فصلنامه محیط شناسی
سال سی‌ام شماره 4 (پیاپی 36، زمستان 1383)

The first greenhouse estate of the country in Guilan province, Rasht city, in 400ha is planned. Two important considerations about greenhouse estate are intensive production and cumulative impacts.The intensive management of plant growing conditions in greenhouse result in yields of greenhouse crops several times that of giled crops.At the same time, greenhouses utilize high level of input and generate more waste as a result of intensive production. In addition, greenhouse estate would be the sum of many greenhouses with relative infrastructure and activities that the effects are aggragted in the same area as environmental cumulative effects. Results of environmental impact assessment (applying modified Leopold matrix method) illustrate that %9 of activities including fertilization, disinfection, pest and disease control, runoff, human sewage, solid wasts, storing of fuel and possible accidents, and %5 of environmental factors including soil chemical quality, health and ground water, will be could cause sever impact. Finally, this project only with considering corrective measures and mitigation plans could be accepted.

Waste materials are increasingly produced by different populations and societies and consequently have great impacts on the environment. Municipal waste waters with their various pollutants and high volumes have intensive and extensive effects on environment as well.Nutrient matters (N&P) have important role on the aquatic ecosystems and their balance. Where as in biological processes various agents are effective on efficiency of process, in this study the effects of C/N and COD/P ratios on the efficiency of nutrient matters (P&N) removal was determined by sequencing batch reactors with activated sludge process.An analytical-descriptive and cross-sectional study was performed on a unit sequencing batch reactor with 18 liter useful volume, feded with waste water in a waste water treatment plant in Tehran. The reason for choosing a municipal wastewater is that the results of the study is applicable to different cities with partial changes.The result showed that with increase of C/N ratio from 8.5 to 14.5, residual nitrate in effluent decreased from 12.3 mg/l to 4.3 mg/l and with increase of COD/P ratio from 31.4 to 46.99, the efficiency of phosphorous removal increased from %56 to %71. It indicates that sequencing batch reactor operating with high load of organic matters is highly capable to remove nutrient matters. Also the effect of temperature on efficiency of Phosphorus removal showed that, minimum of phosphorus removal was been take placed in 10 oC. Furthemore we showed that this efficiency in uppel from 10OC and lower than this temperature has not significant difference.

Soil pollution and accumulation of heavy metals in crops in the industrial areas are the most important bioenvironmental problems that threaten the life of plants, animals and human. The objective of this study was to determine Fe, Zn and Pb distribution in soil and crops shoots around the Mobarakeh Steel plant. In this study, we separated 50 zones based on soil maps and taking into consideration dominant wind direction (south-western to north-eastern). In each zone, soil were sampled at 0-5, 5-10, 10-20 and 20-40 cm depths (200 samples) and DTPA-extractable concentrations of Fe, Zn and Pb were determined in soil samples. Also 36 plant samples from shoots of 19 main crops were collected in the region and the concentrations of heavy metals were determined in crops samples. Results showed that, the maximum DTPA-extractable concentrations of Fe were in two points at southeast of the plant in 0-5 cm layer (224.4 and 221.2 mg/kg.soil respectively). The maximum DTPA-extractable concentrations of Zn and Pb were in southeast of the plant in 0-5 cm layer (16 and 14.3 mg/kg.soil respectively). The maximum concentrations of Fe in shoots of rice, wheat and bean in southeast of the plant were 2290, 1710 and 2006.7 respectively that were higher than the USEPA standards (100 mg/kg.dry.matter). The maximum concentration of Zn in shoot of tomato in north of the plant was 493.3 mg/kg.dry.matter that was higher than the USEPA standards (20 mg/kg.dry.matter).

Water is a life sustaining and scarce resource, whose quality for human consumption is of paramount importance. Physical and chemical properties which is including purity, clarity, softness, salinity and lack or very low concentration of added elements constitute the elusive "water quality".Copper and Lead are two elements that may contaminate the drinking water and their concentrations beyond standard levels may cause health hazards.In this project the concentration of these two elements in the drinking water of Tehran has been measured using the atomic absorption spectrometry technique.This measurement has been carried out on the inlet and outlet of the four water treatment plants as well as 180 samples that were taken from variouse geographical location throughout the piping network that feeds the city of Tehran. Water samples were taken from cold and hot water taps as well as from the boiled water remaining in the teapots.The concentration of the Copper in the cold and hot water taps and in the boiled water were 6.2, 8.2 and 4.0 ng/ml respectively.Likewise the Lead concentration in the cold and hot water pipes and in the boiled water were 1.1, 1.2 and 0.7 ng/ml respectively.Based on these figures and the Iranian standards for the concentration of these two elements in the drinking water it is shown that Copper concentration is well below the standard level of 50 ng/ml. On the other hand the Lead concentration in the drinking water exceeds the preferred standard Level of zero in Iran.

The fuel loss at gas stations is one of the main sources of volatile organic compounds in the ambient air. The study shows 52000 liter of gasoline per day is lost from the gas stations across the city of Tehran. Each station losses approximately 415 liters per day, which makes the area on and around the gas stations polluted. In this study, the BTEX were measured at two gas stations and 20 main cross streets, during summer and winter. The results indicated Benzene concentration is higher than the ambient air limits for both the gas station areas as well as the 20 measured places across the city. The average concentration of Benzene in the gas stations were between 8 to 16 times higher than the threshold limit value – time weight average for work area, and 250 to 500 times higher than the ambient air standard. The average concentration of Benzene near the traffic areas were 60 times higher than ambient air standard. Also we studied the ways to control gasoline vapor. Cooling the vapor has been experimented. The results show, 50% of vapor in 0 – 60C could be recycled.

Migratory waterfowl have considerable role in economic and social status of northern Iran especially Gilan province. This survey was carried out to determine abundance and diversity of hunted waterfowl in this area. Investigation on number of migratory waterfowls was conducted using Total Count Method from January 5, 2002 till February 24, 2002 synchronized with mid winter waterfowl count (MWC), Wetlands International. Results of counting migratory waterfowls during this period declared 607914 birds form 12 family. Also 393693 individual of 42 species and 8 family were harvested form aquatic ecosystems of Gilan during the study period and Anatidae family was the most abundant hunted group represented 249686 individual of 15 different species. In general, the harvested birds value was about Euro 3771210 and Mallard Anas platyrhynchos was the most valuable species about Euro 1312870.

This study which is on reproduction and breeding of Jebeer Gazzelle, one of the endangered species in Iran, was launched through live capturing of five heads (two males and three females) from the wildlife sanctuary in Naybandan, Tabas.The live-captured Jebeers were transferred to a thirty hectares fenced area in Shir – Ahmad, Sabzevar. The biological and behavioral indices of Jebeer species such as: feeding, mating, reproductivity, death rate, population growth, as well as their behavior at the sight of human beings are discussed in this paper. The study procedures which were completed within a period of five years have demonstrated that the sex distribution among the lambs born each year is not equal. Also, the birth rate and death rate and the population growth have been estimated for each year. Territorialism among the male ones in the mating season resulted in brutal fighting and subsequently the death of the young males. Females matured at the age of six months and the first delivery was observed at the age of eleven months. Generally speaking, the population growth of Jebeers in the fenced area was significant except for the first years, however, their high death rate inhibited the population growth during the first years of their transfer.

Gaduk is an area between the two cities of Veresk and Firuzkooh in Centeral Elborz with an area of 3113 ha and two water basins in northeast and southwest. 406 species, subspecies and varities are recognized in this area. Vegetation of the area is divided into three main formations: Dwarf scrub & thorn cushion, Mixed scrubland with scattered trees, Broad leaves shrub & trees and woodland.The 406 determind species and subspecies belong to 59 families and 236 genera. Analysis of plants based on life form in each formation shows that in the formation Dwarf scrub & thorn cushion, hemicrypthophytes (55/55%), and camephytes (16.16%); in the formation of Mixed scrubland with scattered trees hemicryptophytes 62% and therophytes (13.8%) and in the formation of Broad leaves shrub & trees and woodland hemicryptophytes (61.1%) and phanerophytes (15.34%) are the main life forms of vegetation types. From phytogeographical point of view, the formation of Dwarf scrub & thorn cushin with (63.8%) Irano-Touranian elements, the formation Mixed scrubland with scattered trees with (55%) Irano-Touranian elements and the formation Broad leaves shrub & trees and woodland, with (48%) Euro-Siberian elements show the most presence. The endemic rate of the area was indicated as 37 species and subspecies to Iran, 29 endemic species to Elborz and 2 local endemic species grow in the studied area.

Based on Udvardy system of classification in world network maps of biosphere reserves of 1995, the situation of the Miankaleh biosphere reserve of Iran, located in the southern coast of the Caspian Sea, was expressed as rainy and temperate forests and semi-tropical, whereas in 1975 he called it as mixed mountainous biome system. As the Udvardy classification, in large scale, is for national and regional use, it may not be able to separate the various kinds of existing habitats in a Biogeographical Province. T test the Udvardy classification theory and to investigate its probable disorder in it, by recognition of flora, the vegetation of the reserve has been ecologically studied. In the present research, the cluster analysis for classification of plant community and the ordination method for analysis of environmental (water table level and electrical conductivity of soil and water) relationship with plant communities have been used. The flora of the region, with over 200 species, with the origin of Euro- Siberian and Irano- Touranian, have been recognized and the presence of plant communities have been related to water table level and salinity of soil and water. Over 90 percent of plant species are annual grass type and permanent which are for non-mountaneous and proof of the second theory. It should be noticed that formation of plant communities of Miankaleh is more affected by watertable and salinities of water and soil. This means coastal and waterlogging regimes prevail. In relation to Udvardy theory it seems that, based on the existing and paleoecological documents of 1905, the place of the biosphere reserve of Miankaleh, as a unit, was a rainy forests biome. Before fragmentation of Miankaleh winter and Elborz mountainous habitats, due to the urban developments, in the present time, determination of the situation of Miankaleh reserve is difficult due to climatic –ecological changes.

In this paper, vegetation were studied with Anglo-American approach in Ghamisheleh Marivan. In this approach, vegetation samples which could be defined as plant species by their distribution, could be considered as groups. Systematic-random sampling with 76 plots and 256 m2 in area, was selected. Combined methods of cluster analysis, two way indicator species analysis and similarity indices were used for the determination of ecological species groups. The results of this study showed that there are 6 ecological species groups in the region. Indicator species of these groups are:Quercus libani, Quercus infectoria, Pyrus syriaca, Pistacia atlantica, Trifolium campestre and Teucrium polium.

Dodangeh and Chardangeh wildlife refuge(16200 ha) is a mountainous area in 95 KM. SE Sari (360 4' – 10' N, 530 20' – 40' E). The ecological characteristics of the area is diverse. The climate of the area in the altitude 800-2000 meter is cold and wet, and in 2000-2800 meter is cold and semi-arid, according to Emberger climagram.The vegetation of the area has been studied according to the Fery & Probst vegetation classification and land use Atlas of Mazindaran Province (1:250000), and field observations in the scale of 1:50000.Five plant formations including closed forest (closed-deciduous montane forest), wood land (cold-deciduous broad-leaved montane wood land and evergreen needle-leaved wood land resistant to cold), shrub land (cold-deciduous scrub without evergreen, cold deciduous open xenomorphic scrub and evergreen needle leaved scrub), open thorn-cushing formation and grassland have been recognized. The characteristic species, altitude distribution range and picture for each formation have been presented.

The main objective of this paper was to study different social, and economic factors affecting people's willingness to pay (WTP) and their attitudes toward the environmental conservation in Tabriz, a metropolitan city being located on north west of the country. The research carried out, consisted of two main parts, namely, the examination of existing environmental, social, and economic conditions of the study area, and the analysis of survey and interview results. The contingent valuation method (CVM) was applied in order to estimate the amount of WTP. The results showed immense amounts of WTP averaging to 41400(1) Rials per month per person, and found some interesting factors determining people's participation in environmental conservation.