The study developed a method to separate how much carbon dioxide is released by plants above the ground, roots and soil below the ground, and how much is taken in by plants during photosynthesis. They found that in a deciduous forest, the roots and soil release more CO2 than the plants above the ground. This release varies with the seasons and is more sensitive to temperature than plant respiration. Overall, most of the carbon taken in by the plants is released back into the atmosphere, with only a small amount stored in the ecosystem. If light inhibits leaf respiration, the current method of measuring plant respiration may underestimate the amount of CO2 released by plants.