Why carbon content is higher in stem of bird of paradise stem compared to other part of it?

i do my research and found that difference plant contain difference % of carbon and nitrogen.why carbon content is higher in stem of bird of paradise stem compared to other part of it?

but for Garden balsam why %C is higher in it leaves compared to it's stem, flower and roots?

Hibiscus's stem has more%C than other part of it?

can anyone explain?
Why carbon content is higher in stem of bird of paradise stem compared to other part of it?
if you are doing this kind of research why are you doing it if you can't understand your results?
Reply:Any plant region with high densities of woody structural elements would have a high carbon level because cellulose and lignin are carbohydrates. This may include leaves because many plants make them tougher to support a large horizontal photosynthetic area or to discourage herbivory. Only in regions of active metabolism with nitrogen rich proteins would see the ratio shift in a plant.

Impatiens balsamina if grown as an annual does not develop a woody stem so the cellulose %26amp; lignin content would be lower. Lignification happens to mature vascular xylem tissue to provide support.

The areas with proteins would be the cambium or apical growth in stems or roots.
Reply:does it have anything to do with some sort of process taking place in the parts of those plants