Ecosystems and Diversity: Components and Functions

The word ecosystem was first proposed by British ecologist A.G. Tansley in 1935. The word ecosystem,” “eco” refers “environment,” and “system” means “components connected.”

Ecosystems are defined as systems that interact with living and non-living components (air, water, soil, etc.) of the environment that influence each other to sustain life. The animals depended on the plants for food and oxygen, directly or indirectly. At the same time, plants also depend on the available biological environment for raw materials and other organic and inorganic materials to produce food.

Similarly, animals contribute to pollination, seed dispersal, and nutrient cycling, which benefit the plant’s survival. The organic and inorganic materials were present in the soil through the decomposition of dead bodies and the excreta of living beings.

According to Odum 1971, an ecosystem is defined as, “any entity that comprises living organisms in the given region interacting with the physical environment in order of energy flow and produce well-defined biotic structures and cycling of materials between living and non-living elements.”

The ecosystem is a functional and structural unit of ecology. For example, the system can be as tiny as a pond ecosystem, a cropland ecosystem, and as large as an ocean ecosystem, a forest ecosystem, or a desert ecosystem. Thus, the whole ecosystems together constitute the ecosphere.

Table of Contents

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Aspects of Ecosystems

The ecosystem covers a wide range and consists of the following aspects:

It has biotic and abiotic elements that facilitate energy flow and nutrients.
Ecosystems have several relationships with soil, water, producers, consumers, and decomposers to carry out energy flow and nutrient cycles.
The movement of energy and materials recycling through the structural elements are linked to the ecosystem’s function.
The quantity of energy fixed by plants or autotrophs determines how much energy moves through a natural system. The quantity and mass of organisms that can be sustained at each consumption level are limited by the significant loss that occurs when energy is transferred from one consumption level to another. Most of the energy gets lost through respiration from one level to another.
The ecosystems get transferred from fewer complexes to more complex as they mature; thus, this shift is called succession. The early stages of succession have a comparatively high energy flow per unit of biomass, while a mature ecosystem has less energy and waste flow.
The primary functional unit of an ecosystem is a population, which fills a specific functional niche that is connected to the population’s function in energy flow and nutrient cycling.
There is a limitation of the environment, and the rate of energy fixation is called carrying capacity, where a population plays a significant role in stabilizing the ecological limits through low reproduction, starvation, and other factors.
The biosphere, where life exists, is a thin layer of Earth’s surface. It includes the topmost layer of land, water bodies, and a small portion of the atmosphere.

Components of Ecosystems

The ecosystem has two major components:

Abiotic (non-living components)

Inorganic substances: phosphorous, sulfur, carbon, nitrogen, hydrogen, etc.
Inorganic chemicals: chlorophyll, organic materials, protein, carbohydrates, lipids, etc.
The climate, edaphic factor (soil), and topography of the area.

Biotic (living components)

a. Autotrophic Components

The green plants are called autotrophs, which can synthesize food through photosynthesis. The accumulated light energy in simpler form gets changed into complex elements. They are also called producers, in which all the organisms depend on the autotrophs for food.

b. Heterotrophic Components

All the organisms that depend on plants for food are called heterotrophs. They utilize complex elements for survival. They are also called consumers who depend on the plants for their food.

i. Macro-consumers: These include primary, secondary, tertiary consumers, and quaternary consumers.

Primary Consumers: The organisms that depend on the autotrophs (plants/producers) for food are also called herbivores.
Secondary Consumers: The organisms that depend on primary consumers for food and energy are called carnivores or omnivores. They can be both carnivores and omnivores.
Tertiary Consumers: The organisms that depend on the secondary consumers for food. They can be both carnivores and omnivores.
Quaternary Consumers: The organisms that depend on the tertiary consumers for their foods are available only in a few food chains.

ii. Micro-consumers: They are known as decomposers or saprotrophs. They can decompose dead plants and organisms and convert complex forms into simpler forms. They released the inorganic nutrients, made them available to the autotrophs, and had significance for nutrient cycling. For example: bacteria, actinomycetes, fungi, etc.

Functions of Ecosystem

Productivity: Productivity is the accumulation of biomass (organic matter). It is the radiant energy stored by autotrophs (photosynthetic organisms) in the form of organic substances.
Energy Flow: The energy flow is the process of radiating energy to chemical energy utilized by the green plants during the photosynthesis process with the reaction of carbon-dioxide (CO₂) and water (H₂O) with the biproduct of oxygen and glucose. Plants can also use the various nutrients like nitrogen, phosphorous, sulfur, and magnesium.
Decomposition: The process of breaking down dead organic materials or dead materials that are decomposed in the top soil as humus is called decomposition.
Nutrient Cycling: The nutrients that get transferred from a low trophic level to a higher trophic level and which get recycled back by the low trophic level in an ecosystem are referred to as nutrient cycling.
Homeostasis: The capacity of self-maintenance and self-regulation by the constituents of an ecosystem is called homeostasis. It can also refer to a biological system to withstand change in the ecosystem and maintain its equilibrium state.

Types of Ecosystem

The types of ecosystems are categorized mainly into two groups: natural and artificial ecosystems.

A. Natural Ecosystem

The interaction of biotic and abiotic components of the ecosystem without human interference is called a natural ecosystem. This ecosystem can self-sustain and self-maintain by themselves in their natural processes. This ecosystem is further divided into two types, i.e., terrestrial and aquatic Ecosystem.

a. Terrestrial Ecosystem

The land based ecosystem is called a terrestrial ecosystem. This ecosystem is further divided into forest ecosystems, grassland ecosystems, tundra ecosystems, and desert ecosystems which are described below:

Forest Ecosystem: The ecosystem that is made of a wide variety of plants, animals, and microorganisms and gets interacted with each other in a standing environment is called a forest ecosystem. Forest is also one of the major contributors to carbon sinks and helps to regulate the earth’s temperature.
Grassland Ecosystem: The grassland ecosystem is made up of grass and herbs and their interaction. For example: tropical or savanna grasslands; temperate grasslands (Prairie, Steppe, and Pampas).
Tundra Ecosystem: The ecosystems that are exist in cold climates where there is no presence of trees and little precipitation are called tundra ecosystem. For the majority of the years, these were covered with snow. For example: arctic region, high Mountains.
Desert Ecosystem: The desert ecosystem is characterized by drought, high temperatures, and little vegetation. For example: coastal deserts, cold deserts, and hot and dry deserts.

b. Aquatic Ecosystem

The water-based ecosystem is called an aquatic ecosystem. It includes aquatic plants, fishes, amphibians, coral reefs, ocean creatures, and benthic macro-invertebrates. This ecosystem is further divide into two types as freshwater ecosystem and marine ecosystem which is described below:

Freshwater Ecosystem: The aquatic ecosystem such as ponds, lakes, rivers, streams, and wetlands, which is generally salt free, is called a freshwater ecosystem.

Lotic ecosystem: The river and stream ecosystems which is generally referred to as moving water bodies, is called a lotic ecosystem.
Lentic ecosystem: The standing water ecosystem including lakes, bogs, lagoons, ponds, and swamps is called a lentic ecosystem.
Wetlands ecosystem: The ecosystems which consists of hydrophytes and home to a variety of amphibians, reptiles, birds, fishes, and so on.

Marine Ecosystem: The aquatic ecosystem such as seas and oceans that have a significant salt content is called a marine ecosystem. These ecosystems have a higher biodiversity than a freshwater ecosystem.

B. Artificial Ecosystem

The artificial ecosystem is referred to as interference by humans and disturbance of the natural balance of the ecosystem with the addition of energy. For example: agricultural fields such as maize, wheat, mustard field, etc. In this ecosystem, humans tried to manipulate and control the biotic community as well as the physical environment.

Conclusion

Thus, the ecosystem is the interaction of biotic and abiotic components of the environment and their interaction with the physical environment. The ecosystem can be as small as a pond to huge as an ocean or forest ecosystem. But recently, human induced disturbance in the environment caused the degradation of ecosystems and increased the threats to ecosystem balance. As it is necessary to protect and restore the environment by adopting sustainable practices to ensure the well-being of our planets for future generations.

References

Odum, Eugene P. Fundamentals of ecology. Philadelphia: W. B. Saunders Company, 1953. 383 P. (1954). Science Education, 38(4), 314–314. Portico. https://doi.org/10.1002/sce.3730380426
Miller, G. T., & Spoolman, S. (1979). Living in the Environment (p. 470). Belmond California: Wadsworth publishing company.
GeeksforGeeks. (2024, February 14). What is Ecosystem? Definition, Structure, Types, and Functions. GeeksforGeeks. https://www.geeksforgeeks.org/what-is-ecosystem/