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S h o r tt C omm u n fi c a tt fi o n N o tt e s o n tt h e tt a x o n om y a n d d fi s tt r fi b u tt fi o n o f ttw o e n d em fi c a n d tt h r e a tt e n e d d fi p tt e r o c a r p tt r e e s f r om tt h e W e s tt e r n G h a tt s o f K e r a l a , I n d fi a M . S . S a n fi l , V . B . S r e e k um a r , K . A . S r e e j fi tt h ,

A new species of the important timber trees family Dipterocarpaceae, Hopea sasidharanii Robi & Sujanapal, from Shenduruny Wildlife Sanctuary of Kerala, India is described and illustrated.

It has been hypothesized that most Asian tropical lineages have originated in Gondwana with the Indian subcontinent playing a crucial role in the dispersal of ancestral Gondwanan taxa. The disjunct distribution of dipterocarps and the fossil record in India support the Gondwana hypothesis. This is the first comprehensive study addressing the evolutionary and biogeographic relationships of dipterocarps in the Indian subcontinent to test the Gondwana hypothesis. A Bayesian phylogenetic tree of the Dipterocarpaceae family including the Indian counterparts corroborates the monophyly of subfamilies/tribes and shows new biogeographic affinities. Molecular dating reveals the Cretaceous origin of Dipterocarpaceae. Diversification of major lineages occurred during the Pliocene-Miocene epochs. The DEC analysis ascertains the Gondwanan origin and dispersal route from the Madagascar (Africa)-India-Sri Lanka-Seychelles block to Eurasia. The biogeographic analysis suggests early vicariance followed by an outof-India dispersal of Dipterocarpaceae. Three dispersal events from India to the remainder of Asia at 47.6 Ma, 42.53 Ma and 37.6 Ma are identified. There probably was a biotic interchange between India and mainland Asia via Sumatra following the collision of the Indian plate with Eurasia. Molecular dating and dispersal events coincide with the geological events. During the Miocene, uplift of the Himalayan-Tibetian plateau induced climatic variation, which seems to have resulted in the extinction of major Indian dipterocarp lineages and reverse dispersal into India. Hopea-Shorea, one of the earliest diverged lineages, originated in Southeast Asia. The establishment of Southeast Asian monsoon climate may have favoured allopatric speciation and diversification of Southeast Asian lineages also resulting in further dispersal into India.

Syzygium travancoricum Gamble is an endemic, Critically Endangered tree species found in marshy swamps of the Western Ghats. An assessment was conducted on existing distribution pattern and population structure of this species in Kerala. Most of the existing populations are mainly located in sacred groves and this tree is an ideal example on role of sacred groves in conserving biodiversity especially IUCN red listed species. A total of 465 individuals were recorded in which maximum number of sapling density was recorded in Kalasamala Sacred grove followed by patches of Myristica swamps in Kulathupuzha. Fragmentation of populations, habitat modification, over exploitation, pollution and invasion of exotics are major threats to S. travancoricum. Hence urgent intervention is required for restoration programmes, management of habitat and subsequently delisting this species from IUCN red list of threatened species.

Vatica chinensis L. is an endangered Dipterocarp, sparsely confined to the west-coastal regions of the Kerala and Karnataka part of the Western Ghats, especially in the sacred groves and the agro-ecosystems. The current population structure and distribution of the species in the Western Ghats region is poorly studied. Hence, the study attempts to assess the status of the existing populations and their potential distribution by using the Ecological Niche Modeling (ENM). The results indicated that the populations of Vatica chinensis were present outside the forest areas, with a very scattered distribution. Three large populations were identified in the Malabar region, especially in the sacred groves of poyilkavu, muchukunukavu and in the premises of the parappanangadi railway station. The poyilkavu sacred grove showed a higher density (68) compared to the other two sites. The potential distribution prediction, using the ENM, showed a higher probability in the central part of the Western Ghats and a moderate one in the northern part of the Western Ghats region. Furthermore, the high habitat specificity, the restricted distribution along with the anthropogenic intervention (construction of roads and railway lines) has significantly reduced the existing populations of Vatica chinensis. Therefore, urgent interventions are required to restore the populations of this endangered species. As part of initiating the restoration activity we have identified the potential niches and also raised sufficient seedlings for the restoration.

Tropical forests have long been accepted for their productivity and ecosystem services on account of their high diversity and stand structural attributes. In spite of their significance, tropical forests, and especially those of Asia, remain understudied. Until recently, most forest inventories in Asia have concentrated on trees 10 cm in diameter. Floristic composition, plant species diversity, above-ground biomass, basal area, and diversity were investigated across different life forms and two-diameter classes in a large-scale 10-ha plot, in the undisturbed tropical seasonal rain forest of Southern Western Ghats, Kerala, India. The regeneration pattern of the study area was examined by evaluating fisher's alpha and IVI (Important Value Index) across three layers of vegetation (seedling, sapling, and tree). Within the plot, we recorded 25,390 woody plant species ≥1 cm dbh from 45 families, 91 genera, and 106 species. Plant density was 2539 woody individuals per hectare, with a basal area of 47.72 m2/ha and above-ground biomass of 421.77 Mg/ha. By basal area, density, and frequency, the Rubiaceae, Sapotaceae, and Malvaceae families were the most important. Small-diameter trees (1 cm ≤ dbh ≤10 cm) were found to be 78 percent of the total tree population, 20.2 percent of the basal area, and 1.4 percent of the aboveground biomass. They also possessed 6 percent more diversity at the family level, 10% more diversity at the genus level, and 12% more diversity at the species level than woody individuals under 10 cm dbh. Woody individuals of treelets life form and small-diameter classes were much more diverse and dense than the other groups, indicating that results based only on larger canopy trees and larger diameter class maybe not be an appropriate representation of the diversity status of a particular tropical forest type. The lower density of individuals in the initial girth class indicates the vulnerability of the forest system to anthropogenic, natural disturbance and a changing climate. Reduce the minimum diameter limit down to 1 cm, in contrast to 10 cm limit used in most of the evergreen forest inventories, revealed a high density and diversity in the lower stories.