Hosein Tavakoli; Hosein Yoshti; Alireza Khodashenas
Volume 21, Issue 3 , December 2014, , Pages 416-423
Abstract
Study on plant vegetation changes has many applications for range improvement and range management. Plant vegetation percentage, production and composition were studied over four years in a17-year exclusion area and a grazing area in Golestan Research Station in Mashhad City. Soil organic matter content ...
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Study on plant vegetation changes has many applications for range improvement and range management. Plant vegetation percentage, production and composition were studied over four years in a17-year exclusion area and a grazing area in Golestan Research Station in Mashhad City. Soil organic matter content of both areas was measured at 0-30 cm soil depth. Plant composition was determined by identifying the perennial species. Vegetation percentage and plant production were estimated using quadrate and clipping method, respectively. In general, plant vegetation percentage and plant production were higher in exclusion area as compared with grazing area; however, this increase was not statistically significant in some years. Plant vegetation composition also showed some differences, but the changes seemed to be low during the exclusion period. Organic matter percentage was calculated to be 0.57 and 0.54 for exclusion and grazing areas, respectively. In conclusion, in the areas with similar climatic condition, range exclusion will not result in large changes in plant composition and vegetation percentage for fodder production or creating green space.
Mohammad Zadbar; Hossein Arzani; Mojgan Azemi; Vali ... Mozafarian; ghanbar ali Shad; Faredeh Saghafi khadem; Hossein Tavakoli; Hassan Amir abadi zadeh; Somayeh Naaseri
Volume 18, Issue 2 , September 2011, , Pages 231-243
Abstract
Rangelands play a key role in country's economy not only for livestock grazing but also for soil and water conservation and other services.This research was based upon a national plan of rangeland monitoring performed in different climatic regions of Iran. Three sites including Asalmeh Bajgiran, Tavakal ...
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Rangelands play a key role in country's economy not only for livestock grazing but also for soil and water conservation and other services.This research was based upon a national plan of rangeland monitoring performed in different climatic regions of Iran. Three sites including Asalmeh Bajgiran, Tavakal bagh Quchan and Shah jahan Esfarayen were selected based on the vegetation cover which represents a part of vegetation of mountainous rangelands in north Khorasan.The experiment was carried out on six linear transects, each transect included ten quadrates of 1.1 m2 and canopy cover, density and plant production were monitored during the period of four years (2004 to 2007).Average of the canopy cover in the mentioned sites were 69.94% ,41.38% and 48.44% respectively, containing perennial grasses, shrubs, grass-like species, and annual or perennial forbs. Average of the annual production was obtained as 654, 356 and 506 (kg/ha/year) respectively.In Asameh rangeland, there is no spring for drinking water and that is why livestock grazing is light with a good condition of vegetation. In Tavakal Bagh, grazing time is longer due to the vicinity to the village. In Tavakal Bagh and Shah Jehan Esfarayen early and heavy grazing are observed. Therefore, with regard to the same precipitation, it could be concluded that grazing is the effective factor in reduction of the range lands production.
Maryam Heidarian Aghakhani; Ali asghar Naghipour Borj; Hosein Tavakoli
Volume 17, Issue 2 , September 2010, , Pages 243-255
Abstract
It is important to know soil propoerties, particulary its chemical aspects, for the proper management of rangeland ecosystems. The aim of this study is to find the impact of grazing on vegetation and some soil chemical properties, in three areas, the key, reference, and critical, Sisab rangelands, Bojnord. ...
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It is important to know soil propoerties, particulary its chemical aspects, for the proper management of rangeland ecosystems. The aim of this study is to find the impact of grazing on vegetation and some soil chemical properties, in three areas, the key, reference, and critical, Sisab rangelands, Bojnord. The vegetation cover data was collected from 30, 1m2 quadrats in each area through random –systematic method. The soil data was sampled from two depths 0-15, 15-30 cm and five composite samples were collected (each sample was mixed of six samples) from each depth in the each area. Some factors such as the organic carbon, the percentage of soil organic matters, total nitrogen, absorbable phosphorus, pH and EC were measured. The results showed that carbon, nitrogen, soil organic matters, phosphorus, and EC were been decreased by grazing, but pH was increased. According to results, forbs were the dominant life form in the reference site. Shrubs cover percentages were been increased as grazing increased. In addition, reference site had species that are more palatable and invaders were more abundant in critical area. It was concluded that heavy grazing intensity cause to decrease of vegetaton and conversion of composition of the species cause to negative conversion in alimentary mineral of soil, sustainable of ecosystem would be endangered.
Aliasghar Naghipour Borj; Ghasemali Dianati Tilak; Hosein Tavakoli; Maryam Haidarian Aghakhani
Volume 16, Issue 3 , December 2009, , Pages 375-385
Abstract
Climate change and increase of global warming is one of the most important challenges in sustainable development, which is due to increase of concentration of greenhouse gasses in atmosphere. CO2 is the main part of greenhouse gasses. In order to mitigate atmospheric CO2 and create balance in greenhouse ...
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Climate change and increase of global warming is one of the most important challenges in sustainable development, which is due to increase of concentration of greenhouse gasses in atmosphere. CO2 is the main part of greenhouse gasses. In order to mitigate atmospheric CO2 and create balance in greenhouse gasses, atmospheric carbon must be absorbed and sequestrated in different forms. Rangelands ecosystems have approximately half of the worldٰs land area and they store over third of trrestrial biospher carbon. In order to evaluate the effect of grazing intensity on content and distribution of soil carbon sequestration and plant biomass, a study was carried out at Sisab semiarid rangelands of North Khorasn province. After survey, three sampling area has been specified (reference, key and critical). The content of above ground and under ground biomass carbon, litter carbon and soil organic carbon (in two depths 0-15, 15-30 cm) was determined in three area. The result showed that the total carbon sequestration in reference area was 39.79 ton/ha, in key area was 28.97 ton/ha and in critical area was 24.43 ton/ha. The results of carbon distribution showed that the soil organic carbon content was >97% of total carbon sequestration, In addition the carbon content in underground biomass was higher than above ground biomass. It was concluded that the grazing intensity cause to decrease of vegetation cover, content of plant biomass and decrease of carbon sequestration in soil and vegetation biomass, and soil is the most impotant sink for organic carbon storage in this rangelands.
Bahram Mohamadi Golrang; Mohsen Mohseni Saravi; Behrooz Malekpoor; Mansoor Mesdaghi; Jan Skoarz; Hosein Tavakoli; Mohammad reza Afhkamolshoara
Volume 14, Issue 2 , January 2007, , Pages 185-203
Abstract
Understanding the relation between the plants,The environmental factors and the other living creatures is a necessary problem in preserving the constancy in all eco-systems.Man in order to cope his needs ,has used the natural resources and during thousands of years using the eco-system had been effective ...
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Understanding the relation between the plants,The environmental factors and the other living creatures is a necessary problem in preserving the constancy in all eco-systems.Man in order to cope his needs ,has used the natural resources and during thousands of years using the eco-system had been effective in changing them. In this research having the vegetation map of this area which had been provided by Macgoven Australian co,The map of plant type in 1372 using G.I.S has been provided and the changes in plant cover during this period were evaluated. Comparing the two maps,The result was that among the 20 recognized types in 1352, 3 types because of grazing and other factors have been completely wiped out ,and the other types have been changed into newer types or there are some changes in the variance of some other types. In plant coverage studying ,in order to specify the range condition trend,the methods of :1) Four factorial metuod. 2) clipping and weighing method. 3)trend method were used. Using Trend method and comparing the plant cover condition in 1352 and 1372 ,we came to the result that there is no positive trend in any types .In 8 types ,the trends are constant and in 9 ,the negative trends have been reported. In order to explain the 17 trends in 1372,the map of range condition trend in G.I.S system has been drawn.
Hosein Tavakoli; Abbas ali Sanadgol; Uosef Garivani
Volume 13, Issue 2 , February 2006, , Pages 69-73
Abstract
Russian brome (Bromus tomentellus) is a prennial grass with good adaptability to climatic condition of north Khorasan. So, it has promise for using in range improvement projects. Because threre is no enough local information about mangement of this plant, the present experiment has been conducted in ...
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Russian brome (Bromus tomentellus) is a prennial grass with good adaptability to climatic condition of north Khorasan. So, it has promise for using in range improvement projects. Because threre is no enough local information about mangement of this plant, the present experiment has been conducted in Sisab Reaserch Station (SRS) to evaluate the response of this species to grazing intensities and rest grazing. Four grazing intensities of light (20 to 45% of forage removal), moderate (45- 65% of forage removal), heavy (65- 80% of forage removal) and without grazing as control applied by herd of lamb and sheep for three consequent years from 1999 to 2001. The year of 2002 considered as rest period from grazing. Herbage mass and number of plant per unit area measured as an index response. Herbage mass production decreased by reduction in precipitation. Heavy grazing resulted in significant reduction in herbage production and number of plants per unit area, but one year rest from grazing componsated the negative effect of intensive grazing on herbage mass reduction. Management implication based on this results show that plant can tolerate grazing intensity by 45-65% of herbage removal and indicate on the importance of rest grazing on survivance of this plant.
Hosein Tavakoli; Amr ali Shahmoradi; Ali asghar Paryab; Abass ali Farhanghi
Volume 13, Issue 1 , February 2006, , Pages 39-47
Abstract
A vast area of Iran is covered by sand dunes and shifting sands in wich threat the living of habitants in these regions. Biological control is an approprate method for sand dune fixation. So, it is essential to regonize characteristics of psamophyte plant species and introducing suitable speciecs ...
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A vast area of Iran is covered by sand dunes and shifting sands in wich threat the living of habitants in these regions. Biological control is an approprate method for sand dune fixation. So, it is essential to regonize characteristics of psamophyte plant species and introducing suitable speciecs for sand dunes. For this perpose, the ecological characteristics of Ammodendron persicum including phenology, adaptability, soil condition of habitates, response to cutting and grazing, regeneration strategy and seed germination were studied . Ammodendron persicum is a shrub and psamophyte plant with the age of 10 to 50 years. Phenoligically, the growth started in March, flower in about 7 May and reach to seed maturity by 20 June. The seed shaded after maturity but the duration of plant growth depend to amonnt of annual rainfall. Ammodendron is a drought resistant plant, because it is grow well in an area with an average of 150 mm rainfall per year. Ammodendron regenerates by seed and vegetative propagules. Grazer animals use this plant by end of growing season. In general this plant has approparate ecological characteristies in terms of establishment over sand dune and has perspective for using in other sand dune areas. The later case is under investigation.