PLANT AND ECOSYSTEM
Year:2011 | Volume:7 | Issue:28|Papers Count:9

The composition of real floristic associations is as the result of the influence of environmental factors and in potential reaction of plant with their ecological ability. The vegetation of the area was studied by Braun-Blanquet method. The study of region is in 40 kilometers north of Gorgan in 37o14’4” N and 54o29’8” E longitude and 10 meters altitude from the sea level. 4 releves omitted, because they were mostly like the other releves and 64 releves remained and 27 species analysed. Phytisociological data analyzed with factorial correspondante analysis (FCA) and the hierarchical ascendant corresponding (HCA) method. Finally 11 associations were distinguished in the area. These associations are as follow1. Aveno ludoviciana - Aeluropodetum lagopoidis2. Aeluropodo lagopoidis - Artemisietum sieberi3. Puccinellietum distantis4. Plantaginetum coronoputae5. Salicornio europaeae - Halocnemetum strobilacei6. Frankenietum hirsutae7. Frankenietum pulverulentae8. Salsolo turcomanicae - Halocnemetum strobilacei9. Polypogono monspeliensis - Halocnemetum strobilacei10. Halocnemetum strobilacei11. Zingerio trichopodae - Halocnemetum strobilaceithe distribution of the plant association in the intchebroon was mainly affected by salinity moisture and texture of soil.

None hunting area Soofikam is located in North East of Golestan Province. This region is located between longitude 54o29’10” N and latitudes 37o13’26” E. Covers an area of 30000 hectars. Minimum and maximum elevation of study area -16 and 40 meters, respectively. The aim of this research was to identify the plant species, introducing the flora, determination of life forms and geographical distribution of species in the area. For this purpose, plant samples were collected from different habitats of the area during growing seasons in 1387-1388. In this study, 173 species was collected and identified. These species belonged to 40 families and 127 genera. The following families had the highest number of species: poaceae (26 species), Asteraceae (23 species) and Chenopodiaceae (20 Species). Therophytes with 100 species (57.88%) are the most frequent life form. Investigation on geographical distribution of species showed 44 species (26%) belong to Irano-Turanian region, 19.07% belong to IT, ES, M and 15.5% belong to IT, M.

The studies in the world showed that, in spite of using widely of EI30 index, it is as essential as rainfall erosivity factor, in many places, it is not reliable enough and it is necessary to determine the best erosivity factor and also appropriate maps in each region by using geographical condition for further management of farmlands. In this study 18 sediment and runoff plots in two attendance plough along the slope and plough vertical toslope (each of them by three attempts) in dry farming land use and in three classes of slope (0-12,12-20,20-40 percent) in Sohreyne Gharacherian in Zanjan province established. The amounts of runoff and sediment in each plot during fourteen rainfall events, which caused runoff and soil loss, monitored and estimated. The information of intensity and amount of rainfalls were recorded by using data loggers, which located in study station. According to the review of literature on the world, finally 45 rainfall erosivity indexes recognized. By writing a program in visual basic (VB), each of storm events analyzed and all of rainfall erosivity indexes for each of storms determined. The statistical studies between each of the indexes and soil loss amounts, by using SPSS program ware done. The final result showed that the I2 (Square of rainfall intensity average) was the best rainfall erosivity index and it had maximum correlation with soil loss amount in significant level. Finally, by introducing the processes of rainfall erosivity maps in ARC GIS software, the condition of using rainfall erosivity map, in soil erosion management was described.

This study designed to investigate the plant uptake of heavy metals from soils under effluent irrigation and sludge application. This research was done in 3 separated experiments in randomized complete block with 3 replications. For this purpose, five plots were made in Shoush, Wastewater Treatment Plant in south of Tehran. Physico-chemical properties of the soil in the plots were determined. Some plants such as watermelon, tomato, spinach, lettuce, cress, alfalfa, radish and basil were cultivated in the all plots. The main factor was irrigation with 5 different levels and the minor factors were plants. First plot was irrigated with pipe water as control plot, the second one with wastewater from Shoush Plant, the third one with pipe water and sludge, fourth plot with heavy metals solution and the last one with wastewater and sludge. After irrigation period, heavy metals like Ni, Pb, Fe, Cd, Zn and Cu were measured in the crops and the surface and layers of soils. The statistical results that indicated the use of sludge increased Fe, Ni, and Pb in spinach, alfalfa and radish. The use of wastewater for long time increased concentration of Ni and Cd in spinach. There wsa a significant difference for plants and irrigation (0.01).

In this study, clover plants were grown in soil-pots contaminated with a mixture of Cd (II), Cu (II), and Zn (II), (at 60 mg/kg each) at pHs of 4.8, 6 and 7.2. The plants were fertilized using a nutrient solution, which was adjusted appropriately to the same pH. Plants in the control treatment were grown in the absence of the heavy metals mixture. The growth of the control plants was the same at the three pHs studied and the heavy metal stressed plants also showed similar behavior at each pHs. There were statistically significant differences (P<0.01) between the shoot length of the control treatment plants and the length of plants grown in the presence of the heavy metal mixture. Under the effects of the heavy metal mixture, Cadmium was the most accumulated element in the shoot tissue, with 130, 125, and 115 ppm at pH 7.2, 4.8, and 6, respectively. Zinc was found to be second in accumulated concentrations with 108 ppm, 102 ppm, and 101 ppm at pH 7.2, 4.8, and 6, respectively; while copper was third. The maximum relative upta kes (element in plant/element in soil–water–solution) were found to be 3.12 times for cadmium, 7.08 times for zinc, and 2.38 times for copper.

The presence of heavy metals is counted as one of the most important enviromental stresses. In this research, the effects of different treatments of two heavy metals, Lead and Zinc on the growth and rate of Chlorophyll, sugar and protein were studied. The effects of different concentrations of ZnCl2 (5, 10, 15, 20 mM) and PbCl2 (0.5, 2.5, 4.5, 6.5, mM) on Soybean were examined. For this purpose, the seeds were transferred to flowerpots containing Loam – Clay soil after surface sterile. In each flowerpot 5 seeds were cultivated .For each treatment 4 repeats were considered. The duration of treatment period had continued for 14 days. The results showed that the stress of Pb caused the decrease in biomass weight. The stress of Zn terminated in decrease of biomass weight in all concentrations. The rate of Chlorophyll a, b and total Chlorophyll in comparison with control plant showed significant decrease in both treatments. The increase in sugar content except for the concentration of 0.5 mM Pb, was significant in comparison with control plant in other concentrations, but, in the stress of Zn, this increase had significant effect in all concentrations. The containing of protein in plants under treatment with Zn and Pb had significant increase in all concentrations. The obtained results of this research indicated that in comparison with Zn, Soybean had more tolerance to Pb. It seems that in short term stress of Zn and Pb, the plant decreases stress intensity with induction of fast response, but, in spite of definitions that exist for the tolerable plants of Zn and Pb, it does not seem to include Soybean from tolerable plants to these heavy metals.

As canola is a very important and valuable oil plant, it is essential to provide proper conditions to plant it. Based on observations, salicylic acid is a product of phenylpropanoids with effects like: strengthening the plant against pathogens, affecting the activities of the enzymes and genes expression, protecting the plant against soil and environment pollution. Thus, in order to study the effect of different levels of salicylic acid (0, 250, 500, 750 and 1000 micro molar) on three different cultivars of canola (okp, talae and Hyola), seeds were planted and treated under a factorial experiments in a randomized compelet block design with five treatments, four replicates and three cultivars in pot conditions. The results demonstrated that with the increase of salicylic acid levels, the stem and root lengths, wet and dry weights, leaf area, protein and proline contents were increased. The results showed that the cv. Talae was more outstanding in comparison with the other cultivars and the best concentration of salicylic acid in these experiments was 750 micro molar. Thus, salicylic acid can be used for better planting of canola because there would be an increase in photosynthesis and production.

In order to study the effect of plant density on yield and components of yield in four canola cultivars, an experiment was performed in the form of split plot on the basis of randomized complete block design with four replications at research station of Islamic Azad University Saveh Branch in 2008-2009 cropping season.The soil texture was sandy loam. Mean plot included three plant density (80, 100 and 120 plant/m2) and subplot was canola cultivars (Hayola 401, Hayola 308, Okpy and PF). The results indicated that maximum yield obtained in 100 and 80 density respectibily (plants/m2) for Hayola 401. Increase in plant density from 80 to 120 plants/m2 resulted in a significant increase in plant height and biological yield and reduce silique number in plant, side branch number, grain number in plants and harvest index. Plant density had not shown significant effect on grain number in silique and 1000 grain weight.

In this study, Rosa damascena genotypes collected from 10 provinces of Iran were compared for flower yield and components using randomized complete block design with three replications at Research Station of Homand Absard, Damavand, Iran. Flower yield, flower number per plant, petal weight, petal/flower weight ratio, plant height and plant canopy.Results were recorded. The data were subjected to ANOVA, mean comparison, analyses. Showed significant differences for the traits with the highest flower yield for Fars1. By using principal components analysis, the most important variable flower yield characters were identified. First two independent components accounted for 90% of total variation. The first principal component indicated that flower yield, petal weight petal /flower weight and plant height were important characterstics for classification. The results indicated that 1 and 2 components were known as flower yield and plant flower number components respectively. Based on ward's cluster analysis, entries were divided into three groups. In cluster number 1, genotypes including Fars1 had the highest values for flower yield.