What Is a Natural Ecosystem in Biology

An ecosystem can be defined as a community where living beings co-exist in their physical environment and interact with each other to maintain the lifecycle and facilitate the flow of energy and nutrients. It consists of two main components – biotic and abiotic. 

Biotic components include plants, animals, and other living organisms. The physical elements in an ecosystem such as temperature, mineral, rainfall, and humidity make up the abiotic components. Ecosystems can be found anywhere and vary greatly in terms of size and types. It can range from a garden, freshwater ponds to vast oceans and forests. 

Types of Ecosystems 

There are two types  of ecosystems:

• Natural Ecosystem – These are ecosystems that occur naturally and can survive without any intervention from human beings. Examples of natural ecosystems are forests, mountains, rivers, etc.

• Human-Made or Artificial Ecosystem – When human beings modify the already existing ecosystem to meet their purpose or create an ecosystem of their own that mimics the natural condition, those are called artificial ecosystems.

One of the main differences between natural and artificial ecosystems is that the latter requires constant attention as they are not self-sustainable. Examples of this type of ecosystem include aquariums, crop fields, gardens, dams, etc.

In this article, we will focus on naturally occurring ecosystems only.

Natural Ecosystem

Natural ecosystem definition is that it is an ecosystem found in nature where organisms freely interact with other components of that environment. One of the main characteristics of this ecosystem is that it is a self-sufficient system. 

For instance, a forest has both herbivores and carnivores. Herbivores consume grass, fruits, and seeds. They are in turn, consumed by the carnivores. When carnivores die, their body decomposes into the soil and provides it with essential nutrients which help in the growth of trees and grass, which is consumed by herbivores. Thus, the biological cycle continues. 

Categories of Natural Ecosystems

There are two types of natural ecosystems: 

Terrestrial Ecosystem: These refer to the ecosystems found on land. They can be classified based on climate and temperature. These are discussed in detail below: 

1. Forests: 

They comprise about 31% of the total land on the Earth. Based on the climate condition and type of forest, there are three different kinds of forest ecosystems in the world. These include temperate forest, tropical rainforest, and coniferous forest. 

A tropical rainforest is seen in areas that experience heavy rainfall. A coniferous forest can be found in cold, mountainous regions, unlike temperate forests which grow in areas with warm summers and cold winters. 

They act as habitats for a large variety of animals, birds, insects, and other organisms, being the world’s largest terrestrial biodiversity. Additionally, we also rely on forests for a number of things.

2. Deserts: 

There are two types of deserts – hot and cold. These ecosystems have extreme weather conditions – the air is dry, the weather is too hot in the day and too cold at night, and they receive very little rainfall. As a result, the vegetation is sparse and very few animals live in the desert. Camels, desert snakes, and scorpions are few insects and animals that can be found in a desert. 

3. Grasslands:

Some of the examples of natural ecosystems of this type are temperate grasslands and tropical savannahs. The significant vegetations are tall grass with few shrubs and trees. Animals that can be seen in the grasslands are rabbits, wolves, zebras, gazelles, etc.

Aquatic Ecosystem:

As the name suggests, these include the ecosystems found within water bodies. They are the most common types of ecosystem found on the Earth as water covers around 75% of the Earth’s surface. It is divided into two groups –  

1. Freshwater – Freshwater constitutes only about 3% of a total 75%. Some examples of natural ecosystems that fall within this category are lakes, rivers, ponds, streams, wetlands, etc.

Rivers and streams originating from mountains carry essential nutrients which are then deposited in lakes and ponds. Freshwater is also the habitat for a variety of plants, animals, and microbes.

2. Marine Ecosystem – This is one of the most diverse forms of ecosystems. It consists of coral reefs, kelp forests, mangroves, salt marshes, rocky shores, deep sea, the open ocean, and so on. 

Marine ecosystems depend on physical factors like high salt content, availability of light, temperature, tides, geology, and geography. For this reason, some areas, such as mangroves, and salt marshes, are full of life, while the presence of life in areas such as the abyssal plain at the bottom of the sea is scarce.