Green Cover Research Articles

Comparing Alternative Non-Selective Herbicides in Oregon and New Mexico

Abstract Municipalities are considering alternatives to traditional herbicides for suppressing weeds and vegetation in areas frequented by the public. Two field experiments were conducted to test the efficacy of alternative non-selective herbicides: one in Corvallis, Oregon, on a mixed lawn of perennial ryegrass, annual bluegrass, and broadleaf weeds, and another experiment in Las Cruces, New Mexico, on a predominantly bermudagrass lawn with broadleaf weeds. The experimental objective was to quantify and compare the effects of repeated applications of ten non-selective herbicides to terminate a lawn with mixed vegetation. Applications were made every two weeks for four applications starting on 15 April 2022 in Corvallis and 26 May 2022 in Las Cruces. Data collected included the percent green cover over time calculated using an area under the percent green cover progress curve (AUPGCPC), the percent green cover at the conclusion of the experiment, and the change in monocot and dicot density over the course of the experiment. All treatments resulted in a lower AUPGCPC compared to water only except for mint oil + sodium lauryl sulfate + potassium sorbate. The only treatments with an average percent green cover less than 50% was a combination of ammoniated soap of fatty acids + maleic hydrazide (47% green cover) in Corvallis and pelargonic acid (38%) in Las Cruces, suggesting that more applications would be needed to terminate the lawn under similar circumstances. At the conclusion of the experiment, the water only plots averaged 90% and 93% green cover in Corvallis and Las Cruces, respectively. The change of monocot and dicot densities over the course of the experiment indicated that some of the products tested may be more sensitive to dicots, or in some cases monocots, suggesting a potential for future selective herbicide research in certain locations and climates.

Observational Constraints on the Spatial Effect of Greenness and Canopy Cover on Urban Heat in a Major Midlatitude City

AbstractUrban heat stress is a critical issue, particularly in cities where dense infrastructure and limited green space exacerbate temperature extremes. This study investigates the impact of greenery (EVI2), canopy cover (CC), impervious cover (IC), and water bodies on heat index in Chicago using high‐resolution data from the Heat Watch campaign. We find that EVI2, CC and proximity to water body significantly reduce heat while IC increases heat, particularly in the afternoon when solar radiation is intense. Additionally, the effective radius that land cover impacts heat is smaller in the afternoon. The combined effect analysis indicates that enhancing total greenness, not just canopy cover, is the most effective strategy to reduce heat. This study underscores the importance of strategic vegetation management, highlighting the critical role of integrated approaches in reducing urban heat.

Performance of Different Cool-Season Species and Cultivars Overseeded on Bermudagrass and Managed with Autonomous Mower

With global warming, the cultivation area of bermudagrass is moving northwards in the Mediterranean area despite its winter dormancy and loss of green color. The most common solution is overseeding with perennial ryegrass, which can be complicated to remove in spring. DLF breeders have released a new cultivar of annual ryegrass that is stress tolerant and easy to transition in spring. A trial was carried out on a sod farm in Pisa, Italy. Twenty-nine varieties of cool-season grasses, encompassing both forage and turf species, were overseeded on a hybrid bermudagrass variety ‘Tifway’ (Cynodon dactylon x transvaalensis). The aim of this trial was to compare the overseeding potential of various cool-season turfgrass species and cultivars and to identify which ones perform best in terms of cleanness of cut when overseeded on hybrid bermudagrass in autumn and maintained at a mowing height of 25 mm. Moreover, the following parameters were also assessed: actual turf height (cm); cumulated height (cm); turf visual color and quality (1–9 scale); and visual ground cover (%). Plots were managed with an autonomous mower, which adopted a daily mowing frequency and was set to work with systematic trajectories. The results showed differences between cultivars, and the annual ryegrass showed the best spring transition (scoring a mean value of 96% green cover in July 2023) compared to the other entries. The best result of CoC was measured for rough-stalked meadow grass ‘Sabrena 1’ and tall fescue ‘Turfway’ with 0.9 mm.

Effects of Green Manure Cover Crops on Weed Suppression at Mashare and Liselo, Namibia

Small-scale farming communities in northern Namibia often encounter poor soil fertility and financial constraints. They don’t afford buying mineral fertilizers and herbicides, thus highlighting the need for cost-effective cropping systems that enhance productivity. While green manure cover crops (GMCCs) have been extensively studied elsewhere and shown to boost productivity, information on their use remains limited in Namibia. Experiments were conducted over two seasons (2016/2017-2017/2018) at Mashare Irrigation Training Center (MITC) and Liselo Research Station (LRS), which have different soil types, to explore the effects of rotating Pearl millet and maize with various GMCCs on crop weed populations. The experiments compared the effects of rotating nine different GMCCs with Pearl millet and maize separately against monocropping of Pearl millet and maize. Results showed that weed density varied across treatments and locations, with the highest densities observed in certain rotations, such as Pearl millet-pigeon pea and maize-pigeon pea, while the lowest densities were found in rotations involving lablab and velvet bean. This is indicative that lablab and velvet bean suppressed weeds better than all other GMCCs, while pigeon pea was vulnerable to weed infestation. Lablab exhibited the highest biomass yields. Overall, rotating Pearl millet and maize with cover crops demonstrated greater benefits compared to monocropping, emphasizing the need to identify suitable cover crops for specific niches to optimize productivity.

The impact of long-term organic horticultural systems on energy outputs and carbon storages in relation to extreme rainfall events

Enhancing resilience of agroecosystems of Mediterranean area is a challenge that involves both researchers and different stakeholders and, in this context, increasing crop diversity by redesigning agricultural systems can be considered among the most important tools. Therefore, the response of agroecological practices to climate change effects was tested in a long-term experiment on organic horticultural crops (MITIORG), which is characterized by a soil hydraulic arrangement in ridges, strips and the use (with different management options) of cover crops within cash crops rotations. The main objective of this study was to show how powerful is the sustainability assessment of agroecological practices by converting crops yield and biomass into energy outputs and carbon storages, in diversified horticultural systems. The obtained outputs (expressed in energy and carbon equivalents) were evaluated and analyzed considering the site-specific meteorological data in more than 10 horticultural cropping cycles, from autumn-winter 2014-15 to autumn-winter 2020-21. The Ridge and Strips (RS) system 1 (RS1 - cover crops as living mulch on ridges and break crops in strips, both with no-till termination) showed an enhancement of about 18% of energy output and carbon (C) storages compared to RS2 (ridges and strips with green manured cover) when extreme precipitation events occurred. Moreover, RS3 (ridges and strips without cover crops) recorded a reduction of about 5 and 9% of energy output and C storage, respectively, compared to the mean of RS1 and RS2 in periods with extreme events. Our results highlighted that using more diversified agroecological systems improved their overall average outputs, ensuring greater resilience during extreme weather events, since at least part of crop productions was safeguarded. Therefore, it is important to combine techniques that allow long-term resilience, such as choosing and well managing cover crops (agroecological service crops), according to site and systems specific conditions.

Does import trade liberalization worsen residents' health? Evidence from China.

Health is important to human capital and national sustainable development. Based on the latest Chinese Family Panel Studies (CFPS), this paper uses the IVprobit model to test the impact of import trade liberalization on residents' health from the micro-individual perspective and further explores its mechanism. The results indicate that import trade liberalization brings hidden health costs, and that the negative effects on the health of people in eastern China or rural areas, people with a low education background, people under 60 years of age, and women are more significant. In areas with more serious environmental pollution, the health deterioration effect of expanding imports is more obvious. Increasing green coverage and optimizing the quality of public services can effectively alleviate this negative impact. Import trade liberalization does not affect residents' health through income gap, therefore when carrying out import trade liberalization the government should pay greater attention to the health status of the specified groups, adopt various means to improve the ecological and living environments, reduce pollution emissions, optimize the supply of public services, and ultimately improve residents' overall health level.

Carbon dioxide and evapotranspiration fluxes in an urban area of Krakow, Poland

AbstractUrban areas play an essential role in the global carbon balance, being responsible for more than 70% of anthropogenic carbon emissions, entering the atmosphere mainly in the form of carbon dioxide (CO2). Another crucial component of the carbon balance of the urban atmosphere is CO2 exchange with the biosphere, expressed in both emission and absorption fluxes. The biosphere component of the net CO2 flux is inseparably linked to the water (H2O) balance due to evapotranspiration. This article presents an estimation of CO2 and H2O net fluxes based on eddy covariance (EC) tower measurements and in‐depth analysis of its temporal and spatial variability for a typical urban site at mid‐latitude of the northern hemisphere. The source area was divided into two sectors, one representing dense urban development with sources of CO2 from traffic and households, and the second containing predominantly recreation and sports areas. Temporal variability analysis of evapotranspiration showed a clear seasonal cycle closely correlated with incoming radiation and air temperature, with the seasonal mean ranging from 0.4 mm·day−1 in winter to 1.6 mm·day−1 in summer. As a result of similar green coverage between the urban and green sectors, spatial variability was statistically insignificant. The net CO2 flux over a seasonal cycle was less pronounced for the total source area with a mean of 5.0 g C·m−2·day−1 in summer and 7.5 g C·m−2·day−1 in winter. However, significant variations between urban and green sectors were observed with the highest seasonal mean difference of 4.5 g C·m−2·day−1 in winter. The results confirm that while on the local, short time‐scale urban vegetation has a potential to mitigate the emissions, it is not able to offset them.

Unirrigated extensive green roofs in humid subtropics – Plant selection and substrate design for low maintenance and climate resilience

Low-maintenance extensive green roofs hold the potential for adapting to climate change, but there is a limited understanding of their effective design in humid subtropical regions. In this study, we aimed to investigate low-maintenance green roof ecosystems capable of thriving under heat stress. Plant growth performance was evaluated in the second year of an experimental green roof in southwest China. This green roof was unirrigated and involved two plant communities (forbs and grasses) cultivated in four substrate types. Metrics of growth performance, including plant survival, green coverage, visual appearance, leaf stomatal conductance, and substrate volumetric water content were used to analyze the impact of substrate on plant growth. ESP substrate, comprising 30 %v (percent of volume) expanded shale, 25 %v perlite, 25 %v vermiculite, and 20 %v compost, featured the highest porosity and optimal growth of forbs, achieving an average green coverage of 66.76 % and average visual appearance value of 3.56 throughout the monitoring period. The high total porosity of this substrate could be critical in facilitating root development and drainage. Moreover, during the summer’s heat and drought, while substrate water content is not a limiting factor for the survival of some established forbs, it remains crucial for the growth of grasses. Additionally, the same substrate impacts different plant communities variably. Four particularly well-performing forb species, namely Lycoris chinensis, Tradescantia pallida, Liriope muscari, and Salvia farinacea, demonstrated survival rates closed to 100 % and an average visual appearance value exceeding 3 was noted, and thus, they are recommended as plant candidates for unirrigated green roofs. The distinguished performance of these species is attributable to their adaptation to heat and drought through specific physiological traits. Our findings provide insights into vegetation selection and substrate optimization for the successful establishment of extensive green roofs that could be feasibly developed without irrigation in the humid subtropical regions.

Analysis and Comprehensive Evaluation of Urban Green Space Information Based on Gaofen 7: Considering Beijing’s Fifth Ring Area as an Example

Urban green spaces constitute a vital component of the ecosystem. This study focused on urban green spaces located within the Fifth Ring Road of Beijing, using Gaofen 7 (GF-7) as the primary data source for analysis. The main objective was to develop a system for extracting and classifying urban green spaces in Beijing by applying deep learning and machine learning algorithms, and further, the results were validated with ground survey samples. This study provides detailed extraction and classification of urban green space coverage by creating a comprehensive evaluation system. The primary findings indicate that the deep learning algorithm enhances the precision of green space information extraction by 10.68% compared to conventional machine learning techniques, effectively suppresses “pretzel noise”, and eventually aids in extracting green space information with complete edges. The thorough assessment of green spaces within the study area indicated favorable outcomes showing the high service capacity of park green spaces. The overall classification accuracy of the final extraction results was 94.31%. Nonetheless, challenges, such as unequal distribution of green zones and a significant fragmentation level throughout the study area, were still encountered. Consequently, the use of GF-7 high-resolution imagery, in conjunction with the collaborative application of deep learning and machine learning techniques, enabled the acquisition of highly accurate information regarding urban green zone coverage. According to the established grading standards of evaluation indices, the landscape pattern of urban green spaces within the study area was comprehensively assessed. This evaluation offers essential data support for monitoring urban green spaces and planning landscape patterns, thereby contributing to the achievement of sustainable development objectives related to urban greening and ecological conservation.

Regional Coexistence in the Digital Era: Spatial–Temporal Evolution and Sustainable Strategies of the Coupled System in the Yangtze River Basin, China

Against the backdrop of globalization and ecological civilization, this study aims to analyze the patterns of system coupling coordination development in the Yangtze River Basin under the interacting influences of population growth, ecological conservation, energy utilization, and digital economic development. Using a multisource model, this paper explores the state of coordinated development, spatial–temporal evolution characteristics, and influencing factors in the Yangtze River Basin from 2011 to 2020. The results indicate the following: (1) The overall degree of coupling coordination in the Yangtze River Basin shows better performances in the eastern coastal areas compared to the central and western regions. Over time, the spatial autocorrelation of coupling and coordination increases, exhibiting a significant spatial clustering trend. (2) The Moran’s I index increased from 0.327 to 0.370, with high–high clusters primarily distributed in economically developed coastal provinces, while low–low clusters were observed in remote provinces in the central and western regions, revealing regional development imbalance issues. (3) The driving force analysis shows that green coverage and GDP are the core factors influencing the spatial differentiation of coupling coordinated development. Factors such as the urbanization rate, nighttime light index, and energy consumption had significant impacts in certain years but are generally considered minor factors. The results of this study not only contribute to understanding the dynamic mechanisms of regional coupling and development but also provide a scientific basis for formulating regional coordinated development policies, promoting the achievement of win–win goals of economic growth and ecological civilization in the Yangtze River Basin and similar regions.

Green space-building integration for Urban Heat Island mitigation: Insights from Beijing's fifth ring road district

In this research, we delve into the complex arrangement of urban landscapes, where green spaces and buildings are not merely co-existing but are interwoven into a cohesive fabric that shapes the thermal environment. Our approach transcends the conventional methods of analysis, which typically isolate the roles of greenery or built environments. Instead, we adopt a synergistic perspective that recognizes the collective influence of these landscape constituents on the urban thermal pattern. Key insights are: (1) A linear decrease in average land surface temperature with increasing green space coverage is observed. However, substantial temperature variations (up to 8 °C) within the same coverage interval highlight the significant impact of built-up pattern on thermal conditions; (2) High Building Height and Floor Area Ratio, and low Building Coverage Ratio and Sky View Factor, are linked to cooler temperatures in areas with up to 50 % green space; (3) The study suggests that low-temperature areas can inform the adjustment of built-up patterns in high-temperature areas, offering a strategy for thermal environment optimization within specific green space coverage intervals. This research contributes insights into the integrated planning of green spaces and buildings, with implications for urban development and renewal initiatives aiming to enhance the urban thermal environment.

Consolidating building greening: Integrating mobile modular vertical greening systems into prefabricated building

Vertical greening systems increase green plant coverage within built environments, enhancing urban air quality while reducing building energy consumption. But they encounter challenges related to intensive maintenance and significant costs. As a mainstream future building form, the characteristics of modularization and factory customization inherent in prefabricated buildings can effectively address the demands of vertical greening system. This study employs structural equation model and cloud model to examine the feasibility of integrating mobile modular vertical greening system into prefabricated structures, based on a survey of 403 respondents in Shandong Province, China. The study highlights the supportive roles and mediating effects of two maintenance management measures. It confirms the strong correlations between cost control strategies and the successful integration of mobile modular vertical greening system into prefabricated building. The results indicate that integrating intelligent technology and plant-microalgae combined systems are essential exogenous and endogenous maintenance management strategies. They exert a positive influence on prefabricated modular vertical greening systems. A positive interconnection exists between integrating intelligent technology and the plant-microalgae combined system. Carbon credit trading incentive proves more advantageous in reducing mobile modular vertical greening system costs. Plant-microalgae combined system playing a partial mediating role. Although crowdfunding-community participation does not significantly reduce the costs of mobile modular vertical greening system, integrated intelligent technology mediates this relationship. This highlights the indirect role of crowdfunding-community participation in facilitating cost control for these systems.

Response of cool‐season turfgrass monocultures and two‐way mixtures to sequential acute drought periods

AbstractTurfgrass seeds are often sold as mixtures of several species to increase the probability of positive responses toward abiotic and biotic stresses, a response to drought being one of these. Several species of turfgrass are already thought to be better suited for drought, such as hard fescue (Festuca brevipila Tracey) and tall fescue [Schedonorus arundinaceus (Schreb.) Dumort]. However, little is known about the benefit of these species in mixtures with drought‐intolerant and/or drought‐avoiding species during drought. Understanding species mixture composition during establishment, before and after drought stress periods, could help develop more resilient mixtures for this stress condition. We compared monocultures and mixtures of hard fescue, Kentucky bluegrass (Poa pratensis L.), and perennial ryegrass (Lolium perenne L.) during sequential short drought and recovery periods in controlled conditions. We observed that the composition of most mixtures remained similar during drought and recovery periods; however, perennial ryegrass was often less prevalent after drought stress. We found that hard fescue monocultures had better green leaf coverage than Kentucky bluegrass and perennial ryegrass during drought stress. However, the presence of hard fescue in mixtures was not an indicator of greater drought tolerance, and variable fluorescence to maximal fluorescence data indicated that hard fescue was just as physiologically stressed as perennial ryegrass and Kentucky bluegrass during the drought periods. These results indicate that while hard fescue seems visually drought tolerant, it is still physiologically stressed and improved drought tolerance could be achieved through focusing on physiological indicators of stress in this species rather than visual indicators.

The association between green space around schools, screen time for entertainment, and adolescent depressive symptoms: A nationwide study from China

BackgroundNatural green environments are beneficial to people's mental health, while too much screen time may be harmful to adolescents' mental health. However, it is not clear how green spaces and screen time affect mental health together in adolescents. MethodsA total of 22,868 adolescents were recruited from October to December 2021 in eight cities in China, through multistage cluster sampling. The Patient Health Questionnaire (PHQ-9) was used to investigate adolescents' depressive symptoms, and the Normalised Vegetation Index for the 200m, 500m and 1000m buffer zones around the school represents the green cover around the school. We used binary logistic regression to analyse the association between green space, screen time and depressive symptoms. ResultsIn fully adjusted models, the highest quartile of NDVI in the 200m, 500m and 1000m buffer zones around the school was a protective factor for depressive symptoms. For less than 2 h of recreational screen time, the highest quartiles of the NDVI and the association with depressive symptoms were negatively correlated for the 200m, 500m and 1000m buffer zones (NDVI200: 0.904(0.848–0.964)), NDVI500: 0.863(0.808–0.921), NDVI1000: 0.862(0.808–0.920)). The highest quartiles of NDVI in all buffers were not associated with depressive symptoms when the screen time was >2 h. The association between green space and depressive symptoms at lower recreational screen time was observed to be stronger in the group of adolescents with a lower family economic status (NDVI200: 0.780(0.695–0.876), NDVI500: 0.838(0.748–0.938), NDVI1000: 0.783(0.698–0.879)). No potential gender differences were observed. ConclusionsFor adolescents with less than 2 h of recreational screen time per day, the greenery around the school had a protective effect on their mental health, especially for adolescents from economically disadvantaged families. Green spaces around schools are significant in improving health inequities.

Antibacterial performance of biodegradable polymer and hazelnut husk flour antibacterial biofilm with silver nanoparticles

The antibacterial performance of biocomposite films prepared from lignocellulosic waste (hazelnut husk or hazelnut leafy green cover) modified with silver nanoparticles and polylactic acid (PLA) was determined. The amount of hazelnut husk in the PLA matrix ranged from 10 to 40% by weight in 10% increments. The composite pellets were produced using a twin-screw extruder. Biocomposite films of 0.6 mm x 40 mm x 200 mm were produced from the pellets in a laboratory hydraulic hot press. The surfaces of the modified hazelnut husk and biocomposite specimens were analyzed by scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectrometry (ICP-OES). The antibacterial activity of the biocomposite films against Staphylococcus aureus bacteria was determined using the ASTM E 2149 (2020) method. The antibacterial activity of the biocomposite films increased noticeably with the addition of hazelnut husk modified with the silver nanoparticles. Compared to the pure PLA film, the biocomposite films with 10 wt% modified husk flour showed the lowest antibacterial activity (31.3%) against S. aureus over 24-h while the films with 40 wt% showed the highest antibacterial activity (99.9%). The biocomposite films made of hazelnut husk flour with silver nanoparticles and PLA matrix could be considered for food packaging applications.

Exploring the Impact of Public Spaces on Social Cohesion in Resettlement Communities from the Perspective of Experiential Value: A Case Study of Fuzhou, China

With the rapid pace of global urbanization, the urbanization of resettlement communities in China has garnered increasing attention from scholars. This study, grounded in experiential value theory, delves into the relationship between public spaces in resettlement communities and their social cohesion. Focusing on resettlement communities in the central urban area of Fuzhou, this study employs a mixed-method approach to analyze the functional characteristics of public spaces using geospatial data, including their green coverage ratio, spatial accessibility, facility configuration, and neighborhood density. A correlation analysis and multiple linear regression were employed to identify the key elements influencing social cohesion. The results indicate significant disparities in the green coverage, accessibility, facility configuration, and neighborhood density of public spaces. These differences are evident in the quantitative metrics used and also reflect imbalances in spatial layout and resource distribution, highlighting potential pathways for optimizing the quality of public spaces. Further data analyses revealed that both emotional value (β = 0.602, p < 0.01) and functional value (β = 0.136, p < 0.01) have significant positive impacts on social cohesion, with emotional value being particularly influential. This study offers insights for urban planners and policymakers by providing scientific evidence for the optimization of public space design in resettlement communities, with implications for community governance and urban sustainability.

Proposing design strategies for contemporary courtyards based on thermal comfort in cold and semi-arid climate zones

The relationship between urban geometry and microclimate is crucial in urban planning and climatology, significantly affecting outdoor comfort and energy consumption. Compact, dense buildings provide shading in summer, while openness is preferred in winter to maximize sunlight access. Courtyards, as climate-responsive structures, can create localized microclimates tailored to specific climatic conditions. Various components, including geometry, openness, orientation, wall materials, and green cover, influence the microclimate within a courtyard. While previous studies have primarily focused on hot and arid climates, there is a notable research gap concerning the thermal behavior of courtyards in cold and semi-arid regions. This study seeks to fill this gap by evaluating the impact of different courtyard geometries on outdoor thermal comfort specifically in semi-dry and cold climates by exploring optimal configurations for orientation, form, height-to-width ratios, and plan aspect ratios, the research offers strategies that improve both summer and winter microclimates. The study examined the combined effects of geometry and orientation on shading and wind speed in courtyards, modeling their influence on microclimates during warm summers and cold winters using ENVI-met software. Thermal performance indices, specifically PET and UTCI, were employed to assess the courtyards in Tehran. The findings reveal that a height-to-width ratio of 3:1 significantly improves thermal comfort, resulting in a UTCI difference of 19 °C. Furthermore, the model with a 2:1 plan aspect ratio exhibited a UTCI that was 6.7 °C lower than that of the 3:1 ratio. These findings provide valuable insights for designing contemporary courtyards that optimize thermal comfort in similar climates.

Regulation of freshwater filamentous green algae (Cladophora) and its impact on malodorous volatile organic sulfur compound (DMS) by biomanipulation

When improving the water quality of natural bodies such as lakes, the explosive growth of filamentous green alga Cladophora can limit the growth of submerged macrophytes and prevent the water from shifting to a clear state. During the decay of Cladophora, it can cause various water quality issues such as reduced dissolved oxygen, increased nutrient levels and water odor. Biomanipulation, involving the introduction of a suitable density of aquatic animals into the water, can reduce the biomass of filamentous algae. We hypothesized that stocking appropriate densities of aquatic animals could reduce filamentous algal biomass and at the same time reduce the concentration of odorants in the water. Our study investigated the impact of stocking swamp shrimp (Macrobrachium nipponense), rosy bitterling (Rhodeus ocellatus), and silver carp (Hypophthalmichthys molitrix) at low (30 g/m3), medium (60 g/m3) and high (120 g/m3) densities on water quality, biomass of primary producers (such as Cladophora, submerged macrophyte and algae) and malodorous volatile organic sulfur compound dimethyl sulfide (DMS) in the water, respectively. It was found that the swamp shrimp treatment groups and the rosy bitterling high-density groups effectively inhibited the growth of filamentous green algae cover, in which the rosy bitterling high-density group reduced the filamentous green algae mat coverage by 29.65 % compared with the control group. Additionally, the high-density swamp shrimp and rosy bitterling groups notably promoted the growth of submerged macrophytes (Vallisneria denseserrulata), and significantly reduced the concentration of the malodorous DMS in the water. Overall, stocking swamp shrimp and rosy bitterling can benefit the restoration of aquatic ecology and the maintenance of clear water. However, it is essential to consider potential changes in water quality resulting from excessive stocking density. Therefore, the appropriate density and proportion of stocking should be determined in conjunction with the specific scale of the aquatic ecological restoration project.

Spatial-temporal dynamics and influencing factors of city level carbon emission of mainland China

Urban areas are major sources of carbon emissions, making it crucial to understand their emission characteristics for effective carbon reduction and sustainable development. Using carbon emission data from mainland China (2001–2021), we analyzed the spatio-temporal dynamics and future trends of city-level emissions and explored influencing factors using machine learning methods. Results indicate significant fluctuations in carbon emissions, with over 40 % of mainland Chinese cities experiencing a doubling in total emissions. Geospatially, cities in South Coast (SC), East Coast (EC), Northeast (NE), and NorthCoast (NC) show stronger intensity and increasing trends in carbon emissions compared to other regions, with over 80 % of cities in these regions experiencing high or higher increases. Additionally, a continued rise in carbon emissions was detected in most Chinese cities, with an average Hurst index of 0.64, indicating persistent trends. Using the XGBoost method, factors such as population density, built-up area, urban green coverage rate, and GDP were found to strongly correlate with urban carbon emissions, exhibiting significant spatial heterogeneity. This research uncovers the characteristics and influencing factors of urban-scale carbon emissions, offering valuable insights for policymakers to tailor carbon reduction strategies to the specific needs and conditions of various urban areas.

Does Urban Green Space Pattern Affect Green Space Noise Reduction?

The effect of urban green spaces on traffic noise reduction has been extensively studied at the level of single vegetation, hedges, etc., but there is a lack of corresponding studies at the scale of spatial patterns of urban green spaces. Therefore, this study aims to analyze the relationship between the spatial pattern of urban green space and the change in green space’s noise reduction capacity. Through the morphology spatial pattern analysis method, this analysis divides the urban green space in the Fuzhou high-tech zone into seven types of elements with different ecological definitions and simulates the noise condition of the urban environment with the presence of green space as well as without the presence of green space by computer simulation, calculates the distribution map of the noise reduction produced by the urban green space, and analyzes the correlation between the seven types of green space elements and the noise reduction with the geographically weighted regression modeling analysis. The study finds that (1) Urban green space patterns can significantly affect the net noise reduction of green space. Areas with high green coverage can produce a stronger green space noise reduction effect. (2) More complex green space shapes and more fragmented urban green space can produce higher noise reduction. (3) The green space close to the source of noise can exert a stronger noise reduction effect. Therefore, in the process of planning and design, from the perspective of improving the urban acoustic environment, the configuration of high-quality green spaces in areas with higher levels of noise pollution should be given priority, which may have better noise reduction effects.