TY - THES ID - 143995166 TI - Indicators for Peat Stability in Peatlands Influenced by Legacy Effects AU - Van den Eynde, Caro AU - Vancampenhout, Karen AU - Desie, Ellen AU - KU Leuven. Faculteit Industriƫle Ingenieurswetenschappen. Opleiding Master in de biowetenschappen. Land- en tuinbouwkunde (Geel) PY - 2024 PB - Leuven KU Leuven. Faculteit Industriƫle Ingenieurswetenschappen DB - UniCat UR - https://www.unicat.be/uniCat?func=search&query=sysid:143995166 AB - Peatlands, covering over four million square kilometres and constituting 3% of the Earth's surface, have a substantial influence on the environment. Despite their relatively small size, they provide crucial ecosystem services such as carbon storage, water cycling, and biomass production. Peatlands, exemplified in this case study by De Zegge in Belgium, face various challenges, including legacy effects from peat extraction, agricultural activities, and water influx with high nutrient levels. De Zegge is a nature reserve in Geel of 115 ha, with recorded legacy effects. It is designated as a Nature 2000 reserve due to its rich biodiversity. Following a severe drought in the summer of 2018, the occurrence of sudden peat collapse was observed in two locations. These initial 'sinkholes' were small and gradually increased in area over time. Given the limited understanding of the sudden peat collapse phenomenon and the impact of climate change on peatlands with legacy effects, this thesis explores various peat environmental variables in De Zegge. The investigation focuses on key indicators of peat quality, encompassing measurements and analyses of bulk density, MIR spectra, GHGs flux, and mesofauna abundance. Bulk density proves indicative but requires careful consideration due to potential influence by the soils water content. MIR spectra emerge as a promising variable, with top-depth-focused analyses showing comparable results to MIR spectra derived when including the deeper layers. Elemental and isotope composition, although correlated with MIR spectra, yield few conclusive insights, possibly due to site similarities. GHGs flux, emerges as a valuable but time-consuming indicator. Groundwater table depth stands out as a crucial indicator, influencing the interpretation of many other variables like bulk density, GHGs flux, and mesofauna abundance. The thesis concludes that certain variables offer more insightful perspectives on peat quality. Bulk density is influenced by decomposition and water content, requiring critical examination. MIR spectra show promise, especially when focusing on top depths. Elemental and isotope composition may be more informative with less similar sites. GHGs flux demands an extended measuring period, and groundwater table depth proves essential for interpreting various results. While mesofauna abundance data was inconclusive, possibly due to low observed quantities. Overall, De Zegge's peatlands, given their known legacy effects, exhibit signs of degradation across all sampled sites. The study shows the importance of these diverse indicators in comprehensively understanding and monitoring peat quality, especially in the context of potential sudden peat collapse phenomena. Keywords: Peatland, Peat collapse, Carbon, Legacy effects, Peat environmental indicators ER -