نشریه علوم محیطی
سال دوازدهم شماره 4 (پیاپی 46، زمستان 1393)

Environmental factors particularly soil properties influence the species composition and vegetation diversity in rangelands. Soil in some parts of lowland areain Mazandaran province is saline. This made some limitations for establishment of vegetation. In this study the relationship between vegetation and soil properties were assessed in lowland rangeland of Hyrcanian zone in the city of Behshahr, Mazandaran Province. Vegetation was sampled along transects with 100 m length using 1 m2plots. Cluster analysis showed six vegetation types. ANOVA results indicated that greater values of species richness and diversity indices were found in Artemisia sieberi-Medicago rigidulaand Halocnemum strobilaceum-Juncus maritimus. Results from RDA analysis showed that salinity, soil texture and soil moisture are main drivers of vegetation distribution in this area. An increase in EC,CaCo3andsilt was associated with the establishment of Salicornia europaea-Spergularia marinaand Halocnemum strobilaceum-Juncus maritimus. Aeluropus littoralisand Hordeum marinum-Plantago psylliumwere found where soil had lower EC but higher moisture, Organic carbon and clay. A reduction in soil EC and soil moisture was the favorite of Artemisia sieberi-Medicagorigidulaand Juncus maritimus.

Climate change is usually attributed to natural phenomena or in response to anthropogenic activities. Fossil fuel combustion and emission of greenhouse gases accelerate climate change and global warming. There are two main strategies to face climate fluctuations: adaptation and mitigation. Among living organisms, plants exert numerous mitigating effects especially in urban areas. Important climate-related functions of plants; and hence urban green space, include cooling effect, pollution reduction, increasing energy use efficiency, absorption of UV and high energy radiations, reducing surface runoffs, soil maintenance, reducing wind speed, chemical air pollution and fine particles. The efficiency of plant taxa is a function of their morphological and physiological functional traits. This research comprehensively reviews relationships between plant mitigating functions in urban environments, functional traits and climate related management perspective of cities. Plant functional traits such as leaf surface morphology, plant size and height, density and distributional pattern, canopy shape and branching pattern along with life form and physiological properties are of utmost importance in mitigation and adaptability of plants to climate perturbations. We strongly recommend considering future perspective under climate change scenario and substitution of urban plant species based on functional traits as one of the management priorities for urban areas especially Tehran metropolis environment.

Arsenic is a naturally occurring element which pose a potential risk to groundwater quality, as well as food safety through As transportation in soil-water-plant systems. Therefore, plants such as cereal are the main way of As transportation to the food chain. In this study, to evaluate the arsenic transfer rate in agricultural products and the risk of its poisoning, surface water, soil and wheat samples were collected from the Bijar County, which has a history of naturally occurring arsenic pollution. The As concentration of surface water and soil samples are in ranged of 0.52-484.64 μg/L and 138.2 to 1775.2 mg/kg respectively. Also some physico-chemical parameters of water and soil which had direct effects on As pollution were estimated. The As concentration of wheat shoot samples were between 1.79-30.58 mg/kg and As concentration of wheat seed samples were 0.003-0.08 mg/kg. Based on these results, arsenic levels in waters and soils were significantly correlated, but arsenic accumulation in wheat samples were not correlated significantly with soil arsenic concentration.

In order to study theability of hull extracts of Iranian rice cultivars on germination and seedling growth of barnyard grass, two laboratory and greenhouse experiments were conducted ina completely randomized block design with factorial arrangement and three replications. This study wasundertaken to evaluate the allelopathic potential aqueous extract of 20 hull rice (Oryza sativa) cultivars on growth factor of barnyard grass (Echinochloa cruss-galli). This research was performed in 2007 at the Department of Agronomy of Tarbiat Modares University. Aqueous extract of hull rice in four concentrations (control, 5, 10 and 15%) were used for germination test and seedling growth of barnyard grass seeds. In the laboratory, we found that a few varieties product and released allelochemical for inhibiting and more cultivars stimulation growth of barnyard grass. Khazar variety showed the highest inhibition on germination percentage, germination rate, shoot length, root length, root dry weight and shoot dry weight. In addition, the breeding and domestic varieties were inhibitor and simulator of barnyard grass respectively. In the field experiment, Khazar cultivar reduced germination percentage, germination rate, root length, root dry weight, total dry weight and shoot dry weight of barnyard grass and Neda cultivar showed the greatest inhibition on shoot length. This study show that there are differences among the varieties of rice for allelopathic inhibition of barnyard grass seeds and genetic and morphological rice characteristics could be used as selection markets for allelopathic rice varieties and maybe used as a natural herbicide to reduce the population of barnyard grass in field. Increasing concentration of aqueous extract increased effects of inhibition and stimulation of various cultivars on barnyard grass. Survey morphological and genetic traits of rice varieties showed an existing relationship allelopathy potential of rice on barnyard grass.

In order to optimize use of fertilizer on nitrate content and Quality characteristics in green beans (Phaseolous Vulgaris) genotype Sunray, experimental form of split plot design based on randomized complete block in the 2010 Crop Agricultural Research Station Varamin three was carried out. In this experiment, main plots, including urea nitrogen level 1-250 Kg ha-1. 2-300 Kg ha-13-350 Kg ha-1. Three fertilizer treatments include potassium and zinc: 1-120 Kg ha-1potassium. 2 -Foliar of 6 per thousand Zn. 3-120 Kg ha-1potassium and foliar of 6 per thousand Zn (based on soil test) has sub plot. Results of interactions showed that the highest levels of nitrate in pods consumed 350 Kg ha-1of nitrogen (sulfur-coated urea) application of 120 kg (K) was185.4 mg kg-1, The least amount of nitrate in the pod was 250 Kg ha-1(N) combined potassium and foliar Zn with 76.4 mg/kg. Highest level of fresh pod yield was achieved treatment used 250 Kg ha-1N and combined K and foliar Zn on 4306.2 Kg ha-1. The lowest this characteristic was achieved the treatments used 350 Kg ha-1of nitrogen (sulfur coated urea) and potassium applications with 2298.6 Kg ha-1. The highest Number of cutting in pod, Number of pod in plant, Number of pod in m2were achieved treatment used 250 Kg ha-1and combined K and foliar Zn 17.1number, 210.6 number and 1680 number, respectively. The most of Pod length, Number of seed in pod that were achieved application used 250 (N) Kg ha-1and K 18 Cm and 5.6 number respectively. The highest levels of 100 seed weight was achieved treatment used 300 Kg ha-1and combined K and foliar Zn. The lowest characteristic was achieved the treatments used 3250 Kg ha-1of nitrogen and Zn foliar with 36.1 gr. The highest pod yield (4306.2 Kg ha-1) was provided by application of 250 kg Urea.ha-1 with K and Zn fertilizers, however the lowest pod yields (2298 Kg ha-1) was observed at 350 Kg ha-1Urea with K.

Heavy metals such as: arsenic, iron, zinc, lead, cadmium, chromium, copper, manganese and nickel exist in Tehran’s air which is inhaled by inhabitants and causes serious problems for human body. Tehran is a metropolis that faces several environmental problems. Among Streets, roads and highways of Tehran,Enqelab Street is one of the busiest and connects Enqelab square to Imam Hossein Square. In this paper, the results of measuring heavy metals including arsenic, iron, zinc, lead, cadmium,chromium,copper, manganes and nickel in Enqelab Street’s air are presented in the form of charts and GIS maps. The study was performed in Bahman1 1391 and Khordad2 1392 along the mentioned area. The outcome of these studies indicates that concentration of all hevey metals except arsenic&chrmium are in allowed levels of WHOguidelines and despite recording few different the air pollution levels in the whole area, from Enqelab square to Imam Hossein Square,are equal; however,the air pollution level of Valiasr crossroads is relatively considerable.

There is a need of monitoring and analysis of drought condition for water resources management. Given the large difficulties to objectively quantify drought characteristics such as duration, intensity, and magnitude several drought indices have been developed in the last decades. One of shortcomings of current drought indices including standardized precipitation index (SPI) is that it does not include water balance by means of evapotranspiration. Standardized precipitation evapotranspiration index (SPEI) includes water balance in calculating of drought index using precipitation and evapotranspiration.The objectives of current study are to investigate meteorological droughts using SPEI in ten synoptic stations in different climates of Iran and to compare the results with SPI. In view of this, temperature and precipitation data in a long term 1975 to 2007 were prepared and the drought indices were calculated. The comparison was done based on indices values and drought categories class. The results showed that both SPI and SPEI indices have significant correlation, moreover the SPEI showed the quick response to drought. The increasing the timescales of indices also increase the duration of drought. Based on the importance of evapotranspiration in arid and semi-arid regions, the SPEI can be used as a suitable index for determining of droughts. However, further researches are needed in spatial and temporal scales.

Potato is one of the most important agricultural products. Due to high nutritional it has high nutritious value, it is considered as one of the main products in the nutrition of under developing countries. Mycorrhiza fungi increasethe growth of plants with establishing coexistence relation with the plants. The purpose of this work is to identify the mycorrhiza fungi which have mutual relation with roots of potato plant and relation with edible potato plant and study their effects on the growth parameters of this plant.Wet sieving and decanting method was used for purification of the spores the spoors of these fungi are separated with sieve from the wet earth.In this study four species of mycorrhiza fungi belonging to the genus Glomus type were identified. These species were: Glomus aggregatum, Funneliformis.geosporum, Funneliformis mosseae and Claroideoglomus etunicatum, In order to increase the mycorrhizal fungi, the pot culture method was used.Statistical study revealed that there is a significant differences in the number of leaves, flowers, size of stem and root, fresh and dry and weight in treated plants as compare to control Mycorrhiza fungi were inoculated in the potato plants. In this study it was determined that in the potatoes which were inoculated with AMF, the size of plants in dry and wet condition, were so high with regard to the care of fertilize treatments .According to the results of this study, we can hope that in future we will be able to use Mycorrhiza instead of using chemical fertilizers. This method will improve the growth of potato plants and will prevent the chemical contamination of the farms.

The importance and position of water in economical, municipal, agricultural and industrial scopes is evident. Nevertheless, the shortage of the water resources, will duplicate the importance of protecting measures of clean water. Irrigation with treated municipal wastewater is considered an environmentally sound wastewater disposal practice compared to its direct disposal to the surface or ground water bodies. In addition, wastewater is a valuable source of plant nutrients and organic matter needed for maintaining fertility and productivity levels of the soil. In this research, the effects of treated wastewater of Kerman city on chemical characteristics of soil using drip and furrow irrigations were investigated. Irrigation period was 6 days and lasted for 6 months. Samplings were done for the middle part of furrows in two depths of 0-30 cm and 30-60 cm in four irrigation treatments. The experiments were conducted in a split plot design based on the Randomized Complete Block Design (RCBD) with three replications. Results showed the reduction of pH, and increment of salinity, phosphate phosphorus, nitrate nitrogen and heavy metals of using wastewater compare to well water. Moreover, the results indicate the increasing of accumulation of heavy metals in soil depth applying furrow irrigation in comparison to drip irrigation.

Paleocene-Eocene Thermal Maximum (PETM) is a short-term climatic event that occurred about 56 million years ago, crucially affecting the global biological ecosystems, especially calcareous nannoplankton. Analysis of the fossilized remains of calcareous nannoplanktons in the sedimentary successions deposited during the said interval of time in Zagros Sedimentary Basin points to the presence of a rich nannofloral assemblage consisting of 112 species belonging to 31 genera. The observed distribution and calculated abundances of calcareous nannofossils confirm occurrence of PETM event in the area under investigation. The findings which point towards sudden release of carbon to the ocean-atmosphere system, indicate a decrease in pH of oceanic waters leading to shallowing of Carbonate Compensation Depth (CCD) and dissolution of limestones. This is reflected in the diversity and abundance of nannofloral assemblages due to the availability of carbon dioxide and increased rate of calcification process. The phenomenon also brought about a reduction in the oxygen content of atmosphere and global warming. Slower rate of carbon release during PETM as compared to that of present day, points to the possibility of a more catastrophic acidification of today’s oceans. Moreover,expected release of about 2000 pg carbon during the next 200 years (based on current trends) will result in a 2000-4000 pg increase of additional carbon in the oceanic sediments which is much in excess of what happened during PETM, thus accelerating therate of current global warming.

Wind is one of the climate parameters that architecture and environmental designer have paid attention to itfrom past time till now. In some cases, wind flow in the urban open space is useful and it help to the natural ventilation and it causes improve human comfort and reduce energy consumption. On other hands in some cases wind flow causes reduce human comfort in urban open spaces. So in each climate architectures and other designer can decide how wind flow should control in the urban open spaces according to the wind comfort. In this article we want according to the Isfahan climate dates and statistical calculations and compared with wind comfort criteria, find the mount of the wind comfort criteria in the urban open spaces in Isfahan. So in this study three criteria consist of “Wind Chill Factor”, “Beaufort Factor” and “Penwarden Factor” was used. The resultsof this study shown that wind flow just in the January cans reduce human comfort in open spaces and in the design of these spaces have to reduce the amount of the wind flow in this month. In other hand, in the June, July, August months, if the wind flow increase till 6m/s, the human comfort can improve. Wind flow in other month of year has favorable position and it can make human comfort so it is better that the wind speed keeps in the open space and street in this months.

According to global statistics, dementia disease, as the most critical problem of the 21 st centuries, a high percentage of costs allocated to the communities. This is while, according to the country's growing elderly population, an all-round attention to the problems of this disease is needed and it is part of the mission specialists on urban planning and architecture, so you must create an appropriate urban spaces, urban spaces to encourage patients to attend and actually prevented the isolation of patients were at home. The "environment" is considered an important factor in achieving this goal. In this study, after examining the concepts of urban design and urban spaces and the quality characteristics of psychiatric patients, especially patients with dementia and their needs have been studied and the necessity of environmental psychology in order to address these needs in urban areas and ultimately the most effective strategies in environment and quality components make it executable. The presence of dementia patients has been proposed for designing urban spaces desirable area desired to be provided to meet those needs.