Coastal wetlands are valuable aquatic ecosystems with high biological productivity, which provide services such as a reduction in nitrogen loading into coastal waters and storage of organic carbon acting as carbon dioxide sinks. The predicted rise of sea level or freshwater extractions, particularly in the arid Mediterranean biome, will salinize many coastal wetlands. However, there is considerable uncertainty about how salinization will affect microbial communities and biogeochemical processes. We determined the abundance of total prokaryotes, cyanobacteria, and viruses and quantified the heterotrophic production of prokaryotes sensitive- (predominantly Bacteria) and resistant- (predominantly Archaea) to erythromycin in 112 ponds from nine coastal wetlands. We explored the main drivers of prokaryotic abundance and heterotrophic production using generalized linear models (GLMs). The best GLM, including all the wetlands, indicated that the concentration of total dissolved nitrogen (TDN) positively affected the total abundance of prokaryotes and the heterotrophic erythromycin-resistant (ery-R) production. In contrast, heterotrophic erythromycin-sensitive (ery-S) production was negatively related to TDN. This negative relationship appeared to be mediated by salinity and virus abundance. Heterotrophic ery-S production declined as salinity and virus abundance increased. Consequently, we observed a switch from heterotrophic ery-S production towards ery-R production as salinity and virus abundance increased. Our results imply that microbial activity will change from heterotrophic bacterial-dominated processes to archaeal-dominated processes with anthropogenic nitrogen and salinization increases. However, more studies are required to link the mineralization rates of dissolved nitrogen and organic carbon with specific archaeal taxa to enable more accurate predictions on future scenarios in coastal wetlands.

沿海湿地是具有高生物生产力的宝贵水生生态系统，它提供的服务包括减少沿海水域的氮负荷和作为二氧化碳汇的有机碳储存。预计海平面上升或淡水开采，特别是在干旱的地中海生物群系中，将使许多沿海湿地盐化。然而，盐化将如何影响微生物群落和生物地球化学过程存在相当大的不确定性。我们确定了 9 个沿海湿地的 112 个池塘中原核生物、蓝细菌和病毒的总丰度，并量化了对红霉素敏感（主要是细菌）和抗性（主要是古生菌）的原核生物的异养生产。我们使用广义线性模型 (GLM) 探索了原核生物丰度和异养生产的主要驱动因素。包括所有湿地在内的最佳 GLM 表明，总溶解氮 (TDN) 浓度正向影响原核生物的总丰度和异养抗红霉素 (ery-R) 生产。相比之下，异养红霉素敏感 (ery-S) 生产与 TDN 呈负相关。这种负相关似乎是由盐度和病毒丰度介导的。随着盐度和病毒丰度的增加，异养 ery-S 的产量下降。因此，我们观察到随着盐度和病毒丰度的增加，从异养 ery-S 生产转向 ery-R 生产。我们的结果表明，微生物活动将从异养细菌为主的过程转变为古菌为主的过程，人为氮和盐化增加。然而，需要更多的研究将溶解氮和有机碳的矿化率与特定的古菌类群联系起来，以便更准确地预测沿海湿地的未来情景。