Exploring the bacterial community composition of soil from a tropical dry evergreen forest in Tamil Nadu, India

Metagenomics is a cutting edge omics technology that has been employed in various fields including novel product discovery, diagnostics, and pollutant monitoring. 16S metagenome amplicon sequencing is used for understanding the microbial diversity from various environments. Forest ecosystems have been known for the discovery of novel bacteria and also bacteria that produces novel compounds that are pharmaceutically and industrially relevant. In this study we try to show the bacterial community structure of the soil obtained from a tropical evergreen forest in India. We use 16s metagenomics sequencing and then follow it up with various analysis like alpha diversity analysis, to find out the dominant bacterial species found in these soils. Actinobacteria was found to be the most copmmonly found bacterial phylum followed by proteobacteria, firmicutes, chloroflexi, acidobacteria, verrucomicrobia, bacteroidetes, gemmatimonadetes, nitospirae and other unclassified organisms. Further studies can elucidate on the discovery of novel compounds from these bacteria.

Endemic Vascular Plants from the Coromandel Coast of Tamil Nadu, Southern India

Intensive botanical survey was done more than two decades on Tropical Dry Evergreen Forest from four coastal districts viz. Cuddalore, Kancheepurm, Nagai and Villupuram of Tamil Nadu and Union Territory of Pondicherry. A total of 87 protected (hillocks, reserve forest) and unprotected (sacred groves, unclassified vegetation) sites were regularly studied from five districts. From this study 82 endemic taxa were enumerated. In addition 25 endemic species were added for the analysis through literature screening and herbarium consultation from 10 Coromandel coastal districts of Tamil Nadu. In all 107 species were recorded, among them 19 are trees, 18 shrubs, 9 climbers and 61 herbs. Distribution of these endemic species were analysed and categorised into endemic to the country, peninsular India, southern India, Eastern and Western Ghats, state and district level. Interestingly the study found that some endemic species were disjunctly distributed in between districts, states, ghats, climatic regimes and bioregions. The disturbance, threat status and conservation measures of few endemic and IUCN red listed species were also studied and discussed.

Endemic plants of tropical dry evergreen forest, Southern India

During the last two decades of intensive botanical survey of the tropical dry evergreen forest, a total of 82 endemic taxa were found out of 1142 species enumerated from 85 sites in the three Coromandel Coastal districts of the state Tamil Nadu: Cuddalore, Kancheepurm and Villupuram, and in the Pondicherry district. Of 82 species, 17 are trees, 11 shrubs, 9 climbers and 45 herbs. Distribution of these endemic species was analyzed and categorised as endemic to the country, peninsular India, southern India, Eastern and Western Ghats, and at the state and district level. Interestingly, the study found that some endemic species were disjunctly distributed between districts, states, ghats, climatic regimes and bioregions. Anthropogenic disturbance and species threat status were also studied and discussed.

The characteristics, representativeness, function and conservation importance of tropical dry evergreen forest on India’s Coromandel Coast

The central area of the Coromandel Coast, southeastern India, has been subject to a very long history of human habitation and land use change, substantially reducing the coverage of native forest. There are polarised views about definitive characteristics of native tropical dry evergreen forest (TDEF), albeit agreement that the habitat type is locally characteristic though now severely reduced, fragmented and degraded. A literature review was undertaken to determine the evolutionary origins of TDEF as well as its characteristics. A combination of both natural and human factors gives rise to TDEF, explaining the heterogeneity of existing stands even in close proximity to each other. Religious shrines are often associated with ‘sacred groves’, which are influential in the survival of stands of TDEF. These remaining stands are highly fragmented across the wider landscape and subject to species invasions from adjacent habitats as well as increasing human pressures. On the basis of existing evidence, it is not possible to describe TDEF through a definitive community of tree species, though typical constituent species are listed. TDEF may therefore be representative of a larger biome, as for example ‘tropical rainforest’, rather than a specific vegetation type. Nevertheless, there is general consensus about the importance of restoring TDEF, including its many associated plant and animal species, many of which have medicinal, spiritual and other uses and meanings. Regardless of biological definitions of TDEF, the functions it performs and the diversity of ecosystem services that it provides afford it substantial importance and reinforce the case for its protection and restoration. Successful local restoration activities highlight the feasibility of regeneration of TDEF, even from severely degraded and eroded land, and the associated regeneration of ecological and socio-economic values.