Strip Clearcutting Drives Vegetation Diversity and Composition in the Moso Bamboo Forests

Strip clearcutting of Moso bamboo forests in southern China has seen increasing interest as a way of reducing harvesting costs. Previous research has shown that cutting influences the overstory structure and drives changes in the microclimate and soil properties. However, the effects of strip cutting on understory vegetation diversity and composition remain unclear. To better understand the influence of cutting on the understory vegetation, this study compares sites under natural restoration after cut and uncut sites in the Moso bamboo forest. We selected plots that were cut in 2019 (C19) and 2017 (C17), as well as unharvested plots as controls (CK). The results showed that strip clearcutting increased the understory vegetation richness and diversity, and a significant difference (A = 0.23, P = 0.001) existed in the composition of the vegetation between the three treatments. Furthermore, the decrease of soil total phosphorus and total potassium content resulted in the difference in undergrowth vegetation distribution and composition between the uncut plots and the cut plots. Our results suggest that strip clearcutting may not be harmful to biodiversity on a local scale in the Moso bamboo forest. Study Implications: This study demonstrates that strip clearcutting, which is an economically important harvesting method for bamboo, had significant effects on understory vegetation composition and diversity, and understory vegetation has not returned to preharvest levels after two years. The understory vegetation was affected by soil nutrient content and light conditions in the forest. We believe our research has made a significant contribution to the literature because bamboo is commercially important and its sustainable management is needed by many industries. This study highlights the impact of strip cutting on understory vegetation. The retention of understory vegetation characteristics is critical for the sustainable management of these forests, and this study not only demonstrates the dynamics of cut plots recovery but also increases our knowledge of this important species.

Biomass Estimation, Nutrient Content, and Decomposition Rate of Shoot Sheath in Moso Bamboo Forest of Yixing Forest Farm, China

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.

The Influence of Different Management Modes on the Potential of Moso Bamboo Carbon Sink Based on Survey Data of Yuhang and Lin’an

Bamboo forest carbon sequestration has strong development potential in coping with global climate change. The management of Moso bamboo forest can exert its own strong carbon sequestration ability and promote farmers' income, which is the fundamental point of bamboo industry development and can integrate ecological, economic, and social benefits. In this study, two Moso bamboo forests with different management modes in Lin'an and Yuhang of Zhejiang Province were used as research points. Using the system dynamic thinking method, a dynamic system model was constructed to simulate the growth process of Moso bamboo and its carbon sink supply. Then comparative analysis was made of its carbon sink supply potential. It is easy for bamboo forest managers to change management measures according to their requirements and create a dynamic balance between ecology and economics when determining the optimum management mode for the bamboo forest under the supply potential of carbon sink. According to the study results, the carbon sink supply under the intensive model is the most ideal, while the carbon sink supply under the extensive peach blossom model is the least ideal.

Consistent scaling of whole-shoot respiration between Moso bamboo (Phyllostachys pubescens) and trees

Both Moso bamboo (Phyllostachys pubescens) and tree forests have a large biomass; they are considered to play an important role in ecosystem carbon budgets. The scaling relationship between individual whole-shoot (i.e., aboveground parts) respiration and whole-shoot mass provides a clue for comparing the carbon budgets of Moso bamboo and tree forests. However, nobody has empirically demonstrated whether there is a difference between these forest types in the whole-shoot scaling relationship. We developed whole-shoot chambers and measured the shoot respiration of 58 individual mature bamboo shoots from the smallest to the largest in a Moso bamboo forest, and then compared them with that of 254 tree shoots previously measured. For 30 bamboo shoots, we measured the respiration rate of leaves, branches, and culms. We found that the scaling exponent of whole-shoot respiration of bamboo fitted by a simple power function on a log–log scale was 0.843 (95 % CI 0.797–0.885), which was consistent with that of trees, 0.826 (95 % CI 0.799–0.851), but higher than 3/4, the value typifying the Kleiber’s rule. The respiration rates of leaves, branches, and culms at the whole-shoot level were proportional to their mass, revealing a constant mean mass-specific respiration of 1.19, 0.224, and 0.0978 µmol CO2 kg− 1 s− 1, respectively. These constant values suggest common traits of organs among physiologically integrated ramets within a genet. Additionally, the larger the shoots, the smaller the allocation of organ mass to the metabolically active leaves, and the larger the allocation to the metabolically inactive culms. Therefore, these shifts in shoot-mass partitioning to leaves and culms caused a negative metabolic scaling of Moso bamboo shoots. The observed convergent metabolic scaling of Moso bamboo and trees may facilitate comparisons of the ecosystem carbon budgets of Moso bamboo and tree forests.

An index to assess the health of Moso bamboo (Phyllostachys edulis) forest

Background: The Moso bamboo (Phyllostachys edulis) forest is an important forest resource. The health status of the Moso bamboo forest are increasingly affected by a range of unscientific and irrational management, which may permanently alter the Moso bamboo forest economic value and ecological function and disrupt the long-term sustainable management. However, how to assess the health status of the Moso bamboo forest and guide the scientific management of the Moso bamboo forest are little known. Methods: The index system of Moso bamboo forest health assessment was identified and quantified by literature collection, indicators simplification, expert questionnaires, and mathematical analysis. The health index of Moso bamboo forest health assessment was calculated by the comprehensive health index method. The practicability and feasibility of the health index were verified in the Moso bamboo forest in Anhui and Fujian provinces of China.Results: An index system that included four layers and 19 indicators could comprehensively assess the health of the Moso bamboo forest. This index system assessed the ‘Health basis of the Moso bamboo forest’ and the ‘Value and function of the Moso bamboo forest’. The health index of the Moso bamboo forest in Anhui and Fujian provinces ranged from 0.50 to 0.83. Only2.35 % of the Moso bamboo forest showed a health index higher than 0.80, whereas the health index of 22.35 % of the forest was lower than 0.60. The health index of the Moso bamboo forest was higher under irrigation management and fertilization management than others. The treetop cutting was not recommended unless those areas had frequent occurrences of snow and ice disasters. Conclusions: These results suggest that the health status need to be improved in most of the Moso bamboo forest. Scientific management would be the important tool to keep and improve the health status of Moso bamboo forest. Our results can be adapted in the resource management and policy decisions for better management of the Moso bamboo forest.

Nitrogen addition decreases methane uptake caused by methanotroph and methanogen imbalances in a Moso bamboo forest

Forest soils play an important role in controlling global warming by reducing atmospheric methane (CH4) concentrations. However, little attention has been paid to how nitrogen (N) deposition may alter microorganism communities that are related to the CH4 cycle or CH4 oxidation in subtropical forest soils. We investigated the effects of N addition (0, 30, 60, or 90 kg N ha−1 yr−1) on soil CH4 flux and methanotroph and methanogen abundance, diversity, and community structure in a Moso bamboo (Phyllostachys edulis) forest in subtropical China. N addition significantly increased methanogen abundance but reduced both methanotroph and methanogen diversity. Methanotroph and methanogen community structures under the N deposition treatments were significantly different from those of the control. In N deposition treatments, the relative abundance of Methanoculleus was significantly lower than that in the control. Soil pH was the key factor regulating the changes in methanotroph and methanogen diversity and community structure. The CH4 emission rate increased with N addition and was negatively correlated with both methanotroph and methanogen diversity but positively correlated with methanogen abundance. Overall, our results suggested that N deposition can suppress CH4 uptake by altering methanotroph and methanogen abundance, diversity, and community structure in subtropical Moso bamboo forest soils.