Environments Study Guide
Natural events occur in nature and include fire, floods, storms, drought and erosion.
Natural events can cause rapid or slow changes to the environments.
Rapid changes
Fire
Flood
Storms
Earthquake
Landslide
Slow changes
Drought
Erosion
Natural events can have both positive and negative effects on the environment.
Fire- natural and caused by humans
Positive
Make room for new plant growth
Release nutrients
Hot temperatures open some seeds
Negative
Destroy living things & habitats
Smoke causes pollution
Floods- natural
Positive
Flood waters deliver nutrient-rich
sediments to land
Negative
Removes soil that plants need to grow
May make water unclean or spread
disease
Destroy habitats and living things
Storms- natural
Positive
Precipitation from storms provides water
that is needed by organisms in
environments
Lightning helps plants by releasing
nutrients in soil
Lightning also produces a gas, called
ozone that helps protect
environments from the sun.
Erosion- natural and caused by humans
Positive
Soil is delivered to other areas where it can
be used by plants living there.
Negative
Destroy habitats, causing floods, and
hurting or killing organisms
Lightning from storms can start wildfires
Strong winds from storms knock down trees
and can even destroy forests.
Negative
Remove nutrient-rich soil needed for plant
growth
Wind erosion can make dust storms that
block out sunlight.
Droughts- natural
Positive
Negative
Plants die
Animals that eat plants may starve.
More erosion takes place, dust storms form
Rivers, lakes, and wetlands may dry up.
Habitats may be destroyed
Animals may leave to find water
elsewhere.
More fires may take place in areas
experiencing a drought
Pollution- natural and caused by humans
Positive
Dams- caused by humans
Positive
Storing water
Controlling floods
Make electricity
Forrest Clearing- caused by humans
Positive
Negative
Harmful gases in the air may hurt
organisms when they breathe
of the gases, such as carbon
dioxide, cause the greenhouse effect
which is the rise in Earth's temperature
Rising temperatures on Earth could
change weather patterns, cause
droughts, melt glaciers, and cause rising
sea levels.
Water pollution harms organisms that live
in or use the water. It makes organisms
sick and can even kill them.
Plants may not be able to grow in polluted
land, and other organisms may become
sick from the pollution
Negative
May cause rivers to become dry.
Stop nutrient-rich sediments from flowing
downstream. Plants and other organisms
that live in the water are not able stay
healthy without the sediments.
Break habitats into smaller pieces and
separate organisms into different areas
Negative
Causes habitat loss
Crop plants take the place of native
plants
Can lead to erosion
Animals lose resources