نشریه محیط زیست طبیعی
سال شصت و هفتم شماره 4 (زمستان 1393)

The purpose of this study was to compare the heavy metal uptake of Cd in liver tissue of endemic fish Aphanius sophiae in the saltwater Eshtehard of Karaj and fresh water in laboratory conditions، the relationship between cadmium accumulation in the liver، the effect of salinity and different concentrations of Cd uptake. Sampling did randomly from Salt River in the spring and summer 2011. After 18 days storage and feeding in 4 aquarium tank with concentrations ppm (20، 10، 5، 0) cadmium، the fish were sampled. After biometry and sex determination، liver tissue was isolated and were dissolved with the wet acid digestion method، thus The concentrations of the Cd were measured using ICP-OES. In the analysis of samples taken from tanks containing salt water aquarium 24 percent were male and 76 percent of the samples were female and in fresh water aquarium 35% of the sample were male and 65 percent were female. The average length of fish in salt water 3/4 ± 0/3 and in fresh water 2/77 ± 0/17. Mortality percent after exposure to fresh water Aquarium was 56% and Mortality in salt water water did not observed during the test period. Regression analysis don''t show، the relationship between cadmium concentrations in liver and fish body length and age in saltwater and freshwater. The accumulation of cadmium in the liver in fresh water 1/47 more than the concentration in the saltwater. To examine differences in Cd accumulation in both freshwater and saltwater environments، T-test was performed، results showed no significant difference in Cd concentrations in the two environments. Environmental impact by using Split plot analysis in completely randomized design and Duncan test were investigated. Table Analysis of variance showed that there is no interaction between cadmium and salinity. Cadmium accumulation in fresh and salt water at all concentrations (except 20 freshwater) increased with increasing concentrations of cadmium.

Due to the different factors and complexity of their effects on healthy and sustainability of urban forest، this study has been tried by means of determining effective factors in ecosystem، and dividing Sorkhe Hesar man made forest park to homogeneous units according to natural factors (slope، aspect، high، soil depth، mixture and pure planting system) and human factors (amount of irrigation and outdoor recreation intensity)، has been investigated their effects on ecosystem sustainability. Deciduous quantity and quality including Fraxinus rotundifolia، Cercis siliquastrum، Platanus orientalis and Robinia pseudoacaia were studied. Evaluation criteria of homogeneous units were height، basal area، crown diameter، crown simultaneity، vitality، herbal layer density and canopy density. Analyses of results showed complexity of factors have been affected on site healthy and sustainability، while mixture and pure planting system، slope and soil depth are the most important limiting factors. In fact with decreasing the soil depth and increasing slope around more than 15 percent، site allocation to intensive recreation usage، would destroy intensely. Also، researches showed that in the similar condition Cercis siliquastrum is more sustainable than Fraxinus rotundifolia، Platanus orientalis and Robinia pseudoacaia.

This paper aims to detect occurred changes in vegetation cover of forested Helen protected area using extracted NDVIs from Bi-temporal multispectral images of Landsat TM. To do so، at first forest areas with low and moderate density cover were identified and separated on land use map. Then preprocessing applications including radiometric corrections were done on both 1990 and 2009 images. Also for calculating NDVIs، data on 4th (near-infrared) and 2nd (red) bands were extracted from both images. Finally، changes in vegetation cover from 1990 to 2009 were calculated using NDVI of the study area. Results show that density has increased in 12. 4% of the study area including 7. 5% in moderate and 4. 9% in low density areas. Moreover، in 0. 63% of the total area vegetation density was decreased 0. 17% out of which belongs to forested area with moderate density and 0. 46% to low dense. Taking into account precipitation and temperature trends during this period، these results might be related to increasing long term annual temperature and winter seasonal precipitation، respectively. Also، considering this area as a protected area from 1992 and implementing more protective affairs can be related to these outcomes.

Increasing in concentration of heavy metals such as Lead، Cadmium، Nickel، Chromium and Zinc cause considerable harmful effects on soil and environment. These elements are also hazardous to health of humans and wildlife. Petrochemical plants and refineries pollution increase the amount of carcinogenic and tratogenic compounds in environment. The main goal of recent paper is the studying of soil heavy metals pollution surrounding Isfahan refinery، power plant and petrochemical industries are located in margin of Ghamishlou wildlife refuge. In this study، 25 soil samples were collected from 105 km radius around the complex industries. Estimating the background values was executed by sampling rocks adjacent to soil sampling stations. Soil heavy metals were extracted with ISO11466 procedure، and were measured by flame AAS (Analyticjena-350). Geo-accumulation Index (Igeo) and Pollution Index (PIi) were determined and compared in different sample sites. Igeo and PIi in soil samples found to be in order of Cd>Pb>Ni>Zn>Cr. The result shows، in comparison of Igeo with PIi، in the same pollutant concentration، Igeo classifies the pollution in lower qualitative classes. In addition، also mCd and IPI detect different results to classify pollution. According to mCd، there are eight point sample which categorize in moderate level of pollution while these points locate in low class with considering IPI. In this respect، mCd and IPI have shown same result in moderate and high pollution level. Finally، the result showed that margin of petrochemical، refinery and power plant، IPI classified integrating pollution in Moderate to high level but mCd categorized pollution in low to moderate classes.

The aim of this study was to investigate the allelopathic effects of Eucalyptus camaldulensis on germination and early seedling growth of Festuca arundinacea under laboratory condition in order to determine the effect of pretreatments on decreasing the destructive effects of allelopathic compounds. The chemical stimulators used in this study included 3 levels of gibberellic acid، 3 levels of salicylic acid and 5 levels of allelopathic compounds of Eucalyptus camaldulensis. Factorial test in the completely randomized design with four treatments was used to analyse the data. Results indicated that Eucalyptus camaldulensis extract had inhibitive effect on germination and early seedling growth of Festuca arundinacea. Early seedling growth of Festuca arundinacea increased by pretreatment of seeds in chemical stimulators. Interaction effects of allelopathic and pretreatment with chemical stimulators were significance on germination percentage and speed، root، shoot and plant length and seed vigor index.

Urban parks as public green space have played a unique and indispensable role in providing recreation opportunities and functions to urban populations. As a result of population growth and density، the sustainability of urban parks is a challenging management task. There exists a need to adopt effective management strategies for achieving the sustainable development and management of urban parks. In this study main and important Karaj city parks and their recreational problems were recognized by using of Limits of Acceptable Change (LAC) as management model. Also some indicators that influenced on visitor satisfaction were specified in these parks. Based on expert’s questionnaires، ten parks have identified as significant and important parks. Moreover experts introduced the important recreational problems in management، environment and social issues in these parks. 358 questionnaires by visitors completed and Cronbach'' s Alpha was calculated، 0. 8. Results show; Bower، Sport campus، Tap، Buffet، Healthy instruments and Washstand as management indicator، and population and intruder people as social indicator were selected as critical indicators. In fact، managers should quantify standard value for these indicators via visitor’s view and existing standard and then monitor them. Monitoring help manager to maintain desirable conditions in these parks so، visitors will be satisfied.

Biodiversity is being lost at an increased rate as a result of human activities. One of the major threats to biodiversity is infrastructural development such as roads which have important negative and some positive ecological effects on wild birds. In many cases، decreased bird densities have been observed in large zones adjacent to busy roads. Indices of diversity and birds’ correlation with traffic noise and other environmental variables were studied using a Systematic-Random sampling method in Golestan National Park. The sampling stations were selected at 76 points in various distances from the main road crossing the park. Redundancy Analysis (RDA) was used for determination of the measure of association between the birds and environmental variables such as noise level، temperature، number of vehicles and humidity. The equivalent sound level «LAeq»، effective width of road، number of vehicles and horn beeping، species diversity and distribution of birds in the study area and temperature and humidity comprised the variables recorded at the sampling stations. Some bird species such as woodpeckers، nuthatches، robins، chaffinches and blackbirds were most sensitive to sound level. In contrast، golden eagle showed more resistance to adverse effects of proximity to roads.

Determination of the best method to estimate the dispersion rate is very important to ensure accuracy of the computed data. The aim of this research is studying of transport length effects of dispersion of conservative tracer Nacl in soils with different texture using several solute transport models including Brigham، Fried-Combernous and solutions of the advection-dispersion equation with inverse CXTFIT application. Two types of sand (quicksand and gravel with medium-textured) with 4 different textures in the 3 soil columns lengths 25، 40 and 55 cm was used. Conservative tracer NaCl with constant concentration 3. 47 m. S/cm under one-dimensional steady flow was directed into the top of the soil column. The results showed that by increasing the length of columns the dispersion rate will be increased and in composite soil texture the dispersivity coefficient (α) was more than a homogeneous texture and grain. Comparison of three methods shows that by reducing the transport length the Brigham model and by increasing the transport length، the model base on CXTFIT code is better. In all cases، the results of Fried-Combernous model had a noticeable difference between the other two models.

The coastal areas are highly productive system that is degrading due to receiving huge amount of various pollutants. Despite of the important of north Caspian Sea estuaries the quality index of benthic fauna received less attention. In this survey the benthic population of 18 rivers estuaries in southern Caspian Sea were investigated. The benthic sampling and identification were conducted at eight points in each estuary in three periods of winter، spring and summer 2009. The Shannon Wiener diversity and the Hilsenhoff biotic indices were used for evaluation of environmental quality. The result of Shannon Wiener index values in various rivers indicates that Astara and Lemir had the lowest and highest diversity respectively. The station 1 and 2 in river showed the lowest and offshore stations 5، 6 and 7 the highest diversity values. According to Hilsenhoff biotic index for water quality classification، the stations of 1 and 2 with low quality were significantly difference with other stations. The quality of estuaries of Khotbesara، Navroud، Heshmatrud and Shirabad were strongly good and the other were slightly and moderately good condition. In generally، the quality of rivers in western region were better than the other regions، where they were characterized on the base of seasonal condition، biological properties of benthic fauna، morphology and watershed basin of the river.