The transition zone where two distinct ecological communities meet and blend, such as between forest and grassland.

Why are ecotones important?

They frequently support higher species richness than either adjoining community, because species from both plus edge specialists occur together.

Ecotone

noun (countable)

/ˈiː.kəʊ.toʊn/

A transition zone between two adjacent ecological communities (biomes or ecosystems), such as the boundary between a forest and a grassland or between mangroves and open sea. Ecotones are characterised by the 'edge effect': higher species diversity and density than either adjacent community, since they host species from both communities plus specialist edge species. In UPSC ecology, ecotones are important for understanding biodiversity hotspots; the Sundarbans, for instance, represents an ecotone between terrestrial and marine environments.

✍️ Usage in a UPSC answer

The mangrove belt along India's Odisha coast functions as a critical ecotone, buffering the terrestrial hinterland from cyclonic storm surges while supporting a species assemblage distinct from either open ocean or inland forest.

Synonyms

transition zoneedge habitatboundary zoneecoclineinterface zone

Antonyms

biome interiorcore habitathomogeneous ecosystem

🌱 Word Family

ecotonal (adjective), edge effect (noun phrase), ecocline (noun), ecotype (noun)

🔡 Root

Greek oikos = house, habitat; Greek tonos = tension, stretching (related to teinein = to stretch)

📜 Etymology

Coined by American ecologist Frederic Clements in 1905, combining Greek oikos (habitat) with tonos (tension), capturing the idea of ecological tension where two communities meet and compete. The word reflects early 20th-century plant ecology's interest in community boundaries and succession dynamics.

🧠 Memory Hook

ECO (habitat) + TONE (tension/stretch). An ecotone is where two habitats are in 'tension' — imagine two tectonic plates pushing against each other. At the meeting edge, something special emerges: unusual species richness.

🎯 How This Word Works in UPSC Writing

The transition zone between two adjacent ecological communities, such as the boundary between forest and grassland or land and water. The concept that earns marks is the edge effect: ecotones often support greater species richness than either community alone, because organisms from both plus edge specialists occur together. That makes ecotones disproportionately important for conservation relative to their area.

⚖️ Don’t Confuse It With

An ecotone is a transition zone between communities. An ecocline is a gradual gradient without a defined boundary. An edge effect is the change in conditions and species composition at that boundary. A buffer zone is a management designation around a protected area rather than an ecological category.

🇮🇳 Hindi Meaning

पारिस्थितिक संक्रमण क्षेत्र (pāristhitik sankraman kshetra) or इकोटोन.

❓ Common Questions

What is an ecotone?: The transition zone where two distinct ecological communities meet and blend, such as between forest and grassland.
Why are ecotones important?: They frequently support higher species richness than either adjoining community, because species from both plus edge specialists occur together.

🌿 Environment & Ecology 📖 Seen in: Ecology Fundamentals — Ecosystems, Foo...

Relevant across:GS3 · Economy, Environment, S&T & Security

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