Forest structure is fundamental in determining ecosystem function, yet the impact of bamboo invasion on these structural characteristics remains unclear. We investigated 219 invasion transects at 41 sites across the distribution areas of Moso bamboo (Phyllostachys edulis) in China to explore the effects of bamboo invasion on forest structural attributes and diameter–height allometries by comparing paired plots of bamboo, mixed bamboo-tree, and non-bamboo forests along the transects. We found that bamboo invasion decreased the mean and maximum diameter at breast height, maximum height, and total basal area, but increased the mean height, stem density, and scaling exponent for stands. Bamboo also had a higher scaling exponent than tree, particularly in mixed forests, suggesting a greater allocation of biomass to height growth. As invasion intensity increased, bamboo allometry became more plastic and decreased significantly, whereas tree allometry was indirectly promoted by increasing stem density. Additionally, a humid climate may favour the scaling exponents for both bamboo and tree, with only minor contributions from topsoil moisture and nitrogen content. The inherent superiority of diameter–height allometry allows bamboo to outcompete tree and contributes to its invasive success. Our findings provide a theoretical basis for understanding the causes and consequences of bamboo invasion.

Shifts in tree species and their mycorrhizal associations driven by global change play key roles in biogeochemical cycles. In this paper, we proposed a framework of the mycorrhizal-associated nutrient economy (MANE), and tested it using nutrient addition experiments conducted in two tropical rainforests. We selected two tropical rainforests dominated by arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) trees, and established eighteen 20 ​m ​× ​20 ​m plots in each rainforest. Six nitrogen (N) and phosphorus (P) addition treatments were randomly distributed in each rainforest with three replicates. We examined the differences in soil carbon (C) and nutrient cycling, plant and litter productivity between the two rainforests and their responses to 10-year inorganic N and P additions. We also quantified the P pools of plants, roots, litter, soil and microbes in the two rainforests. Overall, distinct MANE frameworks were applicable for tropical rainforests, in which soil C, N and P were cycled primarily in an inorganic form in the AM-dominated rainforest, whereas they were cycled in an organic form in the ECM-dominated rainforest. Notably, the effects of mycorrhizal types on soil P cycling were stronger than those on C and N cycling. The intensified N and P deposition benefited the growth of AM-dominated rainforests instead of ECM-dominated rainforests. Our findings underpin the key role of mycorrhizal types in regulating biogeochemical processes, and have important implications for predicting the ecological consequences of global changes.