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The data collected for all five bamboo species are consistent with the "diminishing returns" hypothesis, i.e., the scaling exponents governing the leaf area vs. dry mass scaling relationship are less than one within and across species and are insensitive to light conditions or elevation.

BackgroundExploiting soil microorganisms in the rhizosphere of plants can significantly improve agricultural productivity; however, the mechanism by which microorganisms specifically affect agricultural productivity is poorly understood. To clarify this uncertainly, the rhizospheric microbial communities of super rice plants at various growth stages were analysed using 16S rRNA high-throughput gene sequencing; microbial communities were then related to soil properties and rice productivity.ResultsThe rhizospheric bacterial communities were characterized by the phyla Proteobacteria, Acidobacteria, Chloroflexi, and Verrucomicrobia during all stages of rice growth. Rice production differed by approximately 30% between high- and low-yield sites that had uniform fertilization regimes and climatic conditions, suggesting the key role of microbial communities. Mantel tests showed a strong correlation between soil conditions and rhizospheric bacterial communities, and microorganisms had different effects on crop yield. Among the four growing periods, the rhizospheric bacterial communities present during the heading stage showed a more significant correlation (p <  0.05) with crop yield, suggesting their potential in regulating crop production. The biological properties (i.e., microbes) reflected the situation of agricultural land better than the physicochemical characterics (i.e., nutrient elements), which provides theoretical support for agronomic production. Molecular ecological network (MEN) analysis suggested that differences in productivity were caused by the interaction between the soil characteristics and the bacterial communities.ConclusionsDuring the heading stage of rice cropping, the rhizospheric microbial community is vital for the resulting rice yield. According to network analysis, the cooperative relationship (i.e., positive interaction) between between microbes may contribute significantly to yield, and the biological properties (i.e., microbes) better reflected the real conditions of agricultural land than did the physicochemical characteristics (i.e., nutrient elements).Electronic supplementary materialThe online version of this article (10.1186/s12866-018-1174-z) contains supplementary material, which is available to authorized users.

1. The whole-plant economics spectrum (PES) refers to the trade-offs among the many plant functional traits that are commonly used as indicators of major adaptive strategies, thereby providing insights into plant distributions, ecosystem processes and evolution. However, there are few studies of what may be called the whole-PES that integrates bark, wood and leaf functional traits for different leaf types and growth habits (evergreen vs. deciduous species).2. To address this gap in our knowledge, 6 bark traits, 7 wood traits (including mechanical support and nutrient transport characteristics) and 12 leaf traits (including chemical, structural and physiological characteristics) of 59 representative subtropical woody species were examined using principal component analysis (PCA) to determine PES strategies.3. The economics spectra of bark (BES), wood (WES) and leaves (LES), and the entire PES indicated that major traits represent resource acquisition strategies and conservation strategies clustering on the opposite ends of the PCA axis. A significant correlation was observed among the 25 functional traits. The data indicated that N and P nutrient levels were at the hub of BES, WES, LES and PES interrelationships. Evergreen and deciduous species had different WES and LES, and thus PES resource acquisition strategies. With the exception of the BES, evergreen species clustered on the conservative side, whereas deciduous species clustered on the acquisitive side. Synthesis.The PES presented here informs our understanding of whole-plant responses to environmental differences, particularly regarding the role of N and P traits at the whole-plant level. It also reveals and further supports the notion that evergreen and deciduous species, respectively, manifest conservative and acquisitive strategies, further informing our understanding of species biodiversity maintenance.