Net primary productivity of two mangrove forest stands on the northwestern coast of Sri Lanka

Abstract

Productivity studies were carried out from September, 1985 to August, 1987 in two mangrove stands, i.e. estuarine and island fringing, in Dutch bay, a lagoon situated on the northwestern coast of Sri Lanka. Net above-ground primary productivity was measured by monitoring litterfall and above-ground biomass increment. The average annual rate of litterfall in the estuarine and island-fringing mangrove stands are 588.14 g mm2 (approximately 6 t ha-') and 407.33 g me2 (approximately 4 t ha-') respectively. The average annual rates of above ground woody growth are 614.74 g mm2 (approximately 6 t ha-') in the estuarine stands and 286.8 g mm2 (approximately 3 t ha-') in the island-fringing mangrove stands. Hence estuarine mangrove stands record a higher annual rate of above-ground net primary production (NPP; 1207.88 g mm2 or approximately 12 t ha-') than the fringing mangrove stands (694.22 g rne2; approximately 7 t ha-'). The annual rate of NPP in the water front zones of the stands (1300.47 g m-2 in the estuarine stands and 874.56 g mW2 in the fringing stands) are greater than those in the backmangrove zones (115.28 g rnp2 in the estuarine stands and 513.88 g m-* in the island-fringing stands). These variations may be attributed to the differences in tidal flushing and influence of freshwater in the two localities.

Carbon Partitioning and Allometric Relationships between Stem Diameter and Total Organic Carbon (TOC) in Plant Components of <i>Bruguiera gymnorrhiza</i> (L.) Lamk. and <i>Lumnitzera racemosa</i> Willd. in a Microtidal Basin Estuary in Sri Lanka

“…Their primary productivity is characteristically high when compared to other terrestrial plant communities (Alongi, 2002;Amarasinghe and Balasubramaniam, 1992a;Kathiresan, 2007;Suratman, 2008Khan et al, 2009 and contribute substantially to all organic carbon sequestration in marine ecosystems (Breithaupt et al, 2012). Carbon that accumulates in the above-ground components such as leaves, smaller branches and non-woody aerial roots decomposes rapidly (i.e., labile carbon) and is quickly returned to the atmosphere.…”

Allometric relationships for estimating the aboveground phytomass and leaf area of mangrove Kandelia candel (L.) Druce trees in the Manko Wetland, Okinawa Island, Japan

“…In most studies, D (DBH) was taken as the only independent variable in the allometric equation (e.g., Nakasuga 1979;Putz and Chan 1986;Day et al 1987;Clough and Scott 1989;Amarasinghe and Balasubrananiam 1992;Mackey 1993;Clough et al 1997;Ong et al 2004). However, incorporation of the variable H (tree height) (i.e., the use of D 2 H) may ensure higher accuracy of biomass estimation (Suzuki and Tagawa 1983;Tamai et al 1986;Kusmana et al 1992;Komiyama et al 2000;Poungparn et al 2002).…”

Community structure and standing crop biomass of a mangrove forest in Futian Nature Reserve, Shenzhen, China

“…corniculatum and K. candel were best estimated by power curves using a combination of tree height and diameter at breast height (DBH 2 * HT) as the independent variables . It was found that estimate of biomass based on only a single parameter, either height (HT) or diameter (DBH), as suggested by many researchers (Amarasinghe & Balasubramaniam, 1992b ;Day et al, 1987 ;Golley et al, 1962 ;Woodroffe, 1985), was less significant . This implies that regression models developed by previous workers for estimating biomass could not be applied directly without modification for mangrove stands in Futian, PRC .…”