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Microbial carbon utilization efficiency (CUE) is a crucial indicator for evaluating the efficiency of soil carbon sequestration and transformation, which is applied to quantify the proportion of soil carbon extracted by microbes for anabolism (growth) and catabolism (respiration). Previous studies have shown that the degradation of Moso bamboo forests (Phyllostachys edulis) destroyed the aboveground bamboo structure, reduced vegetation carbon storage, and weakened ecosystem carbon sequestration capacity. Interestingly, soil organic carbon stocks are gradually increasing. However, the mechanism by which degradation-induced changes in soil and vegetation characteristics affect microbial CUE and drive soil carbon sequestration remains unclear. Here we selected four stands with the same origin but different degradation years (intensive management, CK; 2 years' degradation, DM1; 6 years' degradation, DM2; and 10 years' degradation, DM3) based on the local management profiles. The principle of space-for-time substitution was used to investigate the changes in microbial CUE along a degradation time and to further identify the controlling biotic and abiotic factors. Our finding showed that microbial CUE increased by 12.27 %, 31.01 %, and 55.95 %, respectively, compared with CK; whereas microbial biomass turnover time decreased from 23.99 ± 1.11 to 17.16 ± 1.20 days. Promoting microbial growth was the main pathway to enhance microbial CUE. Massive inputs of vegetative carbon replenished soil carbon substrate content, and altered microbial communities and life history strategy, which in turn promoted microbial growth and increased microbial CUE. These findings provide theoretical support for the interactions between carbon dynamics and microbial physiology in degraded bamboo forests, and reinforce the importance of vegetation and microbial properties and soil carbon substrates in predicting microbial CUE., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024. Published by Elsevier B.V.)

Bamboo forests provide important ecosystem services and play an important role in terrestrial carbon cycling. Of the approximately 500 bamboo species in China, Moso bamboo (Phyllostachys pubescens) is the most important one in terms of distribution, timber value, and other economic values. In this study, we estimated current and potential carbon stocks in China's Moso bamboo forests and in their products. The results showed that Moso bamboo forests in China stored about 611.15 ± 142.31 Tg C, 75% of which was in the top 60 cm soil, 22% in the biomass of Moso bamboos, and 3% in the ground layer (i.e., bamboo litter, shrub, and herb layers). Moso bamboo products store 10.19 ± 2.54 Tg C per year. The potential carbon stocks reach 1331.4 ± 325.1 Tg C, while the potential C stored in products is 29.22 ± 7.31 Tg C a(-1). Our results indicate that Moso bamboo forests and products play a critical role in C sequestration. The information gained in this study will facilitate policy decisions concerning carbon sequestration and management of Moso bamboo forests in China., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Agroforestry management has immense potential in enhancing forest carbon sequestration and mitigating climate change. Yet the impact and response mechanism of compound fertilization rates on carbon sinks in agroforestry systems remain ambiguous. This study aims to elucidate the impact of different compound fertilizer rates on soil greenhouse gas (GHG) emissions, vegetation and soil organic carbon (SOC) sinks, and to illustrate the differences in agroforestry systems' carbon sinks through a one-year positioning test across 12 plots, applying different compound fertilizer application rates (0 (CK), 400 (A1), 800 (A2), and 1600 (A3) kg ha−1). The study demonstrated that, after fertilization, the total GHG emissions of A1 decreased by 4.41%, whereas A2 and A3 increased their total GHG emissions by 17.13% and 72.23%, respectively. The vegetation carbon sequestration of A1, A2, and A3 increased by 18.04%, 26.75%, and 28.65%, respectively, and the soil organic carbon sequestration rose by 32.57%, 42.27% and 43.29%, respectively. To sum up, in contrast with CK, the ecosystem carbon sequestration climbed by 54.41%, 51.67%, and 0.90%, respectively. Our study suggests that rational fertilization can improve the carbon sink of the ecosystem and effectively ameliorate climate change. [ABSTRACT FROM AUTHOR]

Moso bamboo (Phyllostachys heterocycla cv. Pubescens) is known for its high capacity to sequester atmospheric carbon (C), which has a unique role to play in the fight against global warming. However, due to rising labor costs and falling bamboo prices, many Moso bamboo forests are shifting to an extensive management model without fertilization, resulting in gradual degradation of Moso bamboo forests. However, many Moso bamboo forests are being degraded due to rising labor costs and declining bamboo timber prices. To delineate the effect of degradation on soil microbial carbon sequestration, we instituted a rigorous analysis of Moso bamboo forests subjected to different degradation durations, namely: continuous management (CK), 5 years of degradation (D-5), and 10 years of degradation (D-10). Our inquiry encompassed soil strata at 0–20 cm and 20–40 cm, scrutinizing alterations in soil organic carbon(SOC), water-soluble carbon(WSOC), microbial carbon(MBC)and microbial residues. We discerned a positive correlation between degradation and augmented levels of SOC, WSOC, and MBC across both strata. Furthermore, degradation escalated concentrations of specific soil amino sugars and microbial residues. Intriguingly, extended degradation diminished the proportional contribution of microbial residuals to SOC, implying a possible decline in microbial activity longitudinally. These findings offer a detailed insight into microbial C processes within degraded bamboo ecosystems. [ABSTRACT FROM AUTHOR]

Carbon trading and carbon offset markets are potential policy options for mitigating greenhouse gas emissions and climate change. A price on carbon is expected to generate demand for carbon offsets. In a market-based framework, the carbon price should be high enough to compensate for opportunity costs. We studied a highly-modified agricultural system in the Guanzhong–Tianshui economic region of China that is typical of many temperate agricultural zones in western China. We quantified the economic returns from agriculture and from carbon plantings (both monoculture and ecological plantings) under five carbon-price scenarios. The mean carbon sequestration is 34 Mg·hm−2·a−1, and the average annual payment increased to 1146 CNY·hm−2 at a medium carbon price of 50 CNY·Mg−1 CO2−e. Thus, areas of high priority for conservation and restoration may be restored relatively cheaply in the presence of a carbon market. Overall, however, less carbon is sequestered by ecological plantings (i.e., mixed native trees and shrubs) compared to agriculture.

Subtropical forests play an important role in the global carbon cycle and climate change mitigation. In order to understand the effects of climate factors on soil carbon in subtropical forest ecosystems, it is necessary to make full use of carbon sequestration potential. Soil organic carbon (SOC) and soil alkali-hydrolyzed nitrogen (SAN) were tested in 255 plots of subtropical forests in Zhejiang Province, and their forest reserves from 2020 in Zhejiang Province were compared with those from 2010. The results showed that SOC content significantly increased, but SAN content decreased over those ten years. Combined with random forest (RF) and correlation analysis, the contribution of different climate factors (temperature, precipitation, etc.) to soil carbon storage was analyzed, and the main driving factors were evaluated. The RF model explained that winter (December to February) and spring (March to May) were the most dominant drivers to the 0–10 cm and 10–30 cm increases in SOC. There was a significant positive correlation between precipitation and SOC accumulation (0–30 cm) during winter and spring. The minimum temperatures in summer (June to August) and autumn (September to November) were negatively correlated with SOC accumulation (0–30 cm). Increasing the precipitation or irrigation (cloud seeding) in winter could improve the carbon sequestration capacity of subtropical forest soils. This study provides a new perspective on the sensitivity and potential response of the carbon cycle to climate change in subtropical forest ecosystems. [ABSTRACT FROM AUTHOR]

Phytolith-occluded carbon (PhytOC), a promising long-term biogeochemical carbon sequestration mode, plays a crucial role in the global carbon cycle and the regulation of atmospheric CO2. Previous studies mostly focused on the estimation of the content and storage of PhytOC, while it remains unclear about how the management practices affect the PhytOC content and whether it varies with stand age. Moso bamboo (Phyllostachys heterocycla var. pubescens) has a great potential in carbon sequestration and is rich in PhytOC. Here, we selected four management treatments, including control (CK), compound fertilization (CF), silicon (Si) fertilization (SiF) (monosilicic acid can form phytoliths through silicification), and cut to investigate the variation of phytoliths and PhytOC contents in soil, leaves, and litters, and their storage in Moso bamboo forests. In soil, the SiF fertilizer treatment significantly (P < 0.05) increased phytolith content, PhytOC content, and storage compared to CK, while there were no significant differences between the treatments of CF and cut. In leaf, compared with CK, phytolith content of the second-degree leaves under SiF and the first-degree leaves under cut treatment significantly increased, and the three treatments significantly increased PhytOC storage for leaves with three age classes. In litter, the phytolith and PhytOC contents under the three treatments were not significantly different from that under the CK treatment. The PhytOC storage increased by 19.33% under SiF treatment, but significantly decreased by 40.63% under the CF treatment. For the entire Moso bamboo forest ecosystems, PhytOC storage of all the three management treatments increased compared with CK, with the largest increase by 102% under the SiF treatment. The effects of management practices on the accumulation of PhytOC varied with age. Our study implied that Si fertilization has a greater potential to significantly promote the capacity of sequestration of carbon in Moso bamboo forests. [ABSTRACT FROM AUTHOR]

Highlights • Structural factors had positive effects on vegetation carbons stocks, but MAT and MAP had negative effects. • Negative effects of MAT increased, but negative effects of MAP decreased. • Our study reveal the possible response of carbon sequestration to structural development and climate change. Abstract Moso bamboo (Phyllostachys pubescens) is widely distributed in subtropical China and plays an important role in carbon cycling in terrestrial ecosystems. Knowledge of the main driving factors that affect aboveground carbon stocks in Moso bamboo forests is needed to increase carbon sequestration potential. We used a large-scale database from national forest continuous inventory from 2004 to 2014 in Zhejiang, China, and combined Random Forest analysis (RF) with structural equation modeling (SEM) to quantify the contribution of main driving factors on vegetation carbon stocks in Moso bamboo forests, and to evaluate the direct and indirect total effects of the main driving factors on aboveground carbon stocks, as well as to investigate changes in the standardized total effects from 2004 to 2014. The RF model explained 84.9% of the variation in 2004, 78.8% in 2009, and 82.2% in 2014. The SEM that included the average age, average diameter at breast height (DBH), culms density, mean annual temperature (MAT), and mean annual precipitation (MAP) explained 92.5% of the variation in 2004, 88.2% in 2009, and 88.6% in 2014. The results showed that average age, average DBH, culms density, MAT, and MAP were the most crucial driving factors of vegetation carbon stocks in Moso bamboo forests. The values of standardized total effects of the main driving factors showed that the average age, average DBH, and culms density had positive effects on vegetation carbons stocks, whereas MAT and MAP had negative effects. Furthermore, the positive effects of average age on the increase of vegetation carbon stocks increased significantly, the negative effects of MAT increased with the increasing MAT, but the negative effects of MAP decreased with the increasing MAP. Overall, our study provided new insights into the sensitivity and potential response of carbon sequestration in Moso bamboo forests to structural development and climate change in Zhejiang Province. [ABSTRACT FROM AUTHOR]

Moso bamboo ( Phyllostachys pubescens ) is widely distributed in subtropical China and plays an important role in terrestrial carbon cycling. However, the capacity of Moso bamboo forests to sequester carbon and their long-term structural development in large regions remain poorly quantified. We used the national forest continuous inventory data to measure and quantify the carbon stock and structure change from 2004 to 2014. The results of kernel density estimation showed that the culm density and average DBH (diameter at breast height) of Moso bamboo forests had a tendency to increase in Zhejiang Province. However, the culm structure of the Moso bamboo forests in Zhejiang Province was not optimal for high bamboo productivity. The aboveground culm carbon stock increased from 2004 to 2014, indicating that the Moso bamboo forests acted as a carbon sink. The average change in the aboveground carbon stock over the study period was 0.94 Mg C ha −1 yr −1 , smaller than the corresponding value for different forest types in the same region and for the Moso bamboo forests managed by farmers in the lower mountain areas of central Taiwan (8.13 Mg C ha −1 yr −1 ), indicating that Moso bamboo forests have a large carbon sequestration potential. Furthermore, age classes 2–4 contributed positively to changes in the total aboveground culm carbon stock by 23.07%, 36.35%, and 50.17%, respectively. The change in the carbon stock was not correlated with any environmental factors, but the carbon stock increased with increasing culm density, average DBH (diameter at breast height), and culm age. Our results suggest that the Moso bamboo forests of Zhejiang Province have a large carbon sequestration potential if the structure and management strategies of the forests are optimized. This study improves our understanding of the carbon dynamics and structural development in Moso bamboo forests, which could help guide the future forest management strategies. [ABSTRACT FROM AUTHOR]

Using a combination of moso bamboo forest thematic maps derived from Landsat Thematic Mapper (TM) images, field inventory data, and Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) images, moso bamboo forest was extracted using the matched filtering (MF) technique and its aboveground carbon storage (AGC) was then estimated. This study presents a feasible method for extracting large-scale moso bamboo forests and for estimating moso bamboo forest AGC based on low-spatial resolution MODIS images. The results showed that moso bamboo forests in the majority of counties can be accurately estimated between actual area and estimates, with anR2of 0.8453. The fitted accuracy of the AGC model was high (R2 = 0.491). The prediction accuracy of the AGC model was also evaluated using validation samples collected from Lin'an City, with anR2and root mean square error prediction of 0.4778 and 3.06 Mg C ha−1, respectively. The AGC in the majority of counties or cities in Zhejiang Province was between 0 and 15 Mg C ha−1, and to a certain extent the predicted AGC estimates were close to observed ground truth data and representative of the study area. [ABSTRACT FROM PUBLISHER]

• The number and carbon storage of rhizomes exhibited significant "on-year" and "off-year" features. • The rhizomes were mainly distributed in the 10–30 cm soil layer. • The three greatest increases in DBH occurred after rapid rhizome growth occurred. • Accurately estimate the rhizome biomass based on the aboveground biomass. Moso bamboo (Phyllostachys pubescens) forest plays an irreplaceable and significant effect on carbon sequestration and the adaptation of forestry to climate change in South China because of its high growth rate and adaptability to adverse environmental conditions. There may be a relationship between rhizomes and ramets because moso bamboo, as a monopodial running bamboo, grows belowground by rhizome branching and elongation and spreads ramets aboveground. This study used terrestrial laser scanning (TLS) to accurately quantify the above- and belowground structure and dynamics of moso bamboo forests after reforestation, indicating that the number and carbon storage of rhizomes exhibited significant "on-year" and "off-year" features and in even-numbered years were significantly higher than those in odd-numbered years. No significant variation was found in the average diameter of the rhizome (DR), while the average diameter at breast height (DBH) increased significantly from the 3rd year, and the three greatest increases in DBH occurred after the year in which rapid rhizome growth occurred. The depth of the rhizomes ranged from 3.54 to 38.47 cm, and the rhizomes were mainly distributed in the 10–30 cm soil layer. The angles of the rhizome and subrhizome (ARSR) were mainly less than 30°and increased over time. Rhizomes store and allocate nutrients by increasing the length and number of rhizome segments (NRS) and normally maintain connections over tens of metres. Both the number and biomass of culms were significantly positively correlated with the total NRS, total length of rhizomes, number of rhizomes and rhizome biomass under different rhizome-culm systems. We used a linear equation (y = 4.112 x + 9.337 , R 2 = 0.7605 , R M S E = 19.36) to accurately estimate the rhizome biomass based on the aboveground biomass and the ratio of aboveground and rhizome carbon storage (RCS) to accurately estimate RCS in different years after reforestation. [ABSTRACT FROM AUTHOR]

• SOC stocks for B5 and B15 treatments increased by 26.60% and 7.07%, respectively. • Vegetation carbon stocks for B5 and B15 treatments increased by 66.79% and 59.85%, respectively. • Total greenhouse gases emissions increased by 19.70% and 21.23% in B5 and B15 treatments, respectively. • Our study can provide a new strategy for increasing ecosystem carbon stocks in Moso bamboo forests management. Biochar application has been considered as one of approaches to mitigate climate change, however, most of existing studies only focus on its effects on soil carbon pools, rather than the ecosystem level carbon sequestration capacity in forests. Moso bamboo (Phyllostachys heterocycla var. pubescens) has a uniquely growth and development pattern, which can provide a possibility for exploring the short-term effects of biochar application on ecosystem carbon sequestration. We conducted a 24-month field experiment in a Moso bamboo forest to investigate the effects of different biochar application rates (0(CK), 5 (B5) and 15 (B15) Mg ha−1) on soil greenhouse gas emissions, soil organic carbon (SOC) stocks and vegetation carbon stocks. In comparison to CK, SOC stocks for B5 and B15 treatments increased by 26.60% and 7.07%, respectively. Similarly, the vegetation carbon stocks for B5 and B15 treatments increased by 66.79% and 59.85%, respectively. The total greenhouse gases emission increased by 19.70% and 21.23% in B5 and B15, respectively. In terms of non-CO 2 greenhouse gases, biochar application significantly decreased N 2 O emissions in B5 and B15 by 18.02% and 24.42% (P < 0.05), and increased CH 4 uptakes by 16.22% and 8.11%, respectively. In summary, biochar applications increased total ecosystem carbon stocks in Moso bamboo forest by 486.31% and 252.98% under B5 and B15 treatments, respectively. This implied that biochar amendment can significantly promote the carbon sequestration capacity in Moso bamboo forest ecosystems; therefore, it is an effective forest management option to increase carbon stocks and reduce non-CO2 greenhouse gas emissions in Moso bamboo forests. [ABSTRACT FROM AUTHOR]

• Abandonment will lead to mean age and culm density increase. • Carbon stock of the individual culm decreased due to the smaller diameter. • Bamboo carbon stocks in plots still increased due to the increase in culm density. • Carbon allocation pattern changed: carbon accumulation increased in vegetation. Moso bamboo (Phyllostachys pubescens) has high carbon sequestration capacity and plays an important role in mitigating climate change. With the decrease in bamboo prices and the increase in labor costs, many Moso bamboo forests have been abandoned. How the abandonment affects the forest structural factors and carbon stocks has not been studied. 50 Moso bamboo forest plots with different abandonment times were investigated in the subtropical region of the southeast coast of China, and we analyzed the effects of abandonment time on the structural factors and carbon storage allocation pattern. Abandonment affected the forest structural factors, especially after 6 years of abandonment. Compared with general management, the culm density was nearly 3 times as normal, the mean age rose from 2.33 ± 1.14 du to 3.23 ± 1.04 du, and the diameter at breast (DBH) decreased by 15.7% after 15–18 years of abandonment. The carbon storage of the individual culm was reduced by 25% due to the smaller DBH, but the bamboo stand carbon stocks were about 2.5 times normal due to the excessive density. Correspondingly, the proportion of vegetation C in ecosystems has increased from 21.69% to 35.95%, even though the understory carbon stocks were lowest in the forests abandoned for eleven or more years. The soil organic carbon (SOC) in the topsoil layer was higher with the extension of the abandonment time while there was no significant difference in the deep. Litter and understory vegetation account for only a small fraction of the entire ecosystem's carbon stocks, especially in the Moso bamboo forest for a longer abandonment time. These results enrich our understanding of the structure and carbon allocation pattern of abandoned Moso bamboo forests and provide a significant support for Moso bamboo forest management or future recovery. [ABSTRACT FROM AUTHOR]

Bamboo forest is characterized by large carbon sequestration capability and it plays an important role in mitigating climate change and global carbon cycling. Previous studies have mostly focused on carbon cycling and carbon stocks in bamboo forest ecosystems, whereas the carbon footprints of bamboo products have not received attention. China is the largest exporting country of bamboo flooring in the world. Estimating the carbon footprint of bamboo flooring is of essential importance for the involved enterprises and consumers to evaluate their own carbon footprints. In this study, we investigated the production processes of bamboo scrimber flooring for outdoor use, a typical bamboo flooring in China. Based on business-to-business (B2B) evaluation method, we assessed CO2 emission and carbon transfer ratio in each step of the production process, including transporting bamboo culms and producing and packing the products. We found that to produce 1 m3 of bamboo scrimber flooring, direct carbon emissions from fossil fuels during transporting raw materials/semi-finished products, from power consumptions during production, and indirect emissions from applying additives were 30.94 kg CO2 eq, 143.37 kg CO2 eq, and 78.34 kg CO2 eq, respectively. After subtracting the 267.54 kg CO2 eq carbon stocks in the product from the 252.65 kg CO2 eq carbon emissions derived within the defined boundary, we found that the carbon footprint of 1 m3 bamboo scrimber flooring was −14.89 kg CO2 eq. Our results indicated that the bamboo scrimber flooring is a negative carbon-emission product. Finally, we discussed factors that influence the carbon footprint of the bamboo flooring and gave suggestions on carbon emission reduction during production processes. This study provided a scientific basis for estimating carbon stocks and carbon footprints of bamboo products and further expanded knowledge on carbon cycling and lifespan of carbon in the bamboo forest ecosystem. [ABSTRACT FROM AUTHOR]

The selective cutting method currently used in Moso bamboo forests has resulted in a reduction of stand productivity and carbon sequestration capacity. Given the time and labor expense involved in addressing this problem manually, simulation using an ecosystem model is the most suitable approach. The BIOME-BGC model was improved to suit managed Moso bamboo forests, which was adapted to include age structure, specific ecological processes and management measures of Moso bamboo forest. A field selective cutting experiment was done in nine plots with three cutting intensities (high-intensity, moderate-intensity and low-intensity) during 2010–2013, and biomass of these plots was measured for model validation. Then four selective cutting scenarios were simulated by the improved BIOME-BGC model to optimize the selective cutting timings, intervals, retained ages and intensities. The improved model matched the observed aboveground carbon density and yield of different plots, with a range of relative error from 9.83% to 15.74%. The results of different selective cutting scenarios suggested that the optimal selective cutting measure should be cutting 30% culms of age 6, 80% culms of age 7, and all culms thereafter (above age 8) in winter every other year. The vegetation carbon density and harvested carbon density of this selective cutting method can increase by 74.63% and 21.5%, respectively, compared with the current selective cutting measure. The optimized selective cutting measure developed in this study can significantly promote carbon density, yield, and carbon sink capacity in Moso bamboo forests. [ABSTRACT FROM AUTHOR]