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Ragavan P.,Institute of Forest Genetics and Tree Breeding | Mohan P.M.,Pondicherry University | Sxaena A.,Indira Gandhi National Forest Academy | Prasanth R.S.,Institute of Forest Genetics and Tree Breeding | Saravanan S.,Institute of Forest Genetics and Tree Breeding
Biodiversitas | Year: 2014

Sonneratia lanceolata, Sonneratia x urama and Sonneratia x gulngai was collected from Great Nicobar Island, which representing a new addition to the mangrove flora of India. S. lanceolata is distinguished from S. caseolaris by its drooping branches, lanceolate leaves and ovoidal bud without medial constriction. S. x urama and S. x gulngai are putative hybrids. S. x urama is putative hybrid between S. alba and S. lanceolata, whereas S. x gulngai is putative hybrid between S. alba and S. caseolaris. A detailed description along with colour plate and relevant notes is provided for further collection and identification of these species in the field. © 2014, Society for Indonesian Biodiversity. All rights reserved.


Ragavan P.,Pondicherry University | Saxena A.,Indira Gandhi National Forest Academy | Mohan P.M.,Pondicherry University | Jayaraj R.S.C.,Pradesh | Saravanan S.,Institute of Forest genetics and Tree breeding
Journal of Coastal Conservation | Year: 2015

Abstract: The present study was carried out to determine the diversity, distribution and vegetative structure of mangroves of the Andaman and Nicobar Islands (ANI). The results suggest that mangroves of the ANI consist of 38 mangrove species belonging to 12 families and 19 genera, which includes 4 hybrids and 34 species. In other words, about 50% of the global mangrove species are present in ANI. Andaman Islands have 35 species and Nicobar Islands have 21 mangrove species. The average tree density in ANI is 1746/per hectare and varies from 487 to 2383 per hectare. The Shannon diversity index for the whole ANI is 2.94 and Simpson index is 0.07. Family Rhizophoraceae constitutes an important vegetative component in the mangroves of the ANI followed by Acanthaceae, Lythraceae and Malvaceae. Rhizophora spp. constitutes 19% of the Important Value Index (IVI) and R. apiculata is dominant in ANI. Among the eight forest divisions, mangrove diversity is high in South Andaman (30 species) followed by Middle Andaman (28), Mayabunder (25), Diglipur (25), Nicobar (21), Little Andaman (20), Havelock (20) and Baratang (20). The average mangrove plant density and Shannon diversity index (H’) is high in Middle Andaman (2101/hectare; H’ = 2.93). Species richness index (d’) is high in South Andaman (3.32). Evenness index (J’) is high in Little Andaman (0.92). Simpson dominance index (D) ranged between 0.07–0.1, and this agrees with the high diversity in mangroves of ANI. In all the divisions Rhizophora spp. constitutes a major vegetative component except, Diglipur and Nicobar. In Diglipur Bruguiera spp. are dominant, while in Nicobar Sonneratia spp. are dominant. The low similarity value of the Nicobar division with other divisions indicates the difference in floristic structure of mangroves of the Andaman Islands and Nicobar Islands. The present study also indicates that mangrove of ANI are more diverse in its species composition than the other mangrove habitats in India. © 2015, Springer Science+Business Media Dordrecht.


Qayum A.,Jawaharlal Nehru University | Qayum A.,Indira Gandhi National Forest Academy | Arya R.,Jawaharlal Nehru University | Kumar P.,Nepalganj Medical College | Lynn A.M.,Jawaharlal Nehru University
Malaria Journal | Year: 2015

Background: Malaria is a major health problem in the tropical and subtropical world. In India, 95% of the population resides in malaria endemic regions and it is major public health problem in most parts of the country. The present work has developed malaria maps by integrating socio-economic, epidemiology and geographical dimensions of three eastern districts of Uttar Pradesh, India. The area has been studied in each dimension separately, and later integrated to find a list of vulnerable pockets/villages, called as malarial hotspots. Methods: The study has been done at village level. Seasonal variation of malaria, comparison of epidemiology indices and progress of the medical facility were studied. Ten independent geographical information system (GIS) maps of socio-economic aspects (population, child population, literacy, and work force participation), epidemiology (annual parasitic index (API) and slides collected and examined) and geographical features (settlement, forest cover, water bodies, rainfall, relative humidity, and temperature) were drawn and studied. These maps were overlaid based on computed weight matrix to find malarial hotspot. Results: It was found that the studied dimensions were inter-weaving factors for malaria epidemic and closely affected malaria situations as evidenced from the obtained correlation matrix. The regions with water logging, high rainfall and proximity to forest, along with poor socio-economic conditions, are primarily hotspot regions. The work is presented through a series of GIS maps, tables, figures and graphs. A total of 2,054 out of 8,973 villages studied were found to be malarial hotspots and consequently suggestions were made to the concerned government malaria offices. Conclusion: With developing technology, information tools such as GIS, have captured almost every field of scientific research especially of vector-borne diseases, such as malaria. Malarial mapping enables easy update of information and effortless accessibility of geo-referenced data to policy makers to produce cost-effective measures for malaria control in endemic regions. © 2015 Qayum et al.; licensee BioMed Central.


Das D.J.,Arid forest Research Institute | Saxena A.,Indira Gandhi National Forest Academy | Roy P.S.,Indian Institute of Remote Sensing | Roy P.S.,University of Hyderabad
Tropical Ecology | Year: 2016

The present study aims at estimating above ground woody forest biomass carbon stock of Kolasib district, Mizoram based on both ‘planimetric’ as well as ‘surface area’. Surface area is the actual available area for plants and animals of a region for their establishment and development. Geo-referenced orthorectified satellite image (Landsat ETM+) of the year 2001 was classified following hybrid method. The planimetric classified map was then integrated with slope map to get the surface area of each land use/cover. The planimetric area of Kolasib district is 1,382 km2, whereas surface area was estimated as 1,490 km2. The total above ground woody biomass carbon estimated as per planimetric and surface area were 2,404 and 2,587 thousand tonne, respectively with a net difference of 183 thousand tonne. This study, therefore, accentuates the surface area based estimation of biomass carbon in regional and global scale to understand the forestry options to mitigate climate change. © International Society for Tropical Ecology.


Ragavan P.,Pondicherry University | Saxena M.,Andaman and Nicobar Island Forest plantation and Development Corporation Ltd | Saxena A.,Indira Gandhi National Forest Academy | Mohan P.M.,Pondicherry University | And 3 more authors.
Indian Journal of Geo-Marine Sciences | Year: 2014

Actual number of mangrove species found in the Andaman and Nicobar Islands outnumber the number of species recorded to occur there. Present study consists reviewing the literature on mangrove floral composition and distribution as well as highlighting the causes of such apparently large species numbers and apparently incorrect identification of some of the mangrove species in the Andaman and Nicobar islands. Mangrove survey indicates that there are 33 exclusive 'mangrove species', at least 27 'mangrove associates' that occur on the islands.


Ragavan P.,Pondicherry University | Saxena A.,Indira Gandhi National Forest Academy | Jayaraj R.S.C.,Arid forest Research Institute | Ravichandran K.,Haddo | And 2 more authors.
Botanica Marina | Year: 2015

A recent floristic survey revealed the occurrence of three species of Xylocarpus in the Andaman and Nicobar Islands, India. Of these, Xylocarpus granatum and X. moluccensis are true mangrove species, whereas X. rumphii is a non-mangrove species. All three Xylocarpus species were recorded from the Andaman Islands, but none of them have been recorded from the Nicobar Islands. The key distinguishing characters of X. granatum, X. moluccensis and X. rumphii are described to resolve the nomenclatural ambiguity of Xylocarpus spp. in the Andaman and Nicobar Islands. © 2015 by De Gruyter 2015.


Qayum A.,Jawaharlal Nehru University | Qayum A.,Indira Gandhi National Forest Academy | Arya R.,Jawaharlal Nehru University | Lynn A.M.,Jawaharlal Nehru University
BMC Research Notes | Year: 2016

Background: Considering the demand of antimalarial plants it has become essential to find and locate them for their optimal extraction. The work aims to find plants with antimalarial activities which were used by the local people; to raise the value of traditional knowledge system (TKS) prevalent in the study region; to compile characteristics of local plants used in malaria treatment (referred as antimalarial plants) and to have its spatial distribution analysis to establish a concept of geographical health. Methods: Antimalarial plants are listed based on literature survey and field data collected during rainy season, from 85 respondents comprised of different ethnic groups. Ethno-medicinal utilities of plants was extracted; botanical name, family, local name, part used, folklore, geographical location and image of plants were recorded after cross validating with existing literatures. The interview was trifurcated in field, Vaidya/Hakims and house to house. Graphical analysis was done for major plants families, plant part used, response of people and patients and folklore. Mathematical analysis was done for interviewee's response, methods of plant identification and people's preferences of TKS through three plant indices. Results: Fifty-one plants belonging to 27 families were reported with its geographical attributes. It is found plant root (31.75 %) is used mostly for malaria treatment and administration mode is decoction (41.2 %) mainly. The study area has dominance of plants of family Fabaceae (7), Asteraceae (4), Acanthaceae (4) and Amaranthaceae (4). Most popular plants found are Adhatoda vasica, Cassia fistula and Swertia chirata while % usage of TKS is 82.0 % for malaria cure. Conclusion: The research findings can be used by both scientific community and common rural people for bio-discovery of these natural resources sustainably. The former can extract the tables to obtain a suitable plant towards finding a suitable lead molecule in a drug discovery project; while the latter can meet their local demands of malaria, scientifically. © 2016 Qayum et al.


Ragavan P.,Pondicherry University | Jayaraj R.S.C.,Arid forest Research Institute | Saxena A.,Indira Gandhi National Forest Academy | Mohan P.M.,Pondicherry University | Ravichandran K.,Andaman and Nicobar Administration
Taiwania | Year: 2015

In India, Rhizophora hybrids have been recorded in Pichavaram (Tamil Nadu) and in the Andaman and Nicobar Islands (ANI). Rhizophora hybrids in Pichavaram mangrove forest were identified as Rhizophora × annamalayana, a cross between R. apiculata and R. mucronata, whereas Rhizophora hybrids in the ANI were identified as Rhizophora× lamarckii, a cross between R. apiculata and R. stylosa. However taxonomical distinction between them was not much explored. A recent floristic survey revealed the occurrence both R. × annamalayana and R. × lamarckii in the ANI, India. Based on critical analysis of specimens and morphometric analysis, it was found that both R. × lamarckii and R. × annamalayana can be distinguished from R. apiculata by their smooth green bract and bracteoles and 2-4 flowered inflorescences within the leaf axils. Rhizophora × annamalayana is distinguished from R. × lamarckii by its broader leaves (length: width ratio <1.8 vs >1.8), and shorter style (<1.5 mm vs. > 1.5 mm) and stamens in two whorls vs. usually in a single whorl. Rhizophora × annamalayana is the new record from the ANI. Higher relative density of R. × annamalayana than R. × lamarckii in the ANI is attributed to the abundance of its parental species (R. apiculata and R. mucronata) in the ANI. © 2015 College of Life Science. All rights reserved.


Ragavan P.,Pondicherry University | Mohan P.M.,Pondicherry University | Saxena A.,Indira Gandhi National Forest Academy | Jayaraj R.S.C.,Arid forest Research Institute | And 2 more authors.
Marine Biodiversity | Year: 2016

The mangroves of the Andaman and Nicobar Islands (ANI) are recognized as the best in the country in terms of density and growth. However, considerable disparities still exist in the species composition and classification of mangrove species in the ANI. Further, taxonomical identity and occurrence of certain mangrove species in the ANI remain imprecise. Considering these facts, the present study was carried out to provide an updated checklist of true mangrove species of the ANI based on the extensive field surveys and perusal of the existing literature. Surveys were carried out in eight regions of the ANI and in each region, specific sites were selected based on representativeness, importance, and accessibility. Altogether, 51 sites were surveyed during 2009–2014. The results show that the mangroves of the ANI consist of 38 true mangrove species belonging to 13 families and 19 genera, which account for about 50 % of the global true mangrove species. The Andaman Islands have 35 and the Nicobar Islands have 21 true mangrove species. Among the eight regions, the mangrove diversity is high in South Andaman, followed by Middle Andaman, Mayabunder, Diglipur, Nicobar, Little Andaman, Havelock, and Baratang. Given their limited geographical area, the high similarity index values between the regions (>0.6) indicate the homogenous nature of mangrove diversity in the ANI and absence of impassable dispersal barriers. The Nicobar region exhibited low similarity with other regions (0.61–0.69). The changes in species numbers compared to earlier studies could mainly be attributed to the lack of extensive field survey in the past. Thus, periodical information on the extent and status of mangroves in the islands is imperative not only to improve our understanding of phytogeography, but also for better management and conservation. © 2016 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg


Ragavan P.,Pondicherry University | Saxena A.,Indira Gandhi National Forest Academy | Mohan P.M.,Pondicherry University | Jayaraj R.S.C.,Arid forest Research Institute | Ravichandran K.,Andaman and Nicobar Administration
Check List | Year: 2016

Brownlowia tersa, described by C.E. Parkinson from the Andaman Islands during the 1920s, was never recollected. The present report concerns its recent collection from North Andaman and Middle Andaman Islands with updated nomenclature, detailed description and distribution notes. It is considered a near threatened species due to habitat loss. © 2016 Check List and Authors.

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