Ecosystems: Components, Factors, and Species Interactions
An ecosystem is much like the community or biocenosis and the biotope in which it lives. It includes forms from different populations that interact among themselves and with the physical environment that surrounds them, reproducing and perpetuating the whole.
Key Ecological Concepts
Understanding Biocenosis (Community)
Biocenosis, or Community: A group of individuals living in a given area.
Defining Biotope
Biotope: The place or physical environment occupied by a community.
Biotic Factors in Ecosystems
Biotic factors appear as a result of the presence of other living beings, such as the struggle for food or space.
Abiotic Factors and Their Influence
Abiotic factors do not rely directly on living beings, although their capacity can modify them.
Environmental Factors Affecting Life
Species Dependence and Tolerance Limits
- Optimal Area: Where species grow faster and survive better.
- Tolerance Limit: Beyond this limit, the survival of organisms and the population becomes impossible, potentially leading to their disappearance.
- Limiting Factors: These are growth factors that hinder or restrict development.
Temperature’s Role in Organism Survival
Temperature is a critical environmental factor.
- Homeotherms: Organisms that maintain a constant internal body temperature.
- Poikilotherms: Organisms whose body temperature depends on external sources of heat.
Understanding Humidity
Humidity is the amount of water vapor present in the air. In the SI system, it can be expressed in grams of water per cubic meter of air, or as a percentage of the total moisture the air can hold at a given temperature.
Life in Aquatic Environments
Salinity: A Key Aquatic Factor
Salinity refers to the content of salts dissolved in a liquid, particularly in water. Technically, salinity can refer to the dissolved salt content in interstitial water or soluble salts in soils. In oceanography, salinity is a well-defined magnitude referring to the amount of dissolved salts in seawater. This scale, along with temperature, determines water density and is traditionally used to calculate ocean current magnitudes.
Temperature Dynamics in Water
Temperature differences are less pronounced in aquatic environments than in terrestrial ones. The amount of oxygen water carries depends on temperature. Temperature differences also create currents that redistribute nutrients and oxygen.
Interactions Among Organisms
Competition for Resources
Competition refers to the rivalry between two or more entities for something. Normally, competition occurs between different organisms that coexist in an environment with limited resources. For example, animals compete for water, food, or a mate. Humans also compete for recognition, wealth, or recreation.
The Power of Cooperation
Cooperation is the pooling of methods to achieve goals that meet collective needs. In a successful partnership, success always depends on others. It works by joining forces and leveraging the various talents of each group member. It differs from competition, where individuals work independently and in isolation to achieve a goal before others. Cooperation can be forced or voluntary, allowing individuals or groups to cooperate even if they have nothing else in common. Examples include trade, military operations, workplaces, schools, and prisons – generally, any institution where individuals, voluntarily or by force, are part of a collective.
Predation: Predator-Prey Dynamics
In ecology, predation is an interspecific relationship where one species (the predator) hunts, kills, and consumes individuals of another species (the prey) for food. The same individual can be both a predator and prey to other organisms. In predation, one species (the prey) is harmed, while the other (the predator) benefits, facilitating energy transfer in the ecosystem.
Commensalism: One Benefits, Other Unaffected
Commensalism is a trophic relationship where one species benefits by feeding on food scraps or by using another species for shelter or transport, without harming or significantly benefiting the other species.
Mutualism: Beneficial Partnerships
Mutualism is an interspecific relationship where both interacting species benefit from the association. This interaction is crucial for the survival and reproduction of both organisms involved.
Symbiosis: Close Biological Interactions
Symbiosis is a close and long-term biological interaction between two different biological organisms. It is a type of interspecific relationship where both organisms are typically benefited, or at least one benefits without harming the other. Mutualism is often considered a type of symbiosis.