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Environmental Resources Research - Volume:3 Issue: 2, Winter - Spring 2015

Journal of Environmental Resources Research
Volume:3 Issue: 2, Winter - Spring 2015

  • تاریخ انتشار: 1394/12/20
  • تعداد عناوین: 7
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  • F. Mohebbi, A. Mohsenpour Azari, R. Ahmadi, M. Seidgar, B. Mostafazadeh, S. Ganji Pages 111-120
    Artemia is the most widespread live food used in the production of different stages of many aquaculture organisms. It is a non-selective filter feeding organism. Generally, microalgae are the most favorable feeds for Artemia, particularly when the algal species have suitable size, digestibility and nutrient values. This study was performed to compare the efficiency of three microalgae namely Dunaliella tertiolecta, Tetraselmis suecica and Nannochloropsis oculata for growth, survival and reproduction efficiency of Artemia urmiana in laboratory conditions. Artemia cysts were harvested from Urmia Lake and hatched according to standard methods. Live microalgae were cultured using the f/2 culture medium. Artemia survival was determined in treatments on days 8, 11, 14, 17 and 20. The results indicated a significant difference (P
    Keywords: Artemia urmiana, Microalgae, Length growth, Survival
  • S. Arekhi, B. Komaki Pages 121-138
    In Iran, desertification and landscape fragmentation are occurring as a result of demographic pressure, agricultural expansion, government policies and environmental factors such as drought. In this study, land use/cover and landscape change dynamics were investigated using satellite remote sensing (RS) and geographical information system (GIS). Landscape metrics were derived from land use/cover maps of the years 1977 and 2007 to indicate desertification in the study area, Ain-e-khosh region, Iran. Using Ain-e-khosh region as a case, this study aims to test landscape metrics capability in indicating desertification and analyzing temporal fragmentation changes. The temporal change analysis of fragmentation provides detailed characterization of desertification processes. Poor rangeland and barren land areas have become more fragmented and are characterized by the proliferation of much smaller and less connected patches. Results show a decrease in poor rangeland with an increase of agricultural land and sand plate areas. This suggests that anthropogenic activities driven by agricultural expansion are among the main causes of landscape fragmentation, leading to landscape degradation in the study area. This study demonstrates effectiveness of the RS and the GIS in detecting, assessing, mapping, monitoring and generating essential quantitative information on desertification.
    Keywords: Land use, cover types, Desertification, Landscape metrics, Ain, ekhosh
  • Z. Jafari, S. Mesri Pages 139-150
    One approach for reducing CO2 and increasing global carbon storage is carbon sequestration in soils. Watersheds are important biophysical and topographic units representing diverse ecosystems. This study aims to evaluate carbon sequestration in different land uses and its economic aspect in the Award watershed in Mazandaran Province. First, the boundary of the watershed was delineated and controlled by a field survey using GPS. Then, soil samples were selected randomly, taken from a depth of 0-30 cm for each land use (i.e., protected forest, open forest, rangelands, walnut gardens, mixed walnut–apple gardens, cereal croplands and frijol farmland). In total, 21 soil samples were taken from the study area. The selected parameters for analysis were the amount of carbon sequestration and certain soil properties (bulk density and organic carbon). Statistical analysis was performed using the SPSS.16.0 software. After assessment of the homogeneity of variance, analysis of variance (ANOVA) was performed followed by Duncan test at a significance level of 5%. Results demonstrated that the different land uses had different effects on the amount of carbon sequestration. The protected forests and cereal croplands had the highest and lowest carbon sequestration values, respectively. The overall amount of carbon sequestration in this watershed was estimated to be around 743,460 ton/ha.
    Keywords: Soil Carbon Sequestration, Land Uses, Watershed, Award
  • S. Abdollahi Pages 151-162
    Top predators are seen as keystone species of ecosystems. Knowledge of their habitat requirements is important for their conservation and for stability of the interacting wildlife communities. Recent environmental destructions have generally led to major habitat loss, so protection of the leopards’ habitats is regarded as very important. As such, habitat management based on modeling is strongly recommended as a practical solution. The goal of this study was to model the habitat of leopard Panthera pardus in Golestan National Park, where it is endangered, and determine the most important parameters affecting its habitat. In this paper, I apply the technique ecological niche modeling using genetic algorithm for rule-set prediction (GARP) to predict the distributions of this species. The results of this study showed that the distribution of the leopard is affected by altitude, and prey density. This research also provides an algorithm for sample data management, which could be used in modeling habitats of the similar species.
    Keywords: Leopard, Habitat modeling, GRAP, Golestan National Park
  • A. Ahmadpour, R. Yari, H. Shakib Pages 163-178
    In this study we developed and compared allometric relationships at the branch and at the whole plant levels of Artemisia sieberi in three grazing rate treatments in Miandasht Protected area, Iran. Three 100 m2 plots in nograzed, mildly-grazed and over-grazed sites were selected. In each plot four soil samples and five A. sieberi were randomly selected for laboratory analyses. For the soil samples, bulk density, soil water content, soil organic matter, pH, N and P were measured. For the plant samples, density (m-2), BD, CA and aboveground biomass were determined. Coarse and fine roots biomasses were measured in different soil depths in six soil sample columns taken per plot. Vegetation coverage was significantly lower for the overgrazed site than the two other sites but the density of A. sieberi was highest for the mildly-grazed site. Correlations among plant characteristics were significant for all three sites. All of the relationships were significant among the three sites. Coarse and fine roots biomasses were highest and lowest for the mildly- and over-grazed sites, respectively. Aboveground biomass was highest for the mildly-grazed and then for the no-grazed and over-grazed sites, respectively. Vertical distribution pattern of fine root biomass was not significantly different between the no-grazed and mildly-grazed sites (P > 0.05) but it was significantly different for the over-grazed site. This study also revealed that a light grazing in some cases may increase vegetation biomass.
    Keywords: Grazing intensity, Artemisia sieberi, Allometric equations
  • M.O. Hadiani Pages 179-190
    Climate changes is a natural phenomenon which have long-term sequence occurrence and return period. Impact of human activities may aggravate the effects of climate change in ecosystems, intensity of climate change trend and intervals between changes. Climate change can be reviewed using synoptical parameters as their indicators.In this study, based on average annual precipitation trend, temperature and relative humidity using De Martonne index were estimated for the recent 20-year period in Mazandaran Province, IRAN. Mathematical modeling of these changes and trends was conducted using regression models and Curve Expert software. Results showed meaningful changes in temperature and relative humidity during the selected period. The amount of precipitation did not show a significant trend, but a increase at the end of the period as compared with the beginning. There are also relative changes in De Martonne index during recent two decades, but no significant sign of climate change was spotted for this region.
    Keywords: Climate Change, Trend, Modeling, Predict, Mazandaran
  • S.H. Mirkarimi, M. Mohammadzadeh, S. Galdavi Pages 191-202
    For a natural destination to have a wide appeal, it should have sufficient capacity to cater for the needs of different types of users. This paper presents an assessment of the social carrying capacity of tourists visiting Daland Forest Park (DFP), Golestan, Iran. Social factors such as visitors’ perception about the Park’s safety, security and facilities were investigated to determine the level of social capacity and satisfaction. The Mann Whitney U test was used to investigate the likely differences between men and women regarding their social capacity. To do this, 168 questionnaires were filled out by the visitors of the Park during summer and fall 2012. The results showed that about 60% of the visitors preferred moderately crowded environments while the rest preferred low-crowded environments. The results also showed that the Park, in its current condition, does not provide the maximum level of the visitor’s satisfaction; therefore, some changes are needed in the area such as raising health care, welfare services and park’s safety. The results of this study reflect the status and expectations of the Park's visitors which can be useful to improve the level of visitor's satisfaction. A number of recommendations were provided to upgrade the quality of the recreation services of the Park. Furthermore, a general list of criteria was proposed to estimate social carrying capacity and visitors’ satisfaction that can be considered for other similar natural parks.
    Keywords: Forest parks, Tourism, Visitor's perception, Satisfaction, Safety