Search Results (13)

In subtropical regions of China, the expansion of Moso bamboo has become increasingly prominent, resulting in massive mortality of original trees in adjacent forest stands. Significant changes have also occurred in the population characteristics and spatial distribution patterns of these native tree species. This study aims to examine the impacts of Moso bamboo (Phyllostachys edulis) expansion on the successional dynamics of coniferous and broad-leaved mixed forests. Three sample plots were successively set up in the transition zone from bamboo to conifer and broad-leaved forest, including conifer and broad-leaved mixed forest (CF), transition forest (TF), and Moso bamboo forest (MF); a total of 72 10 m × 10 m quadrats (24 per forest type) were included. The species composition, diameter class structure and distribution pattern of living stems and snags (dead standing stems) were studied. The results showed that during the late expansion phase of bamboo, the density of living stems and snags separately increased by 2234 stems·ha⁻¹ and 433 stems·ha⁻¹, basal area increments of 23.45 m²·ha⁻¹ and 7.81 m²·ha⁻¹. The individuals with large diameter in living stems and snags gradually decreased, and the distribution range of the diameter steps mainly narrowed to 10–15 cm. On the scale of 0–10 m, the spatial pattern of standing stems changed from random and weak aggregation distribution to strong aggregation distribution and then to weak aggregation and random distribution in the three stands, while the overall distribution of snags in the three stands was random. The spatial correlation between living stems and snags evolved from uncorrelated in CF, to significant positive correlation in TF, and then to positive correlation and uncorrelation in MF. These results indicated that the bamboo expansion accelerated the mortality rate of the original tree species, leading to the diversity of tree species decreased, the composition of diameter classes was simplified, the degree of stem aggregation increased, and intra- and inter-species competition became the main reasons for tree death. Full article

Bamboo and broad-leaved mixed forest is a kind of forestry management that can effectively improve the ecology of bamboo forests. The aerial structure of the stand can reflect the growth status of the stand, as well as the spatial structure of the stand with respect to maintaining and improving the basis of the stand structure. However, the lack of quantitative studies on how different mixing ratios affect the stand spatial structure of bamboo and broad hybrid forests has further disturbed the development of bamboo and broad-leaved mixed-forest management. In this study, we used 10 bamboo and broad mixed forests with different ratios as the research object, determined the stand spatial structure unit by using the weighted Delaunay triangular network, calculated the stand spatial-homogeneity index from the vertical spatial structure of the stand, horizontal spatial structure, and competition, and constructed the stand spatial-homogeneity evaluation system by combining it with the forest health grading system and the rank classification method of the near-natural forest management, dividing it into five evaluation classes. It was divided into five evaluation levels. Finally, a regression model was used to elucidate the effects of stand spatial homogeneity on moso bamboo (Phyllostachys pubescens) biomass. The results showed that the spatial homogeneity of No. 1 (5%–10% mixed) and No. 3 (15%–20%) samples was classified into five grades; No. 2 (10%–15%) samples were classified into four grades; No. 4 (20%–25%) and No. 6 (30%–35%) samples were classified into three grades; No. 5 (25%–30%) samples were classified into two grades; and Nos. 7–10 (more than 35%) samples were all classified into one grade. It was also found that both the degree of hybridization and the competition index in the bamboo and broad-leaved mixed forest showed highly significant negative correlation with the spatial homogeneity index of the stand and the moso bamboo biomass, while the spatial density index showed highly significant positive correlation with the spatial homogeneity index of the stand and the moso bamboo biomass. From the viewpoint of management purpose, for the management of bamboo and broad-leaved mixed forest with economic benefits, the mixing ratio should be 5%–10% and 25%–35%; for the management of bamboo and broad-leaved mixed forest with ecological benefits, the mixing ratio should be more than 35%; and for the management purpose of balancing ecological benefits and economic benefits, the mixing ratio should be 10%–25%. Full article

Bamboo and broad-leaved mixed forests have been widely recognized for their advantages in maintaining ecological balance, improving soil fertility, and enhancing biodiversity. To understand the effects of mixed broad-leaved tree species and mixing ratios on soil microbial communities in bamboo and broad-leaved mixed forests, we quantified the structure and diversity responses of soil microbial communities to tree species and mixing ratios using high-throughput sequencing of the 16 S rRNA gene. Three bamboo and broad-leaved tree mixed forests were studied, including bamboo–Castanopsis chinensis Hance mixed forest (CCB), bamboo–Alniphyllum fortune (Hemsl.) Makino mixed forest (AFB), and bamboo–Choerospondias axillaris (Roxb.) B. L. Burtt & A. W. Hill mixed forest (CAB). We assessed the impact of tree species and mixing ratios on soil microbial communities by measuring soil properties and the diversity and composition of soil microbes. The results indicate that soil properties and the diversity and composition of microbial communities are highly dependent on broad-leaved tree species in mixed forests. The mixing ratios had a more pronounced effect on microbial diversity than on richness. In CAB, diversity peaked at mixing ratios of 10%–20% and 20%–40%. The presence of broad-leaved trees significantly altered the relationships among soil bacteria, with CAB showing the highest stability, likely due to the increased diversity and quantity of litter from Choerospondias axillaris. Our results show that the choice of broad-leaved tree species and their mixing ratios significantly influence soil microbial diversity and composition in bamboo–broad-leaf mixed forests. An optimal mixing ratio in CAB can maximize bacterial diversity and stability, providing insights for forest management and promoting ecosystem health and sustainability. Full article

Knowledge regarding the response of soil invertebrate communities to typhoon disturbance is limited, although it is known that soil invertebrates are sensitive to forest disturbances and that tropical cyclones (typhoons/hurricanes) are the most destructive natural disasters affecting the structure and function of forest ecosystems. To fill this knowledge gap, soil invertebrates in both litter and topsoil layers were investigated in four representative subtropical coastal forests of eastern China one week before the first typhoon (Hinnamnor) (T1), one day after the first typhoon (Hinnamnor) (T2), one day after the second typhoon (Muifa) (T3), and one week after the second typhoon (Muifa) (T4) in September 2022. Typhoon disturbances decreased the density and taxa abundance of soil invertebrate communities in litter layer, but the first typhoon disturbance increased these values in the topsoil layer. One week after the second typhoon disturbance, soil invertebrate communities in the litter layer showed a gradual recovery trend. Meanwhile, the soil invertebrate communities in the litter layer were more sensitive to typhoon disturbances than those in the topsoil layer. Furthermore, the responses of the soil invertebrate communities to the typhoon disturbances varied greatly with the forest types. The invertebrate densities in the litter layer decreased by 62.1%, 63.53%, 47.01%, and 46.92% in Chinese fir, second broad-leaved, mixed, and bamboo forests, respectively. Particularly, these two non-catastrophic typhoons significantly altered the functional group composition of detrital food webs in the short term, and the proportion of phytophages in detrital food webs in the litter layer increased after the typhoon disturbances. In conclusion, the effects of typhoon disturbances on soil invertebrate communities vary greatly with forest type and soil layer, and soil invertebrate communities can gradually recover after typhoon disturbances. The legacy effects of typhoon disturbances on the functional group composition of detrital food webs may influence carbon and nutrient cycling in forest ecosystems. Full article

To reveal the changes on the stock of the litter layer and its nutrient storage capacity during Moso bamboo expansion in subtropical coniferous and broad-leaved forests, permanent plots were set up in the transitional zone in Wuxie National Park, Zhuji, Zhejiang, China. The plots contained conifer and broad-leaved forests (CFs), transition forests (TFs), and Moso bamboo forests (MFs), which represented three stages of the expansion of Moso bamboo to the surrounding forests. Litter samples were collected and analyzed by un-decomposed, semi-decomposed, and decomposed layers. The stock of the litter layer, the content and storage of the main nutrient elements, and their release rate were measured. It was revealed that the stock of the litter layer and each decomposition layer decreased as the bamboo expands. However, the litter decomposition rate exhibited a positive correlation with the expansion of Moso bamboo, which might be due to the change in the physical properties of the litter. Meanwhile, there were no significant differences in the un-decomposed and semi-decomposed layers of the litter contents of C, N, and P between the three forests, but the contents of C, N, and P in the decomposed layer gradually decreased with the expansion of Moso bamboo. There were no remarkable differences in the N content, C/N, C/P, and lignin/N values of the un-decomposed layer of the three forests, indicating that the litter quality was not the principal reason affecting the decomposition rate. The total nutrient storage in the litter layer decreased significantly with the bamboo expansion, and the release rate of nutrient elements increased, which was adverse to the accumulation and storage of the nutrients. The material cycle of the original forest ecosystem is likely to deteriorate gradually with the bamboo expansion. Full article

Bamboo shoots are a healthy vegetable with significant commercial value, and their appearance quality is a key factor influencing consumer preference and market pricing. Their growth characteristics—after being unearthed, they maintain basal diameter while rapidly growing in height—affect the taste and nutritional quality. However, little attention has been given to the impact of bamboo forest management on shoot appearance. Therefore, this study addressed this research gap through a comprehensive investigation across three types of bamboo forests: evergreen broad-leaved forest (EBF), evergreen deciduous broad-leaved mixed forest (MBF), and pure bamboo forest (PBF). In addition, we further assessed factors that potentially affect the appearance quality of bamboo shoots, including canopy structures, understory light factors and understory soil factors, mother bamboo factors, and shoot internal factors (pigments and cells). The basal diameters of shoots in PBF and MBF were 1.89 cm and 1.97 cm, respectively, which were significantly larger than those in EBF by 0.27 cm and 0.35 cm, respectively. The linear mixed effect model identified the number of bamboo rhizome internodes and the chlorophyll a content as primary factors influencing basal diameter thickening and elongation growth of shoots, respectively. In addition, increasing the bamboo canopy and mean leaf angle reduced the chlorophyll a content and increased the carotenoid content, thereby benefiting the improvement in or maintenance of the taste and quality of shoots. This study highlighted that increasing the number of bamboo rhizome internodes, bamboo canopy, and mean leaf angle is helpful to improve the appearance quality of shoots. These findings offer a scientific foundation for bamboo forest management, contributing to both ecological sustainability and economic benefits. Full article

Bamboo invasion into broadleaf forests is a common phenomenon in karst areas; however, the effect of bamboo invasion on soil organic carbon (SOC) in karst areas and the mechanism of the effect are not clear. We selected the study site with broad-leaved forests (BF), mixed forests (MF), and pure bamboo (Indosasa shibataeoides McClure) forests (IF). Furthermore, we sampled the soil from 0 cm to 20 cm and 20 cm to 40 cm layers in the region and investigated the soil properties, organic carbon fractions, and microbial communities. At the same time, we sampled the litterfall layer of different stands and determined the biomass. The results showed that bamboo invasion increased the litterfall biomass per unit area of karst forest, increased the bulk weight of the 0–20 cm soil layer, and lowered the soil pH in the 0–20 cm and 20–40 cm soil layers, bamboo invasion consistently increased the content of soil AN and AK, whereas the content of AP was significantly reduced after bamboo invasion. Both active organic carbon groups (MBC, DOC, and EOC) and passive organic carbon groups (Fe/Al-SOC and Ca-SOC) increased significantly after bamboo invasion. The bamboo invasion increased the diversity of soil microorganisms and bacterial communities; the relative abundance of Actinobacteriota increased in MF and IF, while the relative abundance of Firmicutes decreased in IF. The structure of fungal communities was altered during the bamboo invasion, with an increase in the relative abundance of Mortierellomycota and a decrease in the relative abundance of Basidiomycota at the level of fungal phyla. Partial least squares path modeling analysis identified bamboo invasion enhanced SOC sequestration mainly by increasing litterfall biomass and altering the structure of the fungal community, and the effect of bacteria on SOC was not significant. Our study suggests that bamboo invasion of broadleaf forests is more favorable to soil organic carbon sequestration in karst areas. Full article

The spatial pattern of coarse woody debris (CWD) within the surrounding forest changes continuously during the expansion of Moso bamboo (Phyllostachys edulis), which partly reflects the death process of trees within the community. In this paper, we sampled an area of 0.72 hm² within the transition zone of Moso bamboo expansion, which included continuous secondary coniferous and broad-leaved mixed forest (SF), transitional forest (TF), and Moso bamboo forest (MF) in Wuxie National Forest Park, Zhejiang Province. The spatial pattern and spatial correlation of CWD with different diameter classes, different decay classes, and different types in the three forests were analyzed using Ripley’s L function. The results showed that, with the expansion of Moso bamboo, the volume of CWD in TF was higher than those in SF and MF, and the total density of CWD in the three forests varied, with a decreasing order of MF > TF > SF. The spatial pattern of CWD in the three forests was aggregated on a relatively small scale, but the pattern changed from aggregated to random distribution with the increase in scale. Moreover, the CWD of Moso bamboo in TF showed aggregated distribution, and the aggregation intensity increased with the increase in scale. With the expansion of Moso bamboo, the spatial pattern and spatial correlation of CWD with different diameter classes, decay classes, and types have changed significantly in the three forests. Our study suggests that the expansion of Moso bamboo is increasingly strengthening the intraspecific and interspecific competition and accelerating the death of neighboring trees. Full article

The Danxia landform is a unique red bed landform in China. The effects of vegetation restoration on soil organic carbon (SOC) components are still poorly understood in the Danxia landform region of southwest China. In this study, soil samples were collected from selected five different vegetation restoration types (shrub (SH), mixed conifer–broadleaf forest (MCBF), evergreen broad-leaved forest (EBF), Chinese fir forest (CFF), and bamboo forest (BF)) at 0–30 cm depth to discuss the concentrations and stocks of SOC and its labile organic carbon (LOC) fractions ((dissolved organic C (DOC), microbial biomass C (MBC), and easily oxidized organic C (EOC)) and their relationship with soil physicochemical properties and enzyme activities. The results indicated that the contents of SOC and LOC fractions as well as SOC stocks declined with increasing soil depth in five vegetation restoration types. At 0–30 cm depth, BF and CFF showed higher the average concentrations and total stocks of SOC and EOC compared with SH, EBF, and MCBF. The highest average DOC content was in BF, but no significant differences was observed in the total DOC stocks among five vegetation restoration types. BF and EBF showed significantly greater average MBC concentrations and total MBC stocks than other vegetation restoration types. SOC and its LOC fractions were positively correlated with soil moisture and three enzyme activities in different degrees under the five vegetation restoration types and closely related with total nitrogen (TN) and total phosphorus (TP) except for TP of CFF and BF and negatively affected by pH (except for CFF and the DOC and MBC of MCBF) and BD. Generally, soil TN, TP, and invertase were found to be the main driver factors for soil carbon accumulation. However, the overall levels of SOC and its labile fractions indicate that BF had the strongest carbon storage capacity, followed by CFF and EBF. This study can provide a good reference for ecosystem management and the selection of appropriate restoration strategies in Danxia landform regions. Full article

Secondary forest accounts for almost 60% of the forest area in Japan. Dwarf bamboo (Sasa senanensis) grows widely in the understory of such forest and could make a significant contribution to the overall CO₂ sink function (gross primary production, GPP) of forest ecosystems. It is, therefore, necessary to evaluate the GPP of Sasa in various forests and estimate its controlling factors. In this study, we estimated the Sasa GPP at the community level by using a chamber system in an evergreen coniferous forest, a mixed forest, and a deciduous broadleaved forest. We hypothesized that (1) the seasonal trends of Sasa community GPP and Sasa annual GPP would differ in different forest types, (2) in addition to light intensity, the seasonal changes of the Sasa community GPP would be controlled by different factors in the different forest types. As a result, although the seasonal trends of the Sasa GPP and the controlling factors differed among the three forests, the annual Sasa GPP was almost the same for the three forests. This study reveals the possible effect of forest type on the seasonal trends of Sasa GPP and its controlling factors; however, for the annual Sasa GPP, the length of the growing periods would also be an important factor. Full article

Ecosystem services are directly related to human well-being. Previous studies showed that management policies and human activities alter the trade-offs and synergies of ecosystem services. Taking effective measures to manage the trade-offs and synergies of ecosystem services is essential to sustain ecological security and achieve a “win-win” situation between society and ecosystems. This study investigated the spatiotemporal changes of water yield, soil conservation, and carbon sequestration in the Jiulianshan National Nature Reserve from 2000 to 2020 based on the InVEST model. We distinguished spatial patterns of trade-offs and synergies between ecosystem services using the correlation relationship analysis. Then we analyzed the response of ecosystem services relationships among different vegetation types and elevation bands. The results showed that water yield and carbon sequestration presented an overall upward trend, while soil conservation remained a marginal degradation. Rising ecosystem services were mainly in the central, western, and southeastern regions, and declining areas were mainly distributed in the midwestern and northeastern fringes. Synergies spatially dominated the interactions among water yield, soil conservation, and carbon sequestration, and the trade-offs were primarily concentrated in the northern, southern, and southwestern fringes. Among the different vegetation types, synergies dominated ecosystem services in broad-leaved forests, coniferous forests, mixed forests, and Moso bamboo forests and in grass. The trade-offs were gradually reduced with elevation. This study highlighted that trade-off of ecosystem services should be incorporated into ecological management policies, strengthening the effectiveness of nature reserves in protecting and improving China’s ecosystem services. Full article

Forest ecosystem succession plays an important role in soil microbiota variation, and soil microbes will re-establish ecosystem function after disturbance events. A distinctive disturbance of the expansion of bamboo forest into the surrounding broadleaved ecosystem is the change in litter type input. We conducted a 6-month microcosm experiment to examine the effects of proportional changes in leaf litter composition due to moso bamboo (Phyllostachys edulis) invasion into a broadleaved forest on soil microbial community. A series of mixed litters were prepared with bamboo litter occupying at 0%, 33%, 50%, 67% and 100% in proportion (with a decrease in litter carbon (C)/nitrogen (N) from 36.23 to 31.35), and they were then amended into a broadleaved forest soil at a rate of 1%, respectively. Soil bacterial and fungal communities at different incubation stages were determined by high-throughput sequencing. With the increasing proportion of bamboo litter, the broadleaved forest soil exhibited strong changes in microbiome assembly, including reducing bacteria alpha-diversity, the relative abundance of Acidobacteria and Basidiomycota, while increasing the relative abundance of Actinbacteria, Proteobacteria and Ascomycota. Moreover, the increased proportion of bamboo litter (0% PP→100% PP) increased the relative abundance of membrane transport and carbohydrate metabolism of soil bacteria but decreased the relative abundance of saprotrophic soil fungi. Redundancy analysis showed that bacteria rather than fungal communities changed greatly during incubation (p < 0.05). Additionally, the activities of soil pH, NO₃⁻-N, NH₄⁺-N, dissolved nitrogen and C- and N- acquiring enzymes were the main factors affecting bacterial and fungal community structure (p < 0.05). The soil physicochemical properties were significantly correlated with the composition of microbial phyla among different litter amendment treatments. These results indicated that different proportions of bamboo litter dramatically alter the soil bacterial rather than the fungal community, most likely by changing edaphic patterns. This study has important implications for understanding the litter–soil–microbe synergy during the bamboo forest expansion and provides a basis for assessing the ecological risk of bamboo forest expansion. Full article

The growth of individual trees in a forest is affected by many factors, a crucial one being the intensity of competition among trees, because it affects the spatial structure of the forest and is in turn influenced by silvicultural practices. In a mixed forest in particular, the growth of trees is affected by multiple interactions. To analyse the competition between moso bamboo (Phyllostachys pubescens (Pradelle) Mazel ex J.Houz.) and broad-leaved trees in a mixed forest, data were extracted by sampling six spots within such a forest using terrestrial laser scanning (TLS). The convex hull algorithm was used for calculating the overlap volume between the crowns of the broad-leaved trees and the bamboo canopy. Bamboos growing at least 3 m away from any of the broad-leaved trees were the most numerous and the diameter at breast height (DBH) is larger than those growing closer than that, which suggests that broad-leaved trees suppressed the growth of bamboo if they are closer but promote it beyond 3 m up to a point at which the distance is too great for any such effect. The modified Hegyi’s competition index was constructed based on the canopy factor, which may better describe the competitive interaction among the trees and bamboos. Using TLS can enhance our understanding of the competition among trees in mixed forests and help in planning the spatial structure of such forests in general and provide a benchmark for choosing planting distances in particular. Full article