ECOPERSIA
Volume:10 Issue: 2, Spring 2022

This study was conducted to compare the effects of three types of light, medium and heavy grazing intensity on the plant functional groups across the Sahand summer rangeland.

First, three areas with different grazing intensities were selected according to the field observations and collected information from herders. Then, the random systematic approach was applied to plant sampling across the selected sites. Afterwards, six transects were randomly established in the selected sites separately where ten plots were then localized on the compounding transects. 

The results of Duncan test indicate a significant difference in the average production, canopy cover percentage and litter percentage across the studied sites under different grazing intensities. The average characteristics of all plant functional groups in sites with different grazing intensities have significant difference at the level of 1%. In this regard, the highest averages with 487.8 kg. ha-1, 62.7% and 12.5% are related to the site with light grazing, respectively. Results revealed that the properties of perennial grasses and forbs in the region under light grazing intensity is higher than two other studied regions which were under medium and heavy grazing.

The finding of this research implied that the livestock grazing intensity can significantly affect the palatability classes and growth form of plants. Therefore, changes in grazing intensity is recommended as a management tool in rangeland improvement to improve vegetation characteristics and move vegetation towards equilibrium.

This study has been done to investigate the hydrogeological drought and groundwater quality changes over the time in Semnan and Damghan plains.

In this research, the groundwater level and groundwater quality changes in of these plains has been evaluated using monthly piezometric wells data for April as groundwater-recharging month and October as groundwater-discharging month and six groundwater quality factors including pH, Chloride (Cl-), Total Dissolved Solids (TDS), Electrical Conductivity (EC), Calcium (Ca2+) and Magnesium (Mg2+) were considered to determine groundwater quality changes. Groundwater Resource Index (GRI) and Groundwater Quality Index (GQI) were used to determine hydrogeological drought and changes in its quality, respectively, in studied plains from 2004 to 2018.

The results illustrated that the trends of groundwater level and GRI are decreasing and there is no steady trend for these indices over the studied period and GRI value is totally higher in city surrounding regions in both plains. According to results of GQI, EC and TDS factors have the highest effect on the groundwater quality, respectively, compared to other factors. GQI value is higher in central and northern parts than compared to other parts in Semnan plain, while in Damghan plain, GQI value in central and western parts is higher than eastern parts.

The correlation between GRI and GQI showed positive results in both plain with 0.542 in Semnan and 0.672 in Damghan, which reflects that the groundwater quality changes with groundwater level changes.

The study of the habitat of Persian leopard as a keystone effective species in the ecosystem services is significantly important in terms of protection. Habitat modeling and preparing the suitability map of that habitat is one of the ways of obtaining information and identifying activity and behavior of species .

   Maxent method was used in the presence data of the leopard and contributing factors in species distribution. Ultimately, habitat suitability maps obtained from this method were validated by using ground monitoring, and are under the curve (AUC) for ROC. The most suitable habitat for this species was introduced.

 Results showed that distance from herds of wild goats is the most important factor in the distribution of Persian leopard in this province, and several factors including distance from the protected areas, slopes, distance from the environmental protection checkpoints, distance from rivers, distance from mines, geographic aspects, distance from water resources, elevation, distance from roads and distance from villages were the other important factors affecting the species habitat suitability. Also, the most favorable habitat in Kohgiluyeh and Boyer-Ahmad province is in cold regions at an altitude of 3300-3700 m, in tropical regions of 2000 to 2500, and on slopes more than 30% and in the west northwest and the north directions.

based on the hidden correlations between the variables used in modeling habitat desirability of the leopard, the model with high performance and accuracy (AUC=0.927) predict desirable and undesirable areas for habitat of this species.

The climate change consequences are more severe in semi-arid regions in the form of drought, desertification, and dust occurrence. The purpose of this study was to investigate the effects of climatic changes on dust occurrence and sand mobility in Kermanshah province, Iran.

The meteorological stations from 1992 to 2017 were selected within Kermanshah province. The trend of climate changes was analyzed by using the Mann-Kendall model. Furthermore, the dust storm index (DSI) method was used to study the frequency and severity of dust phenomenon.

The results explored that the highest precipitation is occurred in March and November in this province. DSI index was found higher value in Islamabad, Kermanshah, and Kangavar than that other station, mainly in the west of the province, occurring in in 2008 and the lowest values were in 2010 and 2013. The average wind speed was 4.6 ms-1, while the highest winds with more than 6 ms-1 speed and dominant west and southwest directions are occurred in the western part of the province. Consequently, the annual dust rose was western. Furthermore, the highest amount of dust with 175 days occurred in Saprobe Zahab (west of the province), which was mostly related to spring and summer seasons. Lancaster index explored that the sand mobility potential was prevalent in the southwestern (along to Iraq border)

The dust incidence is affected by climate change. Thus, maintaining vegetation and controlling land use change is essential management approach to adapting climate change in this region.

Floristic surveys are important methods to find the new herb species and protect natural ecosystems. Since there is no report about floristic survey in Akhardaghe region, the aims of this research were to determine floristic list, life forms, chorological analysis, protected status and endemic of plants species in the Akhardaghe watershed in Bojnourd.

The plant specimens of the study region were collected during active growth periods in 2016 to 2020. Determining the life form was done by Raunchier category, Endemic, rare and endangered species of Iran was determined based on Red data book of Iran and chorology of species is according to vegetative regions classified by Zohary and Takhtajan.

In the floristic survey, a total number of 346 plant species were belong to 234 genera and 63 families. The most important families were Asteraceae with 54 species and Lamiaceae with 36 species. In terms of life forms, the highest percentage for both hemicritophytes and therophytes (61%) were found.Based on chorology, there were a high ratio of Irano-Turanian elements (55%). In addition, 37 endemic species were determined. According to the IUCN, 53 threatened plant species in this area.

The finding of the current floristic research revealed that the vascular plant flora in the area is rich in species and contains numerous endemic, rare and medicinal plants species. However, most of the plants species are severely threatened by human overutilization. Therefore, conservation and protection management policies have to be applied to the Akhardaghe watershed vegetation.

The aim of this study was to investigate the ecological factors affecting the distribution of the rare, endangered and medicinal species of Vaccinium arctostaphylos L. in ecotone rangelands of Namin County in 2019.

Sampling were performed from the presence and absence locations of V. arctostaphylos in eight habitats. Soil samples were taken from a depth of 0-30 cm and physiographic variables in were recorded. Moreover, a digital elevation model, slope and aspect map was derived. Rainfall and temperature gradient maps, was derived using gradient equations, and the values for sampling points were extracted. Data analysis performed by independent t-test and discriminant analysis test.

Results showed the Stream Power Index (SPI) (p<0.05), pH, EC, lime, soluble sodium, organic carbon, soil texture and species density (p<0.01) are significantly different between the presence and absence of the species. Results of discriminant analysis showed the three functions explained 86.4, 10.7, and 2.8% of the total data variance, respectively. Generally, 19 variable including elevation, slope, aspect, precipitation, Topographic Wetness Index (TWI), plan curvature index (PC), SPI, pH, EC, lime, phosphorus, soluble potassium, soluble sodium, magnesium, organic carbon, bicarbonate solution, saturation percentage (SP), sand percentage and species density were identified as the important factors affecting the distribution of V. arctostaphylos. SP was the most important factor in the presence and absence of species.

Generally, by identifying the most effective ecological factors on the distribution of V. arctostaphylos, effective steps have been taken to improve the habitat of the rare species.

With global warming and limited water resources in the world, especially in arid lands of Iran, managing the production of forest seedlings in the country's nurseries is facing a special challenge. In this regard, the study of drought tolerant plants to select them in the mass seedling production programs can be useful.

Potted seedlings of Persian oak (Quercus brantii Lindl.), pistachio (Pistacia atlantica Desf.), Judas-tree (Cercis siliquastrum L.) and black poplar (Populus nigra L.) exposed to a normal irrigation scheme (100% field capacity) and drought-stressed (30% field capacity) conditions were examined over a period of 120 days in a greenhouse of Bam Khorramabad Nursery to judge their tolerance for drought stress.

Drought-tressed seedlings from all species had a lower content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids compared to the control plots, but the content of proline and malondialdehyde (MDA) did, however, increase. Under stress conditions, MDA content in black poplar, Judas-tree, Persian oak and pistachio was 174, 121, 105 and 102% higher than the control seedlings, respectively, and this increase in black poplar over other species ranged from 93.5 to 176.5%.

This study confirms that among four tree species, black poplar has lowest tolerance to drought stress. Thus, Persian oak, pistachio and Judas-tree, should be prioritized in the mass seedling production programs of nurseries in arid areas suffering from limited water resources, due to their higher tolerance to water scarcity.