Tree Diversity Changes over a Decade (2003-2013) in Four Inland Tropical Dry Evergreen Forest Sites on the Coromandel Coast of India

Abstract

Forest tree diversity inventory and its periodical monitoring are important to understand changes in tree population structure and to provide information useful for biodiversity conservation and reserve management. In a long-term forest dynamics program in Indian tropical dry evergreen forest, this communication deals with tree diversity changes at decadal interval. The initial inventory of tree diversity was carried out in 2003, in four tropical dry evergreen forest sites -(much disturbed sites Shanmuganathapuram -SP and Araiyapatti -AP and moderately disturbed sites -Karisakkadu -KR and Maramadakki -MM) on the Coromandel Coast of peninsular India, by establishing four 1ha permanent plots, one in each site. In 2013, the four plots were re-inventoried for tree diversity (≥10 cm gbh) changes which yielded 56 species from 46 genera and 26 families. The studied forest sites are threatened by disturbance due to multiple reasons; cutting of trees inside of the forest, grazing by goats, construction of temple approach road, and some aspects cultural attachment of local people like constructing new, additional strctures of temple by denuding a portion of forest etc.. Tree species richness over a decade increased by four species in site SP, two species in site AP, and one species in site KR, but decreased by one species in site MM. Tree density decreased drastically by 480 (28.92%) and 102 (12.63%) stems ha -1 respectively in sites SP and AP, but moderately increased by 82 (12.09%) stems ha -1 in site KR and 26 in ten years. The long-term forest monitoring data will be valuable to understand forest dynamics and for conservation and management of this and similar tropical forests.

Changes in tree diversity and carbon stock over a decade in two Indian tropical dry evergreen forests

“…In this study, abundance of lost and newly added species was low (one individual) to moderate (16 individuals) (Table 2). This finding was similar to the other TDEF sites (Baithalu et al, 2012(Baithalu et al, , 2013Mani & Parthasarathy, 2009;Pandian & Parthasarathy, 2016;Venkateswaran & Parthasarathy, 2005) and also in rain forest of Brazilian coast (Saiter, Guilherme, Thomaz, & Wendt, 2011) wherein researchers reported that the abundance of lost species was never more than four individuals. These rare species are more prone to extinction due to their low population size, competition between the species, natural death, and humaninduced disturbances.…”

“…This is due to natural death (in site SK), heavy logging, and fuel wood collection especially in the heavily disturbed site PT. Similar trend was observed in other TDEF sites (Baithalu et al, 2013;Mani & Parthasarathy, 2009;Pandian & Parthasarathy, 2016). In just 3-year interval of time, Karst evergreen and deciduous broad-leaved mixed forests in southwestern China witnessed 77% of stem loss in the lower DBH class (Liu et al, 2018).…”

“…Similarly between 1980s and 1990s with peak deforestation, 50% of tropical forests disappeared (Wright, 2005). Therefore, even a small disturbance could result in a notable change in the global carbon cycle (as in Pandian & Parthasarathy, 2016). Thus, accurate data on carbon stocks and the flux in tropical forests are necessary to understand how the dynamics of tropical trees respond to global anthropogenic disturbances (Wright, 2005).…”

“…Although these occur as small fragments, they are reported to provide a suitable habitat for a significant number of species (see Parthasarathy, Vivek, & Anil, 2015). Indian TDEFs are also well studied for biodiversity and ecological aspects, but only few studies have considered vegetation changes at an interval of 10 years (Baithalu, Anabarashan, & Parthasarathy, 2012, 2013Mani & Parthasarathy, 2009;Pandian & Parthasarathy, 2016;Venkateswaran & Parthasarathy, 2005). Furthermore, changes with respect to aboveground biomass are very few (Mani & Parthasarathy, 2009;Pandian & Parthasarathy, 2016), and carbon stocks have not been quantified yet.…”

“…Indian TDEFs are also well studied for biodiversity and ecological aspects, but only few studies have considered vegetation changes at an interval of 10 years (Baithalu, Anabarashan, & Parthasarathy, 2012, 2013Mani & Parthasarathy, 2009;Pandian & Parthasarathy, 2016;Venkateswaran & Parthasarathy, 2005). Furthermore, changes with respect to aboveground biomass are very few (Mani & Parthasarathy, 2009;Pandian & Parthasarathy, 2016), and carbon stocks have not been quantified yet. Given the fact that the TDEFs are unique in terms of geographical distribution with an estimation of 4-5% of the original cover and the disturbance is progressing at higher levels in most of the sites resulted in loss of 30% of tree density in last two decades (Parthasarathy et al, 2015).…”