CORRESPONDENCE

Globally threatened in

Mangroves are uniquely adapted coastal September. The species is disappearing Mangrove forests in India are endowed of great ecological and economic due to absence of freshwater and low with 125 species, accounting for significance, but their habitat continued seed viability. 56% of the world’s mangrove species; of to disappear globally at a rate of 0.66% S. griffithii Kurz. (family Sonnera- which 39 are true and 86 are per year during the 2000–2005 period1. tiaceae; local name ‘Orua chakada’ in mangrove associates. Species of man- This habitat loss has put at least 40% of Orissa) is found rarely at the muddy grove associates comprise 30 trees, 24 the animal species that are restricted to banks of estuarine mouths under tidal shrubs, 18 herbs, 6 climbers, 4 grasses mangrove habitat at an elevated risk of inundation in , Orissa and and 4 epiphytes6. extinction under the International Union Andaman Islands. This species has numer- It is necessary to collate comprehen- for Conservation of Nature (IUCN) cate- ous, short, corky pneumatophores and sive species-specific information for gories and criteria2. However, none of can be distinguished from other species mangroves of India; in the absence of the global mangrove plant species have of Sonneratia by its obovate leaves, large which, identification and implementation been entered in the IUCN Red List. Very solitary white flowers with white stamens of conservation priorities is difficult. It is recently, assessments of mangrove spe- and larger globose fruits with a depres- a matter of urgency to protect and propa- cies were made by 24 global mangrove sion at the apex. Flowering occurs during gate the two globally threatened species, workers including me, in two workshops, February–May and the fruiting during S. griffithii and H. fomes, to increase the one in 2007 in Dominica and the other in June and July. The species is rare and population size in their habitats. Re- 2008 in Philippines. The results pub- locally extinct due to low seed viability. search intervention is required to over- lished in PLoS ONE reveal that 11 of the B. tersa (L.) Kosterm. (family Tili- come the problem of low seed viability 70 mangrove species in the world (16%) aceae; local name ‘Lata Sundari’ in West in these species, as well in the natural are at an elevated threat of extinction3; of Bengal and ‘Lati Sundari’ in Orissa) is hybrids that occur in the families of which, only two species namely Son- found on the soft mud of intertidal estua- Rhizophoraceae and Sonneratiaceae and neratia griffithii (critically endangered) rine banks, commonly in West Bengal also in the ecological varieties of Avice- and fomes (endangered) exist and Orissa; but rarely in Andaman Islands nnia marina and Ceriops tagal. Further in India. Globally, all other mangrove and Godavari estuary of Andhra Pradesh. studies are required on the discontinuous species in India are in the IUCN category The species can be recognized in the distribution and occurrence of mangroves of least concern and only one species, field by its greyish brown branches, along coastal India. Brownlowia tersa is in the category of lanceolate leaves with dull silvery under- near threatened species. In spite of grow- surface, and pear-shaped woody fruits 1. FAO, Forestry Paper No. 153, Rome, 2007, p. 77. ing threats to mangroves, its forest cover with two valved carpels. Flowering and 2 2. Luther, D. and Greenburg, R., Bioscience, increased by 58 km between 2005 and fruiting occur during July–October. The 2009, 59, 602–612. 4 2007 in India . species is experiencing severe loss at its 3. Polidoro, B. A. et al., PLoS ONE, 2010, H. fomes Buch.-Ham. (family Ster- range margins and is near-threatened. 5(4), 1–10. culiaceae; local names ‘Sundari’ in West Of special interest is Rhizophora an- 4. SFR, Forest Survey of India 2007, State of Bengal and ‘Bada Sundari’ in Orissa) is namalayana Kathir., which is endemic to Forest Report, Dehradun, 2009, pp. 27–31. abundantly present in Bhittarkanika of the Pichavaram mangroves in south-east 5. Kathiresan, K., Environ. Ecol., 1999, 17, Orissa, but rarely in Sundarbans of West India5 and it is included in the global list 500–501. 6. Kathiresan, K., Rajendran, N., Nabeel, M. Bengal especially at the borders near of mangrove species1. Its population is A., Thiruneelakandan, G., Manivannan, S. Roymongal block towards Bangladesh. estimated at 170 individual trees, 9–12 m and Kavitha, S., In Conservation and Man- This species occurs in upstream, land- in height with broad, dark green leaves agement of Mangroves in India (Zoologi- ward fringes of low saline areas. This and well-developed stilt roots. It is a cal Survey of India), 2009, pp. 105–127.

species has well-developed buttresses, natural hybrid derived from two parental numerous peg-like pneumatophores or species of R. mucronata and Rhizophora K. KATHIRESAN blind root suckers and can be distin- apiculata. The species rarely produces guished by its shining silvery scales on seeds, making its propagation very diffi- Centre of Advanced Study in Marine lower surface of leaves, sub-globose cult. However, such hybrids were not as- Biology, fruits with longitudinal and transverse sessed as the IUCN Red List Guidelines Annamalai University, ridges. Flowering occurs during January– generally exclude all plant hybrids for Parangipettai 608 502, India September and the fruiting during May– assessment3. e-mail: [email protected]

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