New checklist by Keralam research team records 3,261 flowering plant species in Agasthyamalai Biosphere Reserve

Environment & Ecology · 22 September 2026 · Based on The Hindu (original report)

Worth reading — 1 past UPSC question on this theme (Prelims GS-1 2019).

2-minute summary

A research team from the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI) has compiled a comprehensive checklist of 3,261 flowering plant species in the Agasthyamalai Biosphere Reserve (ABR), located in the southern Western Ghats across Kerala and Tamil Nadu. The study documents high endemism, with 1,018 taxa endemic to India (including 245 steno-endemic species restricted to highly specialized habitats). It also highlights strong biogeographical affinities, sharing 347 taxa with Sri Lanka and 102 with tropical America. The findings underscore ABR's role as an evolutionary refugium and active speciation center, while calling for urgent, region-specific conservation strategies to counter threats like habitat fragmentation, climate change, and biological invasions.

Why it's in the news

A research team from the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI) has published a comprehensive checklist of 3,261 flowering plant species in the Agasthyamalai Biosphere Reserve. Published in the journal 'Plant Science Today', this study resolves historical taxonomic inconsistencies and highlights the reserve's global ecological significance.

Facts to remember

• A research team from the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI) compiled a checklist of 3,261 flowering plant species in the Agasthyamalai Biosphere Reserve.
• The Agasthyamalai Biosphere Reserve was established in 2001, is located at the southernmost end of the Western Ghats, and was included in UNESCO's World Network of Biosphere Reserves in 2016.
• Article 51A(g) outlines the Fundamental Duty of every citizen to protect and improve the natural environment including forests, lakes, rivers, and wildlife.

Background and context

The Agasthyamalai Biosphere Reserve (ABR) was established in 2001 and is located at the southernmost end of the Western Ghats, straddling Kerala and Tamil Nadu. In 2016, it was included in UNESCO's World Network of Biosphere Reserves. ABR is renowned for its unique microclimate, high rainfall, and diverse forest types ranging from tropical wet evergreen forests to grasslands. It is home to several indigenous tribes, such as the Kanikkaran. Over the years, taxonomic inconsistencies and varying nomenclatures have complicated conservation efforts. This new checklist by JNTBGRI resolves these discrepancies by synthesizing classical flora with modern taxonomic databases, providing a robust scientific baseline to address contemporary ecological threats like invasive species and climate change.

Constitutional provisions

• Article 48A — Directive Principles of State Policy (DPSP) directing the State to protect and improve the environment and safeguard forests and wildlife.
• Article 51A(g) — Fundamental Duty of every citizen to protect and improve the natural environment including forests, lakes, rivers, and wildlife.

Committees and reports

• Western Ghats Ecology Expert Panel (WGEEP) Report (Madhav Gadgil Committee) — Recommended designating the entire Western Ghats as an Ecologically Sensitive Area (ESA) with varying levels of environmental protection.
• High-Level Working Group on Western Ghats (Kasturirangan Committee) — Recommended designating 37% of the Western Ghats as ecologically sensitive, balancing conservation with sustainable development.

Government schemes

• Biosphere Reserve Scheme — Provides financial assistance for conservation, research, and monitoring activities in designated biosphere reserves across India.

International organisations

• UNESCO Man and the Biosphere (MAB) Programme — An intergovernmental scientific program that designated the Agasthyamalai Biosphere Reserve as part of the World Network of Biosphere Reserves in 2016.

Previous UPSC questions on this theme

• Prelims GS-1 2019 — Which of the following are in Agasthyamala Biosphere Reserve? (a) Neyyar, Peppara and Shendurney Wildlife Sanctuaries; and Kalakad Mundanthurai Tiger Reserve (b) Mudumalai, Sathyamangalam and Wayanad Wildlife Sanctuaries; and Silent Valley National Park (c) Kaundinya, Gundla Brahmeswaram and Papikonda Wildlife Sanctuaries; and Mukurthi National Park (d) Kawal and Sri Venkateswara Wildlife Sanctuaries; and Nagarjunasagar-Srisailam Tiger Reserve

Mains practice: The Western Ghats are not only a global biodiversity hotspot but also an evolutionary refugium. In light of the recent floral checklist of the Agasthyamalai Biosphere Reserve, discuss the ecological significance and the biogeographical affinities of this region.

The Agasthyamalai Biosphere Reserve (ABR), located at the southern tip of the Western Ghats, is a globally recognized biodiversity hotspot. A recent comprehensive checklist by the JNTBGRI documenting 3,261 flowering plant species reaffirms ABR's status as one of the most significant centers of angiosperm diversity and endemism in the Indian subcontinent.

• **High Floral Richness and Endemism:** ABR hosts 190 plant families, with Fabaceae, Rubiaceae, Poaceae, and Orchidaceae being the most dominant. Crucially, 31.2% (1,018 taxa) of these are endemic to India, including 245 steno-endemic taxa restricted to highly specialized micro-habitats. This high endemism marks ABR as an active center of speciation and an evolutionary refugium for ancient lineages.

• **Biogeographical Affinities:** The flora of ABR exhibits strong biogeographical links. It shares 347 taxa with Sri Lanka, a connection attributed to Gondwanan history, historical land bridges during low sea levels, and shared climatic conditions. Additionally, 102 taxa show affinity with tropical American flora, indicating long-distance dispersal or historical naturalization.

• **Ecological Fragility and Threats:** The region faces severe pressures from habitat fragmentation, biological invasions, climate change, and anthropogenic activities. This threatens narrowly distributed, habitat-specific species.

• **Conservation Strategies:** To safeguard this heritage, there is an urgent need to transition from generic conservation to region-specific, science-based strategies. This includes ecological restoration, ex-situ conservation, and integrating classical taxonomy with molecular phylogenomics and ecological niche modeling.

In conclusion, protecting ABR requires a collaborative approach combining scientific research with community-led initiatives. Preserving this unique evolutionary refugium is vital for maintaining ecological stability and genetic diversity in the face of global climate change.

Prelims practice questions

Q1. With reference to the Agasthyamalai Biosphere Reserve (ABR), consider the following statements: 1. It is located at the southernmost extremity of the Western Ghats, straddling Kerala and Tamil Nadu. 2. It is included in the UNESCO World Network of Biosphere Reserves. 3. The reserve exhibits a high degree of floral endemism and shares significant biogeographical affinities with Sri Lanka. Which of the statements given above are correct?

1. 1 and 2 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3

Answer: D. All three statements are correct. ABR is located in Kerala and Tamil Nadu, was included in UNESCO's MAB network in 2016, and shares 347 floral taxa with Sri Lanka due to historical land connections and Gondwanan history.

Q2. According to the recent checklist compiled by the JNTBGRI, which of the following plant families is the most species-rich in the Agasthyamalai Biosphere Reserve?

1. Rubiaceae
2. Poaceae
3. Orchidaceae
4. Fabaceae

Answer: D. The research documented that Fabaceae is the most species-rich family with 349 taxa, followed by Rubiaceae (194), Poaceae (193), and Orchidaceae (168).

Q3. Which of the following protected areas are located within the Agasthyamalai Biosphere Reserve? 1. Neyyar Wildlife Sanctuary 2. Peppara Wildlife Sanctuary 3. Shendurney Wildlife Sanctuary 4. Kalakad Mundanthurai Tiger Reserve Select the correct answer using the code given below:

1. 1, 2 and 3 only
2. 2, 3 and 4 only
3. 1 and 4 only
4. 1, 2, 3 and 4

Answer: D. All four protected areas—Neyyar, Peppara, and Shendurney Wildlife Sanctuaries in Kerala, and the Kalakad Mundanthurai Tiger Reserve in Tamil Nadu—are integral parts of the Agasthyamalai Biosphere Reserve.

Revision flashcards

• What is the geographical location of the Agasthyamalai Biosphere Reserve (ABR)? It is located at the southern extremity of the Western Ghats, straddling the states of Kerala and Tamil Nadu in South India.
• When was the Agasthyamalai Biosphere Reserve included in the UNESCO World Network of Biosphere Reserves? It was included in the UNESCO World Network of Biosphere Reserves in 2016.
• What are the four biosphere reserves located in South India? Nilgiri Biosphere Reserve, Gulf of Mannar Biosphere Reserve, Seshachalam Hills Biosphere Reserve, and Agasthyamalai Biosphere Reserve.
• What is a 'steno-endemic' taxon? A species or taxon that is confined to highly specialized, extremely narrow geographical habitats. The ABR checklist recorded 245 such taxa.
• Why does the flora of Agasthyamalai Biosphere Reserve share strong biogeographical affinity with Sri Lanka? Due to historical land connections during periods of lower sea levels, a shared Gondwanan evolutionary history, and long-term climatic similarities.