Photosynthetica 2010, 48(4):559-566 | DOI: 10.1007/s11099-010-0073-9

Contrasting leaf characteristics of trees and lianas in secondary and mature forests in southwestern China

L. Han¹, L. J. Xie^2,*, K. J. Dai³, Q. Yang⁴, Z. Q. Cai^1,*

¹ Research Institute of Forestry, Chinese Academy of Forestry/Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Beijing, China

² School of Applied Chemistry and Biotechnology, Shenzhen Polytechnic, Guangdong, China, China

³ China Kunming Branch, Chinese Academy of Sciences, Kunming, China

⁴ Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China

We compared variation in sun-canopy leaf anatomy, morphology and photosynthetic rates of coexisting woody species (trees and lianas) in an 8-year-old secondary forest (SF) and mature forest (MF) in the wet season in Xishuangbanna, SW China. Variability of leaf traits of 66 species within growth-form groups in each forest was quantified using coefficients of variation (CV). For the mean values, the woody species in the SF had significantly higher leaf thickness and stomatal density, but lower nonmesophyll/mesophyll ratios than those in the MF. The average leaf area and leaf mass area (LMA) in the studied woody species did not change greatly during the successional process, but differed significantly between the growth forms, with trees having higher values than lianas. The light-saturated photosynthetic rate per unit leaf area (A _a) of the woody species in the SF ranged from 11.2 to 34.5 μmol m^-2 s^-1, similarly to pioneer tree species from literature data in southeast Asia. The A _a and photosynthetic nitrogen-use efficiency (PNUE) were significantly higher than those in the MF; whereas A _a in the MF ranged between 9 to 21 μmol m^-2 s^-1, with similar values between lianas and trees. For all woody species in both SF and MF, there were no significant differences in the average values of the CV of all measured variables for both lianas and trees. However, considerable variation in leaf anatomy, morphology, and photosynthetic rates within both growth forms and forests existed, as well as substantial variation in leaf size and stomatal density. We concluded that the tropical woody species formed a heterogeneous functional group in terms of leaf morphology and physiology in both secondary and mature forests.

Keywords: leaf morphology; liana; photosynthetic rate; secondary forest; tree

Received: April 14, 2010; Accepted: August 20, 2010; Published: December 1, 2010Show citation