Northern Peatland Drought: The Relationship Among Vegetation Condition Index, Precipitation and Water Table Depth

ABSTRACT Peatlands recognized as areas of water surplus, are highly sensitive to climate change, which induces new ecohydrological realities, particularly under drought conditions. In raised bogs, where precipitation serves as the sole water source, it plays a vital role in maintaining water balance and sustaining the health of peatland vegetation. Integrating ground‐based observations with remotely sensed data offers an effective approach for detecting water stress patterns over large territories, as reflected in the phenological dynamics of these ecosystems. Therefore, the present study assessed drought in the Čepkeliai raised bog (Lithuania), using the correlations between Vegetation Condition Index (VCI), Standardized Precipitation Index (SPI) and in situ water table (WT) measurements. Terra MODIS satellite data of the growing season were used for 12 years (2012–2023) to assess the long‐term vegetation conditions and identify spatio‐temporal drought patterns. Study results showed that WT, as a primary driver of vegetation health is closely linked with 30‐day precipitation (especially in June). Multiple timescale SPI was also strongly correlated with VCI. Significant positive correlations between VCI and WT were found in June and September, confirming the importance of these critical periods for monitoring vegetation water stress in the raised bog. Analysis of the different habitats confirmed the sensitivity of active raised bog to WT fluctuations. The spatial distribution of VCI values during dry years (2015, 2016, 2018 and 2019) revealed areas most susceptible to water stress within the raised bog.