Relevant studies have demonstrated that urban green spaces composed of various types of plants are able to alleviate the morbidity and mortality of respiratory diseases, by reducing air pollution levels. In order to explore the relationship between the spatial pattern of urban green spaces and air pollutant concentrations, this study takes 37 garden cities with subtropical monsoon climate in China as the research object and selects the urban air quality monitoring data and land use type data in 2019 to analyze the relationship between the spatial pattern and the air pollutant concentration through the landscape metrics model and spatial regression model. Moreover, the threshold effect of the impact of green space on air pollutant concentrations is estimated, as well. The results showed that the spatial pattern of urban green space was significantly correlated with the concentrations of PM_2.5 (PM with aerodynamic diameters of 2.5 mmor less), NO₂ (Nitrogen Dioxide), and SO₂ (Sulfur dioxide) pollutants in the air, while the concentrations of PM₁₀ (PM with aerodynamic diameters of 10 mmor less) pollutants were not significantly affected by the green space pattern. Among them, the patch shape index (LSI), patch density (PD) and patch proportion in landscape area (PLAND) of forest land can affect the concentration of PM_2.5, NO₂, and SO₂, respectively. The PLAND, PD, and LSI of grassland and farmland can also have an additional impact on the concentration of SO₂ pollutants. The study also found that there was a significant threshold effect within the impact mechanism of urban green space landscape pattern indicators (LSI, PD, PLAND) on the concentrations of PM_2.5, NO₂, and SO₂ air pollutants. The results of this study not only clarified the impact mechanism of the spatial pattern of urban green space on air pollutant concentrations but also provided quantitative reference and scientific basis for the optimization and updating of urban green space to promote public health.

Introduction: Understanding the birds’ breeding strategies in urban habitats is vital for ensuring their continued existence. Therefore, more research must be conducted on bird breeding and urban adaptation strategies in urban green spaces. This study aimed to address this gap by investigating the influence of landscape factors on the selection of bird nest sites. Methods: Data on the presence and absence of magpie (Pica pica) and gray magpie (Cyanopica cyana) nests were collected through field surveys conducted in the campus of Nanjing Forestry University during the 2023 breeding season. Generalized additive models (GAMs) incorporating landscape variables were employed to assess the effects of these predictors on nest occurrence. The model with the lowest Akaike’s information criterion value was selected among the candidate GAMs.Results: Below is a summary of the main results. Nest tree height (TH), distance from the central lawn (D), and tree coverage (TC) within the sampled area were identified as the primary landscape factors influencing nest site choice. Conversely, factors such as the shortest distance to the water source, herb coverage, shrub coverage, percentage of buildings, and percentage of hard pavement did not significantly impact on nest site selection. Furthermore, the nesting potential of magpies and grey magpies initially increased with tree height, reaching a maximum at ca. TH=25 meters after which it began to decline. The nesting occurrence rate showed an initial decrease tendency with increasing distance from the central lawn, reaching a minimum at D=400 meters, and then increased with further distance. Additionally, nesting potential decreased initially with increasing of TC in the range of 0–20%, fluctuated evenly between 20–60% TC, and decreased rapidly when TC exceeded 60%.Discussion: This study provides valuable insights into the selection of nest sites by birds in urban habitats, specifically with respect to landscape factors. The understanding of the impact of urban green spaces on urban birds and the underlying mechanisms of their behavior contributes to the conservation of wild birds and promotes the harmonious development of urban areas.

Maintaining ecological balance relies on biodiversity, and habitat network construction plays an imperative role in preserving biodiversity in regional areas. Nevertheless, there is a problem with the current habitat network construction, which focuses exclusively on ecological benefits without taking other benefits into account as well. In this paper, six species of birds with varying habitat types and varying adaptabilities to city life are selected as target species to build a habitat network based on the InVEST model, Circuit Theory, and Linkage Mapper, focusing on nuclei, patches, corridors, and islands for the harmonious coexistence of human-green space-birds in the most densely populated area of Nanjing, and to refine landscape design techniques for habitat creation. Below is a summary of the main results. Firstly, there is a direct relationship between species distribution and migration capabilities and the urbanization adaptation capabilities of species. Meanwhile, habitat quality has a significant impact on bird species distribution. Furthermore, the habitat network in Nanjing’s main urban area has a distributed and partially degraded core area, a single connectivity structure with poor functionality, and significant fragmentation of habitat patches. Finally, as a result of the above results, two perspectives of ecological landscape planning and design are proposed to optimize the relevant green space landscape in Nanjing’s central urban areas based on biodiversity and satisfying the tripartite symbiosis of humans, green space, and birds in the city. By planning and implementing habitat networks, it is possible to enhance the habitat quality of urban green spaces to a certain extent and provide new ideas for the overall planning of urban–natural systems.

Spartina alterniflora is recognized as one of the most detrimental invasive species along China’s coastlines, highlighting the need for effective and environmentally safe management strategies to preserve intertidal zones. This study assessed the effectiveness of combining plant growth regulators (PRGs) with physical cutting to manage S. alterniflora, using 16S rRNA and 18S rRNA gene sequencing to evaluate the impacts on the plant and associated soil micro-organisms. The results showed that compared to the control (CK), the regeneration numbers for treatments with abscisic acid (ABA), gibberellin (GA), paclobutrazol (PP₃₃₃), garcinol (GC), and glyphosate (GP) decreased by 29.75%, 23.25%, 15.75%, 94.50%, and 40.50%, respectively. Comparative analysis revealed no statistically significant variation in the inhibitory effects of ABA and GP on the germination of S. alterniflora (p > 0.05). Additionally, applying PRGs and herbicides increased the diversity indices of soil bacteria and fungi. Principal Coordinates Analysis (PCoA) showed that the impact of PRGs on the fungal community was less pronounced than that of herbicides. Significant differences were also noted in the abundance of microbial functional genes related to methanotrophy, hydrocarbon degradation, and denitrification compared to the control (p < 0.05). This study aimed to assess the potential of PRGs in controlling the invasion of S. alterniflora and to elucidate their impacts on soil microbial communities and functional gene expression.

The “leafing intensity premium” hypothesis proposes that leaf size results from natural selection acting on different leafing intensities, i.e., the number of leaves per unit shoot volume or mass. The scaling relationships among various above-ground functional traits in the context of this hypothesis are important for understanding plant growth and ecology. Yet, they have not been sufficiently studied. In this study, we selected four bamboo species of the genus Indocalamus Nakai and measured the total leaf fresh mass per culm, total non-leaf above-ground fresh mass, total number of leaves per culm, and above-ground culm height of 90 culms from each species. These data were used to calculate leafing intensity (i.e., the total number of leaves per culm divided by the total non-leaf above-ground fresh mass) and mean leaf fresh mass per culm (i.e., the total leaf fresh mass per culm divided by the total number of leaves per culm). Reduced major axis regression protocols were then used to determine the scaling relationships among the various above-ground functional traits and leafing intensity. Among the four species, three exhibited an isometric (one-to-one) relationship between the total leaf fresh mass per culm and the total non-leaf above-ground fresh mass, whereas one species (Indocalamus pumilus) exhibited an allometric (not one-to-one) relationship. A negative isometric relationship was found between the mean leaf fresh mass per culm and the leafing intensity for one species (Indocalamus pedalis), whereas three negative allometric relationships between mean leaf fresh mass per culm and leafing intensity were observed for the other three species and the pooled data. An exploration of the alternative definitions of “leafing intensity” showed that the total number of leaves per culm divided by the above-ground culm height is superior because it facilitates the non-destructive calculation of leafing intensity for Indocalamus species. These results not only confirm the leafing intensity premium hypothesis for bamboo species but also highlight the interconnected scaling relationships among different functional traits, thereby contributing to our understanding of the ecological and evolutionary significance of leaf size variation and biomass investment strategies.