3,261 Flowering Plant Species Identified in Agasthyamalai Biosphere Reserve; Western Ghats' Biodiversity and Endemism Highlighted
A new checklist by researchers from JNTBGRI records 3,261 flowering plant species in the Agasthyamalai Biosphere Reserve, spanning 1,139 genera and 190 families. The study identified 1,018 endemic and 245 steno-endemic taxa, underscoring the region's unique biodiversity and conservation significance. Fabaceae emerged as the most species-rich family, and 347 plant species found in Agasthyamalai are also present in Sri Lanka. Measures such as ex-situ conservation, seed banks, habitat restoration, and climate adaptation have been emphasized for the conservation of this Western Ghats region, which straddles Kerala and Tamil Nadu.
A new checklist prepared by researchers at the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Thiruvananthapuram, records 3,261 flowering plant species, 26 subspecies, and 28 varieties within the Agasthyamalai Biosphere Reserve (ABR). These plants belong to 1,139 genera and 190 families. The study was published in Plant Science Today in September 2026.
Endemism: A Key Indicator of Biodiversity:
The study identified 1,018 taxa (approximately 31.2%) as endemic to India, while 245 were classified as steno-endemic—species with a naturally restricted distribution range. Such species are highly vulnerable to habitat alteration, climate change, and anthropogenic pressures. Consequently, it is crucial to tailor conservation strategies for the Agasthyamalai region to suit local ecological conditions.
Major Plant Families and Biogeographical Affinities:
Fabaceae emerged as the richest family in terms of floral diversity, with 349 recorded taxa. It is followed by Rubiaceae (194), Poaceae (193), and Orchidaceae (168). The study also indicates strong biogeographical affinities between the flora of Agasthyamalai and Sri Lanka, with 347 taxa shared between the two regions. This is significant for studying the historical and biogeographical connections between the southern Western Ghats and Sri Lanka.
Geographical and Ecological Significance of Agasthyamalai Biosphere Reserve:
ABR is a crucial biodiversity region within the southern Western Ghats, spanning Kerala and Tamil Nadu. It hosts diverse ecosystems, including tropical forests, high-altitude Shola forests, and grasslands. The region falls within the Western Ghats biodiversity hotspot. Agasthyamalai Biosphere Reserve was notified in India in 2001 and included in UNESCO’s World Network of Biosphere Reserves in 2016.
Significance of the Study for Conservation:
The presence of species with high levels of endemism and restricted distribution makes Agasthyamalai a critically important area for conservation. Researchers have emphasized measures such as ex-situ conservation, seed banks, restoration of degraded forest areas, long-term monitoring, and climate change adaptation. This checklist can provide a scientific basis for future species monitoring, setting conservation priorities, and habitat restoration.
Significance for UPSC:
This news is directly relevant to Physical Geography and Biogeography (GS Paper-1) and Environment, Biodiversity, and Conservation (GS Paper-3). Key topics for the Preliminary examination include Agasthyamalai (Kerala/Tamil Nadu), the Western Ghats, UNESCO Biosphere Reserve, Shola-grasslands, Endemism, and Steno-endemism. For the Mains examination, this topic can be linked to the need for conservation due to high endemism in the Western Ghats, the impact of climate change on mountain ecosystems, and the concepts of in-situ and ex-situ conservation.
