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The objectives of this study were to investigate the allelopathic effects of sesame extracts of on seed germination of moso bamboo, and to isolate and identify the potential allelochemicals. A factorial design with three organs (root, stem and leaf) and five concentrations (0, 25, 50, 75 and 100 mg mL−1) was carried out. Seeds of moso bamboo were soaked in sesame extracts to investigate their germination and growth. The allelochemicals were isolated and identified using the high performance liquid chromatograph (HPLC) system. The germination indices of the same organ decreased with the increase of extract concentrations, while the mean germination time increased, picking at the concentration of 100 mg mL−1. The radicle length and plumule length decreased, while the ratio of radicle length to plumule length increased. The allelopathy inhibition effect increased with the increase of extract concentrations, and it was significantly higher at the concentration of 100 mg mL−1 than that of 25 mg mL−1. The synthesis effect increased with the increase of extract concentrations, and it was significantly higher in leaf than root and stem. Chemical analyses identified 9 allelochemicals species (mostly phenolics and alkaloids) in the aqueous extracts. These results indicated that aqueous extracts of sesame caused the delay in seed germination and growth of moso bamboo, and phenolics and alkaloids in the aqueous extracts maybe the major reasons for the observed inhibition effects of sesame. [ABSTRACT FROM AUTHOR]

• Resource sharing within clonal fragments of moso bamboo was detected both in homogeneous and heterogeneous environments. • The connected ramets of moso bamboo were selfish in homogeneous environments due to the low intensity of physiological integration. • The 15N translocation between the connected ramtes of moso bamboo was determined by the demand-driven source-sink relationship in heterogeneous environments. • Physiological integration significantly improved the NUE of moso bamboo. Physiological integration is a means of adapting to the natural selection of moso bamboo. Connected ramets can translocate and share nitrogen (N). This phenomenon may affect the nitrogen use efficiency (NUE) of moso bamboo. The aims of this study were to investigate the characteristics of N physiological integration and its relationship with NUE of moso bamboo. We established an in-situ experiment to trace the movement of 15N between connected ramets (parent and offspring ramets) of moso bamboo in both homogeneous and heterogeneous N conditions. Results showed that 15N sharing within the clonal systems of moso bamboo was detected in both homogeneous and heterogeneous environments, and 15N translocation was bidirectional between the connected ramets. The intensity of physiological integration (IPI) was relatively low in homogeneous environments, and the connected ramets of moso bamboo were selfish. 15N translocation between the connected ramtes of moso bamboo was determined by the demand-driven source-sink relationship in heterogeneous environments, and the fertilized ramets of moso bamboo were selfish. The NUE of the connected treatment was significantly higher than that of the severed treatment, illustrating that physiological integration significantly improved the NUE of moso bamboo. Additionally, the NUE in heterogeneous environments was significantly higher than that in homogeneous environments. These results clearly demonstrate that N is readily translocated between the connected ramets of moso bamboo, particularly in heterogeneous environments, which provides reference for precision fertilization management in moso bamboo forests. [ABSTRACT FROM AUTHOR]

The root of Moso bamboo (Phyllostachys edulis (Carrière) J. Houz.) develops extremely rapidly at seedling phase and is highly sensitive to water content in soil, but its response patterns and adaptation strategies of its root to drought are little known. The aim of this study was to investigate the response of root morphology and architecture of Moso bamboo to drought at seedling phase and then to explore the drought adaptation strategies of its root. One-year-old potted seedlings of Moso bamboo were planted under three drought treatments (control, moderate drought and severe drought) for three months. Seedling growth, specific root length (SRL), root architecture (fractal dimension (FD), root branching angle (RBA) and root topological index (TI)) and non-structural carbohydrate (NSC) concentrations in roots were measured every month. The results are as follows: (i) The dry weight of root and shoot decreased significantly under drought stress. (ii) The SRL decreased under drought stress in the early duration (the first month), and then increased in the late duration (the third month). Both FD and RBA decreased, while TI and the concentrations of NSCs increased under drought stress. (iii) The NSC concentrations were positively correlated with SRL and TI, but exhibited an inverse relationship to FD and RBA. Our results indicated that Moso bamboo seedlings formed a "steeper, simpler, expensive (low SRL and high TI)" root architecture to adapt to a short-term drought (one month), and formed a "cheaper (high SRL)" root to adapt to a long-term drought (three months). Increase of NSC concentrations supported the root architecture plasticity to some extent. [ABSTRACT FROM AUTHOR]

• N fate was compared in different application methods (furrow and hole) and depths (0–20 and 20–40 cm). • Furrow application at 20–40 cm (F40) increased N use efficiency and decreased N loss. • The N competitive ability of I du bamboo (1–2 year old) was significantly higher than that of the other ages. Appropriate fertilization practice is crucial to increase nitrogen (N) recovery efficiency and decrease N loss. Our aim is to determine the appropriate fertilization placement and the target age in moso bamboo forests. A field experiment was conducted to determine the effects of application methods (furrow and hole) and depths (0–20 and 20–40 cm) on the fate of urea-15N in moso bamboo forests. The 15N tracer technique was used to investigate the fates of the applied 15N fertilizer. The largest biomass was obtained from the bamboo culm (42.25–54.09%), but the maximum absorption and N content occurred in the leaves (28.86–39.31%). The N recovery efficiency of urea-15N was significantly higher for deep applications (30.62–31.14%) than for shallow applications (26.68–27.49%), whereas no significant difference was found between the furrow and hole applications. The residual 15N was mainly concentrated in the fertilized soil layer, and the residual 15N recovered from the 0–60 cm soil layer was 16.29–19.47%. The highest N recovery efficiency (31.34%) and lowest N loss (49.91%) were observed for the furrow application at 20–40 cm. In addition, the N competitive ability and N recovery efficiency of the I du (moso bamboo age, 1–2 years old) bamboo were 0.069 mg kg−1 d−1 and 13.29%, respectively, which were significantly higher than those of the other ages. Therefore, furrow application at depth of 20–40 cm is recommended for practical applications, and the I du bamboo should be the target of fertilization in moso bamboo forests. [ABSTRACT FROM AUTHOR]

Land use change is the second main reason for carbon (C) emissions after fossil fuel combustion, and it is recognized as an important driving force for soil organic carbon (SOC) and soil nitrogen (N) dynamics. Conversion of the secondary forest to Chinese fir ( Cunninghamia lanceolata [Lamb.] Hook) and Moso bamboo ( Phyllostachys heterocycla [Carr] Mitford cv. Pubescens ) plantations represents one of the most important land use changes in subtropical China. However, the effects of these land use changes on the SOC and N stocks were not well documented. Therefore, in this study soil samples were collected in a secondary forest, a 17-year Chinese fir and a 18-year Moso bamboo plantation after the conversion from the secondary forest in November 2013, and total SOC and N concentrations were measured. Total SOC and N concentrations decreased with soil depth over the 0–50 cm in three land uses, and they were significantly higher in the secondary forest than those of Chinese fir and Moso bamboo plantations; however, these concentrations were not significantly different between Chinese fir and Moso bamboo plantations. Top soil (0–10 cm) stored one third of total SOC and N stocks. SOC and N stocks in the secondary forest were significantly higher than those of Chinese fir and Moso bamboo plantations with values of 203.68, 127.34 and 118.25 t·ha − 1 for SOC stock and 9.24, 5.10 and 6.35 t·ha − 1 for N stock. The results indicated that converting the secondary forest to Chinese fir and Moso bamboo plantations significantly decreased the SOC and N stocks over 0–50 cm. [ABSTRACT FROM AUTHOR]