1. Topic 5: Ecology and Human Impact

2. What is Ecology?
Ecology: The Study of organisms and their environment.
Habitat: Where an organism lives
Niche: The organisms role in the environment. Everything an organism must do to survive.
Two species in an ecosystem trying to fill the same niche will create competition, which usually results in one species occupying a niche at any one time. Organisms with similar needs will often divide resources to reduce competition (ex. Birds eat insects during the day, bats eat them at night

3. How organisms interact with each other:
Competition: occurs when two or more organisms need the same resource.
Ex: A squirrel and a chipmunk compete for food.
Feeding: One organism feeds on another.
Producer – An autotroph; organisms that makes its own nutrients from simple substances.
Consumer – A heterotroph; may be an herbivore, carnivore, omnivore or decomposer.
Symbiosis: A close relationship between two organisms in which at least one benefits.
Can include 2 organisms working together for mutual benefit (bee and flower) or 1 organism harming another (parasite-host).

4. Abiotic vs. Biotic Abiotic Factors: Non-living things
Biotic Factors: Living thing 
Organisms interact with the biotic (living) and abiotic (non-living) parts of their environment through food webs and nutrient cycles.

5. Ecological Levels of Organization

6. Populations
A given area can only supply enough resources for a limited number of organisms.
Carrying capacity: The largest population an ecosystem can support.

7. Limiting factors: Anything which limits the size of a population, including:
Food, water, sunlight, soil, predators, disease, dissolved oxygen 
Overpopulation: When a population exceeds the carrying capacity. Usually results in a large number of organisms dying off until a new balance is reached.

8. This is the most important part of the test!!!
Energy is needed to keep an ecosystem going. The energy comes from the sun and is made usable by producers (plants and other autotrophs)

9. Energy in an Ecosystem Sunlight provides all energy for life on Earth.
Sunlight provides all energy for life on Earth.
Sun’s energy is stored in the chemical bonds of food through the process of photosynthesis
Food chain – Shows 1 way that energy can “flow” through an ecosystem.
Energy in an Ecosystem

10. Food Web Food web – Shows many energy pathways.
Energy pyramid: Shows that energy gets lost with each step in a food chain
Energy is lost because every organism uses some of the energy for it’s own life processes. Only about 10% of energy is passed from one step to the next.
This is why populations of predators are typically less than the populations of their prey.

11. Food Web and Pyramid

12. Biodiversity refers to the variety of life on earth
Biodiversity refers to the variety of life on earth. As habitats are lost and species become extinct, biodiversity is reduced. This is considered to be bad because:
Ecosystems with low diversity are less stable than ecosystems with more diversity
Ecosystems with low diversity take longer to recover from environmental changes
We use organisms for many things such as food and medicine; by reducing biodiversity we are losing potentially valuable resources.
Biodiversity

13. Ecological Succession
Ecological Succession: Process by which existing communities are gradually replaces by a series of new communities.
The organisms in each stage of succession change the environment, and allow new organisms to move in and replace them.

14. B. Climax Community: Final stage of succession
The climax community is determined by the local climate.
Ex: Kansas has very fertile soil, but not enough rain to support trees, so succession stops with grasses and shrubs.
C. Any temporary disruption of a community will begin the process of succession all over again.
Ex: If a forest fire kills all the trees in an area, succession will eventually return the area back into a forest, but it much first pass through all the necessary stages

15. Define the following terms:
producer
organism that makes its own food
consumer
organism that gets food by consuming other organisms
omnivore
organism that eats animals and plants

16. Definitions herbivore organism that only eats plants carnivore
organisms that only eats animals
predator
animal that hunts and kills for food
parasite
organisms that lives on or in a host and harms it

17. Definitions place where an organism lives
habitat
place where an organism lives
niche
the role of an organism in its environment
population
a group of the same species living in a defined area
community
a group of populations living in a defined area
ecosystem
all the living and non-living things in a particular area

18. Definitions biosphere
the combined portions of the planet in which all of life exists, including land, water, and air or atmosphere
pollution
harmful materials that can enter the biosphere
renewable resource
resource that can be replaced after a short time or reused

19. Human action (development, industrialization, pollution, farming, over-hunting, overgrazing, clear cutting, introduction of foreign species, soil erosion) often has negative consequences for the ecosystem (and humans too).
Human Impact

20. Human Impact
The negative effects humans have had on the environment are mostly due to the increasing human population.
habitats are decreasing to make room for buildings and homes
more wastes are produced

21. Actions being taken by humans to reduce or repair damage to the environment include:
Recycling wastes
Conserving available resources
Using cleaner resources (ex: solar over fossil fuels)
Protection of habitats and endangered species
Positive Human Impact

22. Positive Human Impact
Use of biological controls instead of pesticides and herbicides
Farming native plants (ex: cocoa in the rainforest)
Planting trees to replace those cut down.
Rotating crops or planting cover crops to reduce soil loss.
Passing laws to control pollution, land management, hunting, fishing, etc.

23. Environmental Issues
For each of the following ecological problems, identify the specific cause, their negative effects on the environment, and a way that people are trying to fix the problem:
Acid Rain
cause
nitric and sulfuric acids released by industry
negative effect
can kill plants, pollute water
fixing
place filters on smokestacks

24. Environmental Issues Loss Of Habitat (Ex: Deforestation) cause
cutting down trees
negative effect
erosion of soil, loss of habitats, less CO2 being removed from the atmosphere
fixing
engage in selective cutting practices, recycle paper

25. Environmental Issues Loss Of Diversity cause
habitat destruction/fragmentation
negative effect
unstable ecosystems
fixing
nature preserves, laws protecting

26. Environmental Issues Global Warming cause
increase in carbon dioxide in the atmosphere due to burning o fossil fuels
negative effect
ice caps melt, more severe weather
fixing
use alternate energy sources

27. Environmental Issues Loss Of Ozone Layer cause
use of CFC’s (chlorofluorocarbons)
negative effect
less protection from UV radiation
fixing
ban the use of CFC’s

28. Environmental Issues Introduced Species (Invasive Species) cause
foreign species accidentally or purposely brought into a habitat by humans
negative effect
out-compete native species
fixing
increase natural predators