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Q49 (IAS/1996) Environment & Ecology › Ecology & Ecosystem Basics › Mangrove ecosystems Answer Verified

Assertion (A) : Mangroves are very specialised forest ecosystems of tropical and subtropical regions bordering certain sea coasts. Reason (R) : They stabilise the shoreline and act as bulwark against encroachments by sea. In the context of the above two statements, which one of the following is correct ?

Result
Your answer: —  ·  Correct: B
Explanation

Both Assertion and Reason are true: mangroves are distinctive coastal forest communities confined to tropical and subtropical tidal coasts, estuaries and muddy shores [1], and they are recognised littoral formations with salt‑tolerant trees and shrubs [3]. The stabilising role stated in R is a valid ecosystem service — mangrove prop roots and pneumatophores impede water flow, enhance sediment deposition, prevent coastal erosion and reduce inundation from storms and tsunamis [2]. However, R does not explain why mangroves are “specialised forest ecosystems” (that status derives from their morphological and physiological adaptations to intertidal, saline conditions), so the Reason is not the explanatory cause of the Assertion.

Sources

  1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 4: BIODIVERSITY > MAngrove (forests). > p. 49
  2. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 4: Aquatic Ecosystem > 4.8. MANGROVES > p. 47
  3. [2] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 4: Aquatic Ecosystem > 4.8.2. Role of mangroves > p. 48
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