# Plants' co2 balance

1. Aug 14, 2009

### EnumaElish

Do plants absorb as much carbon-dioxide as they release? Is there a co2 balance, deficit, or surplus in the plant world?

2. Aug 14, 2009

### Ouabache

CO$_{2}$ is one of the basic inputs for plant growth, along with water, nutrients & energy (sunlight). The output (of photosynthesis) is glucose and O$_{2}$. Plants convert the glucose into various molecules (e.g. starch, cellulose, lignin, pectin) for anatomical structures (leaves, stems, roots) and an important part of its physiology (biochemistry). Plants do respire; deriving energy from stored molecules (e.g. glucose) and releasing CO$_{2}$ & energy, to accomplish physiological functions (e.g. transport of nutrients, cell division, hormonal regulation).

We may deduce intuitively that more CO$_{2}$ is taken up by plants during photosynthesis than there is released during respiration.
That is why forests and the ocean's algae are often referred to as Carbon sinks. To show this directly we would need to write the biochemical equations (for photosynthesis and respiration) as a function of time and mass of living plant tissue.

Last edited: Aug 15, 2009
3. Aug 16, 2009