Some subsidiary principles 4. Organisms in nature are not actually living at the optimum range of a particular physical factor. 5.Reproduction is usually a critical period when environmental factors are most likely to be limiting. 6.Factor CompensationSome subsidiary principles Some subsidiary principles 4. Organisms in nature are not actually living at the optimum range of a particular physical factor. 5. Reproduction is usually a critical period when environmental factors are most likely to be limiting. 6. Factor Compensation