Abiotic Factors

Edexcel A-level BiologyThe Nature of EcosystemsLesson 4 of 39

Abiotic factors are the non-living, physical and chemical features of an ecosystem that affect the organisms living there. The main ones are:
• light intensity and day length
• temperature
• water availability and humidity
• oxygen and carbon dioxide availability
• wind and water currents
• edaphic (soil) factors, such as pH, mineral ions and drainage
• salinity and pH of water
Most of these have their own lesson later in this topic.

Abiotic factors affect organisms in two main ways. They affect the rate of processes such as photosynthesis, respiration and enzyme activity, and so affect growth and reproduction. They also determine where species can live: each species can only survive within a certain range of each factor, called its range of tolerance.

More in The Nature of Ecosystems

• Ecosystem
• Habitat
• Community
• Biotic Factors
• Biosphere
• Primary Succession
• Climax Community
• Secondary Succession

All 39 lessons in The Nature of Ecosystems · All Edexcel A-level Biology topics