Arbuscular mycorrhizal tree dominance affect leaf nutrient status and resorption efficiency in subtropical forest with different tree diversity

In March 2021, we established a randomized block experiment, combining diversity level with AM tree dominance. We selected four AM tree species (Cunninghamia lanceolate (Lamb.) Hook., Schima superba Gardner & Champ., Mytilaria laosensis Lec., Liquidambar formosana Hance) and four EM tree species (Pinus massoniana Lamb., Alnus trabeculosa Hand.-Mazz., Castanopsis carlesii (Hemsl.) Hayata., Castanopsis fissa (Champ. ex Benth.) Rehder & E. H. Wilson in Sarg.) with wide distribution and economic values. Two-year-old tree seedlings were planted either in monoculture or in mixtures, at a density of 256 individuals per plot (plot size is 12 m × 12 m, tree spacing is 0.80 m). We established three diversity levels (one, two, or four species per plot) with arbuscular mycorrhizal (AM) tree dominance of 0% and 100% at 1 tree species level, 0%, 50% and 100% at 2 tree species level, and 0%, 25%, 50%, 75% and 100% at 4 tree species level. Overall, the experiment included 28 treatments, roughly distributed in four blocks, resulting in 112 plots.