Action D1.Impacts of wildfires on the survival of Phragmites australis – 2020
Remote sensing techniques can provide tools for mapping hazards in natural ecosystems, including wildfire events, targeting accurate mapping of distribution as well as post-event monitoring and recovery. Since 2019, whole lakeshore mapping of wildfire events and distribution in Lesser Prespa is implemented targeting solely the effects on reedbeds within the LIFE project Prespa Waterbirds. Based on previous work done in the area (Willm 2019), fieldwork data, coupled with sentinel-2 satellite images and remote sensing methodologies were used as a workflow pipeline in order to improve the delineation of wildfires distribution in Prespa reedbeds. The implementation of the method used in 2019 (Burn Area Index for Sentinel-2 BAIS2) provided poor results in 2020. Therefore, a derivative of BAIS2, namely the deltaBAIS2, was created. This derivative index is calculated as the difference before and after fire events of the value for each pixel of the BAIS2 index. Three different fire events were recorded and mapped in 2020, resulting in 53.9 hectares of burnt reedbed. More than half of the burnt reedbed surface (63.6%) was recorded in Pyli-Daseri area. Most of the areas that were burnt in 2020 were burnt in 2019 as well (37.5 ha), resulting in two successive years of disturbance in the reedbed. The pattern observed in the distribution of the repeatedly burnt areas can maybe serve as an indicator of where the annual “hotspots” of human driven wildfires are in the reedbeds of Prespa National Park. Direct management actions, such as the creation of small firebreaks, can possibly minimize the effect as well as the total burnt area by wildfires. In comparison with 2019, when 300 ha of reedbed were burnt across the lakeshore of Lesser Prespa, the total burnt surface of 2020 can be characterized as having a moderate impact in the reedbeds of the study area.