Abstract:
Abstract
soil organic carbon represents a significant pool
of carbon within the biosphere, which estimated
over three times of carbon that found in the
atmosphere. Mangroves play a important role in the
accumulating higher soil organic carbon among the
other wet lands and terrestrial ecosystems, due to its
superior in primary productivity and extensive root
system enhances the trapping of sediments
suspended in the tidal and flooding water currents.
Study was focused on the stock of total organic
carbon (TOC) and its horizontal and vertical
distribution in mangrove soils of Negombo estuary, Sri
Lanka. Two study sites, Kadolkele, a relatively
undisturbed natural mangrove area and Wedikanda, a
stand have been cultivated and sustainably utilized by
fishermen to extract twigs and branches for “brush
parks”.
Highest TOC content (12.42 %) in its dry weight was
recorded vertically at top soil layer (0-15 cm depth)
and horizontally, between the zone 10- 30 m
landwards from estuarine shoreline. Bulk density of
mangrove soil ranged between 1.10 – 1.20 g cm-3 and
lowest was recorded at upper layer and slightly
increase with the depth. Highest amount of TOC was
calculated, 204.93 t ha-1 at top soil layer (0 -15 cm)
and observed decrease in vertically. TOC of 104.66 t
ha-1 at 15 -30 cm depth and 68.58 t ha-1 at 30 - 45 cm
depth respectively. A statically significant (p<0.05)
positive correlation (r2 = 0.67) was revealed between
TOC in mangrove soil and stem density.
