Key Concepts in Ecology: Biotic and Abiotic Factors

Posted on Jan 12, 2025 in Geology

Key Concepts in Ecology

The group of organisms of the same species living in an area.

The set of populations living in an area.

The physical environment occupied by a community.

A community comprised of the biotope and the set of interactions that are established between different agencies and the environment around them.

A place with the necessary conditions for the life of an organism or species.

Those that arise as a result of the presence of other living things.

They are not directly related to living things.

Texture:
- Sandy soil: coarse particle size.
- Clay soils: very fine particle size.
- Mixed soil: characteristics of intermediate particles between the previous two.
Water and Air: Water needs vary depending on the different bodies of water. Water-loving plants require lots of water, and drought-tolerant plants require little. Air fills soil pores that are not occupied by water.
Chemical Composition and pH: Salty soils are where only some plants can withstand such high salt concentrations; these are called halophilic. Neutral soils are usually preferred by plants.

Salinity: Freshwater has very little salt dissolved, while saltwater has a rather older amount. Among waters that have levels intermediate between the other two are called brackish waters.
Light: According to the light, there are three zones in the marine environment:
- Euphotic: Goes up to 50m average depth.
- Oligophotic (Twilight Zone): From 50m to 500m.
- Aphotic: Zone of total darkness, from 500m downwards.
Temperature: The amount of oxygen that is dissolved in water depends on temperature. Temperature differences are generated between the surface of seas and deep oceans and create currents which redistribute nutrients and oxygen.

Competition:
- Intraspecific: This occurs because individuals of the same species have very similar needs and compete for resources.
- Interspecific: Between individuals of different species that use the same resources.
Cooperation: Cooperation is a type of intraspecific activity that benefits all those who perform it, for raising their young, defense against predators, or obtaining food.
Predation: Interspecific activity in which the predator feeds on the prey. There are three types of predators:
- True Predators: Kill and consume a large number of prey.
- Grazers: Attack a large number of prey in their lifetime but do not kill, just eat parts of them.
- Parasites: The parasite lives often on its host. Although at first non-lethal, attacks may prove to be throughout its life.
Mutualism: Brings benefits to both partners.
Commensalism and Tenants: In this, one species benefits and the other is indifferent.

Temperature: The temperature of the atmosphere varies greatly depending on whether it is day or night and the season. Latitude and altitude changes are accompanied by changes in temperature.
Living Things and Temperature: Organisms cannot survive temperatures over 50ºC or below 0ºC. Organisms are classified according to the heat source that determines body temperature:
- Ectotherms: If the temperature of your body depends on an external heat source.
- Endotherms: If they can control their temperature by producing heat inside their bodies.
Humidity: The amount of water vapor the air contains. The amount of water vapor in a volume of air is called absolute humidity. Relative humidity is defined as the ratio between the amount of water in a gaseous state that an air volume contains and the maximum amount that it could contain at the same temperature.
Living Things and Water: Land animals lose water through evaporation and can incorporate it to replace it with food or drinking water. They also eliminate waste water. Plants can incorporate water through the roots and reduce the size of their leaves with a wax coating.