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Purpose: Soils develop via a complex interaction of time, environment, climate, and human activity. As a proxy for paleoclimate reconstruction, soils have received less attention than other geological systems, and the limited attention was concentrated in loess sequences. Fluvisols form a subrecent natural archive that documents mid-term pedogenic processes and environmental change in floodplains. We investigated the pedological characteristics and pedogenesis of fluvisols in the Beijing region and presented a Late Holocene paleoenvironmental reconstruction based on it. Methods: We applied the radiocarbon dating method to investigate soil formation in the floodplain of the North Canal in Beijing's southeast suburbs. Soil morphology, soil texture, and environmental physical–chemical indicators (calcium carbonate, organic matter, total phosphorus, and total potassium) were selected for comprehensive analysis. Results and discussion: Thorough integrated interpretation of soil development processes in the fluvisols sequence revealed regional paleoenvironmental and climatic developments. The paleoclimate of Beijing underwent a transition from warm and humid to temperate and dry, as well as multiple cold fluctuations. Multiple humic burial horizons in the fluvisol sequence were overlain by a mineral soil horizon with weak soil formation, indicating that fluvic geology processes interrupted the process of the fluvisol formation, corresponding to cold-dry fluctuations in a warm-humid paleoclimatic context in Beijing floodplain. There is a correlation between paleoclimatic environmental conditions and soil texture, organic matter, calcium carbonate, and other physical and chemical properties in the soil chronology. Conclusions: As an emerging paleoenvironmental proxy, the geological process and soil-forming process of fluvisols inferred from soil properties can reconstruct the variation of paleoclimatic-environmental conditions. Fluvisol sequence build-up and illuviated accumulation of mineral material in the soil complex were more pronounced in warm and humid climatic conditions. Millennia of farming practices dominate the development of the uppermost fluvisols. Environmental reconstruction based on fluvisol soil properties is complementary to reconstruction drawing on other prevalent paleoclimate proxies. Fluvisol characterisation allows to disentangle gradual paleoenvironmental developments, including changes of climate, vegetation, and topography. [ABSTRACT FROM AUTHOR]

[Display omitted] • The minimum data set was obtained using principal component analysis and Norm value. • The optimal value was the 75th percentile of the trace element background value. • The urban–rural fringe had a lower soil quality than the other three land use types. The expansion of the urban–rural fringe (URF) has greatly boosted the economy, but haphazard building and chaotic management have severely harmed the soil, particularly valuable arable land resources. The majority of studies have focused on the regional identification of URF, with little research on the influence of URF on soil quality. The soil quality index (SQI) method was used in this study to compare the soil quality of reclaimed land (FKD) in the URF to nearby grain fields (GD), open-air vegetable plots (CD), and facility vegetable plots (DP) in Daxing District, Beijing, China. The results indicated that the SQI of FKD was much lower than that of other land utilization types. Soil organic carbon (SOC), nitrogen, and phosphorus levels were low in FKD and might be improved with proper fertilization in subsequent management. The contents of Na, Mg, Ca, Fe, and total potassium (TK) in FKD were not statistically different from those in GD and CD, but the urease and sucrase activities in FKD were significantly lower than those in the other three land use patterns. A minimum data set including SOC, available phosphorus, TK, clay, Mn, and Zn was obtained for soil quality assessment using principal component analysis with Norm value and correlation analysis. Soil trace elements were standardized using an "optimum is better" scoring function using the 75th percentile of the element background values as the threshold. To our knowledge, this is the first time in soil quality assessment that the 75th percentile of the element background value for a specific soil type has been chosen as the optimum value. [ABSTRACT FROM AUTHOR]