Abstract
In order to make clear the relationships between photosynthesis and leaf N, leaf P and SLA of tropical trees, and test the differences in the relationships among life-form groups (trees, shrub-like trees and shrubs),seedlings and saplings of 101 species from a tropical montane rain forest, located in the Diaoluo Mountain of Hainan Island, were selected. The net photosynthesis based on area and mass (Aarea and Amass), leaf nitrogen content based on area and mass (Narea and Nmass), leaf phosphorus content based on area and mass (Parea and Pmass) and specific leaf area (SLA) were measured and/or calculated.The results showed that Aarea and Amass tended to follow the order of shrubs > trees > shrub-like trees. One-way ANOVA showed that the difference in Aarea between shrubs and shrub-like trees was significant (p < 0.05), and for Amass there were significant differences between shrubs and shrub-like trees and between shrubs and tree species (p < 0.05). The relationships between Aarea and Nmass were highly significant in all three life-form groups and for all species (p < 0.0001). The correlation between Aarea and Pmass was highly significant in shrubs (p = 0.0038), shrub-like trees (p = 0.0002) and for all species (p < 0.0001), but not significant in trees (p > 0.05). The relationship between Aarea and SLAwas highly significant in shrubs (p = 0.0006),trees (p < 0.0001) and for all species (p < 0.0001), however this relation was not significant in shrub-like trees (p > 0.05). The relationships between Amass and leaf N and SLA were highly significant in all three life-form groups and for all species (p < 0.0001). For Amass and leaf P, there were significant correlations in tree groups (p =0.0377) and highly significant correlations in shrub groups (p = 0.0004), shrub-like tree groups (p = 0.0018) and for all species (p < 0.0001). Stepwise regression showed that predicted Amass values were closer to the observed values than those for predicted Aarea values. Thus, it can be concluded that the relationships obtained from seedling and sapling measurements are close to those from mature individuals; correlations between photosynthesis and Nmass, Pmass and SLA traits are significant and the relationships are stronger and more stable for A mass than for Aarea.
NETL
NSTL
万方数据