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Biomass partitioning is important for illustrating terrestrial ecosystem carbon flux. West, Brown and Enquist (WBE) model predicts that an optimal 3/4 allometric scaling of leaf mass and total biomass of individual plants will be applied in diverse communities. However, amount of scientific evidence suggests an involvement of some biological and environmental factors in interpreting the variation of scaling exponent observed in empirical studies. In this paper, biomass information of 1175 forested communities in China was collected and categorized into groups in terms of leaf form and function, as well as their locations to test whether the allocation pattern was conserved or variable with internal and/or environmental variations. Model Type II regression protocol was adopted to perform all the regressions. The results empirically showed that the slopes varied significantly across diverse forested biomes, between conifer and broadleaved forests, and between evergreen and deciduous forests. Based on the results, leaf form and function and their relations to environments play a significant role in the modification of the WBE model to explore more accurate laws in nature. [ABSTRACT FROM AUTHOR]

Million-hectare plantations of Cyclobalanopsis glauca were planted in southwest China to restore the degraded vegetation. Although many studies of these plantations have been conducted, from the genetic scale to regional scales, the role of stand age in regional carbon (C) cycling remains unclear. In this study, we examined the biomass and C storage of the main ecosystem components in five C. glauca plantation stands in Guangxi Province, southwest China, that ranged in age from 8 to 70 years. The ecosystem and tree biomass increased with increasing stand age. On average, the highest C concentration was found in tree branches, whereas the lowest C concentration was found in the underground parts of herb. C concentration in trees, shrubs, herbs, and litter were age-dependent. C storage in C. glauca plant biomass in stands aged 8, 20, 40, 50, and 70 years was 40.45, 78.25, 90.41, 94.46, and 114.69 Mg ha −1 , respectively. Soil organic C (SOC) storage in the top 1 m of soil in plantations aged 8, 20, 40, 50, and 70 years was 70.38, 90.84, 84.39, 47.91, and 107.99 Mg ha −1 , respectively, with SOC concentration decreasing with increasing soil depth. Total C storage in the plantation ecosystem averaged 110.83, 169.09, 174.80, 142.37, and 222.68 Mg ha −1 in the 8-, 20-, 40-, 50-, and 70-year-old plantations, respectively, with most of the C storage in the aboveground biomass and soil rather than in the belowground biomass. Our results suggest that successional development as temporal factor influencing C storage in plantations are important considerations for fully realizing the ecological value of the C. glauca plantations in southwest China. [ABSTRACT FROM AUTHOR]

Abstract: Despite the importance of root density regulation, this has received little attention compared with density regulation of aboveground plant parts and there is a similar lack of comparisons between above and belowground mass–density relationships. Here we report on field investigations in three sites to study these two aspects. We found that the belowground mass–density exponents (α) were closer to −4/3 and they varied less than the aboveground α along an aridity gradient. These differences arose because of variation in root:shoot ratios. [Copyright &y& Elsevier]