Terrestrial and Aquatic Ecosystems: Classification and Characteristics

Terrestrial Ecosystems

Natural Terrestrial Ecosystem Examples

These ecosystems are shaped primarily by natural processes:

• High Mountains: Temperatures vary significantly between winter and summer. In winter, the mountains are covered with snow, and there is little food available. Consequently, many animals migrate.
• Deciduous Forests: Found in regions with cold winters and abundant rainfall. The trees lose their leaves annually, which makes the soil rich and fertile.

Man-Made Ecosystem Examples

These ecosystems are significantly influenced or created by human activity:

• Cultivated Land: An ecosystem in which cereals and other crops are grown. These ecosystems contain a rich biocenosis. The biotope varies depending on the climate.
• Parks and Gardens: Found in urban areas. Animals in these areas have adapted behavior so that they can live near human beings.

Understanding Aquatic Ecosystems

Aquatic ecosystems are environments where organisms live surrounded by water. The abiotic factors which most influence the distribution of organisms are:

Abiotic Factors Influencing Aquatic Life

• Light: Necessary for photosynthetic organisms. Light decreases as the water gets deeper.
• Temperature: Varies with distance from the coast and the depth of the water.
• Pressure: Increases as the water gets deeper. It affects the shape of living creatures.
• Salinity: Varies significantly across different aquatic ecosystems (e.g., marine vs. freshwater).
• Oxygen: Aquatic ecosystems generally have less oxygen and fewer gases dissolved than terrestrial ecosystems.

Characteristics of Freshwater Ecosystems

About 0.3% of the surface water on Earth is contained in freshwater ecosystems. The salinity of fresh water is typically very low (around 0.18 g/L). There is less diversity of species in freshwater than in marine ecosystems.

Types of Freshwater Ecosystems

Freshwater ecosystems are generally divided into two types based on water movement:

• Lentic Ecosystems: Are found in standing water, such as pools and lakes. They vary significantly in depth.
• Lotic Ecosystems: Are found in running water, such as streams and rivers. Living beings have adapted to living in running water. Note: This water is often highly contaminated.

Specific Freshwater Ecosystem Examples

• Rivers and Streams: Characterized by abundant light and high oxygen content in the water. When the water is still, the temperature increases and the amount of oxygen decreases.
• Lagoons and Marshes: Are usually shallow and can dry up seasonally. If the water is still, there may be little oxygen. These areas are susceptible to pollution.