Ecological System Overview

Ecological System

• An ecosystem is a community of living organisms (biotic factors) and non-living (abiotic) factors that interact with one another.
• It includes all of the living things (biotic factors) in a given area, such as plants, animals, and other organisms, as well as non-living components like rocks, temperature, and humidity.

Ecological Levels of Organization

• Ecology organizes its study of the interactions of living things and their environment into 6 levels of focus:
  • Population: a group of organisms that are genetically related and can breed to produce fertile young.
  • Community: composed of all of the biotic factors of an area.
  • Ecosystem: includes the biotic and abiotic factors in an area.
  • Biome: a large area classified according to the species that live in that location, characterized by temperature range, soil type, and the amount of light and water.
  • Biosphere: the part of the planet with living organisms, including part of the oceans and the atmosphere.

Types of Ecosystems

• Terrestrial ecosystems: land-based ecosystems, found on continents and islands.
• Freshwater ecosystems
• Marine ecosystems
• Desert ecosystems

Interactions in Ecosystems

• Biotic factors: the living organisms in an ecosystem, including producers, consumers, and decomposers.
• Abiotic factors: the non-living physical and chemical components of an environment, including temperature, light, water, wind, and fire.

Energy Flow through Ecosystems

• Food chain: a linear sequence of organisms through which nutrients and energy pass as one organism eats another.
• Food web: a network of interconnected food chains that shows the complex feeding relationships in an ecosystem.
• Energy transfer between trophic levels is inefficient, with a typical efficiency around 10%.

Organisms in Ecosystems

• Producers: organisms that make their own food, such as plants, algae, and some bacteria.
  • Photoautotrophs: use energy from sunlight to make food by photosynthesis.
  • Chemoautotrophs: use energy from chemical compounds to make food by chemosynthesis.
• Consumers: organisms that depend on other organisms for food, including herbivores, carnivores, omnivores, and decomposers.
• Decomposers: organisms that break down dead organic matter, including scavengers, detritivores, and saprotrophs.### Ecosystem
• A geographic area where plants, animals, and other organisms, as well as weather and landscapes, work together to form a bubble of life.
• Ecosystems contain biotic (living) and abiotic (non-living) factors.

Types of Ecosystems

• Terrestrial ecosystems: land-based ecosystems, found on continents and islands.
• Can be categorized based on chemical factors: pH, oxygen, and nutrients.

Decomposition

• When organisms die, they leave behind energy and matter.
• Decomposers (scavengers, detritivores, and saprotrophs) break down remains and release simple inorganic molecules back to the environment.

Energy Flow

• Energy is transferred between trophic levels in a food chain or web.
• Each organism occupies a different trophic level, defined by how many energy transfers separate it from the basic input of the chain.
• Energy transfer is inefficient, with a typical efficiency around 10%.

Ecological Levels

• Population: a group of organisms that belong to the same species.
• Community: all biotic factors in an area.
• Ecosystem: biotic and abiotic factors in an area.
• Biome: a large area classified according to the species that live there.
• Biosphere: the part of the planet with living organisms.

Consumers

• Organisms that depend on other organisms for food.
• Herbivores: consume producers such as plants or algae.
• Carnivores: consume animals.
• Omnivores: consume both plants and animals.

Abiotic Factors

• Physical factors: temperature, light, water, and fire.
• Chemical factors: pH, oxygen, and nutrients.

Ecological Interactions

• Biotic factors interact with each other in various ways, such as predation, competition, and symbiosis.
• Abiotic factors influence the survival and growth of organisms.

Ecology

• The study of the interactions between organisms and their environment.
• Interactions can be broadly categorized into two types: biotic and abiotic.### Ecological Organization Levels
• The lowest ecological organization level is a species, which is a group of genetically related organisms that can breed to produce fertile young.
• A population is a group of organisms of the same species that live in the same area and interact with one another.
• A community is composed of all the biotic factors in an area, including plants, animals, and other organisms that interact with each other.
• An ecosystem includes the biotic and abiotic factors in an area, such as living organisms, weather, landscapes, and non-living components.
• A biome is a large area classified according to the species that live in that location, characterized by a specific climate, soil type, and amount of light and water.
• The biosphere is the part of the planet with living organisms, including part of the oceans and the atmosphere.

Energy Flow through Ecosystems

• Energy flows through ecosystems in a linear sequence, with each organism occupying a different trophic level, defined by how many energy transfers separate it from the basic input of the chain.
• Food chains are linear sequences of organisms through which nutrients and energy pass as one organism eats another.
• Food webs consist of many interconnected food chains and are a more realistic representation of consumption relationships in ecosystems.
• Energy transfer between trophic levels is inefficient, with a typical efficiency around 10%.

Decomposers and Decomposition

• Decomposers break down dead organic matter into simple inorganic molecules, releasing nutrients back to the environment.
• Scavengers consume the soft tissues of dead animals, while detritivores consume detritus, or dead leaves, animal feces, and other organic debris.
• Saprotrophs are the final step in decomposition, feeding on any remaining organic matter left after other decomposers do their work.

Types of Ecosystems

• Terrestrial ecosystems are land-based ecosystems, found on continents and islands, and can be further categorized based on factors such as climate, soil type, and amount of light and water.
• Examples of ecosystems include forests, grasslands, freshwater, marine, and desert ecosystems.

Abiotic Factors

• Abiotic factors are non-living physical and chemical components of an environment, including:
  • Temperature: the amount of heat in an environment.
  • Light: the amount and quality of light available.
  • Water: the amount and availability of water.
  • Wind: the movement of air.
  • Fire: the presence or absence of fire.
  • Salinity: the amount of dissolved salts in water.
  • pH: the acidity or alkalinity of an environment.
  • Oxygen: the amount of oxygen available.
  • Nutrients: the essential elements that organisms need to survive and grow.

Interactions between Biotic and Abiotic Factors

• Biotic and abiotic factors interact with each other, influencing the survival and growth of organisms in an ecosystem.
• Examples of interactions include:
  • Predation: one organism eating another.
  • Competition: organisms competing for resources.
  • Symbiosis: organisms living in close association with each other.