“…To adequately capture the signal and variability of Hg cycling in this ecosystem, we increased the spatial and temporal resolution of the sampling regimes to measure process heterogeneity and identify areas of Hg hotspots (i.e., areas with elevated Hg concentrations) caused by soil Hg migration. Techniques of stable Hg isotopes were utilized to improve the knowledge of the Hg biogeochemical cycles in karst forests. ,,,− There are three unique dimensions of Hg isotopic fractionation, i.e., the mass dependent fractionation (MDF, mainly represented by δ 202 Hg), odd mass independent fractionation (odd-MIF, reported as Δ 199 Hg and Δ 201 Hg), and even mass independent fractionation (even-MIF, reported as Δ 200 Hg and Δ 204 Hg). The isotopic fractionation signals had been successfully applied for distinguishing the Hg sources and transport pathways of Hg biogeochemical processes in forest ecosystems, − since Hg source endmembers (e.g., Hg in rainfall, air, geological storages, and etc.)…”