By being in the same area or Causing weathering at the same time or place
Oh boy, there's many, many, many, many...
(many x100)
many ways!
One way is to take shorter showers and conserve water wherever you go, at home, at a restaurant, hotel, etc.
Another way is to not litter on the streets.
Or, spread the word and tell everyone to conserve water, not litter, or just anything to help the environment!
Assuming you mean living matter
All living matter is produced by other living matter
Answer:
competitive exclusion principle