Human Impact 1
If you remove wolves from a forest, what usually happens to the number of deer?
Grass --> Deer --> Wolves
It goes up (increases).
If an ecosystem has many different kinds of plants and animals, we say it has high what?
Biodiversity
When we clear-cut a forest for cattle ranching, what is that called?
Deforestation
When we cut down large forests, which gas increases in the atmosphere because there are no trees to absorb it?
Carbon Dioxide (CO2)
Breakup of a habitat into smaller pieces, usually as a result of human activities.
Habitat Fragmentation
In a chain of Algae → Small Fish → Tuna → Shark, if the Tuna disappear, what happens to the amount of Algae?
It goes down (decreases).
This term refers to the total number of different species present in a specific community.
What is Species Richness?
What is one "Con" (downside) for the environment when a dam is built?
It blocks fish from swimming upstream to lay eggs.
If the fish in a lake are harvested to the point of very few fish left, what is it called?
Overexploitation
If a scientist notices that a decrease in a specific beetle population leads to the death of a certain bird, which then leads to an explosion of a certain caterpillar, they are mapping out this complex network of feeding relationships.
Food Web
What is the term for when a change at the top of a food chain causes a "domino effect" all the way to the bottom?
A trophic cascade.
If you are trying to fix a broken ecosystem, is it better to measure how much money you spent or how many different species returned?
How many species returned (Species richness).
Loss of natural environments due to human activity.
Habitat Destruction/Urbanization
This is the "E-word" for the benefits that humans receive from healthy ecosystems, such as clean water, timber, or pollination.
Ecosystem Services
Which biome would have the greatest biodiversity?
Tropical Rainforest
If you counted 3 species of frogs in year 1 and 10 species of frogs in year 5, did species richness increase or decrease?
Increase
This term describes a species, like the salmon or wolf, that has an unusually large effect on its ecosystem; if it is removed, the whole system collapses.
What is a Keystone Species?
Sometimes humans build "Fish Ladders" on dams. This is an example of a "mitigation" strategy, which means what?
Trying to reduce or "fix" the damage caused by humans.
How do trees help "clean" the air during the Carbon Cycle?
They take in CO2 during photosynthesis.
Burning fossil fuels contributes to what?
Global Warming
If a river restoration allows salmon to return, how does this help the bears living miles away in the woods?
It provides a new food/energy source for them.
What is the main goal of "connecting" two separated habitats?
To let animals move and migrate freely in order to increase biodiversity.
This biological process is the primary way that carbon is "fixed" or removed from the atmosphere and turned into organic matter.
Photosynthesis
Why does plastic pollution last for hundreds of years instead of rotting away like an apple core?
It is not living, it is synthetic/man-made and does not biodegrade.
Meeting the needs of the present without compromising the needs of future generations.
Sustainability