Responses of aggregates and associated soil available phosphorus, and soil organic matter in different slope aspects, to seasonal freeze–thaw cycles in Northeast China

•Soil aggregate stability in shady slope was more sensitive to freeze-thaw cycles.•Well relationships exist between the aggregate fractions and available phosphorus.•Soil organic matter of partial aggregate sizes were sensitive to freeze-thaw cycles. Freeze-thaw is an important factor that affects soil aggregate size and integrity in mid-high latitudes or mountainous regions, which in turn impacts soil erosion. However, there are limited studies on the responses of aggregates and associated soil available phosphorus (AP), as well as soil organic matter (SOM) in different slope aspects to seasonal freeze–thaw cycles (FTCs). In this regard, soil samples at different depths (0–5 [D5], 5–10 [D10], 10–15 [D15], and 15–20 cm [D20]) were collected from sunny (SW) and shady (NE) slopes in Meihekou, Northeastern China. Temporal changes in aggregate size distribution, AP (extracted with 0.5 mol L−1 NaHCO3), and SOM of SW and NE were analyzed during one FTCs season (from October 2017 to March 2018). Seasonal FTCs significantly (p 5 mm and