Lin Zhang, Xin-Sheng Liu
Annales Botanici Fennici 47 (5), 346-352, (1 October 2010) https://doi.org/10.5735/085.047.0504
KEYWORDS: Bergenia purpurascens, elevation, leaf area, leaf length and width, linear measurements, non-destructive methods, timberline ecotone, validation
Accurate and non-destructive methods to determine individual leaf areas of plants are a useful tool in physiological and agronomic research. Determining an individual leaf area (LA) involves measurements of leaf length (L) and width (W), or some combinations of both parameters. Investigation was carried out in 2008 and 2009 to test whether a model could be developed to estimate leaf area of Bergenia purpurascens along an elevational gradient across a timberline ecotone, southeastern Tibet. A total of 786 leaves, 153–159 leaves for each 100-m elevation range, were measured in June 2008 for model construction. Coefficients of LA models incorporating both leaf dimensions (L and W) or W alone were independent of elevation, suggesting that a common model can be employed to estimate LA across the whole elevation range. A single-variable model using the leaf width (LA = 1.44W1.90), which was simpler, more convenient and also allowed reliable LA estimations, was developed. By applying this equation to another independent dataset from a later experiment in June 2009 for model validation, we found that observed and predicted LAs exhibited a high degree of correlation (R2 = 0.95). Therefore, this model can accurately estimate the leaf area of B. purpurascens across a timberline ecotone without use of any instruments.