Ecosystem Dynamics and Species Interactions

Ecosystem Components and Definitions

An ecosystem is a system formed by different organisms (biocenosis), the environment, its physical and chemical characteristics (biotope), and the interactions that are established between them.

Environmental Factors and Biocenosis

Environmental factors are all the components of the ecosystem that have an impact on the biocenosis. They determine the distribution and composition of the biocenosis, the number of organisms present, and the adaptation of the organisms.

Abiotic Factors and Climatic Conditions

Abiotic factors include physical and chemical components such as temperature, water, and light. Climatic conditions form the large terrestrial ecosystems or biomes.

Biodiversity and Organism Adaptations

Organisms exhibit various adaptations to survive in their environments:

• Adaptations to light: This includes processes like photoperiodism.
• Adaptations to water availability: In deserts, plants develop spines; in tropical forests, plants have large leaves to manage an excess of water.
• Adaptations to temperature: In cold environments, animals hibernate or migrate; in high temperatures, they develop nocturnal habits.

Water as an Abiotic Factor

The availability of water, light, and temperature (solar radiation) are crucial. In aquatic environments, we distinguish between:

• Photic zone (sunlight zone): Areas where light reaches.
• Aphotic zone (dark zone): Areas where light is absent and temperatures are cold, reaching 90.

Life thrives in coastal areas and upwelling areas. In coastal areas, plants and algae absorb light, while marine currents provide nutrient-rich water.

Marine Adaptations

• To move, organisms have fusiform bodies, fins, and other structures.
• To resist wave movement, they are flexible or attach themselves to surfaces.
• To live in the abyssal zone, there are luminescent organisms.
• To live in polar zones, they have a layer of fat and regulate their temperature.

Biotic Factors and Relationships

Biotic factors or relationships are established between individuals of a community; they can be intraspecific or interspecific.

Intraspecific Interactions and Associations

Intraspecific interactions take place in the biocenosis between organisms of the same species, such as competition for territory or establishing dominance hierarchies. Common associations include:

• Family associations: Parental, matriarchal, and filial.
• Gregarious associations: Such as flocks (bandada).
• Colonial associations: Such as jellyfish (reproducing asexually).
• State associations: Societies with different tasks and hierarchies.

Interspecific Interactions and Symbiosis

Interspecific interactions take place between organisms of different species. These can be the result of interspecific competition or other dynamics:

• Types of interaction (+, -, 0): Categorized by their impact on the species involved.
• Interspecific competition (--): Produced when two species use the same limited resources.
• Predation (+/-): One species preys on another.
• Parasitism (+/-): One species benefits at the expense of another.
• Commensalism (+/0): One species benefits while the other is unaffected.
• Mutualism (+/+): Both species benefit from the interaction.