Fig 1.
Study area and sampling locations across three West African countries—Liberia, Senegal and Gabon.
Mangroves were sampled along the Cess and Mechlin (St Johns) Rivers in Liberia, in the Saloum Delta, Senegal, Mondah Bay, Akanda National Park, (Gabon North) and the Ndougou Lagoon (Gabon South).
Table 1.
The approximate latitude of sampled mangroves, mean annual temperature, mean annual precipitation, köppen classification of landscapes encompassing the study sites [21], and soil porewater characteristics and soil depth of sampled mangroves.
Climatic data are from http://en.climate-data.org/continent/africa/. Site specific information can be found in S1 Table.
Fig 2.
A: A low mangrove plant community in the Saloum Delta, Senegal. B. Medium mangrove of the Saloum Delta, Senegal. The baobab tree in the background is located on uplands behind the mangrove. C. A tall mangrove, of the Ndougou Lagoon, Gabon. The person in the foreground is about 3 m above the soil surface.
Fig 3.
Mangrove tree density (trees ha-1) in Liberia (A), Senegal (B), Gabon North (C) and Gabon South (D).
Fig 4.
Mangrove tree basal area (m2 ha-1) in Liberia (i), Senegal (ii), Gabon South (iii) and Gabon North (iv).
Fig 5.
Ecosystem carbon stocks (Mg C ha-1) of sampled mangroves of West-Central Africa.
Horizontal lines are the location means (± SE) of tall, medium or low mangroves.
Table 2.
Soil bulk density (g cm-3), carbon concentration (%), nitrogen concentration (%) and carbon pools (Mg C ha-1) of sampled mangroves partitioned into low, medium and tall communities in Atlantic coastal mangroves of Africa.
Table 3.
Ecosystem carbon stocks (Mg C ha-1) across the Western African landscape.
Data are means ± one standard error.
Fig 6.
The relationship between total ecosystem carbon stocks and soil porewater salinity collected at the time when carbon stocks were measured.
Fig 7.
Carbon stocks of sampled mangroves in the Asia Pacific (n = 58), Latin America (n = 49), West Central Africa (n = 33), the United Arab Emirates (n = 18) and a global mean (n = 158).
Data for Latin America are from [12, 22, 33, 34]. Data for the Asia Pacific are from [10, 12, 14, 30, 35]. Data from the Arabia/Oman Gulf are from [32]. Soils in all sites were sampled to bedrock, marine sands or to a depth of ≈300cm when sediments exceeded this depth (i.e., many deltas and estuaries). The IPCC values [17] include aboveground biomass from tropical regions (n = 72). Included in the aboveground carbon pools are dead wood and litter. The IPCC belowground carbon stocks include soils (N = 119) and estimates of belowground plant mass.