Research paper Biomass stocks and carbon storage in Barringtonia acutangula floodplain forests in North East India Shikhasmita Nath a , Arun Jyoti Nath a, * , Gudeta W. Sileshi b , Ashesh Kumar Das a a Department of Ecology and Environmental Science, Assam University, Silchar 788011, India b Plot 1244 Ibex Hill, Lusaka, Zambia article info Article history: Received 27 December 2016 Received in revised form 5 January 2017 Accepted 9 January 2017 Keywords: Above ground biomass Biomass allocation Ecosystem services Family forest abstract Floodplain forests serve a critical function in flood regulation and the global carbon (C) cycle due to their important role in C sink management. Barringtonia acutangula, a tree species adapted to floodplains has been managed traditionally over millennia as family and community forest in North East India. Prevailing traditional management of the Barringtonia forest restricts felling of trees while promoting uses of tree branches in fishery management and fuel wood production. Such management systems might have helped in sustaining floodplain family forests with a steady stock of biomass. However, our knowledge of their role in biomass stocks and C storage is still scanty. Therefore, the present study was undertaken to estimate the biomass and carbon stocks of Barringtonia forests and to understand their role in carbon sink management. The floodplain forest at the study site was stocked with 3204 trees ha 1 of Barring- tonia. Allometric models were developed using harvested tree, and these were used for estimation of biomass and vegetation carbon stocks. Among the various models tested the power model using diameter at breast height (DBH) as an independent variable fitted tree biomass in different tree com- ponents (bole, sprout, branch and leaves) adequately. Total dry above ground biomass (AGB) estimated at 552 ± 23 Mg ha 1 in the Barringtonia floodplain forests was much larger than AGB reported for various forest types and agroforestry systems in North East India. Biomass allocation patterns revealed that out of the total biomass, the bole contributed the highest proportion (45%) followed by sprouts (27%), branches (24%) and leaves (4%). The above-ground carbon stock was estimated at 263 ± 11 Mg ha 1 . The quantity of biomass stock and the carbon storage in vegetation cover of Barringtonia forest suggest its direct in- fluence on local, regional and even global climate. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction Floodplains provide various ecosystem services [1] including serving as reservoirs of biodiversity, supply of resources used by humans, and flood regulation [2] and are increasingly appreciated for their aesthetic value and for recreational uses [3]. Floodplain forests also serve a critical function in the global carbon (C) cycle due to their important role in C sink management relative to other terrestrial ecosystems [4]. In periodically flooded forests, trees display a huge variety of adaptations and a high functional diversity [5] and flooding stress is a strong driver of adaptive evolution [6]. The flood regime, or flood pulse, is considered a major driver of spatial variability in C storage and productivity of flooded forests [7]. These areas are important for playing roles in sustaining regional biodiversity and water quality, and for their capacity to produce trees and fishes [8]. Floodplains not only support large biological diversity but also provide a wide range of ecosystem goods and services [9,10]. Despite their importance for ecosystem and human services, biomass storage and dynamics in floodplain ecosystems remain poorly understood in many of the world's large tropical river basins [11]. Barringtonia acutangula (L.) Gaertn is widely distributed throughout India, Southeast Asia, Australia and Africa [12]. In the floodplain of the Barak Valley in Assam, Barringtonia acutangula is one of the dominant tree species and has been managed by the floodplain people over centuries to meet their livelihood needs [13]. The species grows naturally on the bank of the fresh water river and uniquely adapted to the aquatic conditions [14] and managed by the floodplain people as family forest or community * Corresponding author. Department of Ecology and Environmental Science, Assam University, Silchar 788011, Assam, India. E-mail address: arunjyotinath@gmail.com (A.J. Nath). Contents lists available at ScienceDirect Biomass and Bioenergy journal homepage: http://www.elsevier.com/locate/biombioe http://dx.doi.org/10.1016/j.biombioe.2017.01.014 0961-9534/© 2017 Elsevier Ltd. All rights reserved. Biomass and Bioenergy 98 (2017) 37e42