Temporal evolution of C stock in soils from the cork oak forest in a post-fire scenario

Abstract

<p>Forest fires are increasing their recurrence, intensity and scale in Portugal, increasing also the vulnerability of this region of Southwestern Europe to the impacts of the climate change. In Portugal, several studies have been focusing the dynamic of cork oak forest after fires from tree level to landscape level. However few information is available about the impact of wildfires in the soil quality, namely C stock, and its evolution. This component of the ecosystem and the evolution of its characteristics can be related with the dynamics of the landscape in the post-fire period and its knowledge can help in the management and rehabilitation of plant-soil system.</p><p>Serra do Caldeir&#227;o is located in Algarve region (S of Portugal). The soils are classified as Leptosols with low fertility. The landscape is characterized by cork oak forests with shrub cover which is dominated by Cistus species. To assess the distribution of total organic C in the study area, several soil sampling were intersected, on two sampling dates (2012 and 2013), with the vector information of the burned area in 2004. This information was intended to assess the temporal evolution of C concentration, depending on its location in a burnt or non-burnt area.</p><p>In general, the burnt areas showed greater variability of C concentrations in soils collected in both the years, with maximum values &#8203;&#8203;of 33.0 g/kg for 2012 and 36.5 g/kg for 2013. These maximum values &#8203;&#8203;exceed those obtained for soils in non-burnt areas. Despite of this scenario, and independently of the year, no statistically significant differences were found in the C concentrations of the burnt plots and the control plots. For other chemical characteristics (e.g. nutrients), the variations depended on the area. Implementation of post-fire recovery measures and forest management of the areas can justify this variation.</p><p>Acknowledgment: This work is co-financed by project REMAS (SOE3/P4/E0954) from Interreg SUDOE 2014-2020 program and is also financed by the FEDER Funds through the Operational Competitiveness Factors Program - COMPETE and by National Funds through FCT - Foundation for Science and Technology within the scope of the project &#160;UID/AGR/04129/2020 (LEAF) and &#160;the project UID/BIA/50027/2019 (CEABN/InBIO).</p>