Understanding the Biosphere: Components, Habitats, and Ecological Niches
The Biosphere: An Introduction
The biosphere is the combination of living organisms and the physical environment in which life developed, namely: land, air, and water.
Some authors define it as a thin spider’s web, about 15 km thick, which is taken at the changing shapes of the planet’s surface.
Key Components of an Ecosystem
Biotopes
A biotope is the set of physical factors that exist in an ecosystem: air, water, light, temperature, etc.
Biocenosis
Biocenosis is the set of creatures that inhabit the ecosystem: plants, animals, fungi, etc. It is also called a community.
Habitat
Within an ecosystem, each organism lives in a particular place we call a habitat and, at the same time, has a specific functional position. When we talk about the habitat of an organism, we refer to its natural home, i.e., the place where the conditions for the existence of individuals of the species are favorable.
Ecological Niche
The existence of a species is conditioned not only by its habitat but also by its ecological niche, in which each species or community performs a particular function, i.e., its way of life. How a particular species fits into its overall environment will depend on the lifestyle of other species that live in this environment. These factors not only determine the existence of a species but also its adaptation and evolution, since individuals tend to remain in their ecological niches.
Biotic Components: Living Organisms
Biotic components are a set of organisms that inhabit a forest, savannah, lagoon, or ocean. The relationship that exists between these organisms is intrinsic, with each organism providing and receiving from others. We can list the following components:
Producers (First Level)
These are plants with chlorophyll that can capture light energy and produce food substances from simple compounds like water and carbon dioxide. That’s why they are called autotrophs. In this way, they begin the transformation of energy. Whatever the habitat, their presence is essential. In the terrestrial environment, plants with chlorophyll are among the producers. In the aquatic environment, the largest producer is phytoplankton. Algae are also producers, such as Chlorophyceae, Phaeophyceae, and Rhodophyceae.
Consumers (Second Level)
They consist of all organisms that depend on others and are also known as heterotrophs. Among consumers, we distinguish:
Primary Consumers
These are herbivores. Examples: deer, rabbits, lambs, sheep, cows, horses, etc.
Secondary Consumers
These are carnivores. Examples: fish, tigers, lions, eagles, owls, and snakes.
Tertiary Consumers
These are animals that eat other carnivores. Examples: sharks, whales, lions, humans, etc.
Decomposers (Third Level)
These are heterotrophic organisms, consisting of bacteria and fungi. Their feeding is performed from other dead bodies; they are saprophytes. When they feed from vegetable substances, dead or remains of plants, they are called saprophytic. They are called saprozoic when they get food from debris or dead animals. When decomposers perform this food function, they participate in the cycle of matter. Plants and all living things need the element nitrogen to live.
Abiotic Components: Non-Living Factors
Abiotic components are formed by inert or non-living factors. The environmental factors together determine the kinds of communities that can be part of an ecosystem. These components are: water, soil, sunlight, temperature, air, the medium, and the substrate.
Energy Levels in Ecosystems
The organisms that capture energy from sunlight and convert it into food are called producers, also known as autotrophic beings. Life on Earth would not be possible without producers. They are key components of the biosphere. Finally, there are the decomposers, which can be considered a particular type of consumer that, instead of eating other living things, breaks them down into simple substances.
Ecological Pyramid: Trophic Relationships
Trophic relationships are often schematized in pyramid form. In the pyramid, several levels are distinguished, each representing a large group of living things.