Life zone

An ecological classification system based on climate and vegetation

 This article is about the ecological classification system.
   For other uses, see Life zone (disambiguation).

Diagram of life zones according to Holdridge's system

Life zones are a system of biogeographic classification that categorizes regions of the Earth's surface based on their climate and vegetation. This concept was first developed by C. Hart Merriam in 1898 and later expanded by Leslie Holdridge in 1947. Life zones are used to understand the distribution of ecosystems and biodiversity across different altitudes and latitudes.

Concept

The concept of life zones is based on the observation that similar climatic conditions produce similar types of vegetation and ecosystems, regardless of their geographic location. This allows for the classification of regions into distinct zones that share common ecological characteristics.

Merriam's Life Zones

C. Hart Merriam originally proposed the concept of life zones to describe the distribution of flora and fauna in the United States. He identified several zones based on temperature and precipitation patterns, such as the Arctic zone, Boreal zone, and Tropical zone.

Holdridge's Life Zones

Leslie Holdridge expanded on Merriam's work by developing a more detailed system that incorporates biotemperature, annual precipitation, and potential evapotranspiration. Holdridge's life zone system is represented in a triangular diagram, which categorizes regions into various zones such as tropical rainforest, desert, and tundra.

Classification

Life zones are classified based on a combination of climatic factors, including:

• Temperature
• Precipitation
• Humidity
• Altitude

These factors influence the types of vegetation and animal life that can thrive in a particular zone.

Applications

Life zones are used in various fields, including ecology, conservation biology, and climate science. They help scientists and policymakers understand the potential impacts of climate change on biodiversity and ecosystem services.

Related pages

• Biome
• Ecoregion
• Biogeography
• Climatic zone