Terrestrial Environment: Factors, Adaptations, and Soil

Habitat and Environmental Conditions

A habitat is the environmental conditions in the place where a species lives.

Environmental Factors

Abiotic factors are the biotype and temperature. Biotic factors define the biocoenosis.

Each species is accustomed to living under certain environmental conditions. The term tolerance refers to the range of a factor that a species can withstand.

Limiting Factors in Terrestrial Environments

In the terrestrial environment, the main limiting factors for life are temperature and humidity.

Temperature

The air is cooled or heated quickly, according to the solar radiation it receives. This depends on latitude, altitude, seasons, and day and night.

Terrestrial beings adapt to temperature changes by following habits and adapting their body temperature. There are two types of animals:

• Ectotherms: Their body temperature and activity are dependent on solar radiation.
• Endotherms: They regulate their body temperature.

Humidity

Humidity is the amount of water vapor in the air. This depends on the weather.

All living things need water for their bodily functions:

• Animals: They take in water through food and lose it through respiration and excretion (urine and feces).
• Plants: Water enters through the roots (absorption) and is lost through the leaves (evapotranspiration).

Living things adapt to the lack of water:

• Animals: They store metabolic water (camels and dromedaries) and avoid losses by excreting dry and solid waste.
• Plants: Water is stored in special organs such as stems and roots, and water loss is avoided through spines or modified leaves.

Soil: The Terrestrial Substrate

The soil surface layer is the terrestrial substrate that serves living beings. The following soil features determine which communities develop:

a) Texture

Texture is the ratio between the size of the mineral material that contains oats, flax, clay, and stones. There are different soil types: sandy, clayey, stony, and loamy.

b) Water Content

Water content depends on the texture and climate. Water drains easily in sandy soils, while clay soils puddle easily.

We call plants that need wet soil hydrophilic plants.

We call plants that survive in very dry soils xeric plants.

c) Composition and Chemical Properties: pH

Salt content depends on soil minerals. Sodium chloride causes saline soils where only halophiles live. These are adapted to living in soils with a particular pH. Neutral soils are best. There are plants adapted to acidic soils as well as basic soils, such as pine and oak.