Recent Development

The Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Thiruvananthapuram, has compiled a new checklist of flowering plants in the Agasthyamalai Biosphere Reserve (ABR), underscoring the global biodiversity significance of the Western Ghats — one of the world's eight 'hottest hotspots' of biological diversity.

Key Findings of the Study

  • Floral Diversity: The study documented 3,261 species, 26 subspecies and 28 varieties belonging to 1,139 genera and 190 families.
  • Endemism: A high level of endemism was recorded — 1,018 taxa (31.2%) are endemic to India, including 245 steno-endemic taxa (species restricted to specialised habitats).
  • Species-Rich Families:
  • Fabaceae — most species-rich family
  • Followed by Rubiaceae, Poaceae and Orchidaceae
  • Biogeographic Significance:
  • ABR shows strong floral affinity with Sri Lanka, sharing 347 taxa, due to historical geological and climatic connections (the land bridge between India and Sri Lanka).
  • Some species show affinity with tropical American flora, possibly due to long-distance dispersal or pan-tropical distribution patterns.

About Agasthyamalai Biosphere Reserve (ABR)

  • Location: Southern end of the Western Ghats, straddling Tamil Nadu and Kerala.
  • Area: Approximately 3,500 sq. km.
  • Biosphere Reserves in South India (four):
  1. Nilgiri Biosphere Reserve (first in India, 1986)
  2. Gulf of Mannar Biosphere Reserve
  3. Seshachalam Hills Biosphere Reserve
  4. Agasthyamalai Biosphere Reserve
  • UNESCO Recognition: Included in the UNESCO World Network of Biosphere Reserves in 2016.

Flora and Fauna

  • Neelakurinji (Strobilanthes kunthiana) — blooms once every 12 years — grows in this landscape.
  • Notable fauna: Lion-Tailed Macaque, Bengal Tiger, Nilgiri Marten, Nilgiri Tahr, Malabar Spiny Dormouse, Great Pied Hornbill, Gaur (Indian bison), Sloth Bear.

Tribal and Cultural Significance

  • The reserve is home to indigenous communities, notably the Kani tribe, who depend on the forest for livelihood and culture.
  • The Kanis are also associated with traditional knowledge (e.g., the Trichopus zeylanicus 'Arogyapacha' ethnobotanical benefit-sharing case under the Biological Diversity Act).

Conservation Concerns

  • Habitat fragmentation
  • Climate change
  • Biological invasions (invasive alien species)
  • Ecological degradation

Significance for India

  • Reinforces the Western Ghats' status as a biodiversity hotspot and the need for conservation planning.
  • Provides baseline data for policy-making, protected area management, and climate adaptation strategies.
  • Highlights the importance of integrating indigenous communities (Kani tribe) in conservation under frameworks like the Biological Diversity Act, 2002 and community-based conservation approaches.

Related Concepts for Revision

  • Biosphere Reserve structure: Core, Buffer and Transition zones; notified under the Man and Biosphere (MAB) Programme of UNESCO.
  • Western Ghats: One of 36 global biodiversity hotspots; recognised as a UNESCO Natural World Heritage Site (2012).
  • Endemism vs. Steno-endemism: Endemic species are restricted to a geographic area; steno-endemic species are restricted to very narrow, specialised habitats and are highly vulnerable to extinction.