Understanding Biotic Relationships and Terrestrial Ecosystems

Biotic Relationships

Biotic relationships are the interactions among living organisms in an environment. There are two main types of biotic relationships:

Interspecific Relationships

Interspecific relationships occur between organisms of different species. These include:

• Mutualism: A relationship where both species benefit. Example: Bees pollinating flowers.
• Commensalism: A relationship where one species benefits, and the other is unaffected. Example: Beetles feeding on mammal excrement.
• Inquilinism: A specific type of commensalism where one organism uses another for housing.
• Parasitism: A relationship where one species (the parasite) benefits at the expense of the other (the host). Example: Cochineals feeding on cacti.
• Predation: A relationship where one individual kills and eats another. Example: Cheetahs and gazelles.

Intraspecific Relationships

Intraspecific relationships occur between organisms of the same species. These include:

• Gregarious: Unrelated individuals living together temporarily for mutual benefit. Example: Migrating birds.
• Colonial: Related individuals living together.
• Social: Individuals organized in a hierarchy with divided labor and often physical differences.
• Familial: Related individuals living together for reproduction and protection of young.

Terrestrial Ecosystems

Terrestrial ecosystems are land-based environments where organisms are surrounded by air. Biomes exhibit a wide diversity of life. The distribution of organisms within these ecosystems depends on abiotic factors related to climate:

Key Abiotic Factors

• Temperature: Varies with altitude, latitude, and proximity to the sea.
• Light: Essential for plant photosynthesis and influences animal behavior and vital functions.
• Humidity: The amount of water vapor in the air, crucial for various life processes.

Climate Zones

There are three major climate zones in each hemisphere:

• Frigid Zone: Cold regions from the poles to the polar circles.
• Temperate Zone: Areas between the polar circles and the tropics.
• Torrid Zone: Hot region between the Tropic of Cancer and the Tropic of Capricorn.