Ecosystem as a holistic system

      The basis of the principle of homeostasis is feedback, which is illustrated by the dependence of the population on food resources. Feedback occurs when the product has an effect on the sensor (figure 2). As a result of the deviation from the optimum population density in either direction there an excess or lack of food resources. As a consequence of this increased fertility or mortality, resulting in a reduction of the density of the optimum. This feedback, which reduces the deviation from the norm, is called negative feedback. Positive feedback increases the deviation. Greatest importance for the maintenance of homeostasis of an ecosystem has negative feedback. Thanks to this connection are regulated processes of storing and releasing nutrients, production and decomposition of organic compounds. In other words, the interaction cycle of matter and energy flows in the ecosystem creates a self-correcting homeostasis that is so to maintain that requires no external control.

Negative feedback (in)

                                                                                                                Noise

 

 

 Outcome

 

        Energy source

 

Figure 2. Simplified system of regulation of population density simplified system of regulation of population density (U. Odum, 1975)

 

 

       In addition to the physiological homeostasis and the possibility of regulating the number of populations on the principle of negative feedback, the ecosystem as a complete functional unit has its own natural mechanisms that increase its stability.       One of such mechanisms is redundant functional components. For example, if in the community there are several types of autotrophs, each of which is characterized by its temperature range of operation, the rate of photosynthesis, the community at large may remain the same, despite the changes in temperature. Sustainable communities is also increasing as a result of multiple overlapping food chains at the species level. In a stable ecosystem, each trophic level (consumption) is represented by a large number of animal species, which belong to different taxonomic groups. Each type focuses on using his typical food supply, and a combination of adaptive types provides the most complete for these conditions recycling of organic matter.

    Maintaining homeostasis of ecosystem is possible only within certain limits. Outside the scope of the negative feedback takes effect positive feedback.

In homeostasis are involved not only the organisms and their products, but not organic nature. Abiotic factors control the living organism. In turn, has various ways affect the abiotic environment. 

    Homeostasis is partly dependent on the ecosystem homeostasis individuals. But not only one individual embody homeostasis community. All homeostatic mechanisms, in fact, are devices that collect a lot of geological eras in response to environmental changes.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conclusion.

 

      Ecosystem as a dynamic complex of plant, animal, and microorganism communities and the nonliving environment interacting as a functional unit within an explicit space. Thus, a forest, a grassland, a wetland, a marsh, a pond, a sand dune, and a coral reef, each with its respective species in a particular spatial area, can be studied as a distinct ecosystems.

      Continuous circulation of chemical elements in the biosphere in a more or less closed paths called biogeochemical cycles. The need for such circulation is due to the limited resources of the planet. To ensure the perpetuity of life, should make chemical elements circling. Cycle of each element is part of a grand cycle of matter on Earth, that is, all cycles are closely linked.

Biogeochemical cycles - whether the water cycle, the nitrogen cycle, the carbon cycle, or others - happen in relation with one another. Biogeochemical cycles are "coupled" to each other and to Earth's physical features.

     The three main cycles of an ecosystem are the water cycle, the carbon cycle and the nitrogen cycle. These three cycles, working in balance, are responsible for carrying away waste materials and replenishing the ecosystem with the nutrients necessary to sustain life. If any of these three cycles should become unbalanced, the effects on the ecosystem can be catastrophic.

     The main cause of imbalances in the biogeochemical cycles is a human economic activity. In reality, it would be hard to find any ecosystem that doesn’t show human impact. We have replaced many natural systems with agriculture and urban and suburban developments. The products of our economic activities have polluted and degraded ecosystems everywhere. In reality, it would be hard to find any ecosystem that doesn’t show human impact. We have replaced many natural systems with agriculture and urban and suburban developments. The products of our economic activities have polluted and degraded ecosystems everywhere.

      The ability of an ecosystem to withstand changes in environmental factors, while maintaining its normal functioning is the sustainability of the ecosystem.

      In ever changing physical environment, organisms must maintain a fairly constant internal environment within the narrow limits required by their cells, organs and enzyme systems. They need some means of regulating their internal environment relative to external conditions including body temperature, water balance and others. The maintenance of a relatively constant internal environment in a varying external environment is called homeostasis.

     Human is a part of nature, and of course, of the ecosystem, so he must take measures to protect nature, to limit its negative impact on the environment, before it was too late!

 

 

 

 

 

 

References.

 

А.К. Бродский «Общая Экология», 2009

А.А. Горелов. «Структура и  функции экосистем». Экология. 1998

Smith, Thomas M. Elements of Ecology, 2009

Wright, Richard T. Environmental science: Toward sustainable future, 2008 

Molles, Manuel C. Ecology: Concepts and Applications, 1999

Chiras, Daniel D. Environmental science: Creating a sustainable future, 2001

Lal, Rattan . Sequestration of atmospheric CO₂ in global carbon pools:  Energy and Environmental Science , 2008

Langdon, C.; Takahashi, T.; Sweeney, C.; Chipman, D.; Goddard, J.; Marubini, F.; Aceves, H.; Barnett, H. Global Biogeochemical Cycles , 2000