Journal of Agricultural Sciences and Natural Resources
Year:2007 | Volume:14 | Issue:SUPPLEMENT (SPECIAL ISSUE NATURAL RESURCES)|Papers Count:21

Time of concentration is one of the most important parameters in hydrological studies which represents response time of a rainfall runoff system. One of the efforts in watershed management is construction of dams. In order to study the effects of dams on concentration time, Roodbar-gheshlagh watershed in Golestan province, in which watershed management activities were done, was considered. For this purpose, first longitudinal profile of channels with dams was drawn. Then the new slope and new length of channels with built structures was calculated. After that variation of concentration time in Kirpich formula was determined. The results of this study show that constructed structures in this watershed don't have important effects on increasing of concentration time and the amount of increasing was fewer than one percent in all cases.

A river changes frequently its cross sections, longitude profiles and its patterns by river erosion, transport processes and sediment deposition. Considering the changes of river morphology on the vicinity of a river is necessary for stabilize cultural and economical developments. Madarsoo River with longer than 105km is one of the most important rivers in Gorganroud watershed, which emanate from Esmaeilkhan and Tangrah mountains and finally joints to Gorgan River in Haji-Ghooshan village. The occurrence of a serious flood in August 2001 in Madarsoo river, which its discharge was in excess of 1650 m 3/s, caused severe changes on morphology of this river as worse as human and economic losses as aftermaths. In this research, to study the effects of this serious flood on the morphological characteristics of this river and to determine the amount of destroyed land around the river, a reach with 30-km length in the river was selected. In order to study the morphology of the river before the flood, some 1:50000-scale topographic maps, which were taken by Iranian National Geographical Organization (INGO) as well as Land Sat satellite images of July 2000, were used. Besides, the results of directly widths and depths measurements were used. This data were measured for any cross section with the intervals of 30 meter in length. These measurements were done in the year of 2000. Furthermore, for analyzing the morphological characteristics of the river after the flood, some others large scales maps (scale 1:2000, 1: 100 from the year of 2003) were used to retrieve plans and to measure parameters such as cross-sections and longitude profiles. In each section, the coefficients related to morphological parameters such as wave length, meander length, meander width, mean arch radius, frequency ranges and sinusitis coefficient were calculated. With considering the mean width and depth of the reach for two periods of before and after flood, it was estimated that more than 138 hectares of territory were destroyed. Statistical analysis showed that some morphological characteristics such as: wave length, meander length, mean arch radius and sinusitis coefficient, significantly changed after the flood. Meantime, more than 75% of the highly developed meanders were cracked or changed to the other types of meanders. Finally, similar researches for the other reaches of Gorgan River and other rivers of the country are suggested.

Studies on the spatial variability of soil properties in forest stand scale are limited. In this study, we demonstrated spatial soil variability with use of geostatistic technique in mixed beech forest soil. The main objectives were assessment of geostatistic technique to improve efficiency soil study. Soil samples from 0 to 15 cm depth were collected within 120 locations, on a 50*50 m systematic randomized grid besides 15 transect basis over a 16 ha field. Spatial variability for soil pH and organic matter revealed anisotropic variogram due to same range effect and sill. A geostatistical analysis showed that the soil properties (pH, organic matter) were spatially structured. The nugget-to-sill ratio indicates a strong spatial dependence for soil pH, and a moderate spatial dependence for organic matter. Interpolation using kriging showed a spatial similarity among the soil properties. Soil pH increased in the northwest quadrant of the research area where located in footslope. The result of cross validation with use of MAE, MBE and MSE revealed that the high accuracy of estimation for soil acidity and organic matter.  

Soil quality assessment is necessary for identifying the effects of different management systems on agricultural and natural ecosystems including range and forest degradation. Such studies can be useful for identifying sustainable practices in each region with the intention of preventing land degradation, providing sustainable crop production and environmental protection. The objectives of this study were to compare selected soil quality indices in four different land uses including a pasture with good vegetation cover (>20%), a pasture with poor vegetation cover (<10%), a currently being used dryland farm and a degraded dryland farm which is no longer used. Soil samples were taken from the depth of 0-10 cm in a completely randomized design with four replications. Results showed that organic matter decreases as a result of land use change and the highest decrease was 68.6% in dryland farm. In both dryland farm and degraded dryland farm, total N showed 43% decrease and available P content decreased 50% in dryland farm. Also, cation exchange capacity, microbial respiration, MWD and total porosity decreased and the highest decrease was 37.2%, 57.1%, 72.9% and 32.2%, respectively, in degraded dryland farm. Soil bulk density during land use change in pasture with good vegetation cover has increased considerably. The highest and the least infiltration rate were measured in the pasture with good vegetation cover and degraded dryland farm, respectively. In general, cultivation and disturbance of the pasture in the area have caused a great decrease in soil quality.

Tending operation of forest stands requires an exact understanding and knowledge of the stands natural characteristics and dominance of species in ecosystem. The amount of the light is the most important ecological factor changed by forest tending operations in order to improve the produced wood quality. Light competition is effective on crown expansion and the self-pruning in the forest stands through the light intensity reaching to different stories. The objective of this paper is determination of light competition effect on the trees crown expansion showing the conditions of photosynthesis, food production, self-pruning and obtaining trunk without branch in different stories. The crown specifications include tree height and trunk heights of 2142 trees were measured in the permanent area in series 1 of Shastkola forest. Beech was the dominant tree and maple was the thickest tree in the study area. The crown radiuses of six tree species (including Beech, Hornbeam, Ironwood, Alder, Maple and Persimmon tree) were measured and their mean was compared in eight cardinal and secondary directions. The crown expansion in the northwest direction is more than and in the southeast direction is less than other direction. Beech has a symmetrical crown in the under story because this species is shade tolerant and in the middle story has the maximum crown asymmetry. Unlike beech, hornbeam and ironwood have the maximum crown asymmetry in the under story because they are semi shade tolerant. The effect of light competition on self-pruning of tree in beech multistoried forests stand showed that over story trees have the minimum self-pruning and under story trees have the maximum self-pruning. Alder dose the best self-pruning and the maple tree does the worst self-pruning.

Ship Sturgeon (Acipenser nudiventris) is one of the economic and endangered species in Caspian Sea that has the least frequency among all immigrant Sturgeon. Genetic variation of Ship Sturgeon from the South coast of Caspian Sea was investigated using micro satellite. In this study 95 samples of Ship Sturgeon were collected from six locations on 3 regions, (First region: Kiashahr, Astara, Sefidrud, second region: Babolsar, Noshahr and the third: Gorgan). 4 SSR markers produced DNA bands in 5 loci, that 3 of them were polymorph. Range of observed and expected heterozygosity was (0.5-1) with average of 0.75 and (0.47-1) with average of 0.73 respectively. Analysis of Molecular Variance (AMOVA) indicated that almost all of the variance in data (%92, p£0.01) was within locations. Between locations variance was (%8, p£0.02). No difference was observed among regions (%0, p£0.93). Results also showed that inspite of reduction of fish stocks, there is high level of genetic variation in this species and it seems there is more than one population in south coast of Caspian Sea and serious attempt must be done for protection of these stocks. Results also showed that microsatellites have high ability for showing genetic variation.

In this research was studied the effects of probiotic bacillus on the feeding efficiency and carcass nutrient composition of Huso huso larvae using five blends of probiotic bacillus via bioencapsulation of Artemia urmiana nauplii in March 2006 for 10 days. This experiment was conducted in a completely random design in four treatments. The suspensions of blends of probiotic bacillus are used in three concentrations of (1x108, 2x108 and 3x108) batteries per liter in suspension of broth. Artemia nauplii were bioencapsulated by blends of probiotic bacillus for 10 hours and fedby Beluga larvae in experimental treatments. The controled treatments were fed on unbioencapsulated Artemia nauplii. The larves were fed 6 times a day, every 4 hours with bioencapsulated nauoplii. The results indicated that the probiotic bacillus had positive and significant effects on the protein efficiency ratio (PER), lipid efficiency ratio (LER), protein productive value (PPV) and carcass nitrogen deposition (CND) in experimental treatments in comparison with controled treatment (p<0.05) and also the levels of carcass dry matter, crude protein and ash significantly increased (p<0.05).The significant positive correlation observed between the levels of carcass dry matter, ash, gastero somatic index (GSI) with CFU/liter of probiotic bacillus in suspension of broth. The experiment indicated that the probiotic bacillus efficiently affected the feeding efficiency and the levels of carcass nutrient compositions in Huso huso larvae.

Wood of Brutian pine (pinus brutia Michx.) trees, used in this study collected from Kalaleh area, located in Golestan province. Mean fiber length measured in 3 and 6 year old Brutian pine stems showed significant difference at 1% level. According to Shiokura formula both stem were considered as juvenile wood. Extractive contents of 3 and 6 year old samples were 4.84% and 5.66% respectively, and were not found significant difference between them. Ash content of the two mentioned stems showed significant differences at 1% level. Lignin content of the wood dropped to 4.51% when going to older stem, and vice versa, cellulose content increased to 14.27% in the same trend. By keeping constant sulfidity (25%) as well as other cooking conditions in Kraft pulping process of the two stems, it was found, that increasing 30 minutes cooking time could not affect significantly on the pulp yield. Gradually increase of effective alkaline and cooking time showed, the former affected on pulping process much more than the latter. Optimum cooking time in 3 year old stem in relation to the pulp yield as 43.43% and Kappa number as 29.16, was found 60 minutes, meanwhile in 6 year old stem with yield and Kappa number 43.53% and 27.64, was found 90 minutes. Comparison between the two pulp yields (from 3 and 6 year old stems) showed no significant difference between them at 1% level, therefore pulp from 3 year old stem, because of 1% higher yield and 30 minutes lower cooking time was selected as suitable and optimum pulp for bleaching purposes.

It can be found through the literatures, wood-polymer composites (wpc) might resist against fungal attack when the polymer adsorption is very high, and this makes the product economically impractical. Poplar (Populus deltoids) was impregnated with styrene monomer and polymerized with direct heating methodto make wpc with different polymer adsorption (40%,80% and 120%). Treated and untreated specimens were tested with 19x19x19 mm dimentionaly following laboratory soil-block culture in accordance with the AWPA standard (1999 E10 99). Coriolus versicolor as the white-rot fungus was used to inoculate the specimens. After 12 weeks the results showed that there is significant difference between untreated specimens and treated wood blocks. Weight losses for 120%, 80%, 40% and 0% treatments wpc were resulted that 5%, 9%, 13% and 66% respectively. Considering economic aspect, poplar wpc made of 80% polymer load is recommended for industrial usage.

By emphasizing on the role of the consuming behavior of 316 families by the independent statistical sample in each of the 22 regions from the City of Tehran were considered in the spring of 2005. The statistical method was according to the kind of questions and the statistics which was used in the comparative analysis of research for non-parametric statistics: from the test of Friedman K 2 and parametric tests including: the statistic of normal distribution and eventually the Fikeramer coefficient was used. In a way that there was an important relation between the revenue levels for the Tehrani Families and the consuming tendency of them was not available and some factors suc has quality and freshness, and healthy point of the place of distribution was the most important role in the decision of buying for them and the price of aquatics and reasonable backing of them had equal priorities. About 62.3 % preferred to buy the packed aquatics. The per capita consumption of each person in the city of Tehran was estimated 3.46 Kilogram. The consumers of packed aquatics the register of food values and the increase of ability for the time of storage of pack, clearing the time of production, health's code and having valuable mark and information about the use of aquatics and as a result reducing the sea resources and operation of them, towards the raising aquatics and eventually Trout was selected. After the behavior of consumers and the decision of purchase of them some movements for Fisheries was done. The lack of confidence for the freshness and health of aquatics is one of the main reasons for the use of them. So that the tendency of citizens for buying Fisheries from these representatives and it needs the Marketing and direction of consumers towards the other valuable places for distribution. This research emphasizes the necessity of Marketing management by using of Marketing research and the increase of information for the purpose of knowledge to the advantages of packing for the purpose of reducing the extra materials and creating the increased value and organizing distribution canals for per capita increase and for creation of informative agencies and the Marketing researches and more research in this field.

Delonix regia and Cassia fistula are ornamental trees with beautiful shape, showy flowers, high shading, and tolerant to high temperature, making them suitable alternatives for landscape design in warm - arid regions. Delonix regia and Cassia fistula are commonly propagated by seed. However, seed physical dormancy causes delay in seed germination. Study was carried out to investigate the effects of different scarification treatments on the germination parameters of Delonix regia and Cassia fistula. A completely randomized design with five replications was used. Results of the Delonix regia revealed that highest germination percentage and germination rate and lowest time to reach 50% germinations were obtained from seeds treated with 95% concentrated sulphuric acia for 3 hours followed by soaking in boiling water at 90°C for 10 seconds. Also, results of the Cassia fistula indicated germination percentage, germination rate and time to reach %50 germinations of seeds treated with concentrated sulphuric acid for 30 minutes were significantly different (p<0.05) compared to seeds treated by boiling water at 95°C for 6 minutes, however, treatments of concentrated sulphuric acid for 30 minutes and concentrated sulphuric acid for 20 minutes were not significantly different (p<0.05).

In Iran, the northern boundary of Paleotropics realm is the latitude of approximately 28 N from a phytogeographical point of view. But a few exclusive species of this realm (such as Heteropogon contortus) have been reported from east and north east of Golestan province in north of Iran that is located about 1000km further to the north. Also some other paleotropic species (such as Tetrapogon villosus) were found in this study area. Ten climatic variables were chosen in two categories (moisture and temperature) and their averages were calculated using five weather stations for a l6-year period (1985-2000) in order to analysis of climatic variables affecting on the distribution of these species. Three weather stations were chosen from each phytogeographical zone of Iran (nine stations in total) to calculate the average of the selected variables. Due to different scales of the variables the dita were made dimensionless. The climatic similarities were calculated using Euclidian distance among the study area and the cities that were selected from other zones. The corresponding dendrograms were produced by average linkage method. The results indicate that the climatic similarity between the study area and Sahra-Sindi and Caspian zones are respectively the highest (63 percent) and lowest (25 percent). So the presence of tropical species is expectable in spite of the long distance between the study area and Sahara-Sindi zone. It seems these species dispersionally are relic and remain of Paleogene extending of tropical plant communities that occupied most area of northern hemisphere. These vegetations are reduced in Neogene's and quaternary periods. It recommends that the study area should be receiving more attention for conservation as a rare and limited area in such a high latitude locations.

This research was carried out during May-September, 2003. Zarrinkola and Marzoonabad are the important ab-bandans basis of area and species diversity in Mazandaran province. In both Ab-bandans, seven breeder bird species were observed: three resident species and four summer migratory species. Whiskered Tern (Chlidonias hybridus), Great Reed Warbler (Acrocephalus arundinaceus) and Little Grebe (Tachybaptus ruficollis) were breed in both Ab-bandans. Common Moorhen (Gallinula chloropus), Little Bittern (Ixobrychus minitus) and Penduline Tit (Remiz pendulinus) only breed in Zarrinkola Ab-bandan, whereas, Coot (Fulica atra) only breed in Marzoonabad Ab-bandan. Whiskered Tern (C hybridus) was the dominant breeder species in both Ab-bandans. It depended to Nymphaea Alba, whereas, Great Reed Warbler (A. arundinaceus) has high depended to dead Phragmites. Common Moorhen (G. chloropus) and Little Bittern (I minitus) were preferred Phragmites vegetations. Little Grebe (T ruficollis) and Coot (F. atra) was breed in regions with low and medium vegetation. Salix sp. was selected by Penduline Tit (R. pendulinus) among the marginal regions of Marzoonabad Ab-bandan. Natural and human threats have effects on the breeding habitats in two Ab-bandans. But, human effects have more intensity in Zarrinkola Ab-bandan. 

A study was conducted on population of coot in three important wetlands in northern Iran. Important biological and ecological attributes of birds and their habitats were studied at each study site. The wetlands were Anzali, Freydon kenar and Gomishan located at Southwest, South central and Eastern Caspian Sea respectively. Comparison of ecological factors such as habitat size, water depth, volume of emergent and submerged plants, level of population and hunting pressure showed that Freydon kenar was the poorest wetland followed by Gomishan and Anzali.70 number coots hunted and their attributes studied. The proportion of intestine length to body length was 3.6 and average body weights were 660 and 570 gr for males and females, respectively. 50 percent of the weight of carcass was useful for meal. Birds had low fat reserves at all the three study sites and they were omnivorous. They eat mostly water plants (54 percent), conch and gravel (46 percent).

In the direction of air pollutant sources establishment and activity regulations and regional air quality standard development for Golestan province, a multistage and successive studies were carried out. This paper based on the applied results of its first stage including air pollution potential hazard map extracted from a numerical model and main factors of current state of air quality at the second stage via expert judgment and scoring of 11 key parameters, the standard level and air quality management measures (plans) priority class were determined in separation of hazard zones and nine district areas. Also by combining of correlated data two management strategy scenarios with different aims and implementation capability: 1-mitigative-control development and 2- prevention- protective were developed and compared between hazard zones and district areas. Obtained results show that the difference of standard levels and air quality management plans within the hazard zones is significant at 1 percent level (p<0.10) meanwhile not significant within the district areas at 5 percent level. Therefore implementation of provincial and regional plans and standards of air quality within hazard zones as concentrated in the context of sustainable development plans will be more prior and practical than district areas. In addition, two managerial scenarios of mitigative and protective development have considerable within and between differences in the work units, and creating of logical and up to date balance among the scenarios need to multipurpose and dynamic matrices of management and decision-making. It seems that implementation of more severe standard for the conservational sites(protective strategy) and IV-V hazard class zones (mitigative strategy) and sufficient on current standard for the other regions with a 5 to 10 years periodical monitoring program will be closer to the environmental requirements and management and executive potential of Golestan province.

Rangelands defined as a kind of land with natural vegetation and potential that should be managed as natural ecosystem. Because of over utilization, rangeland health has been moved from health threshold. It is possible to investigate the effects of practical strategies and the area that potentially are moving to degradation by determining characteristics of rangeland health. Thus 3 sites included long term, mid term explosure and overgrazed regions in Roudshour rangelands were selected. The results showed the differences among rangeland health indicators in 3 sites. In overgrazed region, soil characteristics between canopy cover of vegetation has been depredated and perennial vegetation of reference area were removed as a result. So, 3 rangeland ecosystem characteristics value for determining health were in extreme category in compare with reference area for being under threshold line. In long-term explosure site, the characteristics value in compare with reference area (mid –term explosure) was on threshold line (balanced catergory). The results also showed the most important factors for decreasing range1andhealth are vegetation composition changing, domination of invasive plant, increasing bare ground, wind erosion and decreasing resistance of soil surface in the study areas.

Soil, plant and indicators are the main criteria to recognize the function of natural ecosystems, and to evaluate their potentials. The objective of this research was to determine some of the soil and plant indicators at hilly terrain of Inche-Boron in Golestan province. By using the Landscape Function Analysis method, the potential of north and south slopes of the hilly losses were evaluated which were represented in the hilly areas of Inche-Boron. The width, the height, the density of the patches and inter-patch and also, the 11 soil parameters were measured on the 3 transects of 50 meters length. The density and volume of the grasses and shrubs at the two difference geographical directions were measured by using point-center-quarter method. The index of landscape stability was higher on the north aspect than the south aspect for patches of grass, and the index of nutrient cycling was higher in south than the north direction for patches of shrubs. The soil infiltration index was not significant at any of the two aspects. Most ecological indicators of south and north aspects were of the shrub and grass forms respectively.

In order to compare the efficiency of distance methods in based on accuracy, precision and time, four 2-hectar area (100 m*200m) of shrub lands were determined at Bardsir-Sirjan, Kennan province. In each area, all individual shrubs were counted as control. Five 100m-transects were located which spaced40 meters and on each transect sampling points (20) were determined. The points were spaced 5 meters. The first point was selected randomly and others were regularly spaced. Shrub density was determined with eight methods along these transect. These methods were Closest individual, Nearest neighbor, Random pairs, Center-quarter point, Third nearest, Variable-area transect, Angel order method, wandering quarter method and census (full counting) of individuals which considered as control method. Distribution pattern of the plant in the study area was determined using pilou index, ANNOVA and Multiple Duncan test were used to compare these eight methods. For determination of the most efficient distance method to estimate density of production, the Analytic Hierarchy Process was used. The results indicated that the most precise distance method whether density or estimation of production in shrub lands is third nearest and the most fast or low cost method was Angel order. The most accurate method was nearest neighbor. Third nearest was the most efficient method to determine density of the shrub.

Four Hundred specimen were collected during January 2001-September 2002 in Gomishan lagoon in the south-east of Caspian Sea, Iran by using of beach-sein (mesh size 6-8 mm) and 4 times fisheries effort in a month and in mean depth of 1m. Size was measured as total body length (Tl), carapas length (Cl), propodus length (Pl), wet weigth (Wt) and fecundity as number of eggs per female. Results showed that females grew to a larger size than males. Maximum weigth (Wt), total length (Tl), carapas length (Cl), propodit length were 3.82 gr., 56.3 mm, 17.9mm and 8 mm respectively in female and 1.72g, 44.15 mm, 14.65 mm and 6.8mm respectively in male too. 55.61% of specimens were female and 44.38% were male. This study shows gonad maturation, and spawning occurs during April to August in the sampling zone. Average fecundity was 1935.73±703.6 (minimum 270 and maximum 3754). Maximum fecundity and maximum egg diameter were observed in total length range of 55.7-59.6mm. The process of increasing in condition factor occurred in males earlier than females.