Different Leaf Nutrient Use Strategies of Nitrogen-fixing and Non-nitrogen-fixing Leguminous Trees in South China

Abstract:

To reveal leaf nutrient use strategies of nitrogen-fixing leguminous trees (NLT) and non-nitrogen-fixing leguminous trees (n-NLT) under the nitrogen-rich environments in South China, five NLT (Pongamia pinnata, Acacia auriculiformis, Calliandra haematocephala, Ormosia pinnata, Acacia confuse) and three n-NLT (Sindora glabra, Saraca dives, Peltophorum tonkinense) were selected, the concentrations of carbon (C), nitrogen (N) and phosphorus (P) per leaf mass, leaf C: N and C: P, maximum net photosynthetic rate per leaf area (A_area), photosynthetic nitrogen use efficiency (PNUE) and photosynthetic phosphorous use efficiency (PPUE) were measured. The results showed that N and P contents and A_area of NLT were significantly higher than those of n-NLT, whereas their PNUE and PPUE had not significant difference. Although there was no significant difference in leaf C content between two types of species, leaf C: N and C: P of NLT were significantly lower than those of n-NLT. Therefore, these indicated that NLT in South China had stronger nutrient acquisition and photosynthetic capacity than N-NLT, but lower leaf nutrient utilization efficiency.

Key words:Fabaceae;Nitrogen fixation;Nutrient trait;South China