Ibrahim. A. Hassan

Empirical studies worldwide show substantial variability in plant litter decomposition responses to warming, leaving the overall impact of climate change on this process uncertain. We conducted a meta-analysis of 109 experimental warming studies across seven continents, utilizing natural and standardized plant material, to assess the overarching effect of warming on decomposition and identify potential moderating factors. Warming influences decomposition differently across macro-environmental gradients of moisture and temperature. Negative warming effects on decomposition in warmer, low-moisture areas were counterbalanced by the positive, though not significant, warming effects in colder areas, resulting in an overall non-significant effect. We determine that at least 5.2 degrees of warming is required for a significant increase in decomposition. This is particularly relevant given the past decade’s global warmth in higher latitudes, holding a significant proportion of terrestrial carbon. Low-quality plant litter was more sensitive to warming. Therefore, future vegetation changes toward low-quality, temperature-sensitive plants could increase carbon release and reduce the net supply of stored organic matter in the soil by increasing the decomposition of low-quality litter with warming. Our findings emphasize the connection between warming responses, macro-environment, and litter characteristics, refining predictions of climate change’s consequences on key ecosystem processes and its contextual dependencies.

Effects of different types of fertilizers; traditional NPK (1 g plant⁻¹), 2, 4, 6 and 8 gm L⁻¹ of moringa leaves extract (MLE), 10, 20, 40 and 60 mL L⁻¹ of aloe leaves extract (AL) on vegetative growth, flowering Corms production and chemical constituents of Freesia refracta L. were evaluated during two successive seasons (2020–2021 and 2021–2022). Treating plants with MLE caused increases in plant height, number if leaves and number of flowers by 35.2%, 8.2% and 16.3%, respectively, while treating plants with Al caused increases by 33.2%, 7.9% and 15.4% in the same parameters, respectively, averaged between different concentrations and growth seasons. The results revealed that, treating plants with 8 gm L⁻¹ MLE caused a significant increase in the vegetative growth, flowering, and corms production. These improvement fits with the many goals of the 17 United Nation Sustainable Goals (UNSDGs); especially SDG2 (Zero hunger), SDG13 (climate action) and SDG15 (Life on land). Moreover, the chemical composition of plant was improved significantly.

Plastic pollution and its impact on the marine ecosystems is a major concern globally, and the situation was exacerbated after the outbreak of COVID-19. This briefing delivers a synopsis of the environmental and climate impacts of single-use gloves and masks used for COVID-19 protection from June to August 2020. To the best of our knowledge, this study presents the first such information from the Middle East. .It pinpoints the need for further knowledge and action, such as a safe, sustainable, transparent and unconventional waste management processes related to COVID-19 in order to reduce the negative impacts now and in any future events. It identifies the need for further knowledge and action to reduce these impacts now and in any future events.

Chilling (Ch) and salinity (S) are challenging stresses affecting plant physiology, growth, and productivity. The current study investigated the effects of these two stresses, singly and in combination, on photosynthetic performance and ultrastructure of chloroplast of faba beans (Vicia faba L. Cv. Aspani). Plants were exposed to 3 °C and 120 mM NaCl for 16 h in an optimized soil mixture (sand:clay 2:1) under optimized conditions. Results showed that both Ch and S significantly reduced photosynthetic rates, F_v/F_m, chlorophyll content, stomatal index, and stomatal conductance. Chilling caused changes in chloroplast ultrastructure (swelling, ruptured envelopes, and shrunk lamellae), while salinity caused more deformation of the thylakoid membrane and disorganization of the grana structure. However, there was an antagonistic effect between Ch x S. The tolerance of plant to 120 mM NaCl, in the present study, was improved by exposure to Ch which rather allowed the maintenance of chloroplast ultrastructure and morphology of stomata. Moreover, using SEM and TEM gave an effective insight of the ultrastructural damage in plant cells under stress and helps to consider the underlying mechanisms of stress effects. Our results suggest that Ch mitigates the noxious effect of S on the photosynthetic performance of Vicia faba plants.

The government of Saudi Arabia imposed a strict lockdown between March and July 2020 to stop the spread of the coronavirus disease (COVID-19), which has led to a sharp decline in economic activities. The daily temporal variations of PM₁₀, PM_2.5, carbon monoxide (CO), nitrogen dioxide (NO₂), and ozone (O₃) were used to investigate the changes in air quality in response to COVID-19 lockdown control measures from January to December 2020 in Jeddah, Saudi Arabia. Meteorological parameters (wind speed, direction, temperature, relative humidity) were also analyzed to understand the changes during the pandemic. As a result, significant reductions in the concentrations of NO₂ (– 44.5%), CO (– 41.5%), and PM_2.5, PM₁₀ (– 29.5%, each) were measured in the capital city of Jeddah during the quarantine compared to the pre-lockdown average. In contrast, the lockdown caused a significant increase in O₃ by 41%. The changes in air quality during the COVID-19 outbreak by comparing the average pollutant concentration before lockdown (January 1–March 21, 2020) and the following 12 weeks during the partial lockdown (March 22–July 28, 2020), reveal a very significant decrease in pollutants, and consequently a significant improvement in air quality. Observed differences are attributable to changes in point source emissions associated with changes in localized activities, possibly related to decreased economic and industrial activity in response to the lockdown. The results of the present study show during the study period indicated a positive response to lockdown during the COVID-19 pandemic. Furthermore, the results can be used to establish future control measures and strategies to improve air quality.

An interesting area of research is to constantly monitor plants survival when they encounter a complex range of abiotic stresses due to eminent rapid climate change. Chilling (Ch) and salinity (S) are two challenging threats to plant growth and production especially when they act together. The current study aims to investigate the co-occurrence effects of chilling and salinity in Vicia faba L. Aspani cultivar on photosynthetic performance and ultrastructure of chloroplast. Treatments involved exposure to 3 0 C Ch and 120mM NaCl for 16 h in soil mixture (sand: clay; 2:1) under optimized conditions. Results show that 16 h exposure to either Ch or S significantly reduce photosynthetic rate, stomatal conductance, F v /F m , chl a, chl b, chl a/b, stomatal index %, percentage of opened stomata, and stomatal width. As well, chilled chloroplast ultrastructure revealed chloroplast swelling, ruptured envelope, and shrinked lamellae. Salinity caused more deformation of thylakoid membrane and disorganization of grana structure. Unexpectedly, Ch x S combination illustrates antagonistic effect of Ch over S that reflected on all tested photosynthetic parameters. Interestingly, it seems that Ch might rather be used to mitigate the noxious effect of S on photosynthetic performance of Vicia faba plant at least in our dataset.