Lesson 15-Environmental Changes and Cycles in Nature Crossword

___ occurs when harmful substances are released into the environment.
The changes that take place in an ecosystem over time are called ___.
Disturbances are followed by a pattern of gradual changes called
All the living organisms in an ecosystem make up a ___.
___ succession begins on bare rock.
___ succession begins where soil is already present.
The first organisms to inhabit an area after a disturbance
A ___ community is the last stage of succession.
The same organisms living at the same place, at the same time is called a ___.
This occurs BEFORE succession. (examples: drought, pollution, hurricane, fire, tornado, hailstorm, floods, etc.)