A density-independent limiting factor is any force that affects the size of a population of living things regardless of the density of the population. These factors often arise from physical and chemical (rather than biological) causes, such as weather and climate, natural disasters, and pollution
. Examples of density-independent factors include food or nutrient limitation, pollutants in the environment, and climate extremes, including seasonal cycles such as natural disasters like forest fires
. These factors affect population growth irrespective of the density of the population
