Lecture 2&3 Autecology (2) PDF

Lecture 2&3 Topic:. Autecology (idioecology) or Individual Ecology  PLAN Organism and environment Adaptation of organisms to the environment Environmental factors Law of optimum Law of the Minimum Shelford’s law of Tolerance  Autecology studies such characteristi...

Lecture 2&3 Topic:. Autecology (idioecology) or Individual Ecology  PLAN Organism and environment Adaptation of organisms to the environment Environmental factors Law of optimum Law of the Minimum Shelford’s law of Tolerance  Autecology studies such characteristics of the living organisms as adaptation to temperature, humidity, salinity and other environmental factors Organism and environment. Habitat is a part of the nature that surrounds a living organism and directly interacts with it. The components and properties of the environment are diverse and variable. Any living being inhabits in a complex and changing environment, continuously accommodating to it and adjusting its vital functions in accordance with changes to it.  Habitats of living beings aqatic Air and an Different terrestrial underground habitats Adaptation of organisms to the environment. The ability to adapt - one of the primary properties of life in general, because it provides the very possibility of its existence, the ability of organisms to survive and reproduce oneself.  There are a lot of examples, which shows us how living organisms adapt Colour of polar bear and brown bear is result of  properties or elements impacting the organisms are called environmental factors The environmental factors are divided into abiotic and biotic. Biotic factors Biotic factors are the form of impact of living beings on each other.  Abiotic factors Abiotic factors cover all the properties of inanimate nature, which directly or indirectly impact the living organisms: they include both physical and chemical factors. Physical factors of inanimate nature are as follows: space, climate, and geological. Climatic factors are the following: radiant solar energy, humidity, precipitation, ventilation (wind). Chemical factors are the following: components of soil, water, air, pH, impurities, etc. Anthopogenic factors are form of human society activities, which lead to a change in nature.  Anthropogenic factors In the course of human history: first - hunting, later on agriculture, industry, transport have changed considerably our planet. Anthropogenic effects or human impacts on the  Nowadays deforestation is one of the most important ecological problems. It is an example of harmful influence of human activity.  But anthopogen factors are n always harmf Dogs are domesticated wolfs. Their way of living changed, but without harm for them.  Law of optimum. Each factor possesses only defined limits of positive effects on organisms. The result of the variable factor effect depends primarily on the extent of its manifestation. Both insufficient and excessive effects of the factor affects on the species life-sustaining activity. Favorable effect is called an area of optimum environmental factor or simply an optimum for the given species organisms. The greater the deviation from the optimum, the more this factor’s suppressive effect on the organisms (pessimum area). Maximum and minimum tolerable values of the factor are critical points, beyond which the existence is no Effect of the factor intensity on the organisms’ life- sustaining activity  Factors limiting the ability to life activity of organisms, called limiting  Law of the Minimum Patterns of the environmental factors impact on the organism are determined by Liebig's Law of the Minimum and Shelford’s Law of Tolerance. Law of the Minimum was formulated in 1940 by J.Liebig, the German agricultural chemist. According to this law, endurance of the organism is determined by the weakest link in  Development of an organism may depend not only on the major factors or substances that are required in large quantities, but also on those that are needed in small doses (eg minerals) but that are not enough in the soil.  Potassium, sodium and phosphorus and complex of microelements are necessary for plant growth. Potassium, sodium and phosphorus are in large quantities and microelements are in very small amount. The Lack of a single microelement (eg copper), can lead to inhibited growth. Copper deficiency is a limiting factor Shelford’s law of Tolerance. The growth of organisms may be limited or restricted not only by lack but also by excess of one or another factor. Thus, demands placed by organism to environment can be characterized by two values in each factor: ecological minimum and ecological maximum. Limiting effect of maximum was set by V. Shelford in 1913 and is called Shelford’s law of Tolerance. The range between the two  Stenobions and Evrybionts Evrybionts Stenobionts adaptation Orchids -40 -30 -20 -10 0 10 20 30 40 Гfactors, t, C Temperature  Conclucion Due to the "ecology of tolerance" experiments, the limit of existence for many plants and animals was defined. Theoretical justification of maximum permissible concentration (MPC) is based on the law of limiting factor. MPC means the accepted threshold values of a given factor, under which no irreversible pathological alterations can occur in the organism so far. These values are set experimentally.