Endophytic bacteria widely exist inside plant tissues and have an important role in plant growth and development and the alleviation of environmental stress. However, little is known about the response of root-associated bacterial endophytes of Lei bamboo (Phyllostachys praecox) to intensive management, which is a common management practice for high bamboo shoot production in subtropical China. In this study, we comparatively investigated the root endophytic bacterial community structures in a chronosequence of intensively managed (5a, 10a, 15a, and 20a) and extensively managed plantations (as control, Con). The results showed that endophytic Proteobacteria was the dominant bacterial phylum in the bamboo roots. Intensive management significantly increased (p < 0.05) the bacterial observed species and Chao1 (except 5a) indices associated with bamboo roots. The relative abundances of Firmicutes, Bacteroidetes, and Actinobacteria (except 15a) in the intensively managed bamboo roots significantly increased (p < 0.05) compared with those in Con, while the relative abundance of Proteobacteria significantly decreased in intensively managed bamboo roots (p < 0.05). The phyla Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes were the biomarkers in Con, 5a, 15a, and 20a, respectively. Redundancy analysis (RDA) showed that soil alkali-hydrolysable N (AN), available phosphorus (AP), available K (AK), and total organic carbon (TOC) were significantly correlated (p < 0.05) with the bacterial community compositions. Our results suggest that the root endophytic microbiome of Lei bamboo was markedly influenced by intensive management practices, and the available nutrient status could be the main driving factor for such shifts. Although heavy fertilization in the intensive management system increased the diversity indices, the rapid changes in root endophyte communities and their relevant functions might indicate a high risk for sustainable management.

The ramet system is a typical structural type in the life history of clonal plants. This massive structure is formed by many similar ramets connected by underground rhizomes, which are independent and mutually influential. Therefore, the ramet system is unique to bamboo forests, and its role in the construction, maintenance, and productivity of bamboo populations is irreplaceable. Mulch management is a high-level cultivation model for bamboo forests that is used to cultivate bamboo shoots. However, the basic conditions of bamboo ramet systems in this managed model are poorly understood. This study analyzed the underground rhizome morphology, bud bank, and branching of bamboo ramets in a Phyllostachys praecox C.D. Chu et C.S. Chao ‘Prevernalis’ forest to explore the growth patterns of bamboo ramets in high-level management fields. In mulched bamboo forests, the bamboo rhizomes, distributed in intermediate positions of the bamboo ramet system, were long with many lateral buds and branches, and those at the initial and distal ends were short with few lateral buds and branches. The initial end of the ramet system reduced the ramet system, the intermediate part expanded the ramet system, and the distal end promoted ramet system regeneration. Owing to the continuous reduction, expansion, and renewal of ramet systems, the bamboo rhizome system demonstrates mobility and adaptability. This study found that a higher level of bamboo forest management increased the possibility of artificial fragmentation of the ramet system and that improving the efficiency of the ramet system was beneficial for maintaining its high vitality. Thus, this study provides a crucial reference for guiding the precise regulation of bamboo ramet systems in artificial bamboo forests.

Intercropping affects soil microbial community structure significantly; however, the effects on understory medicinal plants in karst areas remain unclear. We investigated the effects of four intercropping systems (Moso bamboo, Chinese fir, bamboo-fir mixed forest, and forest gap) on the rhizosphere microbial communities of giant lily (Cardiocrinum giganteum), an economically important medicinal plant in China. We assessed the intercropping impact on rhizosphere microbial diversity, composition, and co-occurrence networks and identified key soil properties driving the changes. Bacterial and fungal diversity were assessed by 16S rRNA and ITS gene sequencing, respectively; soil physicochemical properties and enzyme activities were measured. Moso bamboo system had the highest fungal diversity, with relatively high bacterial diversity. It promoted a distinct microbial community structure with significant Actinobacteria and saprotrophic fungi enrichment. Soil organic carbon, total nitrogen, and available potassium were the most influential drivers of microbial community structure. Co-occurrence network analysis revealed that the microbial network in the Moso bamboo system was the most complex and highly interconnected, with a higher proportion of positive interactions and a greater number of keystone taxa. Thus, integrating Moso bamboo into intercropping systems can enhance soil fertility, microbial diversity, and ecological interactions in the giant lily rhizosphere in karst forests.

Intercropping is a promising strategy for sustainable medicinal plant cultivation, but its impact on plant–microbe interactions remains poorly understood. This study investigated the influence that intercropping giant lily (Cardiocrinum giganteum) with bamboo (BG), Chinese fir (FG), and mixed forests (MG) had on the giant lily metabolome and microbiome compared to a monoculture control (GG). Metabolomic analysis revealed that BG significantly increased the accumulation of terpenoids (e.g., yucalexin B22, 19.39-fold), alkaloids (e.g., anabasine, 2.97-fold), and steroids (e.g., O-acetyl-lariciresinol, 4.49-fold), while MG induced the production of stress-related metabolites (e.g., aflatoxin G2, 128.62-fold), and FG enhanced nitrogen metabolism (e.g., putrescine, 2.47-fold). Intercropping altered the rhizosphere and endophytic microbial communities, with BG enriching beneficial bacteria (e.g., Acidobacteria and Alphaproteobacteria) and FG promoting symbiotic fungi (e.g., Serendipita and Xylariales). Network analysis revealed strong correlations between specific microbial taxa (e.g., Bacillus and Ceratobasidiaceae) and key metabolites (e.g., norpandamarilactonine A, methylgingerol), indicating their potential roles in shaping the metabolic profiles of giant lily. These findings highlight the complex interplay between intercropping systems, microbial communities, and medicinal plant metabolism and provide a basis for developing targeted cultivation strategies to enhance the production of bioactive compounds in giant lily and other medicinal plants.

Examining the ramet system in bamboo forests can provide an important theoretical basis for strategic management. Moso bamboo is an economically important species in China, and implementing the correct management measures can play a key role in improving bamboo productivity. However, the dynamics of the Moso bamboo ramet system under timber vs. shoot forest management remain underexplored. In this study, we investigated the underground rhizome growth, bud bank structures, branch growth, and distribution patterns of bamboo ramet systems in the two main bamboo cultivation types. Shoot forest ramet systems exhibited stable early-stage rhizome renewal but instability in later stages, characterized by thin, elongated rhizomes. The opposite was observed in the timber forests. The underground bud bank of the ramet system in the shoot forest had a strong renewal ability with stable lateral bud input. However, shoot harvesting disturbed the bud bank balance. The lateral bud input in the timber forest was unstable, with the lateral buds being prone to death. The variation range and quantity of branch types in the ramet system in the shoot forest were greater than those in the timber forest. The number of branches in different parts of the ramet system was in the order of rhizome tip (RT) > middle of rhizome (RM) > rhizome base (RB). The range of variation was greater in the shoot forest. Different management methods led to growth differences in the examined bamboo ramet systems. Bamboo forest management resulted in a correlation between bud banks and ramet system renewal. Operations such as bamboo shoot harvesting significantly impacted branch growth and distribution. These findings not only provide a better understanding of the growth and management strategy of bamboo ramet systems worldwide but also provide a universal theoretical reference for the sustainable management of bamboo forests in other countries.

Bamboo forests are formed by the interlacing of multiple ramet systems. However, the interaction relationships between ramet systems remain unclear. To determine the effects of initial planting density on the construction of ramet systems in typical monopodial bamboos, and to clarify the differentiation rules of underground clonal architecture for bamboo species with different culm diameters, in this study, we selected large-diameter species Phyllostachys edulis and small-diameter species Phyllostachys praecox as study species. A pot experiment with root restriction was conducted using three density gradients of low, medium, and high. Rhizome morphology, underground bud bank dynamics, branching types, and the spatial distribution of the ramet systems were determined. The results showed that density significantly affected rhizome elongation, node allocation, the ratio of dormant buds to germinated buds, and branching hierarchy distribution of ramet systems, with pronounced differences between species. In P. edulis, longer rhizomes, higher dormant bud accumulation, and the branching hierarchies concentrated in low-to-moderate grades were observed at low density. In contrast, rhizome growth and branching were significantly inhibited with increasing density. For P. precox, multistage rhizome extension, higher sprouting activity, and wider branching distribution in the middle and posterior segments of the rhizomes occurred under low- and medium-density conditions. Under high density, however, the peak of dormant buds shifted backward, and a sprouting compensation effect occurred. The initial density reshaped the spatial architecture of ramet systems by altering the intensity of underground competition and preferentially inhibiting the development of new branches and high-grade rhizomes. This study focused on monopodial bamboos during the early establishment stage of mother bamboo development. First, it explored density-driven effects governing ramet system formation. Second, it elucidated contrasting clonal trade-off responses between large- and small-diameter bamboo species. The results will supplement theories on the population construction of woody clonal plants. In addition, they can guide rational close planting and targeted regulation of ramet systems in artificial bamboo stands.