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Moso bamboo (Phyllostachys edulis) forest is one of the important alternative soruces in the tropical and subtropical regions. Its biomass quantification can be a basis of carbon storage estiamtion of the bamboo forest. Based on the destructively sample measurements of the moso bamboo in the Jiangsu Province in China, three forms of the model structures (controlling by sum of equation (CSE), level-1 proportional fitting distribution (L1PFD) and level-2 proportional fitting distribution (L2PFD)), and three estimation algorithms (ordinary least squares (OLS), two stage least square (2SLS) and three stage least square (2SLS)) were evaluated for identifying the best compatible biomass model. Results showed that all the three model structures solved the compatibility problems effectively. With each estimation algorithm applied, difference of the fit statistics between L1PFD and L2PFD was insignifcant. The fit statistics produced by 2SLS were slightly different from those of OLS, but fitting accuracy the latter was slightly higher, and had a more efficient estimation procedure. Thus, we recommend L1PFD model for predicting biomass for moso bamboo with use of diameter at breast height as a predictor variable. Our model will provide a reliable basis for estimating biomass and carbon stock of the moso bamboo forest in China. [ABSTRACT FROM AUTHOR]

Strip cutting has emerged as a new, efficient, and mechanized bamboo forest management model. To shorten the recovery period in strip cutting management, improve bamboo resource quality, prevent soil degradation, and achieve sustainable management, we selected on-year pure Moso bamboo (Phyllostachys edulis) forests for an 8-meter-wide strip cut. Three fertilization methods were applied in a complete two-factor experiment, including spreading, cave, and bamboo stump fertilization, at three fertilization dosages of 600, 900, and 1200 kg/ha (N:P:K = 3.5:1:2). We investigated the effects of different fertilization treatments on the biomass of new bamboo shoots and soil fertility to provide a reference for identifying the optimal fertilization scheme. The results showed that fertilization treatment increased the individual stand biomass of new Moso bamboo shoots, with a decreasing trend in the proportion of branches and leaves and an increasing proportion of culms in biomass allocation. Fertilization treatment significantly increased the total nitrogen, phosphorus, and potassium and available phosphorus contents in the soil. Overall, fertilization at 900 kg/ha using the spreading method showed the best results in promoting individual plant biomass recovery (5% increase in culm proportion and 4.12 kg increase in biomass per plant) and restoring soil fertility (increase the contents of TN, TP, TK, and AP in the entire soil layer) after strip cutting Moso bamboo forests, which addresses these pertinent issues in the strip cut management model. [ABSTRACT FROM AUTHOR]

We aimed to explore the effect of strip cutting width on the physical and mechanical properties of Moso bamboo (Phyllostachys edulis). Four-year-old hairy bamboo with different cutting bandwidths (3 m, 5 m, 8 m, 12 m and 15 m) was used as the experimental material, and the traditional management forest (CK) was used as the control. Eight physical and mechanical properties—radial line shrinkage, chordal line shrinkage, volume shrinkage, total dry density, basic density, compressive strength, shear strength and flexural strength—were studied. ANOVA, bivariate correlation analysis, and principal component analysis were performed, which showed the effect of strip cutting on the physical and mechanical properties of bamboo. The results showed that the density, the total dry density, basic density, flexural strength and compressive strength of the strip cut bamboo were lower than those of the control stand. The radial line shrinkage and volume shrinkage were higher than those of the control stand. The chordal line shrinkage was higher than that of the control stand when the cutting bandwidth was 3 m and 5 m and lower than that of the control stand when the cutting bandwidth was 8 m, 12 m and 15 m. The shear strength was lower than that of the control stand when the harvesting bandwidth was 3 m, 5 m and 8 m and higher than that of the control stand when the harvesting bandwidth was 12 m and 15 m. There are different degrees of correlation between the eight physical and mechanical performance indicators. The comprehensive score of the physical and mechanical properties of bamboo in the control stand was 1.30, and the comprehensive score of bamboo in strip harvesting was between 0.37 and 1.25, with an average score of 0.95. The results show that strip cutting can save the time and costs associated with harvesting Moso bamboo forests, but different cutting widths can reduce the physical and mechanical properties of Moso bamboo in different degrees. [ABSTRACT FROM AUTHOR]

Improved knowledge of nutrient removals from harvesting is essential for the sustainable management of Moso bamboo forests. In particular, the growth and development of bamboo forests are considered to meet the increasing demand for biomass energy. In this study, plots with an 8 m width strip cut (SC) after five years of restoration were selected as the research object and the traditional management forest (CK) as the control. The nutrient content and biomass of Moso bamboo at different ages were studied and the nutrient storage was calculated. The results showed that five years after cutting, the soil nutrient content in different soil layers and the aboveground nutrient storage reached the same level as the CK. The nutrient ranking of each organ of Moso bamboo was nitrogen > potassium > phosphorus. The phosphorus content of bamboo culm in CK was significantly higher than that in SC at different ages (p < 0.05). The biomass accumulation of each organ of Moso bamboo was culm > branch > leaf. In addition, the relationship between nutrient storage and DBH and density in SC is a simple power form, and the coefficient of determination of most computational models is above 0.9. Our results demonstrated that strip cutting is more economical than traditional management, but nutrient addition is needed to improve the quality of new bamboo trees at the initial stage of recovery in consideration of long-term productivity maintenance. [ABSTRACT FROM AUTHOR]

Understanding fine root characteristics in relation to soil properties of bamboo–broadleaf mixed forests may help optimize belowground production management and ecological functions in mixed-forest ecosystems. In this study, we compared four different bamboo–broadleaf mixed forests: Castanopsis chinensis (Sprengel) Hance with moso bamboo (CCB), Alniphyllum fortunei (Hemsl.) Makino with moso bamboo (AFB), Choerospondias axillaris (Roxb.) Burtt and Hill with moso bamboo (CAB), and Castanopsis fargesii Franch with moso bamboo (CFB), and analyzed their effects on the traits of fine roots of moso bamboo, soil nutrient contents, and enzyme activities. In January 2022, fine root and soil samples from four different mixed bamboo–broadleaf forests were collected from a subtropical region of Fujian Province, China. Results showed that CAB significantly increased fine root biomass (FRB) and root length density (RLD); however, specific root length (SRL) was only in the 0–20 cm soil layer. Specific surface area (SSA) was significantly reduced in the CCB in the 0–20 cm and 20–40 cm soil layers. The total phosphorous (TP) and total potassium (TK) contents of AFB and CAB were significantly increased (p < 0.05), and the alkali-hydrolyzable nitrogen (AN) content was significantly increased by CCB in the 0–20 cm soil layer (p < 0.05). Additionally, CFB increased the activities of acid phosphatase (ACP) and catalase (CAT) but decreased the activity of sucrase (SC). Principal component analysis showed that fine root traits (FRB, RLD, SRL, and SSA) were not only positively associated with soil organic carbon (SOC), total nitrogen (TN) and available potassium (AK) but also associated with urease (UE) and CAT. Therefore, belowground interactions between different species have a significant impact on the characteristics of fine roots and soil in bamboo–broadleaf mixed forests. [ABSTRACT FROM AUTHOR]

Moso bamboo (Phyllostachys edulis) is a critical forest resource in subtropical China, and reasonable cutting management of moso bamboo forests is essential for improving the productivity of bamboo forests, increasing the income of farmers, and improving the ecological environment. Therefore, we set up sample plots with different cutting widths at the Yixing Forest Farm in Jiangsu Province in December 2017. Moso bamboo growth surveys and soil sampling were conducted in May 2018 to study the effects of different cutting widths on the growth and nutrient content of moso bamboo forests. Our results indicate that strip cutting had significant effects on degraded bamboo shoots, the number of new bamboos, and their ratios. Soil elements showed surface aggregation, and cutting increased the soil nutrient content. Principal component analysis showed that stand characteristics (diameter at breast height and number of new bamboo shoots) were positively associated with total phosphorus and available phosphorus but negatively correlated with available potassium, total potassium, and soil organic carbon. A cutting width of 8 m resulted in rich nutrient content, which is suitable for bamboo cultivation. These results will provide theoretical guidance for the formulation of scientific and reasonable strip cutting methods for moso bamboo forests. [ABSTRACT FROM AUTHOR]

Height to crown base (HCB) is an important variable used as a predictor of forest growth and yield. This study developed a nonlinear, mixed-effects HCB model through inclusion of plot-level random effects using data from 29 sample plots distributed across a state-owned Yixing forest farm in Jiangsu province, eastern China. Among several predictor variables evaluated in the analyses, bamboo height, canopy density, and total basal area of bamboo with a diameter larger than that of the subject bamboo individual contributed significantly to the HCB variations. The inclusion of random effects improved the prediction accuracy of the model significantly, indicating that the HCB variations within and across the sample plots were substantial. The model was localized using four sampling strategies, and the study identified that using two medium-sized bamboos by diameter at breast height per sample plot resulted in the smallest prediction error. This strategy, which would balance both measurement cost and potential error, may be applied to estimate the random effects and localization of the nonlinear mixed-effects HCB model for moso bamboo in eastern China. [ABSTRACT FROM AUTHOR]

Moso bamboo is characterized by its fast growth and high yield and is important as a carbon sink species. Therefore, understanding the biomass distribution of its components is crucial. Based on the measured individual biomass data of 66 Phyllostachys heterocycla cv. Pubescens plants in the Yixing state-owned forest in Jiangsu Province, nonlinear simultaneous equations with measurement errors were constructed using nonlinear error-in-variable models (NEIVM) (one step, two step) and nonlinear seemingly unrelated regression (NSUR). Variables affecting biomass were evaluated, including diameter at breast height (DBH), bamboo height (H), height to crown base (HCB), node length at DBH (NL), base diameter (BD), and bamboo age (A). DBH, H, and HCB had significant effects on the biomass of each component. They were used to construct a one-predictor system using DBH, a two-predictor system using DBH and H, and a three-predictor system using DBH, H, and HCB. Regardless of the number of variables used, the fitting accuracy of the NEIVM one-step method exceeded that of the two-step method, and that of NEIVM exceeded that of NSUR estimation. As a system using three predictive variables is better than other systems, we recommend using the one-step NEIVM method for Moso bamboo biomass estimation. [ABSTRACT FROM AUTHOR]

Strip clearcutting can significantly reduce the harvesting costs of moso bamboo forests. Although bamboo is characterized by rapid accumulation of biomass, it is still a concern that this management method may reduce long-term productivity. Nutrient cycling has long been considered essential for forests to maintain high primary productivity. However, nutrient cycling of bamboo forests after strip cutting has not been previously reported. We conducted a strip clearcutting experiment and surveyed the litter dynamics for 1 year. We assessed changes in litter nutrients in response to the cutting and calculated the nutrient resorption efficiency and litter decomposition rate to evaluate the effect on nutrient use efficiency and nutrient return. Our results showed that strip cutting had no significant effect on litter production and nutrient return in the moso bamboo forest (p > 0.05). However, annual litter biomass and nutrient return in reserved belts (RB) were significantly higher than those in the control (CK) (p < 0.05). P and K resorption efficiencies in RB were significantly higher than in CK during certain periods of bamboo growth (p < 0.05). We also observed that the annual decay constant of CK was significantly higher than that of plots that were strip clearcut (SC) (p < 0.05). Our results suggest that strip cutting does not affect nutrient use efficiency or storage in the short term. [ABSTRACT FROM AUTHOR]

Bamboo is an important forest type in Southern China, covering an area of 6.16 million ha, > 70% of which is Moso bamboo ( Phyllostachys heterocycla (Carr.) Mitford cv. Pubescens ) forest. Moso bamboo forests are characterized by fast growth and high nutrient dynamics due to the annual timber harvest, and thus a high nutrient input is required compared with other forest types. Soil nitrogen (N), phosphorus (P) and potassium (K) are important micronutrients for plant growth and productivity. Because of the high spatial and temporal variability of soil, information on the spatial distribution of N, P and K contents in Moso bamboo forests is very limited, although this information is important for improving soil nutrient management. Therefore, in this study, soil samples at 0–20, 20–40 and 40–60 cm were taken from 138 locations in Moso bamboo forests across the study area. The N, P and K contents of different soil layers ranged from 1.01 to 4.11 g kg − 1 , from 0.025 to 0.131 g kg − 1 and from 0.42 to 5.40 g kg − 1 , respectively. The coefficient of variation of N, P and K contents ranged from 26% to 43%, suggesting a moderate variability. Ordinary kriging (OK) and inverse distance weighting (IDW) approaches were applied to analyse the spatial patterns of N, P and K contents. Geostatistical analysis showed a moderate spatial dependence of N, P and K contents, indicating that N, P and K contents were controlled by both intrinsic and extrinsic factors. Cross-validation illustrated that OK performed better than IDW. OK and IDW showed a similar spatial pattern of N, P and K contents over the whole study area, demonstrating the suitability of OK and IDW in spatial interpolation. However, OK produced a smaller range of predicted N, P and K contents than IDW, highlighting the necessity of using different approaches when studying the spatial distribution of soil properties. [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]

The biomass, nutrient content and decomposition rate of shoot sheaths remain unexplored in the study of Moso bamboo forests. The rapid growth of shoots means many bamboo sheaths are produced each year, and therefore should not be neglected in the study of the Moso bamboo ecosystem. In our study, we selected 160 bamboo shoots of different sizes in Yixing forest farm, Jiangsu Province. Our analysis was based on the allometric growth equation, using diameter at breast height (DBH), internode length of bamboo at breast height (IL), and bamboo height (H) as independent variables to establish the biomass model of shoot sheaths using all samples. In addition, we also measured the nutrient content of shoots and estimated the decomposition rate of shoots by setting up litter decomposition bags. Our results found that logarithmic regression should be used to fit the biomass model of shoot sheaths. From the perspective of practical application, model W3 fitting DBH and IL was determined. The order of the nutrient elements in the shoot sheath is C > N > K > P. Decomposition tests showed that it took 0.47 years for 50% of sheaths to decompose, and 3.15 years for all sheaths to decompose. [ABSTRACT FROM AUTHOR]

Functional characteristics reflect plant strategies and adaptability to the changing environment. Determining the dynamics of these characteristics after harvesting would improve the understanding of forest response strategies. Strip clearcutting (SC) of moso bamboo forests, which significantly reduces the cutting cost, has been proposed to replace manual selective harvesting. A comparison of restoration features shows that 8 m is the optimal cutting width. However, the precise response of functional features to the resulting harvest-created gap remains unclear. In this study, three SC plots were selected which was performed in February 2019, with three unharvested plots as a control (C). The study focused on 10 functional traits, including leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), nitrogen/phosphorus ratio (N:P), wood density (WD), fine root biomass (FRB), specific fine root length (SRL), and root length density (RLD). A one-way ANOVA was used to compare differences in functional traits and soil nutrients between treatments. Strip clearcutting significantly reduced the soil organic carbon (SOC) and total nitrogen (TN) contents (p < 0.05). In terms of functional characteristics, SC significantly decreased LA and increased LNC, LPC, and N:P (p < 0.05). However, SC had no significant effect on fine root traits (p > 0.05). This study highlighted that root trait, soil content of total phosphorus (TP) and total potassium (TK) returned to the level of uncut plots after a year's recovery. The LPC, LNC, and N:P were negatively correlated with LA, and LDMC and WD were negatively correlated with SLA, while the effect of SC on fine root traits was limited (p > 0.05). Fine root traits (FRB, RLD, and SRL) were positively associated with SOC, TN, and TP, but negatively correlated with TK. The changes in soil nutrient content caused by the removal of biomass were normal. Increased light and the rapid growth of new trees will increase nutrient regressions; therefore, these results further confirm the feasibility of SC. [ABSTRACT FROM AUTHOR]

Moso bamboo forests represent an important forest type commonly found throughout subtropical China and are characterized by fast growing forests, and involves intensive management, such as reclamation, fertilization, and understory removal. However, effects of intensive management on soil respiration ( R S ) and net ecosystem production (NEP) remain unclear. In this study, R S was partitioned into root respiration ( R R ), litter respiration ( R L ), and soil organic matter derived respiration ( R M ) by litter removal and trenching approaches. One-year measurements of respiration rates, soil temperature, and soil moisture were conducted in an unmanaged and an intensively managed stand. Regardless of stand management, R S and source components increased exponentially with soil temperature and linearly with soil moisture. Temperature sensitivity ( Q 10 ) ranged from 1.6 to 2.5, with the highest value for R M , highlighting the importance of R M in regulating the response of R S to soil temperature change. Annual R S , R R , R L , and R M were 32.6, 10.7, 6.9, and 15.0 t CO 2 ha − 1 a − 1 for unmanaged stand, compared to 38.6, 12.5, 7.1, and 18.9 t CO 2 ha − 1 a − 1 for intensive managed stand, respectively, indicating that intensive management increased R S by R R and R M . Intensive management also increased NEP with 17.2 t CO 2 ha − 1 a − 1 for unmanaged stand and 20.4 t CO 2 ha − 1 a − 1 for intensive managed stand. This increase was mainly attributed to the increase in net primary production of bamboo forests under intensive management. However, the sustainability of intensive management needs further investigation due to the reduction of soil organic carbon content after intensive management. Forest management associated with the reduction in soil CO 2 flux and increase in stand production should be developed for Moso bamboo forests. [ABSTRACT FROM AUTHOR]