## 3 Results
### Soil Characterization  
Fluxes of N\({}_{2}\)O were influenced by the decomposition of soil organic matter (driven by the total contents of C, N, and S), and by environmental physicochemical characteristics (Eh and pH). There was no significant difference between bioturbated and crab-exclusion treatments for Eh and pH (\(p>0.05\); Figure 3A,B). However, the seasonal variation led to distinct soil physicochemical conditions when the rainy and dry seasons were compared. Higher Eh values were recorded during the dry season, characterizing the predominance of oxic conditions for both sites (Eh \(>+350\) mV). During the rainy season, though, the Eh values significantly decreased compared to the dry season (p \(<0.05\)), ranging between \(+79\) and \(+395\) mV, which indicated suboxic conditions (Eh: \(+100\) to \(+300\) mV; [55]). The bioturbated site showed slightly higher Eh values (\(202\pm 141\) mV) during the rainy season than the crab-exclusion plot (\(174\pm 156\) mV; Figure 3A), whereas during the dry season, higher Eh values were recorded at the crab-exclusion site (\(489\pm 32\) mV). The pH values were near neutral, with no difference between sites in each season (dry season - crab-exclusion site: \(6.9\pm 0.2\), bioturbated site: \(6.7\pm 0.2\); rainy season--crab-exclusion site: \(7.2\pm 0.2\), bioturbated site: \(7.2\pm 0.3\)) (Figure 3B).  
Figure 3: Soil measurements of mangrove soils for both bioturbated and crab-exclusion plots and over rainy and dry seasons. (**A**) In situ recorded redox potential (Eh), (**B**) in situ recorded pH, (**C**) total organic carbon (TOC), (**D**) total sulfur (TS), (**E**) total nitrogen (TN), and (**F**) C:N ratio. Labelled bars (standard error bars) with different lowercase letters (a and b) on the bars indicate statistical differences among Seasons/Sites (Rainy/Bioturbated, Rainy/Crab-exclusion, Dry/Bioturbated, Dry/Crab-exclusion), at the 5% probability level (non-parametric Friedman test). \(p\)-values for each parameter are provided in Tables S1–S6.  
During the dry season, the TOC content was similar for both sites (crab-exclusion 1.2 \(\pm\) 0.4%, bioturbated 1.2 \(\pm\) 0.3%) (\(p\) \(>\) 0.05), which was similar during the rainy season (crab-exclusion 1.1 \(\pm\) 0.3%, bioturbated 0.9 \(\pm\) 0.1%) (\(p\) \(>\) 0.05) (Figure 3C). The TN contents in the crab-exclusion site ranged from 0.11 \(\pm\) 0.02% in the rainy season to 0.11 \(\pm\) 0.01% in the dry season, whereas in the bioturbated site, TN was 0.10 \(\pm\) 0.01% for both seasons, with no statistical differences for treatments/seasons (Figure 3E). Statistically similar TS contents (\(p\) \(>\) 0.05) were recorded for both crab-bidurbated and crab-exclusion sites (0.09 \(\pm\) 0.03% and 0.133 \(\pm\) 0.12%, respectively), but the TS values were significantly higher in the dry season (0.15 \(\pm\) 0.11%) compared to the rainy season (0.07 \(\pm\) 0.01%) (\(p\) \(<\) 0.05). The C:N ratio during the dry season ranged from 11.1 \(\pm\) 2.1 in the crab-exclusion site to 11.5 \(\pm\) 1.7 in the bioturbated site, whereas in the rainy season, the values were 10.2 \(\pm\) 1.6 and 8.9 \(\pm\) 0.9 for the crab-exclusion and bioturbated sites, respectively (Figure 3F). We observed statistically higher C:N ratios in the dry season compared to the wet season in the naturally bioturbated mangrove soils. Between the dry/wet season, the crab-exclusion treatment had statistically similar C:N ratios (Figure 3F).