Advances in Bamboo Science最新文献

Given the hygroscopic nature of bamboo and its reduction in strength with increasing moisture content, we evaluated the effects of hornification – generated through the application of drying and rewetting cycles – on the physical, mechanical, and chemical properties of the culms of Dendrocalamus asper. Our objective was to assess if the treatment would cause a reduction in water uptake, an increase in the dimensional stability of bamboo, and a stiffening of the material, increasing its mechanical strength. Specimens were submitted to a maximum of 15 cycles, being immersed at room temperature (22 ± 3 °C) and dried at 50 ± 5 °C. Absorption capacity, dimensional stability, density as measured with a helium pycnometer, tensile tests, scanning electron microscopy (SEM) analysis, X-ray diffractometer (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were undertaken. Hornification increased the dimensional stability of bamboo proportionally to the number of cycles applied, and a 5.8 % increase in cross section was seen after 264 h for 15 cycles. The control samples increased by 17.8 %. Reduction in the water absorption was not verified for treated bamboo. The elastic modulus was maintained and the tensile strength after treatment was reduced (258.6 MPa for control and 207.5 MPa after 15 cycles). Chemical analysis and microscopy did not show any significant changes in the composition of the bamboo after the application of wetting and drying cycles.

Adsorption capacities of biochar are mainly influenced by the nature of biomass, the production conditions, or the method of modification. This paper reviews the production, functions, application and regeneration methods of bamboo biochar, showcasing its utilization and importance as an adsorbent for wastewater treatment. The technologies involved in the processing and enhancement of bamboo as well as the performance of its biochar are also discussed. The adsorption performance of bamboo improved following modification, as did its regeneration ability. Future research should focus on industrial-scale treatments and competitive sorption for contaminant removal.

Ethiopia has the largest bamboo resource base in Africa. However, due to the lack of species-specific models, little is known about the biomass storage, carbon stock and sequestration potential of bamboo forests. Here, species-specific allometric models are presented and the potential biomass and carbon storage of the Oldeania alpina (K. Schum.) Stapleton forests of Ethiopia are quantified. A total of 42 bamboo culms covering the full range of sizes were destructively sampled, with a diameter at breast height (DBH) ranging from 3 to 7.1 cm, height (H) of 7.8 – 14.2 m, and age 1 – 6-year-old. Allometric equations were formulated in the form of power models for estimating the total aboveground biomass (TAGB) of O. alpina. TAGB was regressed against DBH and H individually and in combination. Finally, the allometric models were validated and selected based on model performance statistics. Allometric equations for estimating TAGB with higher coefficient of determination (adj.R²), lower residual standard error (RSE), and low Akaike information criterion (AIC) values fitted best. Relationships between observed and predicted TAGB were statistically significant ($p\le 0.05)$ for the selected models. The developed allometric models can be applied to the estimation of the biomass storage potential of O. alpina forests of Ethiopia.

The dynamics of understorey dwarf bamboos are an important factor in forest dynamics. Although there have been a number of recent reports about the regeneration process after the simultaneous flowering and death of bamboos, the long-term dynamics of dwarf bamboos on the forest floor and outside the regeneration process (i.e., non-flowering state) are unclear. The present study aimed to investigate the long-term changes in Sasa kurilensis Makino & Shibata (Poaceae, Bambusoidae) populations in relation to the forest canopy and environmental conditions in the primeval beech forests of Shirakami-Sanchi World Heritage Area, Japan. Ten permanent plots (2 × 5 m) were established at three study sites (1 ha) in beech forests. Each site differed in forest structure. All S. kurilensis culms were censused from 2001 to 2019. The estimated maximum longevity of culms indicated that S. kurilensis culms can survive up to approximately 7000 days, nearly 20 years. The culm density and above-ground biomass varied widely amongst the study plots, and abrupt changes were observed in some plots affected by changes in the forest canopy conditions, such as gap formation. The relationship between canopy closure and culm density in 2001 showed an inverse proportional trend that weakened in 2019, indicating that S. kurilensis developed its population under closed canopies (dark conditions). More attention should be paid to such wide variations and unstable changes in understorey bamboo populations if the dynamics of these forests are to be better understood.

As a building material, engineered bamboo has caught attention around the world due to its advantages in energy conservation and environmental protection. The seismic performance of bamboo buildings needs to be evaluated to further promote the use of bamboo materials in building construction. We studied the seismic response of a 3-story bamboo frame structure numerically using nonlinear dynamic time history analysis. A simplified modeling method for bamboo column-beam joints was proposed in the numerical model. The hysteresis behaviour of the joint was simulated by Pinching 4 material in OpenSEES, with the parameters calibrated through test results. Comparative analysis shows that the proposed modeling method could reasonably reflect the pinching effect and the degradation of the joint hysteretic behavior. A total of 20 ground motions with three intensities were involved in the nonlinear dynamic analysis. The results demonstrate that the frame meets target performance levels, providing evidence for the further popularization of engineered bamboo structures.

Dendrocalamus giganteus Wall. Ex Munro (giant bamboo) is one of the most economically important bamboo species globally. However, propagation of Dendrocalamus giganteus from seed is hampered by the duration it takes to flower – making the large-scale production of planting stock for this valuable species untenable. This study was conducted under greenhouse conditions to determine the optimal doses of indole-3-butyric acid (IBA) and culm cutting position to propagate D. giganteus. Cuttings from the top, middle and basal culm positions were treated with different concentrations of Indole-3-Butyric Acid (0.6 %, 0.8 % and 1.0 %) and a control with distilled water. A mixture of top forest soil and sand in a ratio of 2:1 was used as a growth medium. The experiment was set up in a Complete Randomized Factorial Design (CRFD). Cuttings were monitored for the number of bud sprouts over 18 weeks. Results indicated that cuttings’ position and concentration of IBA greatly influenced the sprouting of D. giganteus. The highest bud sprouts were obtained for 0.6 % IBA and cuttings from the basal position. Bud sprouting was lowest in the control and cuttings from the top position. We conclude that while propagating D. giganteus by culm cuttings, basal cuttings and 0.6 % IBA should be encouraged.

The mechanical properties of bamboo are susceptible to degradation due to both physical and biological agents. Among the non-chemical treatments, we studied the influence of a short-time heat treatment, using an LPG-gas torch, on the mechanical properties of a bamboo (Phyllostachys viridiglaucescens) growing in Italy. The response was very encouraging as we found no significant reduction in either elastic modulus or tensile, compressive and bending strength.

Several samples were subject to tension, compression and bending tests to compare the responses of the treated and untreated culms. The average tensile elastic modulus was slightly greater for the untreated culms. The average tensile strength of the untreated culms was only slightly greater, and the differences can be assumed to be insignificant from a structural point of view. The average value of the treated culms compressive elastic modulus was slightly greater than that of the untreated ones. The compressive strength was essentially the same. The bending mechanical behaviour was barely influenced by the thermal treatment.

A microscopic investigation (optical and electron microscopy) was undertaken to investigate the possible deterioration of the bamboo microstructure due to the heat treatment. No appreciable damage was detectable in the treated material.

The proposed heat treatments can be considered as a reliable and sustainable protection practice for bamboo culms.

The tree slenderness coefficient (SC) has been widely used as an index of the resistance of trees to windthrow, and the slenderness coefficients of different tree species have been intensively studied. However, very little or no information is available for the slenderness coefficients of bamboo in many parts of the world including Nigeria. Here, we evaluated the slenderness coefficient of African giant bamboo (Bambusa vulgaris) in order to ascertain its level of resistance to windthrow and its suitability as a wind break. The study was undertaken in three states of south-western Nigeria (Osun, Oyo and Ondo states), with the diameter at breast height (DBH) and total height (TH) of the bamboo culms being measured. The volume, basal area and slenderness coefficient were evaluated and the relationship among the parameters and the slenderness coefficient was enumerated through correlation analysis. Regression analysis was undertaken to form models for the prediction of the slenderness coefficient for the study areas. The slenderness coefficients of bamboo culms were negatively correlated with diameter at breast height (DBH), volume and basal area but positively correlated with height for the three states. The graphical results indicated that bamboo has a slenderness coefficient below 70 and may not be at high-risk for windthrow, based on the model developed to predict slenderness coefficient values from (i) DBH and (ii) Height. The DBH function provided the best predictions and a Power model was found to have the best fit for prediction. We conclude that B. vulgaris has a low slenderness coefficient and it can be used as a wind break.

Microorganisms are a crucial component of forest soil ecosystems that are involved in the formation and transformation of soil organic matter. The soil microorganisms in bamboo forests have attracted significant attention, but the contribution of microbial residual carbon (MRC) to carbon sinks in bamboo forests is currently poorly understood. This review provides a holistic overview and perspective of the role of MRC in carbon sequestration processes of bamboo forests, reviewing and summarizing current progress in the understanding of forest soil microbial residues and C sequestration and sinks in bamboo forests. We elucidate the feasibility and prospects for future studies on MRC in bamboo forest soil and evaluate the importance of soil microorganisms to the bamboo forest soil ecosystem. Finally, we provide recommendations for the application of forest soil MRC to the study of bamboo forest soil carbon sinks.