The survivаl оf mоst оrgаnisms is immediаtely threatened if they live at the site of a catastrophic forest fire, volcanic eruption, or dust storm. These events, however, can launch soot, ash, or dust into different levels of the atmosphere, measurably lowering available sunlight at locations thousands of miles from the site. The ________ are most quickly and strongly impacted at these distances, with lack of growth and reproduction.