ECOPERSIA
Volume:9 Issue: 2, Spring 2021

the present study aimed to analyze the diameter distribution of Juniperus excelsa m.bieb stands of northeast Iran, using probability distribution functions consider to cardinal directions.

The data have been collected from 168 sample plots of 0.1ha areas in natural juniper stands of Iran. In this study, the diameter distribution of the juniper stands has been evaluated in four main geographical aspects, using various statistical distributions. Weibull (two- and three-parameter), Gamma (two- and three-parameter), Beta, Johnson, and lognormal probability distributions have been used for modeling diameter distribution.

According to the Kolmogorov-Smirnov test, the most appropriate distribution functions in the northern, eastern, and southern slopes were the two-parameter Weibull and Johnson probability distributions western slopes, the most appropriate distribution functions were Beta and Johnson. Besides, considering Anderson-Darling’s fitting test, only lognormal distribution in the northern, eastern, and southern aspects, and lognormal and three-parameter Weibull in western aspect did not show a significant difference compared with the frequency of trees in diameter classes.

Generally, the results show Weibull (2p) and longermal are the most appropriate statistical distribution functions for describing the distribution of trees in the diameter classes of Juniperus excelsa in different aspects.

This study aimed to assess the water quality of Ardak River and analyze its suitability for drinking and agricultural purposes.

In this research, water samples were collected during dry and wet seasons in 2018 from previously selected 5 sampling stations. Then, the water quality index (WQI) and irrigation-related indices were calculated.

The calculated WQI values are between 156.77 and 379.59 in the study area, which shows the water quality of Ardak River is in the “poor” to “unsuitable for drinking” range both periods. The effects of water quality parameters on the WQI were evaluated, and the obtained outcomes indicate that the highest mean effective weight value belongs to the fecal coliform and phosphate parameters compared to the other parameters. Furthermore, various indices such as sodium adsorption ratio (SAR), residual sodium carbonate (RSC), magnesium hazard (MH), Kelly’s index (KI), and Permeability index (PI) were used to assess river water quality for irrigation purposes. The results indicate that the river water quality is generally moderately suitable to safe with exceptions at a few sampling stations in the dry season, which are unsuitable for irrigation purposes.

Due to the negative effects of anthropogenic pollutants such as animal husbandry, intensive agricultural activities, and rural wastewater discharging, the water quality of the Ardak River is deteriorating. Therefore, necessary protection steps should be taken in the Ardak Watershed.

This study aimed to assess the relationship between environmental variables (physiographic and soil) and distribution of Artemisia melanolepis and A. aucheri to find the most effective factors on the distribution of these species southeast faced slopes of Sabalan Mt., in the northwest of Iran.

4 sites with the distribution of the genus Artemisia (site with the presence of Artemisia species) and four sites with the absence of 2 Artemisia species were selected. In each site, five transects with a length of 100m (50 one square meter plots) with random- systematically method was established, and the density of Artemisia species and land cover parameters (including percent of litter, stone and gravel, total canopy cover, and bare soil) were recorded in each plot. Seventy-two soil samples were collected from 0-15cm depth. Sampling was conducted from May to July 2015 in the pick growing stage. One-way ANOVA and Canonical Discriminate Analyses (CDA) were used for data analyses.

The ANOVA and mean comparison results showed that all selected environmental variables except total canopy cover and bare soil had significant differences (p<0.01). The results of CDA showed that two functions justified 76.6 and 23.4 percent, respectively, and 100% of the data variance. Finally, 97.3% of the grouped cases were classified correctly. The elevation, potassium, slope, aspect, stone, and gravel were primarily the most effective factors in the first function in the discrimination of the Artemisia species. Some parameters such as sand, silt, electrical conductivity, total neutralizing value, water-dispersible clay, organic matter, pH, total canopy cover, litter, and bare soil were second effective factors in the discrimination of sites and distribution of Artemisia species.

Although physiography and soil variables affected the establishment of Artemisia species and showed significant differences between the three discriminated groups; however, the degree of importance of physiographic parameters is more significant than soil factors.

This paper aimed to evaluate the socioeconomic impacts of an international carbon sequestration project in Hossein Abad Ghinab in southern Khorasan Province of Iran.

The performance of the project has been assessed from the standpoint of changes in demographic conditions, local communities’ participation, literacy rate, access to health facilities, access to energy sources, satisfaction rate, and status of microfinance funds. The changes in these indicators have been monitored from 2004 to 2017. The required information was also elicited from a social survey, and a questionnaire was completed for 142 households as well through analysis of the previous reports.

According to the findings of this research for the main indicators, the project has successfully improved the economic status for access to credits. As for annual income, the average household income from agriculture, livestock, and handicrafts have declined significantly from 2004 to 2017. Concerning the social implications, although some progress could be seen in access to energy sources and literacy rates, however, the project faces a reduction in public acceptance and satisfaction (from moderate to low).

We have concluded that the project has been partly successful in bringing positive socioeconomic changes to the region, yet given the present obstacles such as budget limitation and public participation, the sustainability of the outputs, in the long run, could be a major challenge for project managers.

This study aimed to evaluate river water quality for any use depends on its level of quality, which can be influenced by several factors.

This study was conducted in Dinavar River, upper Kaekheh Basin, Iran, to evaluate water quality and the factors affecting its uses for irrigation and drinking use during 2017-2019. Seven river sites were selected along the river catchment and subjected to field measurement and sampling. Vegetation cover and river degradation were assessed in the field. Water samples and fresh sediment were collected from the selected sites. Samples were analyzed for various physio-chemical parameters such as pH, electrical conductivity, total dissolved solids, total hardness, cation (Na+, K+, Ca2+, Mg2+), anions (Cl-, HCO3-, SO42-), and sodium absorption ratio.

Water quality analysis showed that the water samples from five sites in plain areas were suitable for both drinking and irrigation purposes, while water quality at two upper catchment sites was significantly (p>0.05) affected by urban wastewater. Moreover, it was found that the Dinavar Riverchr('39')s degradation factors increased riverbank erosion, while land use/cover change in river catchment with pollutant sources strongly affected water quality. The main pollutant sources were urban wastewater, improper agricultural activities, land use/cove change, animal manure, rural swage, and local tourism impacts.

Since river water is of great importance for irrigation, drinking, and environmental applications in semi-arid regions, it is necessary to take measures against the pollutant sources.

This study was performed to investigate the relationship between ecological species groups and environmental factors in Fandoghlou rangelands of Ardabil province in the northwest of Iran, assuming that plant species distribution has been correlated with various of complex environmental gradients.

Data were collected from 180 sampling plots (1m2) in an area of 3.27km2 using the systematic-random method. In each plot, environmental factors (topography, climate, and soil variables) and the percent of vegetation cover for each species were recorded. TWINSPAN method and Canonical Correspondence Analysis (CCA) were used to define ecological species groups and determine the relationship between ecological species groups and environmental factors, respectively.

Results of using TWINSPAN for 180 plots classified rangeland communities into three groups. The first group contained 110 plots, the second group 40 plots, and the third group 30 plots. Using ISA, vegetation species groups in the first group contained 8 species, the second group 11 species, and the third group 8 species. In each group, the name of the species with the highest index value was selected as the groupchr('39')s name. Thus using CCA, the group of Trifolium pratense had a relation with aspect, slope, organic matter, magnesium, temperature, and volumetric soil moisture. The Leucanthemum vulgare was related to phosphorus, elevation, lime, sand, clay, and potassium. The group of Trifolium repense had a relation with pH, electrical conductivity, calcium, diffusible clay, temperature, silt, and sodium. The factors of diffusible clay and electrical conductivity with the first CCA axis and potassium and phosphorus factors with the second CCA axis had the strongest correlations.

Using the results of this study, we can evaluate the habitat conditions and vegetation quality of Fandoghlou rangelands. Moreover, used high-quality rangeland species such as Trifolium to counteract the spread of invasive species such as Leucanthemum vulgare.

Most rangelands of Urmia in Iran have been destroyed and need significant restoration to achieve favorable conditions. This study aimed to investigate the impacts of a 19-years research exclosure on vegetation and soil features in Mahabad Sabzepoush rangelands of Iran.

To conduct research using the random-systematic method, three reference sites inside the exclosure and three reference sites outside the exclosure were selected with similar conditions. In each site, three linear transects, and along each transect, ten plots of one square meter were established. The percentage of canopy cover and the number of plants in each plot were measured using estimation and counting methods. From the beginning, middle, and end of each transect, soil samples were collected from a depth of 30 cm. An independent t-test was used to compare data on quantitative vegetation factors, land surface cover, richness characteristics, species diversity, evenness, and soil characteristics both inside and outside the enclosure.

Based on the results, 75 species belonging to 60 genera and 19 families were identified in the selected sites. Results showed that vegetation factors such as density and canopy cover of forbs and grasses and total canopy cover had a significant difference between the outside and inside of exclosure (p<0.05). The total density, density, and canopy cover of shrubs were not significantly different between exclosure and control sites (p>0.05). In the grazing area, the value of plant density of forbs, grasses, and shrubs was 43.84, 40.62, and 1.10number/m2, respectively. After 19 years of the exclosure, the forbschr('39') density (57.45number/m2) and shrubs (2.17number/m2) were increased. Besides, forbs canopy cover increased from 18.14 to 24.88 (percentage) and shrubs canopy cover increased from 0.91 to 0.97% in 19 years exclosure. Richness, diversity, and evenness did not differ significantly between the exclosure and open grazing sites (p>0.05). The richness and diversity index was increased by 0.03 and 0.05 in the exclosure sites, but the evenness index increased by 0.01 in the open grazing sites. Nitrogen, electrical conductivity (EC), available phosphorus, organic matter, silt, and potassium in the exclosure and open grazing areas, had a significant difference (p<0.05). In the grazing area, EC and potassiumchr('39')s value was 1.35ds/m and 464.24ppm, respectively. After 19 years of the exclosure, the value of EC (1.10ds/m) and potassium (464.24ppm) were increased. Nevertheless, the values of other factors were decreased.

Although exclosure has increased the percentage of canopy cover, density, and diversity of species, but in some cases, non-observance of exclusion will prevent the achievement of the expected goals and desired results. These results indicate that grazing exclosure plays a crucial role in vegetation recovery and soil protection of destroyed rangelands.