Figure 1.
Study area on the Ajuruteua peninsula, Northern Brazil.
The study was performed in Brazil (A) near the city of Bragança (46°38′W 0°50′S, B). The study site is marked by a black dot and is located at the tidal channel Furo Grande (B).
Figure 2.
Total monthly precipitation in 2012.
Precipitation (mm) was recorded by the weather station in Tracuateua (50 km southwest from the study site), Pará, Brazil [28]. The asterisks mark the sampling months (CO2 efflux rate and rH of burrows and control sediment). The circle marks the only control sampling (CO2 efflux rate and rH), which had to be conducted two neap tide cycles later than the corresponding sampling in October 2012 due to technical reasons.
Figure 3.
Vertical and horizontal sampling scheme of the sediment surrounding U. cordatus burrows for the rH measurements.
Table 1.
Field data of measured and estimated parameters.
Table 2.
Data of U. cordatus respiration measurements.
Figure 4.
CO2 efflux rates (µmol m−2 s−1) of plain sediment and sediment with a burrow density of 1.7 and 11.9 burrows−1 m−2.
*For these estimates all burrow entrance diameters were set at 6 cm.
Table 3.
CO2 efflux rates of mangrove sediment.
Figure 5.
Burrow and plain sediment rH values for each sampling campaign in the year 2012.
Mean sediment rH values ± standard error (se) plotted against sediment depth (cm) (sample size (n) for each month: April: n = 308, July: n = 363, September: n = 282 and October: n = 240). Different grey shades and symbols represent the different horizontal sampling distances from the burrow wall sediment (BWS, BWS2 = 2 cm, BWS5 = 5 cm, BWS8 = 8 cm, BWS15 = 15 cm and control >15 cm).