Yufang Bi

Root interactions are crucial in regulating soil microbial metabolism and plant nutrient allocation strategies, especially in mixed plantings. However, the effects of mixed planting and direct root contact on soil properties and plant nutrient allocation remain unclear. Thus, we established potted plants with Moso bamboo (Phyllostachys edulis) and Phoebe chekiangensis and created a physical barrier to the root system without blocking chemical communication using four treatments: mixed planting with root segregation (MT), mixed planting without root segregation (MS), pure Moso bamboo with root segregation (BT), and pure Moso bamboo without root segregation (BS). We investigated changes in soil and Moso bamboo nutrient content, soil enzyme activity, and microbial metabolic limitation. The results show that mixed planting and root segregation significantly affected soil and plant nutrient content and soil enzyme activities. Compared to the two pure Moso bamboo treatments, mixed planting increased microbial carbon limitation but decreased microbial nitrogen limitation. Physical segregation between roots increased microbial carbon use efficiency (CUE) compared to no segregation. Random forest analyses revealed that the best predictors of soil C and N limitations and CUE were microbial biomass and dissolved organic nitrogen (DON), respectively. Partial least squares path modeling indicated that mixed planting and root separation, directly and indirectly, affected soil microbial metabolic limitation through their effects on soil nutrients, microbial biomass, and enzyme activities. Carbon limitation significantly increased plant nutrient contents. Our study provides further insights into factors influencing nutrient limitation, CUE, and plant nutrient allocation strategies in mixed Moso bamboo plantations.

Moso bamboo, which is essential to China’s economy, is currently facing significant threats due to declining profits. Inadequate management of moso bamboo can negatively impact the surrounding ecosystems. This study investigated allelopathy in moso bamboo forests by identifying potential allelochemicals and their effects on coexisting plants. Fresh leaves and litter from moso bamboo were collected to examine allelochemicals released through natural processes such as rainwater leaching and litter decomposition. Seven substances with potential allelopathic effects were identified using liquid chromatography–mass spectrometry (LC–MS). Four of these substances—DBP, PHBA, citric acid, and CGA—were selected for a detailed analysis of their effects on the photosynthetic and antioxidant systems of two naturally coexisting plants, Phoebe chekiangensis and Castanopsis sclerophylla. The results indicated that the four chemicals influenced P. chekiangensis and C. sclerophylla through different patterns of interference. DBP, PHBA, and citric acid negatively impacted the transfer of electrons during photosynthesis in both plants but had a lesser effect on the antioxidant system-related indicators in P. chekiangensis. In C. sclerophylla, these four chemicals led to a significant accumulation of reactive oxygen species (ROS) and increased malondialdehyde (MDA) content and catalase (CAT) activity to varying degrees. Furthermore, the relative abundance of fungi and bacteria in the soil was also affected by the DBP treatment. The identification of allelochemicals from moso bamboo, along with the investigation of their mechanisms, provides valuable insights into competitive interactions among plant species, particularly between moso bamboo and other species, along with the expansion of moso bamboo forests.

Bamboo and wood-mixed forests are management models that remarkably enhance the balance and productivity of bamboo ecosystems. However, the effects of this model on soil nutrients and enzyme activities remain largely unknown. This study compared the soil organic carbon, nitrogen, phosphorus, and enzyme activity, along with the characteristics of fine roots in pure Moso bamboo plantations (CK) and those mixed with Liriodendron chinense (ML), Sassafras tzumu (MS), Cunninghamia lanceolata (MC), and Pseudolarix amabilis (MP). The results showed that mixed forests improve carbon pools in 0–40 cm soil layers, increasing the total organic C(TOC), free particulate organic C (fPOC), occluded particulate organic C (oPOC), hot-water-extractable organic C (DOC), and mineral-associated organic C (MOC). They also increase soil total N, total P, available N, available P, NH4+-N, NO3−-N, inorganic P, organic P, and microbial biomass N. Bacterial and fungal abundances, along with enzyme activities (urease, acid phosphatase, polyphenol oxidase, peroxidase, and β-glucosidase), also improved. MP and MS were the most effective. Moreover, MS and MP supported a higher biomass and length of fine root and increased the nitrogen and phosphorus uptake of Moso bamboo. In conclusion, Sassafras tzumu and Pseudolarix amabilis are optimal for mixed planting, offering substantial benefits to soil nutrient dynamics and preventing soil quality decline in Moso bamboo forests, thereby supporting better nutrient cycling and carbon sequestration. This research offers insights into enhancing soil quality through diversified Moso bamboo forestry.

Moso bamboo (Phyllostachys edulis) is a crucial species among the 500 varieties of bamboo found in China and plays an important role in providing ecosystem services. However, remote sensing studies on the invasion of Moso bamboo, especially its impact on forest biodiversity, are limited. Therefore, we explored the feasibility of using Sentinel-2 multispectral data and digital elevation data from the Shuttle Radar Topography Mission and random forest (RF) algorithms to monitor changes in forest diversity due to the spread of Moso bamboo. From October to November 2019, researchers conducted field surveys on 100 subtropical forest plots in Zhejiang Province, China. Four biodiversity indices (Margalef, Shannon, Simpson, and Pielou) were calculated from the survey data. Subsequently, after completing 100 epochs of training and testing, we developed the RF prediction model and assessed its performance using three key metrics: coefficient of determination, root mean squared error, and mean absolute error. Our results showed that the RF model has a strong predictive ability for all indices except for the Pilou index, which has an average predictive ability. These results demonstrate the feasibility of using remote sensing to monitor forest diversity changes caused by the spreading of Moso bamboo.

The purpose of this study was to investigate whether the Phyllostachys edulis-Carya illinoinensis co-plantation is a feasible forest model. Two treatments and one control were evaluated. The control was a low-density C. illinoinensis forest (CK), and the treatments were a high-density C. illinoinensis forest (DF), and a C. illinoinensis-P. edulis co-plantation forest (MF). Gas exchange and chlorophyll fluorescence parameters, leaf physiology, macromorphology, and anatomical structure of C. illinoinensis were measured and principal component analysis (PCA) was used to evaluate treatment effects. The highest net photosynthetic rate (Pn), which was 13.72 .µmol CO₂·m^-2·s^-1, was recorded for C. illinoinensis under the CK treatment, while the corresponding values for MF and DF treatments were 8.98 and 5.25 µmol CO_2·m^-2·s^-1, respectively. The JIP test revealed that plastoquinone libraries were inhibited under both MF and DF, particularly in the latter. Compared with CK, antioxidant substances in MF and DF leaves increased to a certain extent, again, particularly in the latter. Leaf macromorphology and anatomical structures under the different treatments also changed to acclimated to different environments. The leaf area of MF became lower, and the vascular tissue of DF petiole became larger. Finally, based on the main data, the order of the PCA scores was CK > MF > DF. The results indicated that both co-plantation and high-density planting caused both interspecific and intraspecific competition. Photosynthesis was inhibited in C. illinoinensis to varying degrees under both cultivation models. Nonetheless, the stress levels in C. illinoinensis were significantly lower under the co-plantation forest than under high-density planting. These findings indicate that C. illinoinensis growth was not severely inhibited by co-plantation with P. edulis, as it still developed well. Hence, co-plantation of P. edulis and C. illinoinensis is a promising mixed-forest model.

The genus Bambusa belongs to the subtribe Bambusinae and the subfamily Bambusoideae. The subgenera of Bambusa has not been satisfactorily circumscribed, and this remains a major taxonomic issue. Simultaneously, genera such as Dendrocalamus and Gigantochloa have not been confidently assigned to Bambusa. Here, the phylogenetic relationships among subgenera were investigated using five chloroplast DNA markers (rpl32-trnL, rpl16, matK, rbcL, and trnH-psbA) for a sample of 50 ingroup and 16 outgroup species. A total of 186 key morphological descriptors were studied for the 50 ingroup species. The results indicated that five chloroplast DNA markers were possible to distinguish Bambusa species from other species and divide them into several clusters. Phylogenetic analyses conducted using morphological descriptors and a combined marker (rpl32-trnL+rpl16) revealed three and five distinct lineages, respectively, among the currently recognized Bambusa species. The branching pattern of the dendrogram was not completely consistent with the classical taxonomic classification of Bambusa. In addition, not all varieties and cultivars were clustered with McClure classifications. As the maximum parsimony topology and morphological analyses were inconsistent, some clustering results overlapped. Overall, the results obtained here do not support the current classification of the Bambusa subgenera.

The genus Bambusa belongs to the subtribe Bambusinae and the subfamily Bambusoideae. The subgenera of Bambusa have not been satisfactorily circumscribed, and this remains a major taxonomic problem. Meanwhile, genera such as Dendrocalamus and Gigantochloa have not been confidently assigned to Bambusa. Here, the phylogenetic relationships among subgenera were investigated using five chloroplast deoxyribose nucleic acid (DNA) markers (rpl32-trnL, rpl16, matK, rbcL, and trnH-psbA) for a sample of 50 ingroup species and 16 outgroup species. A total of 186 key morphological descriptors were studied for the 50 ingroup species. The results indicated that rpl 32-trnL and trnH-psbA were more suitable for the identification of Bambusa than the other markers. Using these markers, it was possible to distinguish Bambusa species from other species and to divide them into several clusters. Phylogenetic analyses conducted using morphological descriptors and a combined marker (rpl32-trnL+rpl16) revealed three and four distinct lineages among the members of the currently recognized Bambusa, respectively. The branching pattern of the dendrogram was not completely consistent with the classical taxonomic classification of Bambusa. In addition, not all varieties and cultivars were clustered with McClure. As the maximum parsimony topology and morphological analyses were not consistent, some clustering results overlapped. Overall, the results obtained here did not support the current classification of the Bambusa subgenera.

Background: The decrease in Cunninghamia lanceolata (Lamb.) production on continuously planted soil is an essential problem. In this study, two-year-old seedlings of two cultivars (a normal cultivar, NC, and a super cultivar, SC) were grown in two types of soil (not planted (NP) soil; continuously planted (CP) soil) with three watering regimes, and the interactive effects on plant growth and physiological traits were investigated in a greenhouse experiment. The water contents of the soil in the control (CK) (normal water content), medium water content (MWC) and low water content (LWC) treatments reached 75−80 %, 45−50 % and 20−25 % of the field water capacity, respectively. Results: The results indicated that the CP soil had a negative effect on growth and physiological traits and that the LWC treatment caused even more severe and comprehensive negative effects. In both cultivars, the CP soil significantly decreased the height increment (HI), basal diameter increment (DI), dry matter accumulation (DMA), net photosynthetic rate (Pn), total chlorophyll content (TChl), carotenoid content (Caro) and photosynthetic nitrogen use efficiency (PNUE). Compared to the NP soil, the CP soil also decreased the proline and soluble protein contents, nitrogen use efficiency (NUE) and phosphorus use efficiency (PUE) and increased the nitrogen:phosphorus ratio in roots, stems and leaves. The LWC treatment decreased growth and photosynthesis, changed ecological stoichiometry, induced oxidative stress, promoted water use efficiency and damaged chloroplast ultrastructure. Significant increases in ascorbate peroxidase (APX), peroxidase (POD), soluble protein and proline contents were found in the LWC treatment. Compared with the NC, the SC was more tolerant to the CP soil and water stress, as indicated by the higher levels of DMA, Pn, and WUE. After exposure to the CP soil and watering regimes, the decreases in biomass accumulation and gas exchange were more pronounced. Conclusions: The combination of drought and CP soil may have detrimental effects on C. lanceolata growth, and low water content enhances the impacts of CP soil stress on C. lanceolata seedlings. The superiority of the SC over the NC is significant in Chinese fir plantation soil. Therefore, continuously planted soil can be utilized to cultivate improved varieties of C. lanceolata and maintain water capacity. This can improve their growth and physiological performance to a certain extent.