Spatial distribution of fine root traits in relation to soil properties and aggregate stability of intensively managed Moso bamboo (Phyllostachys edulis) plantations in subtropical China

To demonstrate how intensive management practices affect the belowground productivity of Moso bamboo, we examined the spatial distribution of fine root traits under three stands with high-intensity (T1, tillage plus biennial fertilization), low-intensity (T2, tillage plus quadrennial fertilization), and extensive (CK, no-tillage plus no fertilization) management, and evaluated the relationships among root traits and soil properties, aggregate stability (MWD).

Bamboo fine root and soil samples were collected from three depths (0–10, 10–20, 20–30 cm) and three horizontal distances (20, 40, 60 cm) under three management strategies. Root biomass, root morphology, soil properties, and aggregate composition were determined.

Compared with CK, T1 and T2 had higher fine root biomass (FRB), and the largest FRB in the 10–20 cm soil layer. T1 had significantly higher allocation proportion of D_1–2 class FRB and root length density (RLD) and significantly lower specific root length (SRL) and specific surface area (SSA). Vertically, intensive management led to an increase in FRB in the 10–20-cm soil layer and MWD in the 20–30-cm soil layer. Horizontally, FRB was highest at a distance of 20 cm from bamboo culm. A strong positive correlation was identified among FRB, RLD, and TP in each soil layer as well as among MWD, TP, and RLD.

Intensive management promotes fine root growth with high length in response to more soil P content, and high-intensity management shifts the expression of root functional traits toward transport fine roots proportion and 10–20-cm soil layer, and facilitates aboveground productivity of Moso bamboo. TOC, TP, and RLD are the main three drivers correlated with soil aggregate stability.