The flow of energy and matter in food chains and webs is crucial for the survival of ecosystems.

Food chains and webs are interconnected systems that illustrate how energy and matter are transferred from one organism to another. Energy enters the food chain through the process of photosynthesis, where plants convert sunlight into chemical energy. This energy is subsequently transferred to herbivores, which are then preyed upon by carnivores. As energy moves from one organism to the next, a portion is lost at each step, primarily in the form of heat. This phenomenon is encapsulated in the 10% rule, which states that only $10\%$ of the energy is passed from one trophic level to the next.

In contrast, matter is recycled within ecosystems. Decomposers play a vital role in breaking down dead organic matter, thereby releasing nutrients back into the environment. These nutrients are then absorbed by plants, initiating the cycle anew. This continuous process is referred to as the nutrient cycle and is essential for the sustainability of ecosystems.

Food webs are more intricate than food chains, illustrating the complex interconnections among various organisms within an ecosystem. They highlight that organisms can fulfill multiple roles, and the removal of a single species can have far-reaching consequences for the entire ecosystem.

In summary, the flow of energy and matter in food chains and webs is fundamental to the health and stability of ecosystems. This flow underscores the interconnectedness of organisms and emphasizes the importance of maintaining ecological balance.