Which gas is excreted as a waste product of autotrophic nutrition in maple trees?

Nutrition is the process by which organisms take in nutrients or food, and its metabolism in the body of an organism. Autotrophic nutrition is the mode of nutrition that involves use of simple inorganic substances to generate complex molecules that are used by an organism to generate energy. some plants such as maple trees carry out this type of nutrition where simple inorganic molecules are used to build complex molecules in presence of energy (mainly energy from the sun) and oxygen gas is excreted from the process.