Abstract:

Leaf functional traits are closely associated with resource acquisition and utilization as well as changes of environment. In this study, we studied leaf functional traits of six common species in an evergreen broad-leaved forest in the Jinyun Mountain and their relationships under different light regimes and compared leaf traits of species at different successional stages. The results showed that: 1) specific leaf area (SLA), mass-based leaf nitrogen content (LNC) and N:P ratio in gaps and understory were significantly higher than those in open areas of forest edge. Leaf dry matter content (LDMC) in gaps was significantly lower than that in open areas of forest edge. There were no significant differences in mass-based leaf phosphorus content (LPC) among light regimes. 2) Species at different successional stages had different leaf carbon investment strategies. Early-successional species trend to have higher SLA, LNC, and LPC but lower LDMC and N:P ratio than late-successional species. 3) Across species, LNC was positively correlated with SLA and LPC, and LDMC was negatively correlated with LPC, LNC and SLA. N:P ratio was negatively correlated with LPC, but not correlated with LNC. The relationships between leaf traits under different light regimes were generally the same, but varied significantly along common slope (excepted LNC-LPC) and Y-intercept. These results indicated that the trade-offs of multi-traits had dynamic changes to adapt to different light regimes, and plants adapted to low-light environment by increasing SLA, LNC or maintaining a high N:P ratio.

Key words: evergreen broad-leaved forest, leaf functional traits, adaptation strategy, light regimes, successional stage