Matter and energy behave differently in ecosystems. Matter cycles in closed loops, constantly recycled and reused without loss, following biogeochemical cycles. In contrast, energy flows linearly through ecosystems, starting from the sun, moving through food chains, and eventually dissipating as heat. While matter is conserved and reused within the ecosystem, energy requires constant input from external sources (primarily the sun) and cannot be recycled. This fundamental difference in behavior—cyclical for matter and linear for energy—is crucial for understanding ecosystem dynamics and sustainability.