High Altitude Limits of Living Things.

Area of Science:

• Physiology
• Ecology
• Environmental Science

Background:

• Animal and plant life face physiological challenges at high altitudes, primarily due to reduced partial pressure of oxygen (PO2).
• Different species exhibit varying tolerances and adaptations to hypoxic conditions.
• Global warming may influence the upper altitudinal limits for plant survival.

Purpose of the Study:

• To survey the limiting factors for all living things at high altitudes.
• To identify the highest known altitudes for various life forms, including humans, mammals, birds, insects, and plants.

Main Methods:

• Literature review and synthesis of existing data on high-altitude tolerance.
• Identification of record-holding species for extreme altitude survival.

Main Results:

• Mount Everest (8,848m) is near the limit of human tolerance to hypoxia.
• Highest permanent human habitation is 5,100m, influenced by hypoxia and economics.
• Field mice and jumping spiders inhabit up to 6,700m; birds fly up to 11,000m.
• Tardigrades demonstrate extreme hypoxia survival.
• Vascular plants found above 6,000m, with moss and lichens at even higher altitudes.

Conclusions:

• High altitude poses significant physiological challenges, primarily related to oxygen availability.
• A diverse range of organisms, from microbes to mammals, have adapted to survive at extreme altitudes.
• Understanding these limits is crucial, especially in the context of climate change potentially altering ecosystems.