ORIGINAL RESEARCH Potential of Wetland Macrophytes to Sequester Carbon and Assessment of Seasonal Carbon Input into the East Kolkata Wetland Ecosystem Sudin Pal 1,2 & Buddhadeb Chattopadhyay 2 & Siddhartha Datta 1 & Subhra Kumar Mukhopadhyay 2 Received: 15 March 2016 /Accepted: 2 February 2017 # Society of Wetland Scientists 2017 Abstract Wetland is the largest sink of C among entire ter- restrial C pool, however, species specific efficiency of wetland macrophytes for sequestering C is not studied well. This study reports seasonal variations of the C sequestration efficiency of twelve abundantly grown wetland macrophytes in East Kolkata Wetland ecosystem (EKW) of India. The total amount of dry biomass and in sequel with the C content were higher in monsoon than postmonsoon and premonsoon periods. Considering all plants the C content of the leaf was the highest followed by the stem and root. Among the twelve plants stud- ied, the C in total dry biomass of Phragmites karka was re- corded as the highest followed by Eichhornia crassipes, Typha angustifolia. It was estimated that 1.17 kg C m -2 yr. -1 was captured by marginal aquatic plants, while 0.74 kg C m -2 yr. -1 was captured by the three floating macrophytes in EKW areas. To execute sustainable EKW conservation plans this study would provide an opportunity to refine our under- standing about the role of macrophytes in C sequestration and gives a way to claim carbon credit from this service. Keywords Carbon sequestration . Dry biomass . East Kolkata Wetland . Ramsar site . Post hoc analysis . Wetland macrophytes Introduction The carbon dioxide (CO 2 ) concentration in atmosphere has been increased by more than 40% over the preindustrial period i.e. from 280 ppm of 1850 to 399 ppm as of 2015 (Eggleton and Eggleton 2013; Dlugokencky 2016). As a result, presently the scientists have given much attention on C sequestration by natural ecosystems or bio-sequestration (Pal et al. 2016a), be- cause it is the sustainable regulatory factor of global carbon flux and storage (Plantinga and Wu 2003). Therefore, in this case plants are the most powerful tools to assimilate carbon (C) from the atmosphere and sequester it in the biota, soil and water for long-term storage (Lal 2008). The precise knowl- edge of species-specific C content in plant biomass is very much essential for better understanding of C stock of a con- cerned ecosystem (Thomas and Martin 2012). In forest eco- systems, quantification of C content among trees shows high interspecific variations (Elias and Potvin 2003). Such interspe- cific variations are very critical for understanding the forest potential for capturing and storage of C (Baldantoni et al. 2004; Thomas and Malczewski 2007; Martin and Thomas 2011). The species-specific studies about C concentration of forest trees have revealed that on a mass/mass basis the above- ground biomass consists of 50% C on an average, which re- mains commonplace in forest C estimation (Bradford et al. 2012). This value has been used for large scale estimation of C sequestration in plants of tropical and temperate regions (Lewis et al. 2009; Saatchi et al. 2011) as well as small-scale estimation in agroforestry (Soto-Pinto et al. 2010) and in situ plantations (Beets et al. 2011). Economically wetlands are perceived as less important than forests and marine systems. Moreover, owing to relatively smaller global surface area coverage (4–6%) than forest and marine ecosystems, wetland ecosystem and its associated macrophytes attain little attention in the * Sudin Pal sudindgp1@gmail.com 1 Department of Chemical Engineering, Jadavpur University, Kolkata, India 2 Ecotechnology Research Laboratory, Government College of Engineering and Leather Technology, Kolkata, India Wetlands DOI 10.1007/s13157-017-0885-5