Sun Energy, Ecosystems, and the Flow of Life

Sun Energy and Life

The ecosphere is a hypothetical spherical zone located around any star, such as the Sun, where temperatures and appropriate conditions exist to allow living things to originate and evolve.

What is an Ecosystem?

An ecosystem is a particular area where environmental conditions allow some organisms to develop concretely.

• Biotope: The physical environment in which an ecosystem is stable.
• Biocenosis: All living beings inhabiting a biotope.

Factors of an Ecosystem

They fall into two types:

• Abiotic factors: All environmental factors in an ecosystem.
• Biotic factors: Establishing relationships between living things in an ecosystem.

What Effect do Abiotic Factors Have on Living Beings?

They can be:

• Climatic factors (temperature, rainfall, and humidity)
• Physical and chemical factors (light, salinity, and pressure)
• Soil-related factors (type of rocks and materials that form it)

Climate Factors

Climate is the most important environmental factor for soil organisms.

Temperature and rainfall, the main actors in climate, determine the distribution of various terrestrial ecosystems.

Physical and Chemical Factors

• Light: The amount of light is a very important factor for the distribution of organisms that perform photosynthesis.
• Oxygen: It is in the air, and to a lesser extent, dissolved in water, where aquatic organisms take it.

Edaphic Factors

The soil characteristics are very important because they determine the development of vegetation and, consequently, the ecosystems that are in a place.

Biotic Factors

Biotic factors are the relationships that occur between living things.

• Intraspecific relationships: Between the same species.
• Interspecific relationships: Between different species.

Interspecific Relationships

• Competition: When two organisms compete for the same resource.
• Predation: When an organism called a predator kills another for food.
• Symbiosis: Ongoing relationships between individuals of different species.

Intraspecific Relationships

They can be:

• Family
• Gregarious: e.g., a flock of birds.
• Colonial: e.g., sponges.
• Social: e.g., wasps.

The Flow of Matter and Energy

In an ecosystem, living creatures have distinct roles:

• Producers: Produce organic matter from inorganic matter (e.g., algae, photosynthetic bacteria).
• Consumers: Produce organic matter obtained by producers (e.g., bacteria, protozoa, and fungi).
• Decomposers: They get food from traces of organic matter.