@InProceedings{VedovatoCarvAragFeld:2021:PyCaFo,
               author = "Vedovato, Laura and Carvalho, Lidiany and Arag{\~a}o, Luiz 
                         Eduardo Oliveira e Cruz de and Feldpausch, Ted",
          affiliation = "{University of Exeter} and {University of Exeter} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {University of 
                         Exeter}",
                title = "Pyrogenic carbon and forest dynamics during drought in Amazonian 
                         forests",
                 year = "2021",
         organization = "EGU General Assembly",
            publisher = "EGU",
             abstract = "During extreme drought events, aboveground biomass (AGB) dynamics 
                         in Amazonian forests are altered through reduced productivity and 
                         increased tree mortality and carbon loss. Tree adaptations 
                         developed in response to historical drought may reduce the 
                         severity of carbon loss. Past droughts were likely associated with 
                         fire, which produced Pyrogenic Carbon (PyC), a form of carbon 
                         formed by the incomplete combustion of biomass burn and fossil 
                         fuel. PyC has specific properties that improve soil fertility and 
                         water holding capacity and decrease aluminium toxicity, among 
                         others. PyC can be found in different concentrations across the 
                         Amazon Basin, since it can be produced by local fires and aerosol 
                         deposition. It is unknown whether PyC could explain tree 
                         adaptations or contributes to Amazon forest dynamics, especially 
                         for extreme drought events. We hypothesize that PyC in soil can 
                         serve as a proxy of fire history and fire/drought adaptations and 
                         also support the forest during drought events because of its 
                         properties, decreasing mortality rates and maintaining rates of 
                         AGB gain equivalent to a non-extreme drought year. To evaluate 
                         this hypothesis, we used a dataset with more than 70 plots with 
                         repeat censuses distributed across the Amazon Basin and classified 
                         extreme drought events using maximum cumulative water deficit 
                         (MCWD) analysis. Soil samples were collected from the same plots 
                         during an intensive fieldwork campaign and PyC was quantified by 
                         hydrogen pyrolysis (HyPy). Forest plots were classified into high 
                         and low PyC based on the median across the whole dataset. Our 
                         preliminary results show that during extreme drought events, plots 
                         that have a greater concentration of PyC had significantly higher 
                         rates of AGB gain when compared with plots with lower 
                         concentrations of PyC (t-test, p < 0.05). During non-extreme 
                         drought years there was no significant difference in rates of AGB 
                         gain between plots with different concentrations of PyC. When we 
                         focus on plots with lower concentrations of PyC there is a 
                         significant decrease in rates of AGB gain during drought years 
                         compared to non-extreme drought years (t-test, p < 0.05). However, 
                         in plots with high concentrations of PyC there is no significant 
                         difference in rates of AGB gain, showing trees are able to 
                         maintain normal forest dynamics during extreme drought years. We 
                         conclude that PyC has an important role in mediating drought 
                         resistance and productivity in Amazonian forests.",
  conference-location = "Online",
      conference-year = "19-30 apr.",
                  doi = "10.5194/egusphere-egu21-13194",
                  url = "http://dx.doi.org/10.5194/egusphere-egu21-13194",
             language = "en",
           targetfile = "EGU21-13194-print.pdf",
        urlaccessdate = "28 abr. 2024"
}