Population growth

• Population density refers to how many people live per unit area, such as square kilometers or miles.
• A simple change can affect an entire ecosystem.
• Food webs are how species are interconnected, providing stability in an ecosystem.
• Changes to keystone species can affect the entire ecosystem.
• Keystone species are a species that plays a critical role within a ecosystem.
• When keystone species are removed, ecosystems become less stable.
• Selection pressures in ecosystems are significant, affecting both diversity and abundance of species.
• Keystone species are frequently targeted for conservation efforts.
• Keystone species can also help maintain important habitats.
• Elephants, for example, eat young trees in African savannas, which could transform the landscape into forests or shrublands.
• Keystone species originated from the study of food webs in rock pools.