Sibo Chen’s research while affiliated with Northwest A&F University and other places

Picea neoveitchii Mast. is a rare and threatened species of evergreen coniferous tree in China, commonly facing issues such as damaged seeds, abnormal seed growth, and empty seed shells. These abnormalities vary by location; unfortunately, the reasons behind these inconsistencies are completely unknown. This study compared seeds from two 150-year-old trees located in Taibai (Shaanxi province, TB150) and Zhouqu (Gansu province, ZQ150). The results showed significant differences in 43 metabolites and hormone levels, with higher levels of indole-3-acetic acid (IAA), methyl jasmonate (MeJA), and brassinosteroid (BR) in ZQ150, which were associated with more viable seeds. In contrast, TB150 exhibited more damaged seeds and empty seed shells due to higher abscisic acid (ABA) levels. Moreover, to further investigate these inconsistencies, we performed de-novo transcriptomic assembly and functional annotation of unigenes using high-throughput sequencing. A total of 2,355 differentially expressed unigenes were identified between TB150 and ZQ150, with 1,280 upregulated and 1,075 downregulated. Hormone signaling and sugar metabolism-related unigenes were further examined for their role in seed development. ZQ150 increased the number of normal seeds by enhancing endogenous IAA levels and upregulating auxin signaling and sugar metabolism-related genes. Conversely, TB150 showed more empty seed shells, correlated with elevated ABA levels and the activation of ABA signaling genes. We hypothesize that enhanced IAA levels and the upregulation of sugar metabolism and auxin signaling genes promote normal seed development.

Introduction In recent years, the visible light intensity of lawns has significantly decreased due to obstructions caused by urban shading objects. Carex has a competitive advantage over other turfgrass in low-light conditions and extensive management. Therefore, exploring their survival strategy in low-light environments is of great significance. Methods This study focuses on two species of Carex, Carex parva and Carex scabrirostris, and investigates their response to low-light conditions (150 μmol/m²/s) by simulating urban lawn conditions. Biomass allocation characteristics, leaf anatomical features, biochemical parameters, root morphology and photosynthetic parameters were measured. Results (a) Peroxidase activity, specific leaf area, and relative water content are key factors influencing the photosynthetic capacity of the two Carex species. (b) Under low-light conditions, photosynthetic parameters, leaf physiological indicators, and biomass allocation of the two Carex species were significantly affected (p<0.05). Both Carex species increased their investment in leaf biomass, maintained lateral root growth, and cleared reactive oxygen species to maintain their physiological balance. (c) In the simulated urban low-light environment, neither C. parva nor C. scabrirostris produced dauciform roots. Discussion In terms of response strategies, C. scabrirostris is a high-photosynthesis investing species with high productivity under low-light conditions, whereas C. parva exhibits minimal response, indicating a slow investment. C. scabrirostris has greater potential for application in low-light environments compared to C. parva. These results provide a theoretical basis for the cultivation and application of these two Carex species, as well as the expansion of turfgrass germplasm resources.

Landslides cause significant disturbances to mountainous ecosystems and human activities. Due to climate change, the frequency of landslides as secondary disasters has notably increased compared to the past. Further exploration is needed to understand the effects of different restoration methods on post-landslide plant communities and soil properties over different periods of time. In this regard, we selected Lantian County in the northern foothills of the Qinling Mountains as our study area. We conducted surveys on artificially restored and naturally recovered plots at 1, 6, and 11 years after landslide events. Undamaged areas were chosen nearby as control plots. We identified vegetation types and species diversity after artificial and natural recovery and further analyzed the impact of different restoration strategies on vegetation patterns and soil properties. The research results indicate that, compared with natural recovery, artificial restoration can more quickly improve vegetation and soil. With the increasing time gradient, the average ground cover of the herbaceous layer in natural recovery decreased gradually from 47% at year one to 34% at year eleven. In contrast, in artificial restoration, the average ground cover of the herbaceous layer increased from 27% at year one to 44% at year eleven. For the shrub layer, in natural recovery, the average ground cover gradually increased to 39% over eleven years. While in artificial restoration, the average ground cover for the shrub layer gradually increased to 46% over the same period. In the artificial restoration plots, soil pH gradually increased (from 6.2 to 8.2), while TN content gradually decreased (from 1.7 g/kg to 0.9 g/kg). Similarly, TK content decreased (from 22.4 g/kg to 14.5 g/kg), and AP content showed a decreasing trend (from 20.7 mg/kg to 11.4 mg/kg). In the natural recovery plots, DNA content gradually increased (from 3.2 μg/g/d to 142.6 μg/g/d), and SC content gradually increased as well (from 2.4 mg/d/g to 23.1 mg/d/g). In contrast, on sites undergoing natural recovery, the short-term restoration rates of vegetation and soil are lower, but they show greater stability over a longer time. This study provides a new perspective on vegetation restoration strategies and is expected to offer insights for the optimization of post-landslide recovery in the future.

Urban parks, as an important component of urban green spaces, play a crucial role in improving the urban environment and enhancing residents' quality of life. This review summarizes the main content and research progress of urban park microclimate studies through analysis and synthesis of relevant literature from academic databases such as Web of Science and Google Scholar. Using Citespace or VOSviewer for bibliometric analysis, we found that the number of academic papers on the urban park microclimate has been growing year by year. The research content primarily covers the monitoring and analysis of temperature, humidity, wind speed, and other indicators in urban parks, as well as the impact of park design and planning on the microclimate. Keyword analysis revealed that researchers have mainly focused on the cooling effects of the urban park microclimate, mitigation of the urban heat island effect, and improvement of air quality. In terms of research methods, a combination of field observations and simulation models is commonly employed, with data being analyzed and validated using mathematical and statistical methods. The research results indicate that well-designed and planned parks can significantly improve the microclimate environment, reduce temperatures, and provide comfortable climatic conditions in urban areas. Additionally, vegetation arrangements and water features in urban parks also contribute to microclimate regulation. Moreover, windbreak measures and cooling strategies in parks can help alleviate the urban heat island effect, enhance air quality, and promote the health of ecosystems. However, this review also identified some issues in urban park microclimate research, including limitations in research scope, methods, and practical applicability. Future studies could deepen the comprehensive understanding of the urban park microclimate and explore more effective strategies for park design and planning to optimize and enhance the microclimate environment. It is also important for researchers to continuously innovate in terms of research methods and verify the feasibility of practical applications to better address the challenges of urban development.

The fast urban development leads to many complex problems. A smart city aims to solve these problems using scientific approaches. Urban Green Space (UGS) is a fundamental component of urban infrastructure. It needs to be upgraded simultaneously with the concept of the smart city. Methods of smart UGS planning and sustainable landscape design help integrate ecological performance and other functions of UGS. Smart UGS planning is a technical management tool and a human-centered smart application. A novel UGS classification method based on function combinations is proposed in the present work. Five types of UGS (Scenic UGS, Residential UGS, Commercial UGS, Office UGS, and Road UGS) in Baqiao District of Xi’an, Shaanxi Province, are selected as sample sites. Interviewees’ socio-economic attributes, visiting frequencies, and differences in demands are investigated. Eventually, the UGSs researched in this work are optimized based on public preferences and the current conditions of the sites. Results demonstrate the following. (1) The public’s preference for different types of UGS is different considerably. (2) Based on the public’s preference, Scenic UGS is improved in terms of quantity, function, and management; Residential UGS is upgraded regarding quantity and accessibility; and Commercial UGS, Office UGS, and Road UGS are improved in terms of quality. The results could provide methodological references for planning different types of UGS and innovative insights for smart UGS planning and sustainable landscape design.

Research Highlights: To demonstrate the effectiveness of configuration modes and tree types in regulating local microclimate. Background and Objectives: Urban trees play an essential role in reducing the city’s heat load. However, the influence of urban trees with different configurations on the urban thermal environment has not received enough attention. Herein we show how spatial arrangement and foliage longevity, deciduous versus evergreen, affect transpiration and the urban microclimate. Materials and Methods: We analyzed the differences between physiological parameters (transpiration rate, stomatal conductance) and meteorological parameters (air temperature, relative humidity, vapor pressure deficit) of 10 different species of urban trees (five evergreen and five deciduous tree species), each of which had been planted in three configuration modes in a park and the campus green space in Xi’an. By manipulating physiological parameters, crown morphology, and plant configurations, we explored how local urban microclimate could be altered. Results: (1) Microclimate regulation capacity: group planting (GP) > linear planting (LP) > individual planting (IP). (2) Deciduous trees (DT) regulated microclimate better than evergreen trees (ET). Significant differences between all planting configurations during 8 to 16 h were noted for evergreen trees whereas for deciduous trees, all measurement times were significantly different. (3) Transpiration characteristics: GP > LP > IP. The transpiration rate (E) and stomatal conductance (Gs) of GP were the highest. Total daily transpiration was ranked as group planting of deciduous (DGP) > linear planting of deciduous (DLP) > group planting of evergreen (EGP) > linear planting of evergreen (ELP) > isolated planting of deciduous (DIP) > isolated planting of evergreen (EIP). (4) The microclimate effects of different tree species and configuration modes were positively correlated with E, Gs, and three dimensional green quantity (3DGQ), but weakly correlated with vapor pressure deficit (VpdL). (5) A microclimate regulation capability model of urban trees was developed. E, Gs, and 3DGQ could explain 93% variation of cooling effect, while E, Gs, VpdL, and 3DGQ could explain 85% variation of humidifying effect. Conclusions: This study demonstrated that the urban heat island could be mitigated by selecting deciduous broadleaf tree species and planting them in groups.