Ecosystem Structure, Biotic Interactions, and Adaptations

Components and Dynamics of Ecosystems

Defining Ecosystem Components

• Biotope: Encompasses the non-living components of the ecosystem, such as rocks and water, or physical conditions like temperature.
• Biocoenosis: Is made up of all the living organisms that inhabit the biotope.

Interactions in the Ecosystem

• Abiotic Factors: Affect the biocoenosis (e.g., soil and low temperatures).
• Biotic Factors: Affect the biotope (e.g., herbaceous plants increasing the number of herbivores).

Adaptations to the Environment

Adaptation is an adjustment in the body or behavior of an organism to its environment.

1. Anatomical Adaptations: Physical characteristics of living things that enable them to carry out a specific activity.
2. Behavioral Adaptations: Actions that organisms carry out that benefit them in some way.

How Abiotic Factors Affect the Biocoenosis

1. The Presence of Water

• Plants: Absorb most of their water through their leaves.
• Animals: Have developed waterproof outer coverings.

2. Light

• Photosynthetic Organisms: Capture as much light as possible.
• Animals: Many exhibit nocturnal or diurnal behavior.

3. Temperature

• Plants: Lose leaves and reduce metabolic activity to a minimum during cold seasons.
• Animals: Migrate or hibernate.

Relationships in the Biocoenosis

1. Intraspecific Relationships

These occur between individuals of the same species, often enabling them to better care for their offspring.

• Family Associations: Composed of individuals who are related to one another.
• Gregarious Associations: Formed by individuals, not necessarily related to each other.
• Social Associations: Made up of individuals that form a hierarchy and organize a division of labor.
• Colonial Associations: Formed by individuals that share the same progenitor.

2. Interspecific Relationships

• Competition: A relationship in which both species are harmed.
• Predation: One organism benefits (predator) and the other is harmed (prey).
• Parasitism: One organism benefits (parasite) and the other is harmed (host).
• Mutualism: A relationship in which both organisms benefit.
• Commensalism: A relationship which benefits one species and does not affect the other.