Decline, or deterioration, refers to the gradual process of becoming worse or losing quality over time. This can occur in various contexts, such as the physical condition of objects, the health of individuals, or the state of environments. For example, a building may show signs of decline through crumbling walls and peeling paint, indicating a need for maintenance. In nature, decline can be observed in ecosystems where species populations decrease due to factors like pollution or habitat loss. This deterioration can disrupt the balance of the ecosystem, leading to further negative impacts on biodiversity and the overall health of the environment.