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Modern concepts of ecology in the world


Dear Prof. DSc Ilia Hristov provide the National Association "Black Sea" their scientific material on "Modern concepts of ecology in the world." This is the first of a series of articles about ecology, through which we would like to provide the public with objective and scientifically sound information about what's ecology, its tasks, the possible symbiosis between man and nature, and to break false stereotypes superimposed on various occasions in public.
Prof. DSc I. Christ is a part-time professor in Agroecology; Environmentally-friendly irrigation and drainage; Ecology; Anthropogenic sources of pollution; Technologies for purification of air, water and soil; Biophysics and biophysical methods for purification.
Rich work experience of prof. DSc I. Hristov was conducted at the Institute of Water Problems at the Bulgarian Academy of Sciences (BAS), Chemical Faculty of Sofia University "Kl. Ohridski", New Bulgarian University, Higher Agricultural College in Plovdiv and the Institute of Soil Science and Agroecology "N. Poushkarov ". During his long career he pursued a specialization in Joint Institute for Nuclear Research (JINR) in Dubna; Sofia University "St. Kliment Ohridski", Faculty of Physics; University of California, Davis; Agrofizicheski Institute, St. Petersburg; Faculty of Biology and Soil Science, Moscow State University; Ghent University; Center for Nuclear Research in biology and agriculture Cadarache; International Atomic Energy Agency (IAEA), Vienna and others.
Skills and competencies of Prof.. Christ reflected in 199 scientific papers (articles, monographs, manuals, textbooks, inventions), published in English, Bulgarian, Russian and Slovak, and also introduced a number of developments. Member of the editorial boards of a number of Bulgarian and international publications and scientific organizations.
What is ecology as
leading scientists in the world?
Ecology is the interdisciplinary science that studies the interactions between all living beings and their environment, but also the interactions of living beings among them. Complex object that ecologists study ecosystems. What is it?
Ecosystem is the resource wealth of the people, which is a set of interacting components of organic and inorganic, but bioactive, substance (Wright, 1998). Ecosystems are divided into: natural (natural) and anthropogenic (created intentionally by human activity). Anthropogenic ecosystems are divided into urban and agricultural ecosystems (urban) ecosystems (Figure 1).
All natural and anthropogenic ecosystems are resource riches to the man who is the only intelligent beings on our planet. Protection of all ecosystems is the cardinal task of rational humanity. This protection requires complex knowledge, experience, caring activities in all ecosystems of the reasonable person. Protection should not be understood only as a simple 'preservation of areas which are natural ecosystems (such as wild jungles, deserts, forests and so on..) "Or mechanically transfer their laws in anthropogenic ecosystems. The latter is "unreasonable call of incompetent people: the man to return to the natural ecosystem."
Ecology is the science and practice what is known and not understood by many people (including scientists at home), especially important for those who make decisions. Accuse (1986) believes that agro occupy an intermediate position between the natural and urban ecosystems.
What are the main differences between
natural ecosystems and agro-ecosystems?
Agroecosystems differ from natural ecosystems on the specific structure and functions. The main differences are as follows:
1. Natural ecosystems have a great variety of species of plants and animals. Agroecosystems have reduced diversity of organisms because of deliberate human intervention. Figure 1. Scheme of the main types of ecosystems
2. The production in natural ecosystems is the result of different trophic levels and a long complex food chain. In agroecosystems, the output is the result of autotrophic organisms and the food chain is one or two trophic levels: (A) plant - animal - human; and (B) plant - man.
3. The main source of energy in natural ecosystems is the sun. Solar energy is converted into energy of biochemical bonds in the molecules of the organic substance of the producers (plants). This energy is needed for the next trophic levels. In agroecosystems than solar energy, one brings additional energy from fuels for agricultural equipment and substances such as fertilizers, stimulators, pesticides, insecticides and others.
4. natural ecosystem conditions exist for continuous circulation of the primary nutrients, which consists in the fact that the dead organic matter trophic levels are degraded by redutsentite and is fed back to the producers. On agroecosystems, man delivers a significant proportion of organic matter (output), which is not subject to degradation in it. Agroecosystems open to imports and exports of energy and matter.
5. natural ecosystems has not only a great variety of species, but also from differences in genetic and age characteristics. This provides full biotic interactions therein. Agroecosystems phytocenose has the same requirements for light, water and nutrients, therefore, that the plants are of the same type and age.
6. In natural ecosystems, the dominant species are selected by natural selection in nature. In agro dominate species obtained by artificial selection made by the person in order to obtain maximum productivity thereof.
7. natural ecosystems has a high plasticity. It is self-regulating, self-cleaning and self-healing. Agro low ductility. It needs strong management and interference of man.
8. The stability and high plasticity of the natural ecosystem are the result of complex relationships and interactions between organisms that are in balance with the non-living environment (biotope). In agricultural ecosystems are damaged part of the relations and interactions between organisms and their environment. Biological equilibrium is disturbed. For example, man has created intensive agro-ecosystems in which plants are grown without soil.
9. Any natural ecosystem evolves so formed equilibrium where extreme forms community (climax community) in the final stage (climax). At the climax, the changes gradually slow down and form a relatively stable community that is in balance with the environment. Menopause occurs in the ecosystem when incurred complicated community reproduced without being filled with new components outside. The net output is zero. Energy meets the needs of all living organisms in the ecosystem. Man clears agro-ecosystems of plants and animals, respectively called weeds and pests, by various means such as mechanical tillage, chemicals and others. This is done in order to obtain maximum production that is exported from agroecosystems and does not reach the formation of a sustainable community in balance with the environment.
10. In the natural ecosystem are missing or there are slightly eroded soils. There are no chemical contaminants such as pesticides, fertilizers and others. In agro-ecosystems, much of the soil is eroded. The processes of wind and water erosion can be intense, leading to the destruction of soil structure, washing and treatment of soil colloids. The final output is variable and is dependent on imported energy and additional substances.
11. Natural ecosystems built vertical structure for full use of solar energy. They also have a horizontal structure, which is characterized by various types of biocoenosis. Usually in agro missing vertical structure for maximum absorption of solar energy by agrophytocenoses.
It should be noted that there studies of the geometry of the plants and their distribution in the agricultural field, with the help of which can increase the absorption of solar energy. In common practice, these achievements are not used enough. There are instances of compacting the crop with two types of agricultural crops (such as maize and pumpkin, and so on..), Which form a vertical structure.
Important features of agro following
◄ agro-ecosystems are created by people in order to increase the productivity of a relatively small number of species. To achieve this goal, human activity is aimed at minimizing competition between plants in terms of nutrients. Useful population of plants is artificially introduced into biotope. The types of plants are divided into beneficial and non-beneficial. Human activity is aimed at the destruction or reduction of non-beneficial species. Not always makes a real revaluation of biotic interactions between economic plants.
◄ agro-ecosystems are the product of human activity. Determinants of their performance are not only natural (biotic and abiotic) and technology (system of agriculture), but also economic factors (availability of labor, credit, subsidies, accounting risks, information on prices and the market).


- Nedialkov S. T.2003. Theory of ecology. - Ed. "PablishSaySet-Eco", Sofia, p. 449.
- Popov, P. others. 2003. Agroecology and management of agro-ecosystems. - Eco-PablishSaySet, Sofia, p. 144.
- Gossip, Y. 1986. Эkologiya. - Ed., "Mir", Moscow, t. 1, p. 328; m. 2, p. 376.
- Hristov, I. D. 2004. Evaluation of the water status of agro-ecosystems and the formation of water reserves in the soil. - Monograph Series Ecology, Eco-PablishSaySet, Sofia, p. 216, ISBN 954-749-044-3.
- Hristov, I. D. 2012. Monitoring and management of the water status of agro-ecosystems. - Monograph Series Ecology, Eco-PablishSaySet, Sofia, p. 262, ISBN 978-954-749-098.




- Christov, I. D.2015. Ecological Requirements and Agricultural Activities. – Journal of Balkan Ecology, 18(1), 5-16.

- Christov, I. D.2014. Environmental Education at University and Its Effects on Agrarian Activities and Agribusiness. – Journal of Balkan Ecology, 17(3), 229-231.

- Wright, P. 1998. A-Z of the Environment. – InEnvironment Encyclopaedia and Directory, World Survey, Second Edition, Europa Publications Limited, London, p. 560.