Is Branching Intensity Interspecifically Related to Biomass Allocation? A Survey of 25 Dicot Shrub Species from an Open‐Growing Dry Valley

Abstract

The objective of this study was to test whether branching intensity is interspecifically correlated with the biomass allocation patterns of woody species at the level of the whole plant. For this purpose, we examined leaf size and number and branch size and number at different branch orders and computed both a commonly used measure and a newly constructed measure of branching intensity (i.e., Whitney’s parameter and γ, respectively) to determine whether biomass allocation patterns are correlated with branching intensity for 25 shrub species from a dry valley in southwest China. Whitney’s parameter (BI) was calculated as $$( N_{\mathrm{T}\,}-1) / ( N_{\mathrm{T}\,}-N_{\mathrm{t}\,}) $$ for whole plants, where NT is the total branch number at different branch orders and Nt is the number of terminal branches. Gamma was calculated as Nt divided by the maximum branch order. No significant across‐species relationship was found between BI and the quotient of leaf and stem mass. However, a positive correlation was observed between BI and the quotient of stem and root mass. In contrast, γ was negatively correlated with the quotient of leaf and stem mass but not correlated with the quotient of stem and root mass. The relationship between branching intensity and biomass allocation patterns could be understood from the allometries among the study architectural traits. In conclusion, branching intensity is interspecifically correlated with biomass allocation patterns. However, the correlation is parameter specific, because different measures of branching intensity produce different kinds of correlations.