فهرست مطالب

ECOPERSIA - Volume:4 Issue:1, 2016
  • Volume:4 Issue:1, 2016
  • تاریخ انتشار: 1395/01/10
  • تعداد عناوین: 7
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  • Sedigheh Zarekia*, Ali Ashraf Jafari, Taghi Mirhaji Pages 1225-1238
    This research was aimed to evaluate the effect of planting season (autumn and spring) on ten accessions of two species of Astragalus effusus and Astragalus brachyodontus in the field condition (Homand Absard station, Damavand). After preparing the seedbed, plant species were planted on two lines in 2 m, which the spacing between lines of each accession was 0.5 m and spacing between lines of different accessions was 0.75 meters. The selected design for this study was a complete randomized block with three replications. Evaluation parameters were: forage production, canopy cover, plant height, seed yield, and number of flowering stems. Data were analyzed using split plot in time as year for each plot and mean comparisons were made using Duncan method.The results showed that planting seasons had a significant effect on the most of the measured parameters in different accessions. Autumn planting increased the forage production, height, canopy cover and the number of flowering stems. The species A. brachyodontus (Zereshk), A. brachyodontus (Alamut) and A. effusus (Dareh Shohada) had high production and canopy cover in autumn cultivation. Thus, the mentioned accessions are recommended for the improvement and development of rangelands and abandoned dry land farming with the same weather conditions of Homand Absard station.
    Keywords: Astragalus, Forage, Planting season, Rangeland, Semi arid
  • Mahdieh Ebrahimi*, Elham Miri Pages 1239-1249
    The study was conducted to investigate the effect of humic acid on germination properties of medicinal plants Borago officinalis and Cichorium intybus in a completely randomized design with five replications. Experimental treatment comprised the following dosage 0, 15, 30 g l-1. Results revealed that effect of humic acid on germination properties of C. intybus was significant (p
    Keywords: Allometric coefficient, Medical plants, Seed management
  • Seyed Parviz Jalili Kamju*, Rahman Khoshakhlagh, Yashar Shirinkhah, Saeed Samadi, Gholam Hossein Kiani Pages 1251-1267
    Wetlands as a situ for the growth of native plants, as a habitat for certain species of fish and aquatic birds; and because of their potential economic, cultural and recreational services are valuable heritage and so their protection and conservation is very essential. Mostly due to the absence of wetlands services valuation, the lack of special regulations and no guarantee for these properties, resources and services of wetlands are not utilized appropriately and destructed and evacuated in a free and unrestricted fashion which leads to inefficiency in use. The purpose of this study is the economic valuation of Gavkhony wetland ecosystem attributes, estimation of implicit price for attributes, impact assessment of socio- economic variables such as age, marriage, indigenous, family size and education on willingness to pay (WTP) and analyzing welfare and compensation variation due to variation of hypothetical policy change proposed. The approach being used is choice experiment that is a subset of choice modeling procedure and stated preference method. Data were collected from six different choice experiments provided in questionnaires and filled out by 500 randomly selected households in Isfahan and Varzaneh Cities in the spring and summer of 2013. Each questionnaire contained 72 hypothetical policies, 36 choice sets, 2442 observations and 7327 rows of data. In order to estimate visitors WTP for improving attribute levels for Gavkhony wetland, nested Logitech models and Hausman-acFadden test were used. This procedure was used on the basis of multinomial discrete choice analysis of preferences, Lancaster’s theory of value and the theory of random utility function. The Hausman-Mac-Fadden test results showed that cross elasticity between the first and third option is the same. Thus, these two options were placed in the second nest. Results also showed that the visitors had WTP for preserving forest diversity and vegetation of wetlands and its surrounding; preserve of natural habitats and organisms life of wetland (bird, fish and animals); wetland hygiene (preventing industrial, domestic effluent and water salinity); and increasing the water surface (increasing wetland water inlet). The value estimated for these four aspects correspondingly were 8636, 12584, 11553 and 4740 Rials. Some socio-economic variables such as gender, marriage, age, family expenditure, education and being native have a positive impact on willingness to pay. The Surplus welfare Results showed that in 72 hypothetical policies, option 1 has the most positive welfare and option 5 has the most negative welfare for users of Govkhony wetland. The surplus welfare results based on WTP estimated are providing important tools for policy making.
    Keywords: Valuation, Lancaster Theory, choice experiment, Nested logit model, Gavkhony Wetland
  • Anahita Shariat*, Mohammad Hassan Assareh Pages 1269-1282
    Effect of salt stress on pysiological and biochemical responses of seedlings of eight Eucalyptus species viz. E. kingsmillii, E. tetragona, E. salubris, E. occidentali, E. microtheca, E. camaldulensis, E. globules and E. sargentii were analyzed. Four month-old seedlings grown in greenhouse were watered by five levels of salt solution (0, 50, 100, 150 and 200 mM of NaCl) in five replications with a factorial experimental design. The results indicated that salinity delayed and inhibited seedling growth after one month and induced gradual declines in most of criteria such as leaf area, relative water contents and specific leaf area. Moreover, a significant reduction of chlorophyll a, b and total chlorophyll content was observed. Salinity stress raised the content of soluble sugars, proline and glycine betaine. Eucalyptus sargentii as the most tolerant species had the optimum growth up to 200 mM NaCl but E. globulus presented the most sensitive speciesto salinity stress. At 200 mM NaCl, proline and glycine beatine raised to 10.57 and 27 µg g-1 in tolerant species (E. sargentii), respectively while proline in sensitive species (E. globulus) dropped to 0.003 µg g-1. These results suggest that high tolerance of E. sargentii to salinity stress is closely related to lower specific leaf area and enhancement of compatible solutions such as proline, soluble sugar, glycine beatine. This would encourage the possibility of propagating E. sargentii in the southern coastal area of Iran. Future more, these results provided further biochemical support for the specific abiotic stress tolerance mechanism of Eucalyptus species.
    Keywords: Compatible solute, Osmoprotectants, Photosynthetic pigments, Salinity tolerance
  • Behnaz Attaeian* Pages 1283-1294
    Ongoing climate change has been a major global challenge since the1880s. Sequestration of carbon (C) in rangelands ecosystems could providea net carbon sink to offset increases in atmospheric C in global scale. This research is aimed at estimating the above-ground biomass carbon sequestration potential in Iran. For this purpose, total rangelands area and productivity data were extracted from annual reports of Agriculture Statistical Pocketbook (2006-2013) of the country. Then, productivity data was used to to calculate above-ground C storage per province. The maximum and minimum rangeland area were observed in Sistan and Baluchestan and Mazandaran (Nowshahr) provinces, respectively. Maximum aboveground biomass C storage was about 1.07 Mg C ha-1y-1was observed in Fars province. The minimum amount was occurred in Qom provinces with only 0.023 Mg C ha-1 y-1. In summary, mean carbon CO2 fixation was about 0.25 Mg C ha-1 y-1 in Iran’s rangelands from 2003 to 2013. Considering total rangeland area of the country (≈ 84.8 million hectare) and the productivity, 11770.011 Gg C y-1 carbon has been stored in aboveground biomass annually providing at least 5885 Gg organic C sequestration potential.
    Keywords: Carbon Fixation, Carbon sequestration, Iran, Productivity, Rangeland
  • Aliakbar Hedayati, Kheyrollah Khsoravi Katuli* Pages 1295-1312
    This study reports the incidence of histological alterations in the morphometric changes in liver and ovary of the Acanthopagrus latus collected from an urban stream impaired by anthropogenic activities and from a clean site (reference). Mercury concentration was determined using a standard cold vapor atomic absorption. The results showed that mercury concentration at the creek waters and specially sediments along Mahshahr coast, was higher than the other marine environment and in Zangi was lower than other sites of sampling. Several liver lesions were identified, including enlarged and lateral nuclei, nuclear degeneration and vacuolation, oncotic, apoptic, focal, massive, centrilobular and periportal necrosis, atrophy, lipidosis, hydropic and cloudy swelling, oval cell proliferation, cirrhosis, hemorrhage, macrophage aggregates, bile stagnation, dilation of sinusoid, intracellular edema and dark granules. Ovary histology revealing some changes in higher concentrations such as increase numbers of pre-vitellogenic oocytes, oocyte atresia and adhesion in the ovaries of females that sampled from sites with high concentration of mercury. In this study, existence of mercury in Mahshahr coast demonstrated and high incidence of histological alterations in the liver and ovary of A. latus is an evidence of the poor environmental quality of creek waters. Hence, histopathological changes that induced by the mercury, adversely affected the proper functioning of these organs in these fish.
    Keywords: Histopathology, Liver, Mercury, Ovary, Yellowfin seabream
  • Rezvan Alijani, Mehdi Vafakhah*, Arash Malekian Pages 1313-1330
    Drought is a complex natural phenomenon that can occur in any climate. Hydrologic drought in river flow of arid and semi-arid areas cause serious shortages threatens quality of life and impacts on the economy. Understanding this feature is then essential for the management of water resources. Hydrologic drought in the sense of deficient river flow is defined as the periods that river flow does not meet the needs of planned programs for system management.In the present study changes in the monthly discharge of 14 hydrometric stations throughout the Gorganroud watershed over 30-year period (1980-2010) was studied and the deficit flow was determined based on threshold level method and the results were analyzed. Results showed that periods of severe shortages have happened in very humid and semi-arid climates and downstream of the study area while longer periods (28 months) of low flows occurred in the arid climate. The trend of severity and persistence in the central stations of the watershed was increasing. Also shortages are occurring with greater frequency at the end of the study period and river flow shortage during the years 1998-99, 2007-2008, 2008-2009 and 2009-2010 has occurred in the most stations. So in these years, flow deficit has happened in 50, 85.9, 64.3 and 92.8 percent of the stations, respectively.
    Keywords: Flow deficit, Threshold level, Trend, Zonation, Gorganroud