The Himalayan range is very rich in species diversity. Which one among the following is the most appropriate reason for this phenomenon?

The Himalayan range's exceptional species diversity is primarily attributed to its unique position as a confluence of different biogeographical zones. It serves as a transition belt where the Palaearctic and Indomalayan realms meet . The region encompasses ten distinct biogeographic zones and twenty-five provinces, including the Trans-Himalaya, North-West, West, Central, and East Himalaya [2]. This convergence allows for a diverse range of biotic provinces and biomes within a single mountain chain [2]. Furthermore, the extreme altitudinal variation—ranging from tropical foothills to alpine pastures and cold deserts—creates a vast variety of landforms and climates, supporting a unique wildlife assemblage of global conservation importance [5]. While factors like rainfall and human interference exist, the fundamental reason for the high richness is the overlap of these diverse biogeographical and floristic regions [3].

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 9: Indian Biodiversity Diverse Landscape > t d) Bio-geographic provinces. 'i > p. 153
2. [2] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 9: Indian Biodiversity Diverse Landscape > c) Bio-geographic Zones: > p. 152
3. [3] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 4: BIODIVERSITY > Biogeographic zones of India > p. 25
4. [5] https://portals.iucn.org/library/sites/library/files/documents/PAPS-006.pdf