Mechanisms Underlying the Aggravation of Ageratina Adenophora Invasion in Areas with Acidic and Nutrient-Poor Soils: The Roles of Soil pH and Micronutrients

Research Hypotheses：we aimed to determine (1) whether the soil pH increases with increasing invasion level; (2) how the contents of major soil micronutrients change with increasing invasion level; and (3) the mechanisms through which changes in soil pH and micronutrient levels may facilitate increased invasion. Data Description and Collection Data Collected: Soil Physicochemical Properties:（PC_zjzl） Macronutrients: SOC, TN, TP, TK, AN, AP, AK. Micronutrients: Total and available Fe, Mn, Zn, Cu, B, Ca, Mg, Al.（WLYS_zjzl & WLYSXX_zjzl） pH: Soil acidity/alkalinity. （PC_zjzl） Soil Enzyme Activity: SUE (soil urease), ALP (alkaline phosphatase), SSC (sucrase), NR (nitrate reductase), CAT (catalase). (MLX+zjzl) Vegetation Data: Plant species composition and A. adenophora coverage (%) across invasion levels (C, L, M, S). Sampling Methodology: Site Selection: 24 plots (6 per invasion level) in Pinus yunnanensis forest (slope: 25–40°; elevation: ~1900 m). Soil Sampling: Five subsamples per plot (0–20 cm depth), homogenized, sieved (2 mm), and analyzed for lab assays. （zyh_经纬度） Statistical Analysis for R 4.2.2 （ZJZL_LW.R & .Rhistory & .RData） ANOVA for micronutrient differences across invasion levels. RFM (random forest model) and SEM (structural equation modeling) to identify key drivers of invasion effects.