Can regenerate or can be replenished
Not always unlimited
Example:
- Water can become limited by drought or overuse
Human activity can affect the quality of renewable resources such as:
- land, forests, fisheries, air & freshwater

7. Nonrenewable Resource
Cannot be replenished by natural processes
When they are depleted –
they are gone forever
Example:
- coal
- oil
- natural gas (fossil fuels)

8. Sustainable Development
Way of using natural resources without depleting them
Provides humans with what they need without causing long term environmental harm
This can have a positive impact on the environment we create for ourselves & future generations

9. Biodiversity 2. industrial products
The sum of the genetically based variety of all organisms in the biosphere
Basically, how all living things are so different!!!
Greatest natural resource
The many different species provides us with:
1. food
2. industrial products
3. medicines (painkillers, antibiotics, heart, antidepressants & anticancer drugs)
When biodiversity is lost, potential sources of material with significant value to Earth & mankind may be lost with it

10. Types of Diversity Ecosystem Diversity: Examples:
Variety of habitats, communities, and ecological processes in the living world
Examples:
habitats ecological processes
1. deserts 1. water cycle
2. mountains 2. carbon cycle
3. rain forests 3. nitrogen cycle
4. oceans 4. phosphorus cycle

11. Types of Diversity Species Diversity Genetic Diversity
Refers to the # of different species in the biosphere
Scientists have identified & named about 1.5 million species
They estimate millions will still be discovered
Genetic Diversity
Refers to the total of all the different forms of genetic information carried by all organisms living on Earth today (DNA)

12. Threats to Biodiversity
Altering habitats
Hunting to extinction
Introducing toxic compounds into food webs
Introducing foreign species to new environments