What Are Abiotic and Biotic Factors in an Ecosystem?

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The biotic factors in an ecosystem are physio-chemical or nonliving parts of an environment, while abiotic factors are living components of an environment.

Together, biotic and abiotic factors are the basic components of an ecosystem. The relationship between them is called holocoenosis. Collectively, biotic and abiotic factors create a sustainable ecosystem, which is an interdependence of factors within the ecosystem.

Abiotic Factors

Abiotic factors fall into four main categories, which are climatic factors, edaphic factors, organic substances and inorganic substances. Climatic factors are elements that make up climate and weather, such as wind, temperature and humidity level. Edaphic factors include the physical and chemical properties that comprise soil, such as soil profile, soil type, organic matter, soil water, minerals and organisms living within the soil. Organic substances include lipids, proteins, carbohydrates and humic substances. Inorganic substances include water, sulfur, nitrogen, phosphorous and carbon. Biotic factors include the living parts of the ecosystem, including animals, plants and microorganisms. The relationship between biotic factors in the environment is complex, and many species are interdependent.

Biotic Factors

Biotic factors break down into several different types. Autotrophs are the producers, and they mainly include plants. Autotrophs form the base of the ecosystem, and they live in most environments. Heterotrophs are consumers. This group breaks down into two types, which are consumers and macroconsumers. Consumers are animals that feed on other organisms. They are also referred to as phagotrophs, which means organisms that swallow or ingest. Macroconsumers are carnivores or herbivores. Herbivores, which are organisms that feed on plants, are called primary consumers. Carnivores that feed on herbivores are called primary consumers. Carnivores that feed on other organisms are called secondary consumers. Sometimes, scientists assign third-level and fourth-level carnivore designations if there are large carnivores in an ecosystem that prey on smaller carnivores. In addition to autotrophs and heterotrophs, ecosystems contain saprotrophs. Saprotrophs are microorganisms called reducers or decomposers. These organisms help break down organic substances found in dead and decaying matter.

Abiotic and Biotic Interdependence

Although they contain different organisms, abiotic and biotic factors work together to support a healthy ecosystem. Abiotic factors help create ideal conditions to support life for biotic factors. Abiotic factors also include the different types of environments that organisms live in and influence the adaptations that abiotic organisms have to survive in specific conditions. While abiotic factors largely shape the behavior of biotic factors, biotic factors have a small role in supporting abiotic factors. Biochemical reactions that are carried out on plant roots by nitrogen-fixing bacteria, for instance, help regulate the nitrogen cycle in an environment, which helps maintain a healthy balance between the environment and living organisms. Having a proper balance within an ecosystem helps it carry out important processes, such as energy transformation.

Ecosystems appear all around the world, and they take many different forms. Ponds, coral reefs, jungles and deserts are all types of ecosystems. Some ecosystems are hot and dry with little life, while others teem with biotic factors. Arctic and tundra ecosystems lie far north of the Equator, while jungle and desert ecosystems lie closer to the Equator. Climactic differences, and essentially a variation in abiotic factors, account for many of the differences in ecosystems.