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This case study examined the effect of grazing exclusion on the soil and vegetation characteristics to provide support for the restoration of the degraded desert steppe rangelands of the Arshagh ec...

Plant growth and development are vastly affected by different abiotic and biotic stresses. Seed priming is an effective tool for increasing seed germination and plant growth that will eventually increase productivity under different environmental conditions and stresses. Efficient seed germination promotes successful establishment and deep root system of plants. Among the different seed priming methods, nano-priming is more effective mainly because of its small size and unique physicochemical properties. Since plant species are physiologically different, they differ in their uptake of nanoparticles in nano-priming, and hence in their rate and manner of growth. Most previous studies have separately investigated the effect of nanomaterial on seed germination, growth, and development of one plant at a time. However, very few studies have reported nano-priming effects using different particles on seed germination and seedling growth of forage and medicinal plants together. Therefore, this review summarizes studies of nano-priming effects using various particles on seed germination and seedling growth of forage and medicinal plants. Furthermore, the effect of different nanoparticles on the most important characteristics of germination, morphology and physiology affecting the establishment, growth and production of these plants are reviewed. In general, nano-priming increased seed germination, seedling growth and development, vigor, rate of seedling emergence and subsequent performance in most of the medicinal and forage plants. While the use of nanoparticles enhanced environmental stress resistance of these plants, negative effects of nano-priming on seed germination, seedling and plant growth traits were observed. In addition, future research areas of focus are discussed briefly.

Aboveground Net Primary Production (ANPP), an indicator of ecosystems’ ability to capture and convert solar energy, is critical to evaluate and manage ecosystem carbon balance index including rangelands. Measuring ANPP over a large area is difficult at it varies with different factors including climate and anthropogenic, while satellite-based information shows strong opportunity. The aim of this study was to estimate the ANPP of Plant Functional Types (PFTs) using Landsat-8 imagery over the rangelands of Hir-Neur from Ardabil Province, Iran as a case study area. Landsat-8 Operational Land Imager (OLI) satellite images were collected on 9th June 2017 aligning with the field sampling of PFTs ANPP. Eleven sampling sites with 10 plots at each site (locations recorded with a Global Positioning System, GPS) were selected along a transect with elevation gradient and the ANPP of PFTs were recorded. Twenty-two vegetation indices were calculated from the Landsat-8 imagery and the index values were extracted for the sampling plots. Correlation between derived indices and field collected ANPP data were calculated. Predictive relationships between PFTs and total ANPP and satellite indices were developed using a 3rd-order polynomial model and the model was used to map the whole study area. The best estimation of PFTs and total ANPP was obtained using the Vegetation Index (VI3) for grasses (R2=0.47), Iron Oxide (IO) for forbs (R2=0.51), and Renormalized Difference Vegetation Index (RDVI) for shrubs (R2=0.50). The Difference Vegetation Index (DVI) was the best estimator for the total ANPP (R2=0.49). The overall accuracies of the maps were acceptable (MAE, MDE, RMSE

The leaf area index (LAI) is an important vegetation biophysical index that provides broad information on the dynamic behavior of an ecosystem’s productivity and related climate, topography, and edaphic impacts. The spatiotemporal changes of LAI were assessed throughout Ardabil Province—a host of relevant plant communities within the critical ecoregion of a semi-arid climate. In a comparative study, novel data from Google Earth Engine (GEE) was tested against traditional ENVI measures to provide LAI estimations. Moreover, it is of important practical significance for institutional networks to quantitatively and accurately estimate LAI, at large areas in a short time, and using appropriate baseline vegetation indices. Therefore, LAI was characterized for ecoregions of Ardabil Province using remote sensing indices extracted from Landsat 8 Operational Land Imager (OLI), including the Enhanced Vegetation Index calculated in GEE (EVIG) and ENVI5.3 software (EVIE), as well as the Normalized Difference Vegetation Index estimated in ENVI5.3 software (NDVIE). Moreover, a new field measurement method, i.e., the LaiPen LP 100 portable device (LP 100), was used to evaluate the accuracy of the derived indices. Accordingly, the LAI was measured in June and July 2020, in 822 ground points distributed in 16 different ecoregions-sub ecoregions having various plant functional types (PFTs) of the shrub, bush, and tree. The analyses revealed heterogeneous spatial and temporal variability in vegetation indices and LAIs within and between ecoregions. The mean (standard deviation) value of EVIG, EVIE, and NDVIE at a province scale yielded 1.1 (0.41), 2.20 (0.78), and 3.00 (1.01), respectively in June, and 0.67 (0.37), 0.80 (0.63), and 1.88 (1.23), respectively, in July. The highest mean values of EVIG-LAI, EVIE-LAI, and NDVIE-LAI in June are found in Meshginshahr (1.40), Meshginshahr (2.80), and Hir (4.33) ecoregions and in July are found in Andabil ecoregion respectively with values of 1.23, 1.5, and 3.64. The lowest mean values of EVIG-LAI, EVIE-LAI, and NDVIE-LAI in June were observed for Kowsar (0.67), Meshginshahr (1.8), and Neur (2.70) ecoregions, and in July, the Bilesavar ecoregion, respectively, with values of 0.31, 0.31, and 0.81. High correlation and determination coefficients (r > 0.83 and R2 > 0.68) between LP 100 and remote sensing derived LAI were observed in all three PFTs (except for NDVIE-LAI in June with r = 0.56 and R2 = 0.31). On average, all three examined LAI measures tended to underestimate compared to LP 100-LAI (r > 0.42). The findings of the present study could be promising for effective monitoring and proper management of vegetation and land use in the Ardabil Province and other similar areas.

Soil contamination refers to a decrease in soil quality because of the entry of heavy metals, petroleum compounds, and metalloids, which in turn will cause soil loss. Therefore the subject of soil contamination must be addressed urgently. Many methods have been used, including excavation and tillage, soil washing, ion exchange, oxidation reduction, incineration, solvent extraction, heat dissipation, reverse osmosis, encapsulation, and phytoremediation, to deal with soil contamination. However, many of them are less studied due to being time consuming, having high costs, with limited use area, harmful side effects, and low efficiency. Therefore they are not currently the best tool for addressing environmental pollution issues. At present, the quick advancement of nanotechnology and the widespread use of nanomaterials in soil remediation have opened a new path for soil remediation. Though nanoparticles have useful functions, there are concerns about what happens to the environment and ecosystems after they are released (environmental hazards). Hence, it is essential to assess the suitable risk assessment of such products along with appropriate risk-related measures.

Vegetation canopy cover is an important biophysical indicator for monitoring rangeland condition and rangeland management. The main purpose of this study is to assess the capability of Landsat 8 (OLI) image-derived vegetation indices (VIs) to estimate the vegetation canopy cover (CC) in Sablan rangelands. Field CC measurement was performed using the transect-quadrats method in 12 selected sites on the study area according to three vegetation life-forms canopy cover including, Forbs (FCC), Grasses (GCC), and Shrubs (SHCC) along with a combination of three life-forms as Total canopy cover (TCC). The estimated CCs were correlated and regressed with Landsat OLI reflectance values and vegetation indices. Results revealed that all the slope-based, distance-based, and orthogonal transformation VIs had the highest significant correlations with Grass canopy cover data (mean of R2 = 0.70) at the 95% confidence level. The weakest and insignificant correlations were derived for FCC followed by SHCC. A number of VIs (with mean R2 = 0.6) significantly correlated with TCC. The results of linear regression for GCC, TCC, and SHCC indicated that the reflectance values of spectral bands and vegetation indices were convincingly regressed with CC field data having R2 values in the range of 0.72 to 0.83, while the FCC due to the third-order logarithmic regression models gained the weakest relationship with spectral data and also VIs (R2 = 0.14 and 0.42, respectively). Results of validity test of the regression models declared that the models developed for SHCC are the best predictors followed by those made for TCC, GCC, and FCC, respectively. In this study, there was not observed an obvious difference between the performances of the three groups of VIs in predicting the CC of life-forms in the studied sites. It can be concluded that the studied VIs are more strong predictors of Grass canopy cover as the dominant life-form.

13 páginas.-- 8 tablas.-- 40 referencias.-- the articles are free to use, with proper attribution, in educational and non- commercial applications., [EN]: This study was conducted to evaluate Pb and Zn uptake, mobility, and accumulation in Stipa hohenackeriana using field soil in pot and field experiments. Moreover, the effects of Municipal Solid Waste Compost (MSWC) (0, 1, and 2%) and Nano-Silica (NS) (0, 250, and 500 mg/kg) on Stipa biomass, Pb and Zn availability in the soil, and Pb and Zn uptake and accumulation were studied using pot experiments. Samples of soil, root, and shoots of Stipa were collected from field and greenhouse and after drying, extraction of Pb and Zn was done by acid digestion. Bio-Concentration Factor (BCF) and Translocation Factor (TF) were calculated to determine Pb and Zn phytoremediation efficiency. The amount of Zn and Pb remediation by Stipa from soil was determined by remediation factor (RF). The results of field experiments showed the Pb and Zn level decreased in the order of: soil >shoot>root. Results of the pot experiments also showed that plants grown in NS500-amended pots had 33% and 32% higher Pb in roots and shoots compared to control pots, respectively. In comparison, roots Pb concentration in pots amended with MSWC1% and MSWC2% decreased 22.4% and 1.7%, respectively. Roots and shoots Zn concentration in NS500-amended pots was 5.6% and 6.5% higher, respectively. However, root Zn concentration in treatments of MSWC1% and MSWC2% decreased 52.3% and 39.4%, respectively. Shoots Zn concentration decreased 52.5% and 40.0%, respectively. Although MSWC decreased the uptake and accumulation of Pb and Zn in Stipa roots and shoots, it improved the plant growth and consequently increased RF and soil remediation compared to the NS. Thus, it seems that applying MSWC and NS simultaneously can be a suitable strategy for the purpose of improving phytoremediation capability of Stipa in the Pb and Zn contaminated soils. In general, Stipa can be a suitable candidate for the accumulation of heavy metals, especially for Pb and Zn contaminated soils., [PO]: Este estudo foi conduzido para avaliar a absorção, mobilidade e acumulação de Pb e Zn em Stipa hohenackeriana em experiências usando solo de campo em vaso e em campo. Além disso, os efeitos do Composto Municipal de Resíduos Sólidos (MSWC) (0, 1 e 2%) e de nanopartículas de sílica (NS) (0, 250 e 500 mg/kg) na biomassa de Stipa, na disponibilidade de Pb e Zn no solo, e na absorção e acúmulo de Pb e Zn foram estudados usando experiências em vaso. Amostras de solo, raiz e brotos de Stipa foram coletadas do campo e da estufa e, após a secagem, a extração de Pb e Zn foi feita por digestão ácida. O Fator de Bioconcentração (BCF) e o Fator de Translocação (TF) foram calculados para determinar a eficiência de fitorremediação de Pb e Zn. A quantidade de remediação de Zn e Pb pela Stipa a partir do solo foi determinada pelo Fator de Remediação (RF). Os resultados das experiências de campo mostraram que o nível de Pb e Zn diminuiu na seguinte ordem: solo > broto > raiz. Os resultados das experiências em vaso também mostraram que as plantas cultivadas em vasos corrigidos com NS500 apresentaram teores de Pb 33% e 32% maiores em raízes e brotos em comparação com vasos de controle, respectivamente. Em comparação, a concentração de Pb em raízes em vasos corrigidos com MSWC1% e MSWC2% diminuiu 22,4% e 1,7%, respectivamente. A concentração de Zn em raízes e brotos em vasos corrigidos com NS500 foi de 5,6% e 6,5% maior, respectivamente. No entanto, a concentração de Zn da raiz nos tratamentos de MSWC1% e MSWC2% diminuiu 52,3% e 39,4%, respectivamente. A concentração de Zn nos brotos diminuiu 52,5% e 40,0%, respectivamente. Embora o MSWC tenha diminuído a absorção e acumulação de Pb e Zn nas raízes e brotos de Stipa, melhorou o crescimento da planta e consequentemente aumentou o RF e a remediação do solo em relação ao NS. Assim, parece que aplicar MSWC e NS simultaneamente pode ser uma estratégia adequada com o objetivo de melhorar a capacidade de fitorremediação de Stipa nos solos contaminados com Pb e Zn. Em geral, a Stipa pode ser um candidato adequado para a acumulação de metais pesados, especialmente para solos contaminados com Pb e Zn.

The purpose of this study is to evaluate the capability of Secale montanum trusted for phytoremediation of contaminated soils with lead (Pb) and cadmium (Cd). To conduct this study, soil samples were taken from contaminated rangelands soils around National Lead & Zinc Factory, Zanjan, Iran. In this study, which was performed in a greenhouse, after preparing the pot and treating soils with nano-silica (NS) and municipal solid waste compost (MSWC) amendments, 20 Secale seeds were cultured in each pot. The translocation factor (TF), the bio-concentration factor (BCF), and remediation factor (RF) were calculated to determine the phytoremediation capability of Secale. Six months after establishment, plant organs were harvested and Pb and Cd concentrations were measured in shoot and roots of Secale. For statistical analysis and to compare the obtained means, ANOVA and Tukey's tests were performed, respectively. The pot experiment results showed that Pb uptake and accumulation by roots of S. montanum were highest in pots amended with NS500. In comparison, Pb concentration in shoots of Secale was highest in pots amended with MSWC 2%. In general, it seems that NS500 and MSWC 2% help phytoremediation capability of Secale in the Pb-contaminated soils.

This research was carried out to assessing the potential of Bromus tomentellus for phytoremediation with biochar and municipal waste compost amendments to improving the clean-up efficiency of soils contaminated with chromium (Cr) and zinc (Zn). Soil amendment was added to contaminated soil in three levels (%0: Control; without organic fertilizer, biochar and compost 1%, biochar and compost 2%). It also determines the applicability of artificial neural network (ANN) in the modeling of the extraction process. The physiochemical properties of the contaminated soil, including pH, Electrical Conductivity (ECe), Cation Exchange Capacity (CEC) and Sodium Adsorption Ratio (SAR) were determined. After validation of the applied artificial neural network, the effect of municipal waste compost and biochar treatment on the absorption of heavy metals in different parts of the plant was investigated. Also, the range of adding amending factors to the soil through the neural network increased from 2% in experimental data to 5% in predicting data. The neural network was taught for heavy metals in soil and plant, so the amount of Correlation coefficient (R2) value in most cases was higher than 0.9 and close to 1 which means the Group Method of Data Handling (GMDH) and artificial neural network was usable for over-predicting data. The results indicated that by adding compost percentage, the absorption of Zn is also increased. The highest concentration of Zn (274.82 mg/kg) and Cr (26.66 mg/kg) was observed by adding 0.8% compost and 0.52% biochar, respectively. The maximum Cr concentration for compost (25.19 mg/kg) was detected by adding 1% compost.

The aim of this study was to assess preference values for plant species in the Kordan rangeland using multivariate analysis techniques. Measurements were taken for forage production each month for the duration of the study. A species selection index was used to assess values for species’ preference. The additive effects of data obtained from four years’ study and in three growth stages were examined with factorial analysis. Comparisons of values for species’ preference were determined by Duncan's test. Multiplicative interaction was used to examine multiplicative effects and additive main effects. The results of ANOVA for preference values for species selected for the study during four years and during the specified grazing months showed meaningful difference for main effects of species and months. Interactions between species and month and among year, species and month were also meaningful at the level of 0.01. Based on the additive main effect and the multiplicative interaction (AMMI) model or the inter...

This study provides a checklist of species distributed at the altitude gradient of Moghan-Sabalan rangelands in Ardabili province, Northwest Iran. We evaluated the changes in species composition, growth types of species, Raunkiaer’s life forms, geographical distribution, threat and endemicity status, and palatability of species along two altitudinal gradients in the sampling plots, which were conducted in eleven sites/habitats with 300 meters above sea level (masl) altitude intervals (from 100 to 3300 masl). We assessed the plant species composition with special reference to the gradient analysis, and identified overall 396 species, which was comprising 44 families and 194 genera. Results showed that Asteraceae family is by far the most species-rich family, followed by Poaceae, Fabaceae, Caryophyllaceae and Brassicaceae. Among the genera, Astragalus is the most diverse genus, followed by Allium, Veronica and Bromus, Galium, Silene and Ranunculus. Results indicated that the number of species increased as the altitude increased to 1200–1500 masl, but then starts to decline to 3300 masl. Family-to-genera ratio was 1:4.4, the family-tospecies ratio was 1:9, and the genera-to-species ratio was 1:2.04. Growth type of species analysis shows that the frequency of perennial plants was higher in the study area followed by annual species while the lower group was biennial species. The number of annuals showed a decreasing trend towards higher altitude. Hemicryptophytes and therophytes were the most frequent life forms constituted each with (41.9%). Hemicryptophytes showed an increasing trend with altitude, while therophytes showed a decreasing trend with altitude increase, followed by geophytes, chamaephytes, and phanerophytes. Results showed more than half of the species of the study area belonged to Iran-Turanian region and these species showed an increasing trend with altitude. In contrast, Sahara-Sindian species comprise a minor component of the spectrum, with decreasing trend with altitude. The rare and endangered species out of the surveyed taxonomic groups comprised 53 species in total which 29 of them are considered lower risk (LR), 13 data deficient (DD), 5 vulnerable (Vu) and with 3 rare (R) and identified endemic plants comprised 24 species. Some 56.6% species were identified as class III, 22.6% were class I and 20.8% were class II as the palatability variation. Moghan-Sabalan rangelands require strong conservation management policies in case of species loss and changing natural communities due to the occurrence of conversion into cropland, over-grazing and other anthropogenic effects.