Masterarbeit

Detecting effects of the 2018 drought event on the Franconian Jura Forest edges using Remote Sensing.

Donald Mwaba (11/2022-05/2023)

Betreuer: Carl Beierkuhnlein, Frank Weiser

Severe droughts have been known to cause widespread tree mortality in many biomes with destructive effects on the function of ecosystems. Climate change and climate models have indicated that the regularity, duration, and intensity of droughts will increase for many locations around the globe. According to the IPCC report, the magnitude and frequency of extreme events such as droughts, floods, cyclones, heatwaves, and fire have increased in many regions. Drought events are known to be one of the major drivers of reduced Aboveground Net Primary Productivity (AGNPP), although it is worth noting that the sensitivity of land ecosystems to drought differs, particularly between forests and grasslands. The 2018 drought event was unprecedented in Central European drought history and confirmed climate projections of how hotter and drier future climate will be in Central Europe. The trend analysis of rapid rising temperatures, which started in the 1980s in the DACH region clearly showed that the 2018 drought event was the most severe in as far as rising temperature trends are concerned. The severity of the drought surpassed the record set by the 2003 drought event, which initially was classified to be the most severe prior to the 2018 drought. In this study, we investigated the effects of the 2018 drought on the forest edges of the Franconian jura compared to those of the interior. We also investigated whether different forest types i.e., deciduous vs coniferous trees were affected differently by the drought. We further looked at whether the 2018 drought had different effects on different edge orientations in terms of direction to forest edges. Several factors were found to be contributing to the effects of the 2018 drought on forests in the Franconian Jura. These factors include but are not limited to forest edge direction, distance from forest edge, elevation, tree cover density and the type of trees in question i.e., whether deciduous or coniferous. Our results show that the effects of the 2018 drought event were more pronounced at the forest edges compared to the interior though the difference only started showing beyond 200m from the forest edges. Our results also show that deciduous trees are more prone to drought effects in the Franconian Jura compared to coniferous trees. We could not convincingly determine whether the north facing forest edges were affected differently from the edges facing the south.