Speaker
Description
Tree diversity and mycorrhizal types are key drivers of belowground ecosystem processes, yet their interactive effects on microbial and soil faunal life-history strategies across soil depths remain poorly understood. In this study, we investigated how tree species richness and mycorrhizal types influence the r/K life-history strategies of soil bacteria, fungi, and nematodes, and how these soil biodiversity responses are linked to soil physicochemical properties across a deep soil profile. The study was conducted in the MyDiv experimental platform, a nine-year field biodiversity experiment with manipulated tree species richness (1, 2, and 4 species) and mycorrhizal association types (arbuscular mycorrhizae [AM], ectomycorrhizae [EM], and mixed AM+EM communities). Soil samples were collected across eight depth intervals (0–5, 5–10, 10–20, 20–30, 30–40, 40–50, 50–60, and 60–100 cm). We quantified soil chemical and physical properties including total carbon (TC), total organic carbon (TOC), inorganic carbon (TIC), labile organic carbon (LOC), recalcitrant organic carbon (ROC), total nitrogen (TN), soil pH, and soil moisture, alongside microbial and nematode community composition and r/K life-history strategies. Our results demonstrate several significant interaction effects of mycorrhizal type, tree species richness (TSR), and soil depth on microbial and nematode r/K strategies. Across the soil profile, bacterial and nematode r/K ratios increased with soil depth, whereas fungal r/K strategies showed an opposite trend, resulting in a pronounced depth-dependent divergence in fungal r/K patterns. In particular, AM-associated systems exhibited significantly higher r/K values compared to AM+EM and EM systems. Distinct vertical stratification patterns were observed between soil properties and ecological strategies. The topsoil layer (0–30 cm) was primarily associated with higher concentrations of TOC, LOC, TN, soil moisture, and fungal r/K strategies, whereas deeper soil layers (40–100 cm) were mainly characterized by higher TIC and soil pH, and were more strongly associated with bacterial and nematode r/K strategies. Overall, our findings demonstrate that mycorrhizal type and soil depth jointly structure belowground life-history strategies, with these effects being mechanistically driven by depth-dependent shifts in soil carbon fractions and nutrient availability.
| Status Group | Postdoctoral Researcher |
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