Response of N and P stoichiometric characteristics of evergreen broad-leaved forest plant leaf to Phyllostachys edulis expansion

In order to explain the difference of survival response of plants at different levels in evergreen broad-leaved forest to the Phyllostachys edulis expansion from the perspective of ecological stoichiometry homeostasis, this study used the method of space-time substitution, a typical P. edulis evergreen broad-leaved forest interface including P. edulis forest, P. edulis broad-leaved mixed forest and evergreen broad-leaved forest was selected in Jinggangshan National Nature Reserve, Jiangxi Province. The N and P contents of soil and leaves of P. edulis, broad-leaved trees, shrubs and herbaceous layer plants in each forest were compared and analyzed. The results were as follows: (1) From bamboo forest to evergreen broad-leaved forest, the soil N content and N∶P increased, while soil P content decreased; the leaf P contents of tree species (Machilus thunbergii, Alniphyllum fortunei and Daphniphyllum macropodum) decreased and the N∶P increased. Unlike the trees, the leaf N and P stoichiometric characteristics of plants both in shrub and herbaceous layers showed no significant change, except the shrub tree Lindera erythrocarpa. (2) The soil N∶P was positively correlated with the leaf N∶P of trees, negatively correlated with that of shrubs and had no correlation with that of herbaceous plants, respectively. (3) The leaf N and P contents and N∶P for P. edulis remained stable. In conclusion, P. edulis expansion changes plant leaf N and P stoichiometric characteristics by altering the soil N and P stoichiometric characteristics. Shrubs and herbaceous plants are less affected, however, it causes the imbalance of plant N and P stoichiometric characteristics of tree layer plants, which may be an important reason for the survival of tree species in evergreen broad-leaved forest.