environmental factors that affect the world around us, a lot.They are combined into three groups: abiotic, biotic and anthropogenic.The first is the factors of inanimate nature, direct or indirect effects on the body: light, temperature, humidity, chemical composition of the soil and air, etc.In other words, the properties of the medium, which does not depend on the activity of biological objects.Biotic factors are living beings form of influence on each other, for example, exposure to microbes to plants, animals and plants on the contrary.Anthropogenic - a variety of human activities that lead to a change in living conditions of organisms or affect their existence.
nature of the impact of these factors ca
n be set.Any organism living in a particular environment and can exist only within the established boundaries of its variability.The optimum level of environmental factors is called optimal.Excessive exposure of its vital activity falls.The area of tolerance, or the range of action of environmental factors limit the maximum and minimum points.Beyond the existence of the body impossible.For each substance characterized by its limits, such as housefly lives at temperatures from 7 to 50 degrees, and Ascaris - only at human body temperature.
Please be aware that any living organism affects complex factors, but only one is restrictive (limiting).For example, the spread of certain animal and plant species from the south to the north limited by the lack of heat, and in the south a limiting factor for these same plants can serve as a shortage of moisture.
The magnitude of the effective range of a factor, you can judge the endurance.Biological objects that exist in a variety of environments, called eurybiontic.These include brown bears living in warm and cold climates, in wet and dry areas, is used as a vegetable and animal food.Stenobiontic organisms adapt to life in a narrow range of environmental conditions.For example, trout only live in clean water cold mountain rivers.