Scaling Relationship Of Twig Size To Leaf Size Across Hierarchical Branches For Woody Plants In An Evergreen Broad-leaved Forest In Tiantong Region, Zhejiang Province

Allocation of biomass among plant organs affects both plant structure and functioning, as well as ecosystem production and energy flow. Biomass allocation in plants is a very complex process. Many studies have tried to explain the biomass allocation strategy. Recently, relationships between plant growth and metabolic process are expounded in view of biomechanics and hydraulics through metabolic theory, attempting to link plant metabolic relationship with community pattern and process. Although mechanic basis was reasoned, the quantitative examination remains in blank.We have studied the scaling relationships between branch size (cross-sectional area and dry mass) and leaf size (leaf area and leaf dry mass), for woody plants in a 1 hectare permanent plot with evergreen broad-leaved forest in Tiantong region, Zhejiang Province. The result showed:1) branch size was positively correlated with leaf size. In species mean level, there is a common slop between different layers, the Y-axis intercept can be inferred that if the size of branch is certain, branch with more layers will support fewer leaves. The scaling relationship between twig size and leaf size was isometr(?)In the species level, different species have own allocation strategy, there will be no universal law of biomass allocation.2) Branch size (volume or quality) and branch intensity (based on volume or quality) is negative correlated which show that there is a trade-off between the branch size and branch intensity, and larger shoot with the lower intensity and fewer branches. If branch size is certain, branch with more layers and higher intensity will support smaller branches and vice versa.3) According to the growth correlation model which established by size and number of branches and leaves, the relationships between branches and leaves could be scaling up from twig to shoot and crown. The shoot and crown biomass of Castanopsis fargesii in one hectare plot is estimated as an application. Estimation results:the average total mass of branches and leaves is about 62.61kg per plant, in which the branches weight 48.77kg, mean leaves weight 13.84kg.