Abstract: Modern surface soil pollen assemblages serve as a bridge linking modern vegetation, climate, and paleoenvironmental reconstruction, which can reveal the mechanisms underlying ecosystem responses to environmental changes and provide a scientific basis for assessing the impacts of human activities. Here, we conducted pollen analysis on 20 surface soil samples collected at different elevations in Qingcheng Mountain, aiming to understand the associations between modern surface pollen assemblages and vegetation, as well as their indicative significance for human activities. Results showed that the surface pollen in Qingcheng Mountain was dominated by Pinus, Taxodiaceae, Castanopsis, evergreen Quercus, Cyclobalanopsis, Alnus, Betula, Pterocarya, deciduous Quercus, Ulmus, Juglans, Rosaceae, Poaceae, and Polypodiaceae. Among them, woody plant pollen accounted for an absolute advantage (91.9%), with the average ratio of arboreal to non-arboreal pollen (AP/NAP) reaching 15.9, indicating the main characteristics of subtropical forest. Comparative results of pollen assemblages between evergreen broad-leaved forests and secondary forests in low-altitude areas indicated that the pollen content of dominant evergreen broad-leaved species (Castanopsis, evergreen Quercus) in secondary forests decreased significantly, while the proportion of pollen from pioneer species (Pinus or Alnus) increased accordingly, accompanied by large enrichment of fern spores. Meanwhile, pollen concentration, AP/NAP, and E/D value (ratio of evergreen broad-leaved tree to deciduous broad-leaved tree pollen) all showed a downward trend, while the pollen diversity index increased slightly. The coordinated changes in those indicators reflect the disturbance effect of human activities on natural vegetation and indirectly confirm the effectiveness of vegetation conservation in the national reserve. Our findings provide a scientific basis for regional paleoclimate reconstruction, extraction of information on human activities in historical periods, and ecological civilization construction.

Key words: surface pollen, relationship between pollen and vegetation, elevation gradient, human activity, Qingcheng Mountain