低营养条件下外来种火炬树与本地种麻栎幼苗在生物量分配策略上的差异

Nitrogen (N) and phosphorus (P) are essential mineral nutrient elements in plant and play vital roles in individual life history and community structure. Anthropogenic nitrogen emission has led to eutrophication in many ecosystems, and changed the relative importance of nutrient elements and raised the availability of N relative to other elements, which may change the relationship between exotic and native plants. We conducted a greenhouse experiment to examine the effects of different nutrient conditions on the relationship between an exotic plant and a native plant. Native species Quercus acutissima and alien species Rhus typhina, were grown in monoculture or mixture, under three N: P ratios. After 12 weeks of treatment, biomass partitioning and leaf traits for nutrient absorption were determined. R. typhina was the dominated species in competition and the dominance increased with increasing N: P ratios. The strong competitive response of R. typhina was associated with high capacity for carbon assimilation and nutrient absorption. R. typhina invested more photosynthate to leaves, enabling its great biomass production and high growth. The trade-off in biomass and nitrogen partitioning between two species is the main reason for their different performance in competition and has crucial influence to plant properties in changing environment.