Part 1: During the process of combustion, wood undergoes a chemical reaction whereby carbon molecules within its structure bond with oxygen from the surrounding atmosphere, resulting in the formation of carbon dioxide and water vapor. This exothermic reaction liberates the energy that was previously stored within the chemical bonds of the wood, manifesting itself in the form of heat and light. The remnants, known as ash, consist of inorganic minerals that persist after the combustion process, as they were not subject to combustion. Consequently, the mass of the ash is invariably less than the initial mass of the wood, as a substantial portion of the original matter is transformed into gaseous byproducts and subsequently dissipated into the atmosphere.
Part 2: Decomposers fulfill an indispensable role in ecosystems by facilitating the breakdown of dead organic matter and various waste products into simpler, more utilizable substances. This critical process not only ensures the efficient recycling of nutrients but also enriches the soil with essential elements such as nitrogen, phosphorus, and potassium. These nutrients, once liberated through decomposition, become readily available for absorption by plants via their root systems, thereby underpinning their growth and development. Thus, the activities of decomposers are vital for maintaining the intricate balance of nutrient cycling and promoting the overall health and sustainability of the ecosystem.