The evolution and diversification of ancient megathermal angiosperm lineages with Africa-India origins in Asian tropical forests is poorly understood because of the lack of reliable fossils. Our palaeobiogeographical analysis of pollen fossils from Africa and India combined with molecular data and fossil amber records suggest a tropical-African origin of Dipterocarpaceae during the mid-Cretaceous and its dispersal to India during the Late Maastrichtian and Paleocene, leading to range expansion of aseasonal dipterocarps on the Indian Plate. The India-Asia collision further facilitated the dispersal of dipterocarps from India to similar climatic zones in Southeast Asia, which supports their out-of-India migration. The dispersal pathway suggested for Dipterocarpaceae may provide a framework for an alternative biogeographic hypothesis for several megathermal angiosperm families that are presently widely distributed in Southeast Asia.

Many plant families lack substantive fossil records, limiting our understanding of their origin and evolution. The abundance and preservation potential of pollen through geological time have helped to overcome such limitations and have provided reliable fossils for reconstructing biogeographical history and character evolution in many angiosperm families. Here, using scanning electron microscopy, we identified six Ebenaceae-type fossil pollen grains from early Palaeogene sediments of western India. Phenetic and phylogenetic analyses using pollen characters of fossil and extant taxa reavealed affinities of these fossils to three genera of Ebenaceae (Euclea, Royena and Diospyros). Furthermore, our divergence dating analysis using these fossils as priors suggested a Gondwanan origin for the family during the mid-Cretaceous [c. 107 Mya, 95% highest posterior density (HPD): 100–112 Mya] and supports the boreotropical and ‘out of India’ dispersal hypotheses as the most probable explanations for the present global distribution of the family. The study also supports the dispersal of the family into India, from Africa, through the Kohistan–Ladakh Arc during the Palaeocene. Finally, comparative phylogenetic analyses suggest significant synapomorphic and phylogenetic signals for a few selected pollen characters in Ebenaceae. Our findings have important implications for understanding the biogeography and evolution of the highly diverse and ecologically and economically important family Ebenaceae.

Studies on the residual impact of logging on the diversity and composition of tropical forests are scarce in India. We examined the impact of selective logging on tree species richness, composition and structure prevalent after 27 years. Trees ≥ 30 cm girth at breast height were inventoried in four 1 ha plots in selectively logged patches and two 1 ha plots in an adjacent unlogged patch of lowland dipterocarp forest continuum, Uppangala, central Western Ghats, India. We enumerated 2343 trees (598 trees ha–1) belonging to 116 species (63 species ha–1) and 1345 trees (672 trees ha–1) belonging to 68 species (55 species ha–1) in logged and unlogged plots, respectively. The species richness in logged plots as compared to unlogged plots varied with spatial scale of sampling: at 1 ha scale two logged plots had higher species richness whereas it was high in only one plot at 400 m2 scale. Logged plots had low floristic similarity between them and also with the unlogged plots. Mantel and partial Mantel tests proved that logging was the main driver for the species composition rather than the elevation and spatial distance. Higher abundance of species belonging to canopy, intermediate and light wood categories and lower density of emergent, understory and medium wood types were recorded in the logged plots. As compared to unlogged plots, logged plots had 20–59% less above ground biomass (AGB) due to paucity of larger trees, especially in the emergent and medium wood types but higher AGB in canopy and hardwood categories. Our study shows the residual impact of logging even after 27 years and suggests that the recovery process may depend on the resurgence of emergent and medium wood categories.

The genus Memecylon L. has a paleotropical distribution, with about 300 species in the World, and about 30 in India. In this note we report the distribution extension of Memecylon macrocarpum Thwaites based on our diversity inventories in tropical evergreen forests at Uppangala in the Western Ghats, India. Additional distribution records of the species at Courtallum and Malayator were taken from the herbarium of the French Institute of Pondicherry (HIFP). This study highlights the importance of quantitative ecological inventories in determining species distributions and also confirms a greater range of occurrence of this species.