Aboveground and belowground biomass and its' allometry forSalsola passerinashrub in degraded steppe desert inNorthwesternChina

Knowledge of the biomass allometry and partitioning is essential for understanding shrub adaptive strategies to degraded habitats as well as for estimating organic carbon storage. We studied biomass accumulation, allocation patterns, and allometric models ofSalsola passerinashrub in the Alxa Desert steppe, Northwestern China. We measured aboveground and belowground biomass accumulation across different ages (0-50 years) by destructive sampling. The biomass allocation patterns between aboveground biomass, leaves, branches, and roots were studied by fitting allometric functions for both pooled and age-classed data. Allometric biomass models were developed by regressing on single-input variable of basal diameter, crown area, height, and age alone or on the pairwise variables of above four parameters. Biomass accumulation increased with age, aboveground components represented 86-89% of the total biomass, root to shoot biomass ratios increased with shrub age. Allometry patterns ofS. passerinawere relatively constant, and the growth rate of root was faster than that of aboveground components. Allometric models with two-input variables were obviously better than single variable models. Crown area and basal diameter were the best predictors for biomass ofS. passerinashrub.

Automated summary

The study on biomass allocation patterns and allometric models ofSalsola passerinashrub in the Alxa Desert steppe revealed that biomass accumulation increased with age, aboveground components accounted for a high proportion, and root to shoot biomass ratios increased with shrub age. Allometric models with two-input variables outperformed single-variable models, with crown area and basal diameter being the best predictors for biomass ofS. passerinashrub.