Understanding Earth's Living Systems

The Biosphere

The biosphere is the set of all living things on Earth.

Understanding Ecosystems

An ecosystem consists of interconnected components:

• Biotic Components: Living things that inhabit a particular place and interrelate.
• Abiotic Components: All the physical environmental conditions or non-living elements within the dwelling of living beings.

Relations Between Components: Living organisms in a specific location are adapted to certain conditions of their physical environment and, in turn, modify it.

Ecological Relationships

There are relationships between individuals of the same species and between different species, such as predation, parasitism, symbiosis, and commensalism.

Photosynthesis

Photosynthesis is the process of converting light energy from the sun into chemical energy contained in organic matter.

Food Chains and Trophic Levels

Food chains describe relationships based on the transfer of food energy from one organism to another. Food chains are formed by trophic levels. Each trophic level is made up of organisms that obtain food in a specific way.

Producers

Producers are organisms capable of producing their own food, typically through photosynthesis.

Consumers

Consumers are organisms that obtain their food by eating other living beings. They are categorized based on their diet:

• Herbivores
• Carnivores
• Omnivores

Herbivores (Primary Consumers)

Herbivores, also known as primary consumers, feed only on producers. Examples include animals eating leaves, twigs, grass (some with complex stomachs like ruminants, formed by the rumen, reticulum, omasum, and abomasum), nectar, sap, fruits, and seeds.

Secondary Consumers

Secondary consumers are carnivores that eat herbivores or other carnivores. This group includes predators and scavengers.

Omnivores

Omnivores are animals that eat both plants and other animals. Depending on what they are eating at a given time, they can function as primary or secondary consumers.

Detritivores

Detritivores are animals that feed on waste or dead organic matter from other living beings.

Decomposers

Decomposers are organisms, such as bacteria and fungi, that use the remains of other living beings as a food source. They break down this organic matter, returning essential mineral nutrients to the ecosystem.

Trophic Pyramids

In food chains and food webs, energy flows from producers to consumers. An ecosystem typically has more chemical energy stored in producers than in herbivores, and more in herbivores than in carnivores. This energy distribution across trophic levels is often represented as a trophic pyramid, illustrating the decrease in energy at each successive level.

Biodiversity

Biodiversity refers to the variety of life forms on Earth, encompassing the diversity of species, ecosystems, and genes. Maintaining biodiversity is crucial for the equilibrium of ecosystems. However, biodiversity is threatened by factors such as pollution, fires, habitat exploitation, and other human activities.