This article will give an overview of the ecosystem. What makes ecosystems different from other systems found in nature? Do you think an indoor aquarium is also an ecosystem? The answer to all those questions will be in our detailed article below.
1. Overview of the ecosystem
1.1. Definition of Ecosystem
An Ecosystem is a combination of a biome with the physical environment in which that biome exists, in which organisms interact with each other and the environment to create material cycles and energy conversion. An Ecosystem is also a structural part of the global ecosystem or biosphere.
1.2. What is the difference between ecosystems and other physical systems found in nature?
An ecosystem is an open, dynamic, and self-regulating system because the system always receives material and power from the environment in the existence and development process. Those make the ecosystem different from other physical systems in nature.
Because it is a dynamical system, its behavior obeys the first and second laws of thermodynamics. The first law states that energy cannot be created or destroyed and can only convert from one form to another. In ecology, the second law states that energy can only transfer from a concentrated form to a diffuse form. For example, heat can only be transferred from a hot object to a cold one, but not vice versa if without other devices.
The ecosystem is as complete as an organism, so existing in nature, the ecosystem also has a definite ecological limit. When subjected to a moderate external influence, the system will respond adaptively by rearranging internal relationships and the system as a whole to suit the environment through the backlink to maintain its stability in volatile environmental conditions. All changes in the system occur as in a black box whose aggregate result is the response (or output) corresponding to the input effects on the system. In ecology, this process is called homeostasis.
2. Structure of the ecosystem
A typical ecosystem has a structure with the following components:
– Primary producer Organism (autotroph)
– Consumer Organism
– Decomposer Organism
– Inorganic substances (CO2, O2, H2O, CaCO3, …)
– Organic substances (proteins, lipids, carbohydrates, vitamins, enzymes, etc.)
– Climatic factors (temperature, light, humidity, precipitation, etc.)
The first three components are biomes, and the last three are the physical environment in which that biome exists and develops.
2.1. Primary producer Organism (autotroph)
They are autotrophs, including colored plants, some fungi, and bacteria capable of photosynthesis or chemosynthesis. They are indispensable components in any ecosystem. Their photosynthesis and chemosynthesis create initial food sources to feed themselves and the rest of the world, including people.
2.2. Consumption organism
They are heterotrophs, such as animals and microorganisms incapable of photosynthesis and chemosynthesis. In other words, they survive on their primary food source produced by autotrophs.
2.3. Decomposer organisms (saprophytic)
They are heterotrophic, saprotrophic microorganisms. When decomposing substances, they receive chemical energy to survive, grow, and release substances from complex compounds into simple minerals or chemical elements (CO2, O2, N2, etc.) to the environment.
Heterotrophic organisms and microorganisms are also considered consumers. Unlike microorganisms, animals decompose substances in the raw and intermediate stages, while microorganisms decompose substances in the final stage (the mineralization stage). Under certain environmental conditions, a system is considered an ecosystem when it has autotrophs and saprophytic microorganisms.
3. Ecosystem Examples
3.1. Natural Ecosystems
Cuc Phuong National Park is a small part of the tropical rainforest biological zone, at an average altitude of 300-400m above sea level in the tropical monsoon climate belt of Southeast Asia. Cuc Phuong National Forest has a diverse and complex species composition, spatial differentiation, biological relationships, and functional activities.
Ba Be lake is a typical example of an aquatic ecosystem. As terrestrial ecosystems, the lake receives material from outside due to soil erosion after rains and energy from solar radiation.
3.2. Artificial Ecosystems
Artificial ecosystems are those created by humans. They are also diverse in size and structure. They can be as large as reservoirs, fields, cultivation fields, cities, and urban areas; as small as experimental ecosystems (an aquarium, an in vitro ecosystem, etc.). Many systems have diverse structures as natural ecosystems (cities, reservoirs, etc.). There are also simple structural systems in which dominant species are selected for human-intended use, such as fields, shifting cultivation, etc. Those systems are often unstable. Their existence and development are dependent on human care. When human intervention is absent, the system will replace by a stable natural system.
4. Energy flow in the ecosystem
Ecosystems or the entire biosphere exist and develop sustainably because of solar. Solar power converse into chemical power during photosynthesis is the starting point of energy flow in ecosystems. Solar power is transmitted to the planet by streams of light radiation. Radiation is converted from primitive form to chemical power by photosynthesis of producer organisms and then from chemical energy to mechanical and thermal energy in cellular metabolism in groups of consumers. Successive transformations are the key to the energy strategy of the body and the ecosystem. The total power put into the ecosystem is only about 50%, which plays an indispensable role in the reception of the producer organism, that is, the part of the power that is mainly in the visible spectrum. Autotrophs create a primary food source from those energy sources, starting the food chain.
5. Ecological succession
The development of ecosystems is also known as ecological succession. Ecological succession is the process of changing an ecosystem from an initial state through transitional stages into a final, steady state over time. That is the climax state.
Climax: the ecosystem or community in the process of succession. If the ecosystem is not affected by destructive factors, it will eventually reach a stable state. At this stage, populations, life-and-death levels, and energy are all steady, and biomass is in equilibrium. The community at its peak is not static, it is still changing very slowly, and those changes will happen quickly if the environment has large changes.
Reference: Book of Ecological Foundations – Vu Trung Tang – Second Edition, 2003.
Author: Do Thi Hue
Tiếng Việt
日本語