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 causes can be grouped loosely into two camps: problems outside the heart (noncardiac syncope), which account for the majority of faints, and problems in the heart (cardiac syncope).Getting to the heart of a faintFiguring out what caused a fainting spell is the best way to prevent it from happening in the future.