In tropical and subtropical regions, much research is still required to explore the dendrochronological potential of their trees. This study aims to evaluate the anatomical structure and ...dendrochronological potential of three Mediterranean desert shrubs in Egypt (
var.
,
, and
subsp
) supported by X-ray density. The results showed that the target species had distinct growth rings at macroscopic and microscopic levels. The vessel traits reflected the adaptability of each species with the prevailing arid climate conditions. After the exclusion of the non-correlated series, we obtained three site chronologies that cover the years 2013-2022 for
, 2012-2022 for
, and 2011-2022 for
. The mean series intercorrelation was 0.746, 0.564, and 0.683 for
,
, and
, respectively. The EPS (expressed population signal) values ranged from 0.72 to 0.80, while the SNR (species-to-noise ratio) ranged from 9.1 to 21.5. Compiling all series of
raised the EPS value to 0.86. The chronologies developed for the studied species were relatively short since we dealt with multi-stemmed shrubs. The average percentage difference between latewood density (LWD) and earlywood density (EWD) in
,
, and
were 11.8% ± 5.5, 5.2%± 1.87, and 3.6% ± 1.86, respectively. X-ray densitometry helped in the precise determination of the ring borders of the studied species. The relationships between the radial growth of the studied species and the climate variables were weak to moderate but mostly not significant (i.e., r < 0.7). Generally, the radial growth of the target species had a weak to moderate positive correlation with temperature and precipitation during the wet season (winter), while negatively correlated with temperature for the rest of the year, particularly in summer. Our data agrees with earlier findings that ring formation starts at the beginning of the long vegetative stage, then the rest of the assimilated carbohydrates are directed to the flowering and fruiting at the end of the vegetative stages. For more efficient dendrochronological studies on subtropical and Mediterranean trees, we recommend carrying out xylogenesis studies, collection of phenological data, sampling 45-80 trees per species, using new techniques, and choosing homogeneous and close sites for wood sampling.
Phytoremediation is a promising, cost-effective, and eco-friendly process for wastewater treatment. Herein, the dry biomasses of Vossia cuspidata (Roxb.) Griff. leaves (PL) and rhizomes including ...aerial stems (PR) were used to effectively remediate methylene blue (MB) dyes. Interestingly, the adsorption uptake and removal efficiency of MB by PR were higher than those of PL; exceeding 97 and 91% in 35 and 25 min for 0.1 and 0.4 g/L MB, respectively. The MB diffusion within the PL and PR was insignificant and the adsorption kinetics was principally controlled by the surface MB-adsorbent interaction, as consistently approved by the pseudo-second order kinetic model. In addition, the adsorption increased rapidly with the plant dosage with high dependence on the initial MB concentration. Moreover, the impact of shaking speed on the adsorption was minor but temperature played a critical role where the highest efficiencies were recorded at 30 and 40 °C on PL (91.9%) and PR (93.3%), respectively. The best removal efficiencies were attained with PR at pH 6, but with PL at pH 8. The Temkin isotherm could perfectly simulate the experimental data (R
> 0.97); suggesting a linear decrease of the adsorption heat of MB with the plant coverage.
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Studying the population ecology of endangered plants provides important baseline information for its monitoring and conservation.
Juniperus phoenicea
L. is an endangered species in arid ecosystems in ...Africa and the Middle East. The static life tables, survival curve and age structure of
J. phoenicea
populations from two mountains in North Sinai, Egypt (Gabal (G.) El-Halal and G. El-Maghara) were investigated. In each mountain, fifteen plots were selected, and field measurements such as stand density, tree height, and crown diameter were conducted. Moreover, 44 trees were cored and cross-dated according to standard dendrochronological procedures. The results showed that the tree ages ranged from 50 to 262 years at G. El-Halal and 96 to 431 years at G. El-Maghara. Mature
J. phoenicea
individuals dominated the study area, with only a few individuals being younger than 100 years. Moreover, seedling recruitment was extremely limited. Since the studied
J. phoenicea
populations showed high mortality rates among both old and young individuals, there is an imminent need for establishing a conservation program to prevent its extinction in the future. Therefore, management and conservation efforts should be made to minimize human disturbance and protect the relic habitats of this endangered species at its southern distribution limits in Africa.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The biosynthesis of metal nanoparticles using plant extracts is an eco-friendly and inexpensive solution that has strong potential and applications in science and industry. This study aims to ...synthesize Cu, Ag, and Au monometallic and trimetallic nanoparticles (NPs) using the extracted polysaccharides (PS) of
Vossia cuspidata
(Roxb.) Griff. leaves. Besides, the anti-cancer, anti-inflammatory, and wound healing potentials of the synthesized NPs were tested. The synthesized NPs were characterized using standard technological methods. We succeeded in green synthesizing CuO, Ag, Au, monometallic, and CuO-Ag-Au trimetallic NPs. The synthesized NPs had weak cytotoxicity at low concentrations (6.5 µg/ml), but the viability of cancer cells was reduced by increasing the concentration, suggesting that the synthesized NPs have potent anti-cancer properties against the cells. The synthesized NPs had 19.44–45.9 μg/ml cytotoxic activity (IC
50
) against the MCF-7 cell line, 16.50–51.92 μg/ml against A549, and 115.90–165.9 μg/ml for normal lung cells (WI-38). TMNPs were the most effective cytotoxic agents against all the tested cell lines, followed by AuNPs on MCF-7 and CuONPs on A549. The cotton fabric-treated TMNPs and CuONPs exhibited anti-inflammatory properties greater than fabric-treated AgNPs and AuNPs and showed the highest odema inhibition (84.61% and 79.28%, respectively). In the wound healing assay, CuONPs and TMNPs caused the highest percentages of inhibition (87.82% and 61.98%, respectively) for the wound compared to AgNPs and AuNPs. TMNPs and CuONPs were more efficient in restoring the tissue integrity of wounds than AgNPs and AuNPs. Accordingly, we recommend using TMNPs and CuONPs in the wound healing dressings.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
One of the most significant environmental challenges in the twenty-first century is heavy metal pollution. The potential use of fresh
Azolla pinnata
to alleviate the toxic effects of Cd and Co on the ...germination measurements of wheat seeds (
Triticum aestivum
L.) and the biochemistry of seedlings was studied. Two concentrations (80 and 100 mg L
−1
solutions) of CdNO
3
and CoCl
2
were used before and after treatment with
A. pinnata
. The highest removal efficiency (RE) by
A. pinnata
was obtained on the fifth day, with a Cd RE = 55.9 and 49.9% at 80 and 100 mg L
−1
, respectively. Cadmium and cobalt solutions reduced the germination percentage, and the measured variables of wheat seeds meanwhile increased the radicle phytotoxicity. In contrast, the presence of
A. pinnata
in the germination medium increased all the measured variables and decreased radicle phytotoxicity. At 80 and 100 mg L
−1
, Cd significantly reduced the fresh and dry biomass, and height of wheat seedlings after 21 days of cultivation compared to Co. Cadmium and high concentrations of cobalt increased the contents of H
2
O
2
, proline, MDA, phenolic, and flavonoid compounds. The application of treated Cd and Co solutions by
A. pinnata
showed a decrease in H
2
O
2
, proline, phenolic, and flavonoid compounds levels accompanied by a reduction in catalase and peroxidase activities compared to the control. This study showed the positive role of
A. pinnata
in alleviating the metal impacts, particularly Cd, on the seedling growth of wheat and its germination.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Juniperus phoenicea
is a medicinal conifer tree species distributed mainly in the Mediterranean region, and it is IUCN Red Listed species, locally threatened due to arid conditions and seed ...over-collection for medicinal purposes, particularly in the East-Mediterranean region. Several studies have addressed the potential distribution of
J. phoenicea
using bioclimatic and topographic variables at a local or global scale, but little is known about the role of soil and human influences as potential drivers. Therefore, our objectives were to determine the most influential predictor factors and their relative importance that might be limiting the regeneration of
J. phoenicea
, in addition, identifying the most suitable areas which could be assumed as priority conservation areas. We used ensemble models for species distribution modelling. Our findings revealed that aridity, temperature seasonality, and clay content are the most important factors limiting the potential distribution of
J. phoenicea.
Potentially suitable areas of the output maps, in which
J. phoenicea
populations degraded, could be assumed as decision-support tool reforestation planning. Other suitable areas, where there was no previous tree cover are a promising tool for afforestation and conservation planning. Finally, conservation actions are needed for natural habitats, particularly in the arid and semi-arid regions, which are highly threatened by global warming.
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The present study evaluated the effect of untreated wastewater irrigation and its health risks in
Triticum aestivum
(wheat) and
Zea mays
(maize) cultivated at south Cairo, Egypt. Morphological ...measurements (stem and root lengths, number of leaves per plant, and dry weights of main organs) as well as soil, irrigation water, and plant analyses for nutrients and heavy metals were conducted in polluted and unpolluted sites. Wastewater irrigations leads to reduction in the morphological traits of the plants and reduced its vegetative biomass and yield production, with more negative impacts on maize than wheat. The concentrations of Pb, Cd, Cr, and Fe in roots and leaves of wheat were above the phytotoxic limits. Conversely, Pb, Cd, and Fe were significantly high and at phytotoxic concentrations in the leaves of maize at polluted site. The present study indicated that wheat plants tend to phytostabilize heavy metals in their roots, while maize accumulates it more in their leaves. Maize and wheat had toxic concentrations of Pb and Cd in their grains under wastewater irrigation. The health risk index showed values > 1 for Pb and Cd in polluted site for both crops, in addition to maize in unpolluted site. Consequently, this will have greatest potential to pose health risk to the consumers.
This study investigated the growth response of
Ranunculus sceleratus
to pollution and its capacity to accumulate trace metals for its use as a phytoremediator in Lake Maruit, Egypt. Three basins ...(main basin, fish farm, and southwestern basin) representing the natural distribution of the plant as well as the pollution loads in the lake, were chosen for collecting plant and sediment samples. In each basin ten quadrats (0.5 m × 0.5 m), distributed equally along two sites, were selected for measuring growth parameters, nutrients, and trace metal concentration. The highest biomass of the shoot and root (610 and 236 g m
−2
) was recorded in the main basin and fish farm, respectively.
R. sceleratus
accumulated high concentrations of Cu and Pb (27.7 and 9.9 mg kg
−1
), while toxic concentration of Mn (2508.0 mg kg
−1
) in their roots compared to shoots. The bioaccumulation factor (BF) for the investigated metals was greater than one, and in the decreasing order: Ni (27.1) > Zn (20.0) > Cd (16.4) > Cu (7.7) > Mn (3.9) > Pb (3.6). The translocation factor of all analyzed trace metals was less than one. The ability of
R. sceleratus
to accumulate Mn, Ni, Cu, and Pb in its roots indicates the potential use of this species for phytostabilization of these metals (mainly Mn) in contaminated water bodies.
The present study was conducted to evaluate the potentiality of the aquatic macrophyte
Pistia stratiotes
to accumulate trace metals, perspective of phytoremediation, and the probability for using it ...as a bioindicator for the different pollution types. Plants were collected from the different Lake Mariut basins (main basin, south-west, north-west, and fish farm), through five quadrats each, for measuring some growth parameters such as plant density, rosette diameter and height, root length, number of living and dead leaves per individual, and leaf length and width. In addition, nutrients and heavy metals in plant organs as well as water samples were analyzed. The bioaccumulation and translocation factors of trace metals were calculated. Water physicochemical data of Lake Mariut showed significant variations of all variables, except temperature and pH as well as Cd metal, among the lake basins. Fish farm was characterized by the highest plant density, individual size, biomass, and the number of living leaves, while the north-west basin had the lowest, except the number of dead leaves. In contrast to trace metals,
P. stratiotes
accumulated concentrations of macronutrients in the leaves higher than in roots. The bioaccumulation factors of the investigated metals, except Cu, were greater than one, while the translocation factors (TFs) of all trace metals were less than unity, and this may render
P. stratiotes
suitable for rhizofiltration. In addition, the significant positive correlation of Ni and Cd in water with those in plant roots and leaves as well as the growth response of this plant to the different pollutants may suggest its potential use as bioindicator for these pollutants in water.
Heavy metal (HM) concentrations in edible plants can develop many serious health risks to humans. The precise prediction of plant uptake of HMs is highly important. Thus, the present investigation ...was carried out to develop regression models for predicting the concentrations of HMs in cucumbers (
Cucumis sativus
L.) from their concentration in the soil and using the organic matter (OM) content and soil pH as co-factors. The results showed that cucumber roots had the highest significant concentrations of all HMs at
P
< 0.001, except Cd, Cu, and Zn were in fruits. The lowest concentrations of Cd, Co, Cr, Mn, Ni, and Pb were recorded in stems. HM concentrations in cucumbers were strongly correlated with soil HM, pH, and OM content. Soil pH and OM content had negative and positive correlations with all HMs in cucumber tissues, respectively. Regression analysis indicated that soil HM, pH, and OM contents were good predictors for HM concentrations in cucumbers. The regression models for root Co, Cr, Fe, and Zn were described by high model efficiency values that explain 48–58% variability. The best regression models for cucumber stem were for Cu, Mn, Ni, and Zn that are characterized by high
R
2
and model efficiency values. For cucumber fruits,
R
2
values were ranged from 54 to 82%, with best models for Cr, Pb, Cd, Cu, Ni, and Co in the fruit. We expect that these models will be beneficial for risk assessment studies on sewage sludge utilization in agriculture.
