Carbon, Nitrogen, and Phosphorus Stoichiometry between Leaf and Soil Exhibit the Different Expansion Stages of Moso Bamboo (Phyllostachys edulis (Carriere) J. Houzeau) into Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook.) Forest

The expansion of Moso bamboo (Phyllostachys edulis (Carriere) J. Houzeau) has triggered native forest retreat and a range of ecological issues, especially for the Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) forests with similar growing conditions. In order to reveal the stoichiometric characteristics of Moso bamboo succession and scientifically control the forest retreat caused by the expansion of Moso bamboo into Chinese fir, mixed forests including 0%, 30%, 50%, 60%, and 80% of Moso bamboo expanded into Chinese fir forests were used to simulate the expansion stages I, II, III, IV, and V, respectively. In addition, by measuring the C, N, and P contents in Moso bamboo leaves and soils and calculating the correlation stoichiometric ratios, the correlation and coupling of which were explored and combined with an ecological homeostasis model at different stages of Moso bamboo expansion. The results demonstrated that P was a key element for the high utilization of Moso bamboo growth, and the expansion principle was influenced by N limitation. The conclusion was that the anthropogenic regulation of C content in soil could achieve the purpose of expansion control and exploit the carbon sequestration capacity in the mixed forest with half Moso bamboo and half Chinese fir, which should discourage the expansion.