Some of the dynamic processes that can occur within an ecosystem are flooding, temperature changes, vegetation growth, invasions by non-native species and human intervention. In riparian ecosystems, such as floodplains, the role of human intervention can be significant as man-made structures such as levees, dikes and dams alter the course of water flows and flood pulses. Hydrologic alterations are an example of how changes made to an ecosystem carry the potential to disrupt critical nutrient cycling, change seed dispersal patterns and hamper the establishment and growth of vital plant communities.
Ecosystems are highly dynamic and experience significant changes through internal and external processes. Time can be a critical factor in the successful recovery of an ecosystem's equilibrium after a major disturbance such as a wildfire, hurricane or flood. An extended length of recovery time can also provide an opportunity for an invasive plant or animal species to enter and cause major and potentially permanent alterations to vital abiotic and/or biotic factors.
One of the primary external dynamics affecting an ecosystem is climate. A drought or change in a seasonal rainfall pattern can decrease the amount of plant life in an ecosystem and significantly alter the balance of producers to consumers in the food chain. The amount of energy and carbon introduced into an ecosystem through photosynthesis can also be affected.
Anthropogenic, or human, actions represent a dynamic force, which causes severe damage to ecosystems in the form of deforestation, pollution, and wildlife depletion. It has been estimated that 40 percent or more of the Earth's ice-free land mass has been either degraded or transformed by human intervention.