Structure of Ecosystem – Biotic and Abiotic Components

Ecosystem is the basic structural and functional unit of the environment. Both the living and non-living component of the nature, when interact with each other to establish a stable living community, it is called as Ecosystem. That means there is a constant exchange of something between these living & non-livings, is called an Ecosystem. Without the living component, establishment of an ecosystem is not possible and vice versa. Both are two sides of a coin or very much complementary to each other.

It is very easy to study or understand the structure of ecosystem from the flow chart (Fig. 1) described below.

Biotic Components

Biotic components are also divided into 3 categories basing upon their food-fed relationships.

1. Producers: Producers are the autotrophs (auto means self, troph means to nourish) of the ecosystem. They are the green plants and green microorganisms who can make their own food material by using carbon dioxide and water in presence of sunlight with the help of chlorophyll present in them. Ex. All green plants, Algae, Cyanobacteria,
2. Consumers: Consumers are the heterotrophs (hetero-not self troph to nourish) of an ecosystem. They depend on the producers of the nature to get energy. Consumers are also different types like
   1. Primary Consumers – They are the herbivores who eat directly the autotrophs / plants. They cannot eat any animals. Ex. Grasshoppers, Rabbits, Goats.
   2. Secondary Consumers – They cannot directly eat the producers of the ecosystem, that is the plants. They can eat only herbivores. Ex. Frogs, Jackal, Snakes
   3. Tertiary Consumers – They are carnivores in nature means they are the meat eaters. Thus, they depend on the secondary consumer for their food. They are the top-level carnivores. Ex. – Tigers, Lions, Vulture, Kite
3. Decomposers: Decomposers are also to some extent heterotrophic in nature. They do not contain chlorophyll, so depend on other material for food and energy. These organisms can grow on the dead and decay materials of the environment. That is why they are known as the decomposers or saprophyte, or scavengers of the nature or they can be called as the detrivores (Detri means dead particulate organic material). They can live in any type of soil with organic waste. They play a very important role for the completion of the Biogeochemical Cycle in the environment. Ex. Bacteria, Fungi, Earthworm

Abiotic Components

These are the non-living factors in form of solid, liquid or gas found in the nature (ice, water, moisture). They can be categorised into 2 types: Climatic factors and Edaphic factors.

1. Climatic Factors
   1. Light – It is an essential factor for all the living organisms like producers, consumers as well as decomposers. In presence of the sunlight plants are able to prepare their food material, which in turn eaten by the heterotrophs & ultimately by the decomposers. Without sun light photosynthesis is not possible thus it is one of the most important abiotic factors of an ecosystem. Quantity as well as quality of light has different impact on different organism. Let’s discuss.
   2. Temperature – Temperature increase the physiological activity. Thus, the types of plants grow in a desert ecosystem are different from the type of plants of a forest ecosystem and an aquatic ecosystem. Different types of plants need different range of temperatures for their growth. Summer growing plants are different from winter season growing plants. Best example is an aquatic ecosystem. The organism growing at surface layer are different as they need more temperature and light than the organisms grow at a deeper level in an aquatic ecosystem.
   3. Water: Life is never possible without water. So, water is a very important abiotic factor in an ecosystem. The amount of water present in an area decides the type of ecosystem to be developed there. In this regard sometimes aquatic ecosystems also develop for ex. Pond & Lake ecosystems. If for a longer period of time, due to any reason, a huge amount of water got deposited & replenished repeatedly due to rainfall etc., then through the process of succession an aquatic ecosystem develops and get established there. Beside for photosynthesis & other metabolic activity plants needs water for circulation of minerals throughout its body. Water in forms of rainfall also needed by the ecosystem. It maintains the humidity & content of moisture in the atmosphere. Amount of rainfall also decides the kind of plants to grow over there.
2. Edaphic factors
   1. Soil: Soil is a natural resource and provides platform for the plants to grow and animals to dwell on it. Thus, the fertility and quantity of soil decides the type of vegetation in that area. To be more specific, pH of the soil is the deciding factor. If pH of the soil is less than 7, then it is acidic soil & if pH is more than 7 it is alkaline. Thus, the acidity & alkalinity of the soil decides the number & kind of plants & animals to stay over there (Fig.3). But needless to say, neutral soil, i.e. when the pH ranges from 6.5 -7.5 is the preferred condition for most of the living organism. Soil is also associated with different kinds of minerals & nutrients. Some are required in more quantity, are called macronutrient and some are micronutrients which are required in a small quantity. They also play a vital role in development and sustenance of an ecosystem.