Biodiversity is highest in

Biodiversity is not distributed uniformly across the globe; it follows a latitudinal gradient where species richness is consistently higher in the tropics. The tropical region, located between the Tropic of Cancer and the Tropic of Capricorn, contains the world's mega-diversity centers and biodiversity hotspots due to favorable climatic conditions like high rainfall and warmth [4]. Tropical forests alone are estimated to harbor approximately 50% of the world's terrestrial biodiversity [1]. In contrast, as one moves toward the polar regions, such as the Tundra zone, biodiversity decreases, resulting in larger populations of significantly fewer species. While the 'Torrid zone' is a traditional geographical term for the tropics, 'Tropic zone' (or the tropics) is the standard ecological and geographical designation used in modern scientific contexts to describe the area with the highest concentration of flora and fauna [t4].

Sources

1. [3] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > Biotic: Living > p. 125
2. [4] https://education.nationalgeographic.org/resource/five-major-types-biomes/
3. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 14: Biodiversity and Conservation > BIODIVERSITY AND CONSERVATION > p. 115