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.
The head-up tilt table test is a way to find the cause of fainting spells. The test involves lying quietly on a bed and being tilted at different angles (30 to 60 degrees) for a period of time while various machines monitor your blood pressure, electrical impulses in your heart, and your oxygen level.