Relative pollen productivity in subtropical evergreen broadleaved forest: Implications for reconstructing paleovegetation dynamics in East Asia

• First RPP dataset for the western part of subtropical evergreen broadleaved forest. • RPP variations driven by topography, plant composition and reference taxon. • REVEALS reconstruction at Dajiuhu during the Holocene: mixed forest transition, optimum, and decline. The accurate determination of Relative Pollen Productivity (RPP) is fundamental for applying the Regional Estimates of VEgetation Abundance from Large Sites (REVEALS) model to achieve robust quantitative paleovegetation reconstructions. This study established the first RPP dataset for the western part of the subtropical evergreen broadleaved forest region in Southwest China, focusing on the Daloushan Mountains. Using systematic vegetation surveys (31 sampling sites) and pollen analysis, we employed the Extended R-Value (ERV) model to quantify both the Relevant Source Area of Pollen (RSAP) and RPP values for 11 dominant plant taxa. Furthermore, synthesized RPP data for the subtropical evergreen broadleaved forest was applied with the REVEALS model to reconstruct regional vegetation dynamics in the Dajiuhu Lake area during the Holocene. Key findings include: (1) Optimal parameterization was achieved using ERV sub-model 3 coupled with the Prentice model, yielding an estimated RSAP of 475 m. The RPP values, ranked in descending order, were as follows: Pinus (16.93 ± 1.909), Gleicheniaceae (1.42 ± 0.102), Quercus (1.00 ± 0.000), Poaceae (0.79 ± 0.197), Euphorbiaceae (0.18 ± 0.041), Cunninghamia (0.12 ± 0.019), Ericaceae (0.12 ± 0.033), Theaceae (0.10 ± 0.020), Asteraceae (0.10 ± 0.014), Bambusoideae (0.03 ± 0.008), and Urticaceae (0.02 ± 0.012). (2) Quantitative vegetation reconstruction based on the REVEALS model reveals the historical dynamics of the subtropical evergreen broadleaved forest in the Dajiuhu Lake area: progressive expansion during the Early- to Mid-Holocene, followed by a Late Holocene contraction aligned with intensified anthropogenic activities. This study provides critical RPP parameters for East Asian monsoon regions, addressing a critical knowledge gap in pollen-based vegetation modeling.