PHOTOSYNTHETICA

Photosynthetica 2012, 50(3):337-342 | DOI: 10.1007/s11099-012-0039-1

Leaf shape alters the coefficients of leaf area estimation models for Saussurea stoliczkai in central Tibet

Z. Wang^1,2, L. Zhang^1,*

¹ Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

² Graduate University of Chinese Academy of Sciences, Beijing, China

Nondestructive methods to estimate individual leaf area (LA) accurately, by leaf length (L) and/or width (W), is helpful for the in situ and successive LA measurements. However, leaf shape and size may covary with environment and thus alter the coefficients of LA estimation models. To test such hypothesis, we carried out an experiment by measuring Saussurea stoliczkai C. B. Clarke leaves along an altitudinal transect in Damxung county, central Tibet. In July 2011, we selected seven sites at about every 150 m in altitude from 4,350 m to 5,250 m a.s.l. A total of 1,389 leaves (182 to 203 leaves for each site) were measured. For each site, models developed by two leaf dimensions [LA = a (L×W) + b] could estimate LA more accurately than those by single dimension. L, W, LA and leaf shape index (L:W ratio) all decreased with increasing altitude, leading to significant differences in coefficients of two-dimension model between almost every two sites. Accordingly, a common two-dimension model is unlikely to occur for S. stoliczkai across the whole altitudinal transect, indicating that the varying leaf shape may alter the coefficient of LA estimation models.

Additional key words: alpine grassland; altitude; leaf area; leaf length and width; nondestructive methods

Received: November 7, 2011; Accepted: March 29, 2012; Published: September 1, 2012  Show citation