Fig. 3From: Nitrogen addition method affects growth and nitrogen accumulation in seedlings of four subtropical tree species: Schima superba Gardner & Champ., Pinus massoniana Lamb., Acacia mangium Willd., and Ormosia pinnata LourEffects of N addition levels and methods on N accumulation in four tree species (mean ± SD). Different lowercase letters above the error bars indicate significant differences among N addition level in each species (p < 0.05). S-CK: ambient N addition to the soil, S-MN: medium N addition to the soil, S-HN: high N addition to the soil, C-CK: ambient N addition to the canopy, C-MN: medium N addition to the canopy, and C-HN: high N addition to the canopyBack to article page