The scaling relationship of leaf area and total mass of sample plots across world trees

The scaling relationship between leaf area and total mass of plant has important implications for understanding resource allocations in the plant. The model of West, Brown and Enquist (WBE model) considers that a 3/4 scaling exponent of metabolic rate versus total mass to be optimal for each plant and has been confirmed numerous times. Although leaf area is a better proxy of the metabolic rate than leaf mass, few studies have focused on the scaling exponent of leaf area versus total mass and even fewer have discussed the diversification of this scaling exponent across different conditions. Here, I analyzed the scaling exponent of leaf area versus total mass of sample plots across world plants. I found that as the plant grows, it allocates fewer resources to photosynthetic tissues than expected by the WBE model. The results also empirically show that this scaling exponent varies significantly for different plant leaf habit, taxonomic class and geographic region. Therefore, leaf strategy in response to environmental pressure and constraint clearly plays a significant role.