Aquatic ecology and Biodiversity

Unit 4- Community ecology

4.2.1. Concept of limiting factors
• The law of minimum
• The law of tolerance
• The combined concept

The law of minimum (Liebig, 1840)
Any single factor exceeds the tolerance level or reduced below the minimum, the species will be eliminated. This is known as the ‘law of the minimum’. Each species in a community has certain tolerances to varying environmental factors – temperature, light, nutrient, salinity, etc.

The law of tolerance (Shelford, 1913)
It is the survival of organisms in a good condition is possible only at a particular range of intensity zone called tolerance. Each organism has two zones


The successful survival of the organisms depends on its adjustment to these factors under this extreme environment conditions by showing tolerance and minimum availability.