These fluctuations may also affect the predators that feed on these prey items, such as wolves, foxes and owls. These predators must either find an alternate source of prey or risk starvation and death. Ecological Succession. When changes to either abiotic or biotic factors affect an entire ecosystem, ecological succession occurs.
A temporary decrease in blood flow to the brain results in unconsciousness, or fainting. Many disorders, some of them serious, can cause this.
Fainting is a sudden and temporary loss of consciousness in which the person fainting falls or slumps because of reduced blood flow to the brain. Fainting is relatively common, often affecting people who are otherwise healthy. A person may not actually feel faint but feel lightheaded, which is called presyncope.