南亚热带人工林16种木本植物重要叶特征参数的相互关系

Relationships of Key Leaf Traits of 16 Woody Plant Species in Low Subtropical China

摘要:

以南亚热带退化丘陵生态恢复进程中16种3 a生木本植物为对象，研究叶片重要特征参数间的相互关系。结果表明，植物叶片的N、P含量平均值低于全国平均值，N: P平均值则高于全国的平均水平；成熟叶片的N和P含量之间有极显著正相关关系(P<0.00001)，N: P与N有弱的正相关关系(r=0.322, P<0.01)，与P显著负相关，推断植物叶N: P主要由P决定(r=0.639, P<0.00001)。含N量高的植物具有高的最大净光合速率(Pmax)、光合N利用效率(PNUE)和低的比叶重(LMA)，反之，含N量低植物具有低的Pmax、PNUE和高的LMA；Pmax与PNUE极显著正相关，LMA与PNUE极显著负相关。

Abstract:

Nitrogen content (N), phosphorous content (P) in leaves, leaf mass per area (LMA), max. net photosynthetic rate (Pmax) and photosynthetic nitrogen use efficiency (PNUE) of 16 woody species were examined, which were used for the restoration of degraded hilly land. The results showed that contents of N and P in leaves were 18.8 mg g-1, 1.07 mg g-1, that were 6.9% and 26% lower than the national average levels (20.2 mg g-1, 1.46 mg g-1), respectively. The average N: P ratio in leaves was 18.4, 12.9% higher than the national average level (16.3 mg g-1). N content in leaves was positively correlated with P content in leaves, and the N: P ratio was significantly correlated with P content in leaves, and weakly with N content in leaves. It suggested that N: P in leaves was mainly dependent on P content in leaves. The species with high N content in leaves generally had high Pmax, PNUE and low LMA, while those with low N content in leaves had low Pmax, PNUE and high LMA.