Railway Science (Environment – Ecosystem & Ecology)

Examples of Biotic components (living things present in the ecosystem) - Producers, consumers, decomposers, and detritivores). Examples of Abiotic components (all non -living things present in the atmosphere, hydrosphere, and lithosphere) - Sunlight, air, precipitation, weather, water, temperature, humidity, altitude, minerals, and soil.

Energy Flow - The flow of energy through living organisms in an environment. The producers and consumers in the ecosystem are arranged into different feeding groups and are known as trophic level or the feeding level. The producers (plants) represent the first trophic level.
Herbivores (primary consumers) present the second trophic level. Primary carnivores (secondary consumers) represent the third trophic level. Top carnivores - Tertiary consumers. At the top of the system are the apex predators.

Ecosystems is a system in which a group of living organisms that live in and interact with each other in a specific environment.
It can be divided into two types: Natural Ecosystem (ponds, rivers, lakes, forests, etc.) and Artificial or Man Made Ecosystem (aquariums, agriculture fields, zoos, etc.).
The word Ecosystem coined by Sir Arthur G. Tansley, the word Ecology coined by Ernst Haeckel.

A food chain outlines who eats whom. A food web is all of the food chains in an ecosystem. Each organism in an ecosystem occupies a specific trophic level or position in the food chain or web. Energy transfer between trophic levels is inefficient—with a typical efficiency around 10%. This inefficiency limits the length of food chains.

Level 2 (Primary Consumers / Second trophic level / Herbivores) - Zooplankton, Grasshopper, cow. Level 1 (Producer / First trophic level / Plants) - Phytoplankton, grass, Tree.
Level 3 (Secondary Consumers / third trophic level / Carnivore) - Birds, fishes, wolves. Level 4 (Tertiary Consumers / Fourth trophic level / Top carnivores) - Man, Lion. Trophic level is the relative position of an entity in the food chain.

Predator - An animal that kills and eats other animals. The food chain of the given organism is - Grass (Producer) -> Grasshopper (primary consumer) -> Mouse (Secondary Consumer) -> Python (tertiary consumer) -> Eagle (final consumer).

Decomposers - Feed on dead things (dead plant materials such as leaf litter and wood, animal carcasses, and feces, etc.). Decomposers play a critical role in the flow of energy through an ecosystem.
They break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers. Producers - Convert water, carbon dioxide, minerals, and sunlight into the organic molecules.
Consumers - Animals that get their energy by eating plants or other animals.

The atmosphere is a mixture of gases that surrounds the Earth. It helps make life possible by providing us with air to breathe, shielding us from harmful ultraviolet (UV) radiation coming from the Sun.

Food chain - A linear sequence of organisms where nutrients and energy is transferred from one organism to the other. Four major parts of the food chain - Sun, Producers, Consumers and Decomposers.

Protected areas are regions or zones of land or sea which are given certain levels of protection for conservation of biodiversity and socio -environmental values. Six Protected Area Management Categories.
Category I a (Strict Nature Reserve), Category I b (Wilderness Area), Category II (National Park), Category III ( Natural Monument or Feature), Category IV (Habitat/Species Management Area), Category V (Protected Landscape /Seascape), Category VI (Protected Area with sustainable use of natural resources). The Wildlife (Protection) Act of 1972 (WLPA) established the concept of a protected area (PA).