Weizhong Li’s research while affiliated with Northwest A&F University and other places

Background and aims Soil invertebrates are an indispensable component of forest biodiversity, and play irreplaceable roles in carbon and nutrient cycling in forest ecosystems. Although decaying logs and canopy gaps might affect the structure and function of soil invertebrate community via multiple pathways, knowledge regarding the interactive effect of decaying logs and gap positions on soil invertebrate community is limited. Methods Minjiang fir (Abies faxoniana) logs of decay classes I, II, III, IV, and V were simultaneously incubated on the floor from the gap center to the closed canopy in an over-mature Minjiang fir forest. After a 6-year incubation, soil invertebrate communities in the litter and topsoil layers beneath and away from logs were investigated in the growing season. Results Soil invertebrate taxa compositions beneath logs differed from those away from logs. Invertebrate densities in the litter and topsoil were significantly higher in microhabitats away from logs than those beneath early- and highly-decayed logs. Meanwhile, the Shannon–Wiener index of invertebrate communities in the litter and topsoil was significantly higher beneath the middle-decayed logs. Furthermore, invertebrate densities and the Shannon–Wiener index in the litter and topsoil markedly increased from the gap center to the closed canopy. Additionally, densities of fungivores and detritivores beneath logs were markedly lower than those away from logs, and densities of fungivores and omnivores increased significantly from the gap center to the closed canopy. Conclusion Decaying logs and gap positions jointly mediate the structure and function of soil invertebrate communities, implying that reserving logs and intermediate gap disturbances are crucial for maintaining soil biodiversity in the subalpine forest.

Background Phosphorus in the soil is mostly too insoluble for plants to utilize, resulting in inhibited aboveground biomass, while Carex can maintain their aboveground biomass through the presence of dauciform roots. However, dauciform roots lead to both morphological and physiological changes in the root system, making their primary mechanism unclear. Methods A greenhouse experiment was conducted on three Carex species, in which Al-P, Ca-P, Fe-P, and K-P were employed as sole phosphorus sources. The plants were harvested and assessed after 30, 60 and 90 days. Results (1) The density of dauciform roots was positively correlated with root length and specific root length, positively influencing aboveground biomass at all three stages. (2) The aboveground phosphorus concentration showed a negative correlation with both dauciform root density and aboveground biomass in the first two stages, which became positive in the third stage. (3) Aboveground biomass correlated negatively with the aboveground Al concentration, and positively with Ca and Fe concentration (except Al-P). (4) Root morphological traits emerged as critical factors in dauciform roots’ promotion of aboveground biomass accumulation. Conclusion Despite the difference among insoluble phosphorus, dauciform roots have a contributing effect on aboveground growth status over time, mainly by regulating root morphological traits. This study contributes to our understanding of short-term variation in dauciform roots and their regulatory mechanisms that enhance Carex aboveground biomass under low available phosphorus conditions.

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.

In this study, typical open spaces were selected in the urban area of Lanzhou, China, with varying distances from the Yellow River and different plant configuration spaces. Then, the thermal perception of respondents was investigated through meteorological measurements, thermal comfort questionnaires, and parametric modeling. The findings indicate the following: (1) Wind speed decreases significantly as the distance from the Yellow River increases in the three open green spaces. (2) The cold lake effect of the Yellow River dominates the wind environment. (3) The closest site to the Yellow River exhibits the strongest correlation between wind speed and the respondents' thermal sensation. (4) There is a strong positive correlation between the model output and different spatial measurement values. (5) There is a certain discrepancy between the UTCI values and the actual measurements, but the fit is high and consistent with an R-squared value of 0.936. This study quantitatively evaluated the thermal comfort and perception in typical spaces and validated the reliability of parameterized modeling for such spaces, providing a reference basis for thermal environment planning in these spaces.

Introduction The drought and phosphorus deficiency have inevitably become environmental issues globally in the future. The analysis of plants functional trait variation and response strategies under the stress of phosphorus deficiency and drought is important to explore their ability to respond to potential ecological stress. Methods In this study, Carex breviculmis was selected as the research object, and a 14-week pot experiment was conducted in a greenhouse, with two phosphorus treatment (add 0.5mmol/L or 0.05μmol/L phosphorus) and four drought treatment (add 0-5%PEG6000), totaling eight treatments. Biomass allocation characteristics, leaf anatomical characteristics, biochemical parameters, root morphology, chemical element content, and photosynthetic parameters were measured. Results The results showed that the anatomical characteristics, chemical elements, and photosynthetic parameters of Carex breviculmis responded more significantly to main effect of phosphorus deficiency. Stomatal width, leaf phosphorus content and maximum net photosynthetic rate decreased by 11.38%, 59.39%, 38.18% significantly (p<0.05), while the change in biomass was not significant (p>0.05). Biomass allocation characteristics and root morphology responded more significantly to main effect of drought. Severe drought significantly decreased leaf fresh weight by 61% and increased root shoot ratio by 223.3% compared to the control group (p<0.05). The combined effect of severe drought and phosphorus deficiency produced the highest leaf N/P ratio (291.1% of the control) and MDA concentration (243.6% of the control). Correlation analysis and redundancy analysis showed that the contributions of phosphorus and drought to functional trait variation were similar. Lower epidermal cell thickness was positively correlated with maximum net photosynthetic rate, leaf phosphorus, chlorophyll ab, and leaf fresh weight (p<0.05). Discussion In terms of response strategy, Carex breviculmis was affected at the microscopic level under phosphorus deficiency stress, but could maintain the aboveground and underground biomass well through a series of mechanisms. When affected by drought, it adopted the strategy of reducing leaf yield and improving root efficiency to maintain life activities. Carex breviculmis could maintain its traits well under low phosphorus and moderate drought, or better conditions. So it may have good ecological service potential in corresponding areas if promoted. This study also provided a reference for plant response to combined drought and phosphorus deficiency stresses.