What is the natural method by which carbon dioxide is released into the atmosphere?

During the natural carbon cycle, carbon is released into the atmosphere from various sources and absorbed through "sinks." For example humans and plants give off carbon dioxide through respiration, making them a source of carbon dioxide, while plants absorb carbon dioxide during photosynthesis, making them a sink.

i'm pretty sure it's spores

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.