Ecological Terms and Ecosystem Dynamics
Key Definitions in Ecology
Definitions:
- Aphotic: Total darkness area from 500m.
- Biocenosis: The set of populations living in a determined area.
- Biotope: Place or physical environment occupied by a community.
- Ectotherm: The main source of body heat depends on external sources.
- Endotherms: Control body temperature through the production of heat inside the body.
- Stenosis: Short interval of tolerance.
- Density: A factor that determines the size of the population.
- Euphotic: Area that receives sufficient light to perform photosynthesis.
- Eury: Large tolerance interval.
- Abiotic factors: Factors that are not directly dependent on the presence of other living beings.
- Biotic factors: Factors that arise as a result of the presence of other living things.
- Subsidiaries: Approach or need something.
- Phobia: Fear or rejection of something.
- Photic: Area of lighting or source of growth and food.
- Habitat: The place where a number of animals or living beings live.
- Hydrophilic: Water-intensive plants.
- Xeric: Plants that subsist on low water.
- Hygrophilous: It can absorb humidity.
- Homeotherms: Can control their body temperature.
- Ecological niche: The function that a species plays in an ecosystem.
- Oligophotic: Penumbra area.
- Poikilotherm: Cannot control body temperature.
- Tolerance: Ability to live outside the optimal range.
- Halophile: Plants that can withstand high salt concentrations.
Any plague organism is undesirable if it interferes, directly or indirectly, with humans.
Pesticides: The most utilized to combat plagues has been a chemical capable of killing organisms considered as undesirable.
Biological Rhythms
- Daily rhythms: Organisms comply with these periodic changes, alternating rest and activity, depending on the time of day.
- Seasonal rhythms: A variety of behaviors is associated with seasonal changes. In plants, the leaves fall, and the fruits mature. In animals, periods of reproduction, molting, or hibernation occur.
- Marine rhythms: Changes in sea level periodically affect the organisms living on the shores.
Trophic Levels in Ecosystems
- Producers: Autotrophs are organisms that manufacture their own organic matter from inorganic matter and use light energy.
- Consumers:
- Herbivores: Also called primary consumers, they feed on plants.
- Carnivores: Secondary consumers that feed on herbivorous animals.
- Omnivores: They feed on both plants and animals.
- Decomposers: These are heterotrophs that feed on detritus (remains of living organisms or excrement). Some animals, like the earthworm, are detritivores.
Energy Flow in Ecosystems
What do producers do with the organic matter produced in photosynthesis?
- A part is degraded during respiration. The energy released is used for the functioning of the body and returns to the environment as heat.
- Another part becomes waste, such as dead branches. These wastes go directly to the decomposers.
- The rest is stored in organic matter and organs. This matter can be used by the next trophic level, taken by herbivores. However, animals cannot consume all the organic matter stored by producers. This matter goes directly to the decomposers. Finally, a small part of the matter is transformed into the herbivore itself.
Ecosystem Productivity
The increase in biomass per unit of time is called production. Production can refer to a specific level or to the entire ecosystem:
- Net primary production: Refers to the increase in biomass of producers.
- Net secondary production: Refers to the increase in biomass at the different levels of consumers.
- Net ecosystem production: The increase in biomass that accumulates in an ecosystem in a given period.