Biotic Factors and Ecosystem Roles

Biotic Factors in Ecosystems

Biotic factors are relationships that occur among living beings. They are classified as:

• Intraspecific: Between individuals of the same species.
• Interspecific: Between individuals of different species.

Intraspecific Relationships

Their purpose is the protection of the young, finding food, and defense.

• Family

  Made up of both parents and offspring, often to feed and protect the young.

• Gregarious

  Associations of organisms moving together, such as flocks of birds.

• Colonial

  Organisms that live intimately united, such as corals or sponges.

• Social

  Where a hierarchy and distribution of tasks are established, such as in colonies of bees and wasps.

Interspecific Relationships

• Competition

  Occurs when two organisms compete for the same resource, such as light, space, food, or mates for reproduction.

• Predation

  The relationship in which an organism, called a predator, kills another, called prey, to feed itself. These relationships form food chains or food webs.

• Symbiosis

  An ongoing relationship between individuals or associates of different species where both individuals derive mutual benefit.

• Mutualism

  A relationship in which both species benefit each other, for example, certain bacteria living in organisms.

• Commensalism

  A relationship in which one species benefits and the other is neither benefited nor harmed, such as clownfish and sea anemones.

• Parasitism

  One species benefits and the other is harmed. The parasite lives in close connection to another living being named the host.

Trophic Relationships in Ecosystems

Living beings in an ecosystem have different roles in the process of production and transfer of matter and energy. These groups are:

• Producers

  Autotrophic living beings able to produce organic matter from inorganic matter. Examples include plants, algae, and photosynthetic bacteria.

• Heterotrophs (Consumers)

  Beings that must obtain organic matter from the producers who manufacture it. These are the consumers. Within the group of consumers, those that feed on producers are primary consumers or herbivores. Those who eat primary consumers are secondary consumers or carnivores. Large predators such as wolves or eagles are tertiary consumers.

• Decomposers

  Organisms that get their food from the remains of organic matter.