## 4 Discussion  
### Impact of Storm Surges on Carbon Fluxes (NEE, GPP, Reco, and CH\({}_{d}\))  
The response of carbon balance to storm surges in restored and natural mangrove ecosystems varied significantly between the HK and the PYR site. Our findings suggest that the magnitude of storm surge impact was more pronounced at the HK site given its more immediate exposure to the storm event, while the PYR site exhibited a more moderate response. The storm surge significantly disrupted carbon exchange in the mangrove ecosystems, leading to a reduction in carbon uptake, as indicated by an increase in NEE and a decline in GPP and Reco during the storm (Figure 4). The decline in GPP was likely due to reduced photosynthetic efficiency and defoliation or tree mortality under storm surge disturbances [19]. Meanwhile, Reco suppression suggests reduced microbial and root respiration, possibly due to lower temperatures and water saturation [21; 22]. After the storm, NEE, GPP, and Reco showed signs of recovery but had not yet returned to the levels before storm surges within 14 days, indicating legacy impacts of storm surges on mangrove carbon cycling. Studies reported that the leaf area index (LAI) of disturbed mangroves can return to pre-disturbance levels within one year, whereas ecosystem respiration and maximum photosynthetic rates may require a longer recovery period to reach their peak, and all lost carbon can be recovered within four years in most mangroves [23]. The spatial and temporal dynamics of mangrove recovery are largely governed by pre-disturbance forest structural characteristics--such as canopy height, vegetation density, and gap fraction--as well as by ecological and environmental factors, including species composition, sapling recruitment capacity, site topography, tidal connectivity, and exposure to sea-level rise [24; 25; 26]. According to [PERSON] et al. [27], taller mangrove forests (>20 m in height) required up to 2.5 years for canopy recovery due to factors such as greater structural damage, higher hydraulic failure risk in complex xylem networks, and lower regrouting capacity in mature trees. In contrast, shorter mangroves (<5 m) experienced less damage and exhibited quicker recovery owing to their flexible stems, higher bud bank activity, and faster nutrient cycling in associated soils [24]. [PERSON] et al. [28] also  
Figure 7: Findings from the path analysis investigating the relationships between half-hourly environmental variables and fluxes at restored ((**a–c**), PYR site) and natural ((**d–f**), HK site) mangrove forests in pre-storm ((**a,d**)), during-storm ((**b,e**)), and post-storm ((**c,f**)). Red lines represent positive effects, and blue lines represent negative effects. \({}^{**}\) indicates \(p<0.001\) and \({}^{*}\) indicates \(p<0.01\). observed an 18% rise in soil CO\({}_{2}\) emissions along with a transition of CH\({}_{4}\) fluxes from net uptake to net release seven months after the hurricane. This shift was particularly evident in mature stands where extended waterlogging suppressed root respiration and stimulated sulfate-reducing microbial activity, whereas juvenile mangroves exhibited quicker soil redox recovery due to their shallower root systems [25]. The HK site represents a mature, natural mangrove forest with a taller canopy structure and greater exposure to storm surge intensity due to its proximity to the coastline. In contrast, the PYR site is a restored mangrove stand with lower canopy height and more sheltered positioning, resulting in comparatively milder disturbance impacts. These structural and spatial differences likely contributed to the greater reduction in NEE and CH\({}_{4}\) fluxes at HK during the storm surge period, as well as the slower recovery in the 14 days that followed. CH\({}_{4}\) fluxes exhibited a different pattern, with relatively minor changes before the storm, a slight reduction during the storm, and a notable increase afterward.