Environment and Ecology

Environment

• Environment refers to the surroundings or conditions in which an organism lives or operates.
• It includes both living (biotic) and non-living (abiotic) components.

Components of Environment

• Abiotic factors: land, energy, water, climate, gases, winds, fire, gravity, and soil.
• Biotic components: living things in an ecosystem, such as plants, animals, and microorganisms.

Ecology

• Ecology is the study of organisms and their environment, as well as how they interact with each other and their environment.
• The term was coined by German biologist Ernst Haeckel.
• Ecology studies the relationships of individual organisms, populations, communities, ecosystems, biomes, and the biosphere.

Levels of Organization

• Individual: a single organism.
• Population: a group of individuals of the same species.
• Community: several interacting populations that inhabit a common environment.
• Ecosystem: a community and its abiotic factors.
• Biome: a region of the Earth with a specific climate and flora.
• Biosphere: the life-supporting portions of the Earth, comprising air, land, freshwater, and saltwater.

Ecosystem

• An ecosystem is a functional unit of nature where living organisms interact with each other and their environment.
• Structure and function of ecosystems: two main structural features are species composition and stratification (trophic structure).
• Each animal is present in a different trophic level.

Trophic Levels

• Producers (first trophic level): plants and algae that can synthesize glucose from carbon dioxide and water in the presence of sunlight.
• Consumers: organisms that obtain energy by eating other organisms.
• Herbivores (primary consumers): second trophic level.
• Carnivores and omnivores: third trophic level.
• Decomposers: break down dead organic matter, producing energy that is returned to the atmosphere.

Energy Flow in Ecosystem

• Energy is the capacity to do work and is the basic force responsible for running all metabolic activities.
• Energy flow in an ecosystem is unidirectional, from producer to consumer level.
• The main source of energy in an ecosystem is sunlight.
• About 80% of energy is lost during the flow of energy from one trophic level to the next.

Food Chain in Ecosystem

• A food chain is the transfer of energy from one trophic level to another in succession.
• A tropic level can be defined as the number of links by which it is separated from the producer or as the position of the organism in the food chain.
• Energy is transferred from primary producers to various components of heterotrophs, maintaining biodiversity.