Application of leaf size and leafing intensity scaling across subtropical trees

Understanding the scaling between leaf size and leafing intensity (leaf number per stem size) is crucial for comprehending theories about the leaf costs and benefits in the leaf size–twig size spectrum. However, the scaling scope of leaf size vs. leafing intensity changes along the twig leaf size variation in different leaf habit species remains elusive. Here, we hypothesize that the numerical value of scaling exponent for leaf mass versus leafing intensity in twig is governed by the minimum leaf mass versus maximum leaf mass (Mmin vs. Mmax) and constrained to be ≤ -1.0.

We tested this hypothesis by analyzing the twigs of 123 species datasets complied in the subtropical mountain forest. The standardized major axis regression (SMA) analyses showed the Mmin scaled as the 1.19 power of Mmax and the -a (-1.19) was not statistically different from the exponents of Mmin vs. leafing intensity in whole data. Across leaf habit groups, the Mmax scaled negatively and isometrically with respect ...