Lakshadweep vs Andaman Islands: Biodiversity Differences Explained

This question asks us to identify the primary reason why the Lakshadweep Islands exhibit lower biodiversity when compared to the Andaman and Nicobar Islands. Biodiversity refers to the variety of life in a particular habitat or ecosystem. Several geographical and environmental factors influence biodiversity levels.

Factors Influencing Island Biodiversity

Key factors that contribute to the level of biodiversity in island ecosystems include:

• Land Area: Larger islands generally support more species because they offer a wider range of habitats and resources, and can sustain larger populations less prone to extinction.
• Habitat Availability: The presence of diverse habitats, such as forests, wetlands, and different soil types, allows for a greater number of ecological niches, supporting more species.
• Geological Origin: The way an island formed (e.g., volcanic activity, coral reef formation, continental fragments) influences its soil composition, topography, and subsequent colonization by species.
• Climate: Temperature, rainfall, and other climatic conditions play a crucial role in determining which species can survive and thrive.
• Isolation: While isolation can lead to unique species (endemism), extremely small or resource-poor islands may struggle to attract and maintain diverse life.

Comparing Lakshadweep and Andaman & Nicobar Islands

Let's examine the characteristics of both island groups in relation to these factors:

Lakshadweep Islands

• Geographical Origin: These are coral islands, primarily atolls formed on submerged volcanic ridges.
• Land Area: They consist of numerous small islands and islets, with a very limited total land area.
• Habitat: The islands have sandy soil, limited freshwater sources, and lack extensive, dense forests. Vegetation is often sparse, dominated by coconut palms.
• Biodiversity: Due to their small size, limited terrestrial habitats, and specific conditions associated with coral atolls, they generally support lower terrestrial biodiversity compared to larger, more diverse landmasses.

Andaman and Nicobar Islands

• Geographical Origin: These islands are believed to be extensions of the mountain ranges of Myanmar, with both sedimentary and metamorphic rocks, and some volcanic activity.
• Land Area: They form a larger archipelago with significantly greater land area compared to Lakshadweep.
• Habitat: The islands boast rich tropical rainforests, diverse vegetation, varied topography, and numerous freshwater bodies, creating a wide array of habitats.
• Biodiversity: The larger land area, diverse habitats (especially dense forests), and favorable tropical climate contribute to a significantly higher level of biodiversity, including numerous endemic species.

Evaluating the Options

Based on this comparison, let's look at the provided options:

1. Smaller land area and absence of forests: This option accurately describes key limitations of the Lakshadweep Islands that directly impact biodiversity. A smaller land area restricts the number of species that can be supported, and the lack of extensive forests means fewer terrestrial habitats are available compared to the Andaman and Nicobar Islands. This is a strong explanation.
2. Volcanic origin and infertile soil: While the Andaman and Nicobar Islands have some volcanic history, Lakshadweep are coral atolls. Coral origins themselves don't necessarily lead to low biodiversity. Furthermore, soil fertility is just one aspect; the lack of significant soil development and deep forest ecosystems is more impactful. This is less precise than option 1.
3. Higher human population density: While human activities can impact biodiversity, the primary difference in the *potential* for biodiversity between these two archipelagos stems from their fundamental physical characteristics (size, habitat type) rather than population density alone. The Andaman and Nicobar Islands also have significant populations and development.
4. Higher altitude and colder temperatures: Both island groups are located in tropical regions and do not have significantly high altitudes or cold temperatures that would be the primary reason for low biodiversity.

Conclusion

The most significant differentiating factor explaining the lower biodiversity in the Lakshadweep Islands compared to the Andaman and Nicobar Islands is their comparatively smaller land area and the general absence of extensive, dense forests, which limit the variety and number of available habitats for terrestrial species.