Ecosystem Dynamics: Biocenosis, Biotope, and Ecological Interactions
Ecosystem Dynamics
Biocenosis: A community of organisms living in a specific area.
Biotope: The physical environment where a biocenosis lives, characterized by its environmental conditions.
Ecosystem: The interaction between the biocenosis and its biotope, including all relationships between organisms and their environment.
Ecology: The scientific study of interactions between living organisms and their environment.
Habitat: The specific place where an organism finds the necessary conditions for life.
Factors Influencing Habitats
- Biotic Factors: Influences resulting from the presence and activities of other living organisms.
- Abiotic Factors: Non-living environmental conditions that affect living organisms.
Tolerance Limit: The range of environmental conditions within which an organism can survive.
Limiting Factors: Environmental factors that restrict the growth or distribution of a population.
Abiotic Factors
Temperature: Varies by day, night, altitude, and latitude.
- Ectotherms: Organisms whose body temperature depends on external heat sources.
- Endotherms: Organisms that can generate heat internally.
Humidity:
- Absolute Humidity: The amount of water vapor in a given volume of air.
- Relative Humidity: The ratio of the current water vapor content to the maximum possible at the same temperature.
Water Management:
- Terrestrial Animals: Obtain water through food and drink, and excrete concentrated waste.
- Plants: Lose water through aerial parts, absorb water through roots and leaves with waterproof wax linings.
Soil Texture:
- Sandy: Predominantly coarse particles.
- Clay: Very fine particles, poorly porous, and prone to waterlogging.
- Mixed: Intermediate characteristics.
Water Needs: Vary among organisms; some are hydrophilic (need much water), while others are drought-tolerant.
Air in Soil: Fills pores created by soil texture and biological activity.
Soil Composition and pH:
- Salty Soils: Some plants (halophytes) tolerate high salt concentrations.
- Neutral Soils: Generally favored by most plants.
- Acidic/Basic Soils: Some plants prefer more acidic or basic conditions.
Light:
- Euphotic Zone: Sufficient light for photosynthesis (up to 50m).
- Oligophotic Zone: Dim light.
- Aphotic Zone: Total darkness (below 500m).
Biological Interactions
Intraspecific Competition: Competition between individuals of the same species for resources.
Interspecific Competition: Competition between individuals of different species for the same resources.
Cooperation: Intraspecific interactions that benefit all involved (e.g., raising young, defense, food gathering).
Predation: Interspecific relationship where one organism (predator) consumes another (prey).
- True Predators: Kill and consume multiple prey.
- Grazers: Attack multiple prey but do not kill them, feeding on parts.
- Parasites: Live within or on a host, feeding slowly throughout their life, potentially causing death.
Mutualism: A relationship that benefits both organisms, sometimes essential for survival (symbiosis).
Commensalism: A relationship where one organism benefits, and the other is unaffected.
Inquilism: One organism uses another for shelter without affecting the host.
Ecological Niche: The role a species plays within its ecosystem.