Ecology: Organism Interactions and Environmental Factors

Temperature Effects on Water Oxygen

Temperature: The amount of dissolved oxygen in water depends on temperature differences between the surface and deep oceans. These differences create currents that redistribute nutrients and oxygen.

Relations Between Organisms

In a community setting, multiple relationships exist:

• If the relationship occurs between two individuals of the same species, it is called intraspecific.
• If it happens between different species, it is called interspecific.

Competition

Competition occurs when two individuals use the same resource. Intraspecific competition is common because individuals of the same species have similar needs and compete for the same resource.

Cooperation

Cooperation: A type of relationship between individuals of the same species that provides benefits to the individuals involved.

Predation

Predation: A relationship where one organism (predator) feeds on another living organism (prey). Two types are distinguished:

• True Predators: Kill and eat many prey.
• Parasites: The parasite establishes a very close relationship with the host, often living on or inside it.

Commensalism and Inquilinism

Commensalism and Inquilinism: One species benefits from another when it eats its leftovers (commensalism) or uses the host for shelter (inquilinism).

Mutualism

Mutualism: Both organisms benefit, although their existence does not strictly depend on this relationship.

Symbiosis

Symbiosis: A type of relationship where the association is so close that the two organisms cannot live apart.

Threatening Species Survival

Each species can persist only within a certain range of conditions for its life. If these conditions change, the species can become extinct.

Habitat Destruction and Fragmentation

This decreases the measure of populations, potentially falling below the threshold required for survival. It also prevents the exchange of individuals between populations and leaves organisms exposed to external interference.

Introduction of Exotic Species

If a new species causes changes in native species' relationships, some native species may disappear.

Overexploitation of Species

Direct pressure on a species due to various concrete motivations, such as for meat or collection.