Mahdi Khansefid

This study evaluated vitamin B12 in mitigating freezing stress in thyme (Thymus vulgaris). Treatments included two temperatures (25°C and −5°C) and foliar VB12 application (0 and 100 mg L−1), applied once and twice. Freezing (−5°C) severely damaged roots and reduced shoot biomass by 84%. Although VB12 enhanced growth in non-stressed plants (height: 34 cm, diameter: 63 cm, fresh weight: 232 g), it did not alleviate freezing stress effects. In the absence of VB12, electrolyte leakage increased tenfold under stress, with VB12 having minimal impacts on membrane permeability. A single VB12 application increased Fv/Fm by 31.36%, and non-photochemical quenching declined by 49.5% under freezing. Photosynthetic pigments and chlorophyll stability index increased during stress but declined post-recovery. VB12 application had no effect on malondialdehyde content under stress but reduced levels post-recovery (51.8 and 45.4 μmol g−1 fresh weight for one and two applications, respectively). Hydrogen peroxide levels were 61.16% under stress, decreasing to 56.62% after recovery with one-time VB12 application. These findings suggest that VB12-treated plants’ reductions in electrolyte leakage and reactive oxygen detoxification may improve thyme’s freezing tolerance.

The arbuscular mycorrhizal fungi (AMF) form symbiotic, mutually beneficial relationships in the rhizosphere, and modulate phosphorus’ (P) availability to regulate plant growth, nutrient uptake, and quality. However, their roles in cut-flower species remain poorly understood. The aim of this study was to evaluate the effects of single and dual inoculation with Glomus intraradices and G. mosseae on Lisianthus (Eustoma grandiflorum) grown under three P levels (10, 20, and 40 mg kg⁻¹) in greenhouse conditions. Under intermediate P, dual-inoculated plants exhibited the greatest above-ground vigor, with increases in stem length (+31%), dry shoot weight (+67%), and highest shoot P (+54%) and N (+23%) content, compared with non-inoculated controls. Under low P, dual inoculation maximized dry root weight (+63%) and mycorrhizal colonization, whereas AMF effects diminished at high P. Principal component analysis showed that there were distinct mycorrhizal interactions (PCA2, 20.3% variance) and a close integration between vegetative growth and nutrient accumulation (PCA1, 54.3% variance). For the first time, this study demonstrates that Lisianthus exhibits a strong response to dual AMF inoculation, offering a novel strategy to enhance growth, nutrition, and ornamental quality when P fertilization is optimized. By reducing chemical fertilizer use, this dual AMF–P management offers a sustainable framework for high-quality cut-flower production.

Urban areas in semi-arid regions face rising thermal stress and carbon emissions due to rapid densification and scarce vegetation. This study evaluates the effectiveness of green infrastructure (GI) in mitigating these challenges in District one of Karaj, Iran, within a zero-carbon city framework. To address limited evidence on microscale modeling in arid contexts, satellite-based time series analysis was combined with ENVI-met simulations. Environmental indicators including CO (Sentinel-5P) as a proxy for CO₂, Land Surface Temperature (LST, Landsat-8), and vegetation cover (NDVI, MODIS) were extracted via Google Earth Engine for October 2024 to March 2025. Two scenarios were examined: Scenario A as current conditions, and Scenario B with green roofs, vegetated walls, moss, and microalgae panels. Scenario B achieved a 4.6% reduction in CO₂, from 441.8 to 421.4 ppm, an NDVI increase of 0.17 (0.21 to 0.38), and a district-wide temperature decrease of 4.1 °C. Calibration yielded a root mean square error of 1.7 °C for temperature and ±6.3 ppm for CO₂. These interventions improve environmental performance and socio-economic resilience through public health gains, lower energy costs, and equitable green access. Findings highlight hybrid greening strategies as effective for advancing climate resilience and provide a replicable model for zero-carbon interventions in semi-arid cities.

The effects of urban sprawl and global population growth have directly and indirectly negatively affected human health and well-being. Paying attention to the function of natural systems for survival and healing throughout history and the current expansion of urban green infrastructure and paying attention to salutogenic (origin of health) solutions in solving environmental problems are effective strategies for improving the quality of life and achieving appropriate health and well-being of city residents. Today, salutogenic parks are an important part of the green infrastructure of a sustainable city that improves the quality of the environment to improve health outcomes. This article examines topics such as the relationship between the development of urban areas and the expansion of urban green infrastructure with human health, and expresses the salutogenic approach to urban parks based on their cultural ecosystem services in various dimensions of human health as important health-generating resources in the city. It highlights the role of landscape architects in achieving these goals. Finally, it reaches a conceptual framework for the salutogenic effect of urban parks based on cultural ecosystem services on human health, and highlights its application in densely populated urban areas such as the metropolis of Tehran, the capital of Iran.