نشریه اکوبیولوژی تالاب
سال یازدهم شماره 2 (پیاپی 40، تابستان 1398)

Climate change and human activities have increased negative pressure on natural ecosystems. Wetlands are such ecosystems that widely affected by these negative changes. Birds as a part of wildlife in a wetland have damaged by destruction of wetlands, so, a large group of them, are at risk of extinction. Habitat destruction in wetlands in arid and semi-arid areas has more negative effects on these birds because of water limitation in these regions. Hamun wetland on the boundary of Iran and Afghanistan is one of the vulnerable ecosystems that are faced by the effects of drought and human activities. Since this wetland has international importance for breeding and resting of migrant water birds, determination of habitat requirements and spatial distribution of water birds in this wetland are essential. In this study, by field studies and Maximum Entropy model, suitable habitats of water birds and waders were determined in 2015. Based on these results, southern parts of Hamun_e_ Saberi and some parts of Hamun_e_ Himand and Pouzak were determined as suitable habitat for water birds. Results of this paper are useful for conservation activities in this wetland.

High demand to wood and its products followed by decrease in forests area leads to give special importance to forest plantation. This study aimed to consider the impact of 20-year pure and mixed plantation of Eucalypt and Arizona cypress on above-ground growth features and soil properties in Seymareh Park in Ilam province, Iran. A complete randomly design was conducted with two treatments of pure plantation of Eucalypt, and mixed plantation of Eucalypt and Arizona cypress with three repetitions in 2014. In total, 42 sample plots were determined. The quantity characteristics were as follow: diameter at breast height (DBH), diameter of collar (DC), tree height (H), crown coverage (CC), slender coefficient (SC), Form quotient, tree volume (V), leaf dry mass (LDM), leaf area index (LAI), total growth ring width (TWR), and wood density (WD). In order to determine the chemical and physical properties of soil, three soil samples from each plot at the depth of 0 to 30 cm were collected and a mixed sample was transformed to the laboratory for the further works. The results showed that DBH, DC, H, V, TWR of Eucalypt in pure plantation was significantly higher than those of mixed plantation (P< 0.05). According to the analysis of main components and growth features of Eucalyptus, two groups were separated across first and second axes as each of them indicated high adaptation with place of sampling (mixed or pure mass). The measuring soil properties between two plantations showed that potassium, nitrogen, phosphor, organic carbon and saturation moisture content were significantly more than that in pure plantation.

Wetlands are some of the most beautiful landscapes that can be creator or stimulus of a development process for sustainable development in local communities and ecosystems if they are properly planned and managed for tourism development. Geo-tourism or geological tourism has been used as the equivalent for environmental tourism in recent years. Environmental tourism is a natural resource-based tourism market. Considering the fact that the hunting and fishing area of 11 Poldokhtar wetlands has a high potential in the field of tourism, creating the necessary infrastructure and introducing it as a geo-tourism attraction pole in the province with regard to the high power of these wetlands, Tourism and help to grow and expand the economy, increase income and raise the level of employment in the region is necessary. In order to determine the Geo-tourism sites, it is necessary to identify and evaluate susceptible sites. Therefore, in this research, two Rhineard qualitative models and Pereira quantitative model were used to evaluate the tourist potential of Poldokhtar wetlands. Based on the results of the Pereira model, the geomorphologic characteristics of the wetlands (4.49), visibility (2.65), protection value (2.15) and applied value (4.05) were about 86.6, 58.8, 71.6, and 57.8 Percent of the standard pattern surface. Based on the Rhineard quality model, under the indicators of scientific value, the level of sustainability with the score of 506 and the long-standing geography with 1 point, with a good and excellent quality level and below the value added indicators, are below the ecological index (good), Cultural (good), beauty (good) and economical (weak). The results of this study indicate that the hunting and fishing area of Poldokhtar wetlands requires strengthening the conservation status, changing the attitude of the current islands management and turning to the management of the ecosystem, creating infrastructure for tourism facilities.

International Shadegan wetland is the one of large Iranian wetlands. This wetland is located in south west Iran in Khuzestan province. Dams construction and not observing of wetland water needs, breeding fish, Saccharum industry sewages, oil pipes crossing, activity of 30 petrochemical unit and urban wastes discharge, entered this unique wetland, from 1992 in red list of international wetlands (Montreo list). Water of this international wetland that to be in 5 degrees in terms of registered degrees in UNESCO, supply from Jarrahi and Karun and also Persian Gulf tide that in spite of seasonal of its fresh water section, wetland salt water because of connection to Persian Gulf is continual. Absorption and removal of reactive red and reactive blue dyes that enter to Shadegan wetland with chitosan, are investigated. This study carried out in the interval of February 2018 until June 2018. Anionic dyes like reactive red and reactive blue that used in this research, belong to the sulphunated food azo dyes and dissolved in water. This matter use for coloring of different products like sugar cane, Nutritional supplement, soft drinks, jelly, different fruit juices and etc. We can see from results that the maximum removal percentage of reactive red and reactive blue, with the chitosan in the pH =5 and in the upper and lower pH values, the yield is decreased. It can be seen from results that the maximum removal for reactive red in the 50 min and for reactive blue is in the 40 min for chitosan absorbent.

Flocculation of metals is one of the most important estuarine processes that occur due to the mixing of seawater and river water and colloidal metals undergo this process come in the form of flocculants. Due to the important role of flocculation process in producing suitable food sources for aquatic organisms and reducing the amount of input pollution into aquatic environments, the present study examines the mechanism of heavy metals flocculation in the estuary of the Jarahi River. In the present research, flocculation of dissolved Cd, Ni, Zn, Pb and Mn in the 5 aquariums with salinities ranging from 1 to 3‰ during laboratory mixing of Jarahi River water with the Musa Estuary water (2017) was studied for the first time in 2017. After preparation of samples, the concentrations of elements were measured by ICP. Cluster analysis, a statistical method, was used to determine the effect of chemical and physical parameters of estuarine environment on the flocculation process. The average final flocculation rates of metals are in the following order: Cd (94.9%) > Zn (85.5%) >Pb (58%) >Ni (19%) >Mn (11%). The highest flocculation of metals occurred between salinities of 1 to 2%. Due to the flocculation of trace metals during the estuarine mixing, about on average 64.7, 65.8, 231.7, 52 and 61.4 ton/year of Cd, Ni, Zn, Pb and Mn, respectively, were removed from the river water. Statistical analysis showed that the flocculation rates of Ni, Zn, Pb and Mn are controlled by the same factor. Moreover, it was found that all the investigated parameters (electrical conductivity, salinity, potential reduction, sulfate, chloride and pH) control the flocculation of cadmium but do not play any role in the flocculation of other studied metals (Ni, Zn, Pb and Mn).

Heavy metals tend to be adsorbed and accumulated in sediments as opposed to water or suspended solids. Sediments and biota bodis can act as a final sink for heavy metals in the aquatic environments. They accumulate through the food chain posing potential biological and ecological risks. Therefore, research on the heavy metal concentrations in aquatic ecosystems can help to protect human health and reduce the risks of heavy metal contamination. In this study, the contamination of heavy metals (Fe, Zn, Mn, Cu, Ni, Pb, Cd and Co) in surface sediments (0–5 cm) from 16 stations within four river intertidal zones (Neka, Tajan, Siahrood and Talar) were sampled and analyzed for metal contamination assessment in summer 2016. Results show that the mean concentration (mg kg-1) of heavy metals in surface sediment samples followed the order; Fe (23300.00) >Zn (2028.87) >Mn (701.25) >Ni (36.77) >Pb (25.77) >Cu (19.62) >Co (18.62) >Cd (5.62). The mean concentration levels of the heavy metals Pb, Zn and Cd were more than mean background value. The statistical analyses showed that concentration of elements Fe, Mn, Co and Cu in the Siahrood River, Cd in Neka River and Zn in Tajan River is different (P<0.05). Application of contamination factor (Cf), potential ecological risk factor of individual metals (Er), enrichment factor (EF) and geo-accumulation index (Igeo) showed that the highest value of the above factors belongs to cadmium element. Also an assessment potential ecological risk index (RI), contamination degree (Cd) and pollution load index (PLI) suggests a considerable to very high ecological risk in Neka River. In addition to revealing potential ecological risks due to cadmium and other elements, our investigation markedly highlighted anthropogenic control over sediment quality deterioration and some immediate sediment quality management strategies are needed to remediate and control river bed contamination.

Sediments are one of the biological indicators of the accumulation of heavy metals in aquatic ecosystems, which, due to the stability of a region, can well measure pollution. This research was conducted in 2018 with the aim of investigating heavy metals of Cobalt, Chromium, Manganese, Selenium and Molybdenum in sediments of Hooralazim wetland in Khuzestan province. A total of 27 sediment samples from 3 stations with 9 replications were prepared according to the ASTM D2488 standard. To measure heavy metals the ICP-OES Varian 710-ES model was used. The highest amount of Cobalt, Chromium and Selenium in the deposits of Hooralazim Wetland was obtained respectively 0.019, 93.39 and 29.45 mg/Kg at the third station and Manganese and Molybdenum were 451.12 and 0.88 respectively at the second station. The lowest values ​​of heavy metals were Cobalt, Manganese and Selenium in the sediments at the first station, but the lowest Chromium concentration at the second station and Molybdenum was observed at the third station. The contamination of Cobalt, Chromium, Manganese and Molybdenum was less than 1, indicating a low contamination of these metals. Regarding Selenium metal, the contamination factor higher than 6 was found to indicate the severe contamination of the metal in sediments. Therefore, according to the results, it can be stated that Selenium is the most important metal contaminant than Cobalt, Chromium, Manganese and Molybdenum. Cobalt metal enrichment factor showed the low pollution level and Chromium, Selenium, Molybdenum and Manganese metals showed high level of contamination, which can be said these metals had origin of human. According to the ecological risk assessment of Cobalt, Chromium, and Molybdenum metals in Hooralazim wetland sediments and ecological risk factors they were classified into low ecological risk potential.

Precise study of geophysical and ecological characteristics of benthic habitats is very important, because the seabed type of these habitats has close relationship with presence or absence of particular benthic species as well as with their distribution in the benthic communities. The aim of this study was Investigation of Relationship between Ecogeomorphology and Granulometry of Bed Sediments and evaluates the ecological macrobenthos stations sampled, study of environmental factors temperature, electrical conductivity, salinity, acidity (pH) and dissolved oxygen (DO) in River Bahmanshir respectively. This project was during two seasons in the winter of 2011 and summer of 2011 and in the three parts elementary, middle and end of Bahmanshir River. Samples were transported to the environmental laboratory in Khorramshahr University of Marine Science and Technology. After the laboratory tests, the results were analyzed using the SPSS statistical software. Overall in this study, six species belonging to the class Polychaeta (Nephtys sp. Nereis sp.Capitellacapitata), crustaceans (Sphaeroma sp.), Gastropod (Triphora sp.) And nematodes (Nematode sp.) were observed. Fine- grained sediments in the study area forming particles (mμ063 / 0>). With increasing depth (200 meters) grading scale is finer and more organic substrate. study also suggests that the aggregation of clay-silt particles were deposited. The results also show that the percentage of coarse particles of silt and clay in the summer has increased, which can cause it to flow from the river in the summer Bahmanshir.