BEVAE-181 Environmental Studies - Block 1 Vocabulary

Vocabulary flashcards covering key concepts, definitions, and terminology from Block 1 (Units 1-3) of the BEVAE-181 Environmental Studies course material.

Natural Environment

The sum total of living and non-living components, influences, and events surrounding an organism.

Determinism

An approach to human-environment relationship developed by Friedrich Ratzel stating that nature controls human and human life is subordinate to the physical environment.

Possibilism

An approach coined by Lucien Febvre indicating that the physical environment is passive and human beings are active agents free to choose among environmental possibilities.

Environmentalism

An ecological approach describing humans as an integral part of nature with a unique role in maintaining a healthy environment through restrained resource use.

Sustainable Development

Development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs, as defined by the Brundtland Commission.

Sustainability

The capacity to endure; a process which can be continued indefinitely without depleting the resource base on which it depends.

In-situ Conservation

The conservation of living organisms within their natural habitat situations.

Ex-situ Conservation

The conservation of living organisms outside of their natural habitats.

Ecosystem

A biosystem including all organisms functioning together in a given area, interacting with the physical environment so that energy flow leads to defined biotic structures and material cycling.

Biosphere

Also called the ecosphere, the narrow region of earth, water, and atmosphere extending up to $22.5\,km$ in height where life exists.

Autotrophs

Chlorophyll-bearing green plants and chemosynthetic bacteria that manufacture their own food from simple inorganic substances.

Heterotrophs

Organisms unable to make their own food that depend on other organisms to meet their energy needs for survival.

Saprotrophs

Microscopic heterotrophs, such as bacteria and fungi, that break down and decompose dead organic matter; also called decomposers or reducers.

Trophic Level

A position or step in a food chain or ecological pyramid occupied by a group of organisms sharing a similar feeding mode.

Food Chain

A linear sequence of links of organisms in which food energy is transferred as one organism eats another.

Grazing Food Chain

A food chain starting from green plants (producers) and passing to herbivores (primary consumers) and carnivores.

Detritus Food Chain

A food chain starting from dead organic matter (detritus) to microorganisms (detritivores) and subsequent predators.

Biogeochemical Cycling

The continuous circular movement of mineral nutrients from non-living to living and back to non-living components of an ecosystem.

Gaseous Cycle

A nutrient cycle where the primary reservoir is located in the atmosphere or hydrosphere, such as the water, carbon, or nitrogen cycles.

Sedimentary Cycle

A nutrient cycle where the primary reservoir is the Earth's crust, such as the sulphur, phosphorus, or calcium cycles.

Ecological Succession

The orderly, predictable process of community development or species replacement in an area over time.

Pioneer Community

The first group of organisms, such as lichens, to colonize a previously bare or uncolonized surface during primary succession.

Climax Community

The final, relatively stable stage of ecological succession in a community.

Seral Stage

An intermediate community stage in ecological succession progressing towards a climax community; also called a sere.

Primary Succession

Ecological succession initiated on a newly formed area that has never previously supported an ecological community.

Secondary Succession

Ecological succession occurring in an area where an existing community has been drastically disturbed or destroyed.

Silviculture

A branch of forestry concerned with the establishment, care, and reproduction of monocultures of valuable timber trees like teak and sal.

Neuston

Unattached aquatic organisms living at the air-water interface, such as water striders.

Periphyton

Aquatic organisms, mainly sessile algae and associated animals, that remain attached or clinging to stems and leaves of rooted plants or emerging surfaces.

Plankton

Microscopic floating aquatic plants (phytoplankton) and animals (zooplankton) whose distribution is controlled by water currents.

Nekton

Relatively large and powerful swimming aquatic animals capable of overcoming water currents, such as fish and whales.

Benthos

Organisms found living in or on the bottom floor of an aquatic ecosystem, such as crabs, sponges, and sea anemones.

Lentic Ecosystem

A standing or static fresh water ecosystem, including lakes, ponds, pools, swamps, and marshes.

Lotic Ecosystem

A running or flowing fresh water ecosystem, including rivers, streams, and brooks.

Estuary

A semi-enclosed coastal transitional zone between rivers and the sea containing brackish water where fresh water mixes with saltwater.

Phumdis

Heterogeneous floating masses of soil, vegetation, and organic matter found on Loktak Lake in Manipur, India.