Research team documents 3,261 flowering plant species in Agasthyamalai reserve

Why in the News

A research team at the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Thiruvananthapuram, has compiled the first comprehensive checklist of the flowering plants of the Agasthyamalai Biosphere Reserve (ABR). The checklist records 3,261 species, 26 sub species and 28 varieties. It has been published in the journal Plant Science Today. The work reaffirms the global significance of the Western Ghats as a biodiversity hotspot. It also states a claim that follows from the data, that protection of the range requires focussed, region specific strategies rather than a uniform one.

What does the checklist actually record?

1. Taxa documented: The team documented 3,261 species, 26 sub species and 28 varieties in the Agasthyamalai Biosphere Reserve.
2. Taxonomic spread: Those taxa belong to 1,139 genera across 190 families.
3. Standing claim it supports: The scale of the reserve’s floral wealth upholds its position as one of the most significant centres of angiosperm diversity and endemism in the Indian subcontinent.
4. Publication: The checklist has been published in Plant Science Today as the Comprehensive checklist of the flowering plants of the Agasthyamalai Biosphere Reserve, South India.

Which families dominate the reserve’s flora?

1. Fabaceae leads: The legume family Fabaceae is the most species rich in the reserve with 349 taxa.
2. Rubiaceae: The coffee family Rubiaceae follows with 194 taxa.
3. Poaceae: The grass family Poaceae records 193 taxa.
4. Orchidaceae: The orchid family Orchidaceae records 168 taxa, and Paphiopedilum druryi, an orchid endemic to Agasthyamalai, sits within it.

What does the endemism pattern show?

1. Share endemic to India: A remarkably high level of endemism was recorded, with 1,018 taxa, or 31.2 per cent of the total, endemic to India.
2. Narrow range endemics: That figure includes 245 steno endemic taxa, meaning taxa confined to highly specialised habitats within a very small range.
3. What narrow endemism implies: A taxon restricted to one specialised habitat cannot relocate when that habitat is altered, so the loss of a single slope or stream margin can remove it entirely.

What do the shared taxa say about the reserve’s biogeography?

1. Affinity with Sri Lanka: The flora shows a strong biogeographic affinity with Sri Lanka, with the two regions sharing 347 taxa.
2. Explanations offered: The reasons range from historical land connections during periods of lower sea level, to a shared Gondwanan history, to long term climatic similarities.
3. A transatlantic element: 102 taxa display affinity with tropical American flora.
4. How that is explained: That pattern possibly reflects long distance dispersal events, or naturalisation after introduction by humans.

Why does a region specific checklist matter for conservation?

1. Baseline for protection: A complete inventory establishes what exists before change is measured, which is the precondition for any claim that a species has been lost.
2. Fragility of the landscape: The hill systems and vegetation of the reserve constitute a biologically unique yet ecologically fragile landscape.
3. Administrative spread: The reserve is spread over Keralam and Tamil Nadu, so any protection strategy has to work across two State administrations.
4. Position among reserves: The ABR is one of four biosphere reserves in south India, which places the checklist within a comparable set rather than as an isolated record.

Challenges to conserving the Agasthyamalai Biosphere Reserve

1. Fragmentation of the habitat: Plantation estates, roads and reservoirs cut continuous forest into blocks and isolate the populations of narrow range plants. Eg. Tea and cardamom estates in the Agasthyamalai landscape sit between the protected blocks of the reserve.
   The Fix: Notify and restore the identified corridor stretches between the reserve’s blocks as eco restoration zones under the State forest working plans.
2. Invasive species displacement: Introduced plants colonise disturbed ground and crowd out the endemic understorey that the checklist records. Eg. Lantana camara and Mikania micrantha have spread widely through Western Ghats forest margins.
   The Fix: Fund a scheduled removal and native replanting cycle at forest edges, with monitoring keyed to the checklist’s endemic taxa.
3. Collection pressure on high value taxa: Orchids and medicinal plants with narrow ranges face extraction for horticulture and for the herbal trade. Eg. Paphiopedilum druryi, endemic to Agasthyamalai, has been depleted by collection from the wild.
   The Fix: Place the steno endemic taxa on the State’s restricted collection list and pair it with nursery propagation at JNTBGRI to supply legitimate demand.
4. Split administration across two States: A single ecological unit managed by two State forest departments produces divergent rules on the same slope. Eg. The reserve is spread over Keralam and Tamil Nadu with separate working plans on each side.
   The Fix: Constitute a standing joint management committee for the reserve with a common monitoring protocol and a shared annual report.
5. Climate driven upslope shift: Warming pushes montane species upward, and taxa already at the summit ranges have nowhere to move. Eg. Shola grassland systems in the higher Western Ghats are already recording shifts in species composition.
   The Fix: Establish permanent altitudinal monitoring plots along the reserve’s elevation gradient, so range shifts are detected against the new baseline rather than inferred later.

Conclusion

The reserve now has a documented floristic baseline where it previously had none. The value of that baseline is that endemism can be located precisely, down to taxa confined to single specialised habitats, which is what makes uniform protection inadequate for this landscape. The finding the checklist leaves unresolved is how two State administrations manage one ecological unit against a single standard. What follows is whether the endemic taxa the list identifies are translated into a protected species schedule and a monitoring cycle.

Back2Basics: Agasthyamalai Biosphere Reserve

1. Designation: It was designated a biosphere reserve in 2001 and was added to the UNESCO World Network of Biosphere Reserves in 2016.
2. Location: It lies in the southern Western Ghats across Keralam and Tamil Nadu, and takes its name from the Agasthyamalai peak.
3. Constituent protected areas: It includes Neyyar, Peppara and Shendurney Wildlife Sanctuaries and the Kalakad Mundanthurai Tiger Reserve.
4. Cultural association: The Kani tribal community inhabits the landscape and its knowledge of the plant Trichopus zeylanicus produced India’s first benefit sharing arrangement for traditional knowledge.

Matching Previous Year Question

“[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 Brahme-swaram and Papikonda Wildlife Sanctuaries; and Mukurthi National Park (d) Kawal and Sri Venkateswara Wildlife Sanctuaries; and Nagarjunasagar-Srisailam Tiger Reserve | Answer: (a)”