Background Mangrove tannins can participate in wetland biogeochemical cycling.However,their fate and dynamics during leaf litter leaching have yet to be elucidated in coastal aquatic environments.Methods By using a si...Background Mangrove tannins can participate in wetland biogeochemical cycling.However,their fate and dynamics during leaf litter leaching have yet to be elucidated in coastal aquatic environments.Methods By using a simulated microcosm experiment,changes in leaf litter mass and tannin compounds,including total phenolics(TP),extractable condensed tannins(ECT),and bound condensed tannins(BCT),were examined in the litters and leachates of four common mangrove species:Kandelia obovata(Ko),Aegiceras corniculatum(Ac),Sonneratia apetala(Sa),and Avicennia marina(Am).Results Leaching caused a notable decline in litter mass,TP,and ECT in the leaf litter of Ko,Ac,Sa,and Am,while BCT increased significantly in Ko and Ac.Loss in foliar TP was higher than in leaf litter mass,and loss in foliar ECT was higher than in TP of Ko and Ac,but Sa showed the opposite result.The temporal changes of TP and ECT concentrations in leachates followed a similar trend,with an initial increase followed by a decrease.ECT dynamics in Ko and Ac leachates correlated with their TP concentrations,while in Sa leachate,the peak ECT occurred 72 h later than its TP peak.The leachate ECT concentrations were highest in Ac,followed by Ko,and significantly lower in Sa.The peak TP and ECT proportions in leachates accounted for 9.2-23.9%and 7.7-9.4%of the total decreases in foliar TP and ECT,respectively.Conclusion During the leaching process,tannins’fate was species-specific,while the dynamics were almost similar.展开更多
基金supported by the National Natural Science Foundation of China(41876090,32101367,41976161)the Guangdong Basic and Applied Basic Research Foundation(2022A1515010698)+1 种基金the Science,Technology,and Innovation Commission of Shenzhen Municipality(JCYJ20220818095601003,JCYJ20170818092901989,20200827115203001)the Research Grants Council of the Hong Kong Special Administrative Region,China(UGC/IDS(R)16/19).
文摘Background Mangrove tannins can participate in wetland biogeochemical cycling.However,their fate and dynamics during leaf litter leaching have yet to be elucidated in coastal aquatic environments.Methods By using a simulated microcosm experiment,changes in leaf litter mass and tannin compounds,including total phenolics(TP),extractable condensed tannins(ECT),and bound condensed tannins(BCT),were examined in the litters and leachates of four common mangrove species:Kandelia obovata(Ko),Aegiceras corniculatum(Ac),Sonneratia apetala(Sa),and Avicennia marina(Am).Results Leaching caused a notable decline in litter mass,TP,and ECT in the leaf litter of Ko,Ac,Sa,and Am,while BCT increased significantly in Ko and Ac.Loss in foliar TP was higher than in leaf litter mass,and loss in foliar ECT was higher than in TP of Ko and Ac,but Sa showed the opposite result.The temporal changes of TP and ECT concentrations in leachates followed a similar trend,with an initial increase followed by a decrease.ECT dynamics in Ko and Ac leachates correlated with their TP concentrations,while in Sa leachate,the peak ECT occurred 72 h later than its TP peak.The leachate ECT concentrations were highest in Ac,followed by Ko,and significantly lower in Sa.The peak TP and ECT proportions in leachates accounted for 9.2-23.9%and 7.7-9.4%of the total decreases in foliar TP and ECT,respectively.Conclusion During the leaching process,tannins’fate was species-specific,while the dynamics were almost similar.
