Assessment of liana diversity and carbon stock in differently disturbed tropical dry evergreen forests of southern India

Abstract

Lianas are important components of tropical forests that play a crucial role in forest dynamics. We investigated biodiversity and carbon stock of lianas in two tropical dry evergreen forest (TDEF) sites, the relatively undisturbed Sendhirakillai (SK) and disturbed Palvathunnan (PT) by establishing one-hectare plot in each site. All lianas ≥ 1cm diameter (measured 1.3 m from rooting point) and trees ≥ 10cm girth (measured at 1.3 m from ground) were enumerated to ascertain species richness and stem density of lianas and trees with respect to site disturbance. Liana diversity totaled 24 species (16 in SK and 20 in PT) in the two studied sites. Liana density totaled 1182 individuals (744 ha1 in SK and 438 ha1 in PT). Fifty percent of species were shared between the two sites. A considerable variation in the density, dominance and basal area of different species was found between the sites. No dominant family was common to both the sites. Stem twining and zoochory was predominant in both disturbed and undisturbed sites. Lianas comprised 36.4% (SK) & 48.8% (PT) of the total woody species richness (lianas + tress) and 37% (SK) and 38.3% (PT) of the total woody species density. The mean aboveground biomass and carbon stock of lianas were 7.2 Mg ha and 4.5 Mg ha, accounting for 1.94% of total woody species community (trees + lianas). The aboveground biomass and carbon stocks were highest in undisturbed site SK compared to disturbed site PT. The extent of liana diversity and their contribution to the total woody plant abundance and biomass highlight the importance of lianas in forest functioning, dynamics and mitigating climate change. Considering the biodiversity TDEFs hold and the current level of human disturbance, a holistic approach in conservation is emphasized.