Ecological Factors and Adaptation: Organism Survival Strategies

Ecological Factors

Characteristics of the environment that affect all living things, can be abiotic or biotic. Abiotic are the physical and chemical conditions that influence living beings. Biotic are those who share the same environment.

Limiting Factor

The factor closest to the value at which an organism cannot thrive.

Adaptation

The evolutionary adaptation of organisms to a given environment.

Eurioic Organisms

Organisms that have a wide tolerance to changes in their environment.

Stenoic Organisms

Organisms that have a narrow margin of tolerance to changes in their environment.

Adaptations to Water Scarcity

• Water stored in tissues
• Drought-resistant seeds
• Large and deep roots
• Small plants with hard leaves born in spring
• Resistant structures to desiccation
• Low water excretion
• Water produced in metabolism
• Nocturnal habits

Adaptations to Temperature Changes

If the temperature is appropriate, the activity is good; if it is bad, the activity is bad.

• Cutaneous isolation
• Concentration of individuals to have warmer zones for cold
• Plants close to the ground
• Panting
• Fall foliage
• Sweating
• Nocturnal life

Adjustments to Light

Sunlight passing through water absorbs long waves. Certain green algae living in the top half have a pigment in addition to chlorophyll. Red algae have a pigment.

Adaptations to Salt Concentration

If the medium is very salty, the organism loses water. If it is not kept low, water enters in freshwater environments. Fish drink water and eliminate salty urine. Fish in slightly salty water compensate for the loss by excreting salts through the gills and little urine.

Adaptations to Lack of Oxygen

• Increased number of red cells
• Increased pulmonary ventilation

Adaptations to Lack of Food

• Reserves stored in the body
• Migrations

Population

A group of organisms belonging to the same species that live and reproduce in the same place.

• Increased ease of reproduction
• Increased ease of feeding
• Competition between individuals
• Disease
• Lack of space
• Protection against others

Types of Populations

• Colonial: United among themselves
• Family: A family of animals together
• State: Division of common labor
• Gregarious: They help each other

Biotic Potential

The difference between births and deaths.

Community

A group of people living in the same area and interacting.

Biodiversity

The number of variants of an ecosystem.

Ecological Succession

A sequence of communities that occur in an area over time. When nothing is settled, pioneer agencies like lichens and mosses arrive. The soil is enriched, and biodiversity increases with herbaceous plants and later shrubs. This ends up providing a climax community of trees like oaks and pines. It can take hundreds or thousands of years to produce primary succession. Secondary succession occurs when a community loses some of its populations due to climatic changes, catastrophes, or human actions. A regression process begins, leading to a new community, which is secondary succession.