This study aims to investigate evapotranspiration and its response to environmental factors and ascertain the land-atmosphere interactions in Pinus sylvestris var. mongolica plantations of China. The eddy-covariance technique and corresponding environmental sensors were used to continuously measure evapotranspiration and environmental factors in a P. sylvestris var. mongolica plantation in the western Liaoning Province in 2021 and 2022. The results showed that the plantation had the annual evapotranspiration of 394. 93 mm and 455. 99 mm, the precipitation minus evapotranspiration of 237. 87 mm and 119. 11 mm in 2021 and 2022, respectively. Net radiation, air temperature, air relative humility, top soil water content, and normalized difference vegetation index were the key controlling factors of evapotranspiration, and the correlation coefficient with normalized difference vegetation index was highest during the growing seasons in the two years. Canopy conductance had exponential relationships with crop coefficient, Priestley-Taylor coefficient, and decoupling coefficient, and the threshold value of canopy conductance was 10 mm ·s^-1. When normalized difference vegetation index was greater than 0. 55, canopy conductance, crop coefficient, Priestley-Taylor coefficient, and decoupling coefficient increased rapidly with the increase in normalized difference vegetation index. The vapor pressure deficit had significantly negative effects on those surface parameters. And those surface parameters were promoted linearly by top soil water content in this plantation.The P. sylvestris var. mongolica plantation in the western Liaoning Province stored a part of precipitation.Canopy development dominated the seasonal variationsof evapotranspiration, and four surface parameters were significantly influenced by vegetation greenness and soil and atmospheric water status.

Mechanical harvesting can cause damage to the flower buds of Camellia oleifera, which affects the fruit yield of the following year. In order to investigate the influence of mechanical harvesting of fruits on the yield of C. oleifera in the second year and ease the nutritional competition by rational loading, this study designed flower thinning treatments at the intensities of 0%, 30%, 50%, and 70% for the 10-year-old plants of the C. oleifera cultivar 'Cenruan 3' and then determined the fruit yield and oil quality. The results showed that the fruit volume, fruit weight, ratio of seeds to fresh fruits, ratio of kernels to seeds, and kernel oil content increased with the increase in flower thinning intensity. The yield per plant and oil yield per plant in the 50% thinning treatment of C. oleifera in the second year increased significantly by 44.51% and 43.25%, respectively, while they had no significant difference between 30% and 70% treatments and the control. The 50% and 70% treatments showed increased content of oleic acid and palmitoleic acid but decreased content of palmitic acid, stearic acid, linoleic acid, and linolenic acid. The unsaturated fatty acid content and oleic acid content were in the descending order of 70% treatment > 50% treatment>30% treatment. Through the flower thinning treatment, the unsaturated fatty acid content reached 88.88%-89.01% and the oleic acid content reached 78.2%-79.1%. In summary, 50% of flower thinning can significantly improve the fruit yield and oil quality compared with the control. The results provide a reference for artificial flower (bud) thinning and mechanical harvesting of C. oleifera fruits.

To evaluate the influencing mechanisms and potential risks of understory cultivation of medicinal plants on nutrient cycling, we compared pure Castanopsis hystrix (non-intercropping) stands with the stands intercropped with Aspidistra elatior on Maofeng Mountain. Carbon (C), nitrogen (N), and phosphorus (P) content of understory plants, litter, and soil was measured to analyze their stoichiometric characteristics and differences between treatments. The results showed that intercropping increased the total nitrogen (TN) content in the aboveground part of the herbaceous layer (P < 0. 05), while decreasing the organic carbon (OC) content as well as the C/N, C/P, and N/P ratios in the stems and leaves of the shrub layer (P < 0. 05), indicating enhanced N and P absorption and utilization efficiency in understory plants. In the litter layer, intercropping reduced the OC content (P < 0. 05), decreased the C/N ratio in the semi-decomposed and fully decomposed layers (P < 0. 05), and increased the TN content in the fully decomposed layer, which reflected accelerated litter decomposition and enhanced N mineralization, while the P release was delayed. In the soil layer, intercropping increased OC, TN, and the C/N, C/P, and N/P ratios (P < 0. 05). The rise in soil N/P indicated the mitigation of N limitation, while the decreases in total phosphorus (TP) and available phosphorus (AP) suggested an increased risk of P limitation. Soil enzyme activities were enhanced under intercropping (P < 0. 05), reflecting stronger microbial decomposition and mineralization. Redundancy analysis revealed close coupling relationships among the C, N, and P characteristics of plants, litter, and soil. Overall, intercropping A. elatior in C. hystrix forests optimized nutrient utilization, promoted litter decomposition, and enhanced soil C and N accumulation, thereby altering the C, N, and P allocation patterns within the plant-litter-soil system, while highlighting the potential ecological risk of reduced soil P availability.

To explore how primary forest conversion affects soil nitrogen (N) fractions, this study selected a primary evergreen broad-leaved forest and a converted Cunninghamia lanceolata plantation, an orchard (Citrus reticulata or Actinidia chinensis), a sloping cropland, and a paddy with similar geographical background conditions and clear land use history in northwestern Hunan. The physicochemical and biochemical properties of 0-20 cm soil layer were analyzed to study the responses of N fraction content and the related enzyme activities in the red soil derived from slate to the primary forest conversion. Primary forest conversion significantly reduced nitrogen components, associated enzyme and protein content by 15.83% to 87.36%, 20.04% to 39.15% and 30.97% to 66.18% in the red soil derived from slate. The soil dissolved organic N, microbial biomass N, and nitrate N showed higher response ratios than the total N in soil, sensitively indicating the short-term changes of total N in the red soil derived from slate. The primary forest conversion to plantation showed lower reductions in content of N fractions and activities of associated enzymes in the red soil derived from slate than the primary forest conversion to other land use types, demonstrating the preservation of soil N content and the stabilization of associated enzymes. The conversion of primary forest to other land uses led to a decreasing trend in the content of N fractions and activities of related enzymes in the red soil derived from slate, suggesting the negative effect of primary forest conversion on soil health.

To reveal the dynamic patterns of carbon accumulation and allocation during the vegetation restoration process of Pinus tabulaeformis plantations at the subtropical to warm temperate transitional zone, this study focused on young and middle-aged Pinus tabulaeformis plantations in the southern Qinling Mountains, with grassland serving as the control. The variations in content of organic carbon and relative abundance of the stable carbon isotope (δ_¹³C) within the needle-litter-soil continuum were analyzed across these three vegetation types. The results showed that: (1) The content of organic carbon in the needles of the young forest was significantly higher than that of the middle-aged stand. However, there was no significant difference in δ_¹³C of the needles between young and middle-aged forests. Furthermore, neither the content of organic carbon nor δ_¹³C in the litter layer differed significantly across the three vegetation types. (2) Within the soil depth range of 0-30 cm, the organic carbon content (C) decreased with the increase in soil depth, and the average organic carbon content of both the middle-aged forest and the grassland was higher than that of the young forest. Soil δ_¹³C showed a pattern of young forest > middle-aged forest > grassland. δ_¹³C gradually increased as the soil depth increased but had no significant differences among different soil layers. (3) Soil δ_¹³C exhibited a negative correlation with lg C (P < 0. 05), and the soil carbon turnover rates of the three vegetation types followed the order of grassland > young forest > middle-aged forest. (4) δ_¹³C exhibited positive correlations across various soil layers (P < 0. 05). δ_¹³C in the 0-20 cm soil layer showed a negative correlation with that in the litter (P < 0. 05) but no significant correlation with that in needles.

Canker was a newly found disease causing branch canker, branch dieback, and even death of Cinnamomum chekiangense. The study aimed to identify the causal agents of branch canker on C. chekiangense, thus providing theoretical support for forecasting and controlling this disease scientifically and effectively in practice. A total of 15 fungal isolates were obtained from diseased samples via the tissue isolation method. Pathogenicity assays demonstrated that strains JYZJZ2 and JYZJZ6 could infect the branches of C. chekiangense and reproduce typical canker symptoms, while they showed a difference in pathogenicity, with JYZJZ2 showing stronger pathogenicity. JYZJZ2 and JYZJZ6 were identified as Lasiodiplodia pseudotheobromae and L.iranensis, respectively, by comparing the DNA sequence data of internal transcribed spacer (ITS), translation elongation factor 1-alpha (tef1-α), β-tubulin (tub2), and largest subunit of RNA polymerase Ⅱ (rpb2) gene regions using the PhyloSuite platform, and by Ⅱ the morphological features. This is the first report of L. pseudotheobromae and L. iranensis causing canker on C. chekiangense worldwide.

To elucidate the genetic basis of early flowering and the molecular mechanisms underlying floral regulation in plants of Rosaceae, this study selected Prunus campanulata, an early-flowering ornamental plant endemic to East Asia, as the target species. Genome-wide comparison, phylogenetic analysis, conserved motif and cis-acting element prediction, weighted gene co-expression network analysis (WGCNA) were employed to characterize the PEBP gene family and its role in floral induction. The results revealed that the member composition and motif structure of the PEBP gene family in P. campanulata were highly conserved compared with those in related species, and no significant positive selection was detected based on branch-site models, indicating a lack of functional divergence among family members. Expression profiling showed that PcamFT gene exhibited high tissue-specific expression in floral organs. Promoter analysis indicated an enrichment of light-responsive G-box elements and the absence of AE-box and GT1 repressive elements, suggesting its transcriptional regulation may be highly responsive to photoperiodic signals. WGCNA identified 33 co-expression modules, among which the module 25 showed the strongest positive correlation with floral tissue. PcamFT gene was assigned to this module and was co-expressed with several core MADS-box floral regulators, including AP1, SEP3, and AGL1. Protein-protein interaction analysis indicated that PcamFT gene may interact with these transcription factors to form regulatory complexes that promoted floral meristem identity establishment and organ differentiation.

Michelia odora is a rare and endangered species unique to China. In recent years, it has been discovered that this species has been suffering from leaf blight. In this study, the symptoms were observed to reveal the pathogen of M.odora leaf blight. A fungal strain Fg-1 with high pathogenicity was isolated from the diseased leaves of M.odora by conventional tissue isolation. The pathogenic strain Fg-1 was identified as Colletotrichum gloeosporioides by morphological observation and multi-gene sequence analysis of internal transcribed spacer(ITS), ribosomal large subunit(LSU), and ribosomal small subunit(SSU). The results showed that the optimum growth temperature for the pathogen was 25 ℃, and the optimal light condition was 12 h light/12 h darkness. The pathogen could grow in the potato dextrose agar with pH 4-12, with the optimal pH 7. The colonies grew on all six types of culture media tested, namely water agar, synthetic low-nutrient agar, potato sucrose agar(PSA), mung bean agar, wheat agar, and corn agar. The colonies demonstrated the best growth on PSA. The most suitable carbon source was sorbitol, and the most suitable nitrogen sources were beef extract.

This study aimed to explore the feasibility of applying close-range photogrammetry in the quantitative analysis of spatial structure of mixed forests. A smartphone imagery-based method was developed to analyze the spatial structure of a coniferous-broadleaved mixed plantation in Jiufeng Experimental Forest Farm. A multi-path and multi-angle image acquisition strategy was employed to construct a three-dimensional (3D) point cloud model of the stand below the canopy. The optimal circle algorithm was utilized to identify and estimate the positions and diameter at breast height (DBH) of individual trees. The measured data of DBH, tree height, and crown width, along with DBH estimates derived from the 3D model, were used as weighting factors, and weighted Voronoi diagrams were constructed based on measured DBH, estimated DBH, and an equally weighted combination of measured DBH, tree height, and crown width. The effects of different weighting factors on key spatial structure parameters—mingling degree (M), neighborhood comparison (U), and uniform angle index (W)—were systematically analyzed. The results showed a strong correlation (R²=0. 977 2) between estimated DBH and measured DBH. For the estimated DBH of entire stand, the root mean square error (RMSE) of 1. 427 5 cm, the relative RMSE of 8. 224 1%, the deviation of 0. 503 8 cm, and the relative deviation of 2. 902 4%, which indicate the estimated DBH of the entire stand was underestimated. In addition, the results revealed similarities in the stand spatial structure units derived from different weighting factors. Although significant differences existed among some key spatial structure parameters, these did not affect the overall consistency in characterizing the stand's spatial structure. All the approaches consistently indicated that the stand exhibited moderate competition intensity, a moderate mixing degree, and a random distribution pattern.

This study explored the effects of different host plants on the growth and drought resistance of the hemiparasite Malania oleifera, aiming to screen the suitable host plants of M. oleifera during the seedling stage. A pot co-culture experiment was conducted with Eupatorium capillifolium, Cajanus cajan, Liquidambar formosana, Alnus nepalensis, Camphora officinarum, Quercus acutissima, Crotalaria pallida, Pistacia weinmanniifolia, and Illicium verum as host plants. The growth indicators, nutrient content, and physiological characteristics of M. oleifera under drought stress were evaluated. The results showed that the host plants improved the growth and survival rate (P < 0.05), increased the biomass and nutrient accumulation, and enhanced the drought resistance of M. oleifer. Different host plants exerted varied effects on M. oleifera (P < 0.05), with E. capillifolium, C. cajan, and L. formosana showing the most significant promoting effects on the seedling height, ground diameter, survival rate, and biomass accumulation. L. formosana, A. nepalensis, C. cajan, E. capillifolium, and C. officinarum had the most significant promoting effects on nutrient accumulation. Moreover, host plants exerted different effects on the accumulation of different nutrients. A. nepalensis, C. cajan, and E. capillifolium effectively promoted the accumulation of N and K, while L. formosana effectively promoted the accumulation of P. Under drought stress, C. cajan, L. formosana, A. nepalensis, and E. capillifolium promoted the accumulation of protective enzymes such as superoxide dismutase and peroxidase in M. oleifera to protect the cell membrane from damage. L. formosana, C. cajan, and E. capillifolium promoted the accumulation of proline, soluble sugar, and soluble protein for osmotic regulation and effectively reduced the content of malondialdehyde, thereby reducing the cell membrane damage caused by drought stress and enhancing the drought resistance. After rewatering, the physiological indicators of M. oleifera basically recovered to the levels before drought treatment. The comprehensive evaluation results suggest that L. formosana, C. cajan, and E. capillifolium are the most suitable hosts for the growth of M. oleifera, and A. nepalensis, C. officinarum, Q. acutissima, and C. pallida can also be used as suitable hosts for M. oleifera.