Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Sci 7- Unit 1- Topics 6-7
Transcript of Sci 7- Unit 1- Topics 6-7
(cc) photo by theaucitron on Flickr
(cc) photo by theaucitron on Flickr
Organisms to first appear are those that can cling to the rock and grow, such as mosses and lichens. These organisms break down the rock and died. Other organisms use the nutrients to begin to grow.
Examples of areas in which a community has never lived before would be:
new lava or rock from a volcano that makes a new island or a new landscape
a sand bar that arises from shifting sands in the ocean
The gradual growth of organisms in an area after a disturbance, such as a fire, or when a large tree falls, is known as secondary succession.
Some Species Adapt Better Than Others
Cowbirds adapt to farmland easily,
while others cannot.
The coyote has been able to adapt to the spread of urban areas, whereas other animals, such as the wolf have not
This occurs with a pesticide that is designed to kill lygus bugs (who damage canola crops). The pesticide will also kill bees. If the pesticide kills the pest predators, then the pest population may actually increase.
The species that is introduced may have no natural predators and will overtake the area (using up the food supply) so that other organisms cannot survive.
Many species in North America and in Canada specifically are in danger of extinction.
If a species becomes extinct, it can no longer be found anywhere in the world.
Sometimes the organism is only lost in a large region.
If this occurs, the species is extirpated.
There are special protection programs and laws made to protect endangered species.
Primary succession is the gradual growth of organisms in an area that was previously bare , like a rocky slope.
The gradual process by which some species within an ecosystem replaces other species is called succession.
read p 56
Changes Caused by Human Activity
Humans affect the environments around them in many ways, including activities and technologies such as: forestry, industrial processes, transportation, urban development, construction and farming.
When an ecosystem is changed by human activity, there can be unexpected consequences.
please read p 60 - 61
Pests that can affect human health and crops are a major problem. Besides controlling the pest population a pesticide can also damage other organisms that are not targeted.
Using their own natural enemies is another way to control pests. This method is known as biological control
what do you think is bad about introducing a new species to manage another?
Biological control can however cause other problems.
read pages 62- 63
Species In Danger
Topic 7 :
p. 68- 79
The word Environment can mean:
Monitoring can be done in 4 ways
Physical Monitoring uses Satellites
to track changes over time...
Ever wonder what a Hurricane looks like from space?
tracks changes in climate,
temperature, and weather patterns.
watches the quality of the
air, soil, and water
Last, but not least, is the Biological Monitoring!
This monitors the changes in organisms (this can be population, or growth)
Continuous monitoring gives us the scientific data we need to make informed decisions about how we affect the environment over time.
Monitoring involves the use of indicators and indicator species. The presence or absence of the indicator or of an indicator species reflects environmental conditions.
Can you please explain in your own words why Frogs and other Amphibians are good indicator species?
read pages 68- 70
gives scientists a starting point to compare changes in the environment.
Scientists to monitor change use permanent plots, or study areas.
The report that provides the data that has been collected - identifying how a certain activity will affect the environment - is called an Environmental Impact Assessment.
please read p. 74 and page 78
Topic 6-7 WRAP UP
#1 to #8