A general allometric model for urban vines to estimate above-ground biomass

Abstract

Vines play an important role in urban vertical greening, while there is no practical method to estimate above-ground biomass of urban vines. Allometric equation is an effective approach for non-destructive estimation of biomass. However, due to lacking mechanical support tissue, vines may have distinctive allometric laws which existing allometric equations derived from self-supporting plants may not be applicable. Here, we collected 259 branches from 12 different species of urban vines to analyze the allometric relationships by standard major axis (SMA). We also built mixed-effect models and used ANOVA to investigate the effects of biotic and abiotic factors on these allometric relationships. Our results showed that leaf-stem biomass partition scaling allometric relationships of vine branches were stable and there was little significant difference among species and life forms, which showing strong biophysical constraints and supporting the predictions of theoretical allometry model such as metabolic scaling theory (MST). Almost all the biotic and abiotic factors have no significant effect on the exponents of diameter-leaf/stem biomass allometric relationships while only had weak effects on constants. Based on these results, we proposed a series of generalized equations to estimate above-ground biomass of common urban vines. Considering our finding that vines exhibit robust biophysical constraints and phylogenetic niche conservatism, which are hardly being affected by environmental factors, the utilization of general allometric equations may be a highly promising method to predict above-ground biomass of urban vines in the future.