Assessing carbon accumulation through peat vertical displacement: The influence of climate and land use across diverse peatland characteristics.

With their net carbon accumulation determined by the balance between gross ecosystem productivity (GEP) and carbon losses (from processes such as oxidation and decomposition), peatlands can function as either carbon sinks or carbon sources. Healthy, pristine peatlands are vital carbon sinks, while degraded peatlands can release significant amounts of carbon (C) into the atmosphere. This study investigates the use of peat vertical displacement (VD), detectable via remote sensing, as a proxy for net carbon accumulation in northern boreal and temperate peatlands. Various environmental factors, including peat body and vegetation types, climate conditions, and land use changes, were analyzed to assess their influence on carbon dynamics. Strong positive correlations between air temperature (TMP) and VD suggest that TMP is a key driver of VD, likely due to increased GEP. Conversely, negative correlations with precipitation (PCP) indicate that increased water input generally reduces VD. Unexpected inverse relationships between PCP and VD are likely driven by peat accumulation's complex hydrological and temporal dynamics. The land use analysis revealed that drained agricultural regions experience significantly higher subsidence rates than well-preserved peatlands, with drainage accelerating peatland degradation by up to 66.7 %. These findings highlight the critical role of land use change in peatland degradation, while also revealing that degradation is occurring even in well-preserved areas-suggesting that peatland health is a global challenge. The average VD was negative in all regions studied, ranging from -0.9 cm/year in Rospuda to -1.5 cm/year in Wizna, indicating ongoing degradation. This pattern suggests that regional factors, likely linked to climate change, are affecting the stability of peatlands in northeastern Poland. This alarming trend highlights the limitations of restoration efforts in fully restoring peat-forming processes and achieving a stable ecological state. These conclusions should be considered when planning peatland conservation strategies, as climate change may significantly limit the effectiveness of restoration efforts.