PLANT AND ECOSYSTEM
Year:2013 | Volume:9 | Issue:36-1 (SUPPLEMENT)|Papers Count:9

Gundelia tournefortii L. is a herbaceous perennial wild plant that grows in some parts of Iran. Some of the habitat characteristics, morphological traits, and seed content (i.e. oil, protein, and fatty acids) of the plant were studied in this experiment. The results indicated that the species grows well in the study area with an average annual rainfall of 8.241 mm and an annual mean temperature of 18°C. Gundelia tournefortii prefers clay- and sandy-loam soils where the average soil pH and electrical conductivity (EC), respectively, are 18.8 and 1.3 dS/m. The phenological studies revealed that the growth of rosette leaves started in early February and late May was the time of seed formation. The amount of oil in the kernel was 44.2% and the amount of protein in kernel and aerial parts were 14.7% and 3.87%, respectively. Of the 10 fatty acids identified in G. tournefortii seed oil, linoleic acid and oleic acid, respectively with 45.46% and 38.5%, had the highest rates.

The growing concerns regarding global warming and climate change have significantly increased attentions to the soil and its sequestration potential. Accordingly and along the same veins, the present experiment was carried out at three different depths in an attempt to evaluate the role and effect of topographical factors (elevation) on the carbon sequestration potential of the foot soil of the plant species under study. For so doing, a key area containing three dominant vegetation types (Gundelia tournefortii, Astragqlus verus, Stipa barbata) was selected in the grasslands of Siah Khor region in West Islamabad in Kermanshah Province. Three elevation levels (i.e. 1400-1600, 1600-1800, and 1800-2000) were identified using topographic maps, geographic information systems (GIS), and GPS. The density and coverage per hectare as well as the air and ground biomass were determined in all three plant species. The foot soil of all three plant species was studied at three different soil depths and three elevation levels with three replications for each sample. Walcott-Block method was applied to measure carbon sequestration of the soil. Carbon sequestration of the soil at the foot of biomass was directly correlated with biomass carbon sequestration. Comparing the average carbon sequestration found at the foot soil of the three plant species under study at three elevation levels indicated that the highest average belonged to Gundelia tournefortii (Kangar) and Astragqlus verus (Gavan Zard), respectively. The lowest average soil carbon sequestration belonged to Stipa barbata (Stepiye Rishdar). Of the three elevation levels, the highest average of carbon sequestration of the soil at the foot of the three plant species was respectively observed at the heights of 1800-2000 and 1600-1800. The lowest average in this regard was observed at the height of 1400-1600. The results of carbon sequestration of the soil at the foot of the three species at different soil depths indicated that the highest carbon sequestration average belonged to the first depth (i.e. 0-30 cm). It also revealed that carbon sequestration decreases by an increase in soil depth.

Assafoetida, with the scientific name of Ferula assa-foetida L., is one of the most important medicinal Umbelliferus plants and one of the medicinal, industrial, and food species with no valuable forage utility. However, in addition to the role it plays in soil conservation, Assafoetida produces a kind of myrrh with medicinal and industrial values. The present experiment was carried out in an attempt to determine the ecological needs of this species to plan and manage its sustainable use. The distribution of the species was determined by means of field studies. The ecological characteristics of the habitat including: climate, topography, elevation from the sea level, slope, vegetation, associated species, phenology, and soil were studied. The results indicated that Chah-e Sookhteh Region in Sabzevar is one of the significant habitats of this species in Khorasan Razavi province. The total area of the region was approximately 7228 hectares, 1858 hectares of which was a useful and applicable habitat. The elevation from the sea level in these habitats ranged between 1350 to 1918 meters with a rainfall of more than 5.189 mm, the average maximum and minimum annual temperatures of 9.23 and 4.11°C, the slope between 10 to 50%, and a semi-arid climate mostly in areas with aridiosol which were composed of sand, stone, and red marl. The amount of ECe and pH respectively ranged between 5.0 to 1.2 dS/cm and 5.7 to 8. The amount of the calcareous material in this kind of soil was between 15 to 17%. Plants such as Artemisia aucheri, Ferula assa-foetida L., and Sophora pachycarpa respectively comprised the first plant type. Artemisia aucheri and Zygophyllum atriplicoides formed the second plant type in this habitat.

Understanding the nutritional value of the rangeland forage is essential for providing proper ratios that meet the nutritional needs of livestock. The purpose of this study was to evaluate the nutritional value of a number of plants in winter and summer rangelands of Maneh and Semalghan regions of Northern Khorasan Province in terms of meeting the needs of the livestock in the region. Accordingly, samples of a number of dominant species in the rangelands under study were collected at three phonological stages (i.e. vegetation, flowering, and seeding), following a completely randomized design (CRD). Afterwards, some of the most prominent nutritional value indices of the forage including crude protein (CP), metabolistic energy (ME), and dry matter digestibility (DMD) were determined and compared with the critical levels. Generally speaking, the results of the study indicated that the livestock will not face any problems in terms of crude protein and dry matter digestibility in winter rangelands under study. However, regarding the metabolistic energy and except for the vegetation period, the livestock will probably face shortage and this may reduce livestock performance and consequently the income of the ranchers. Therefore, it is essential to use nutritious grains, forage, and energy supplements during this period. Livestock need regarding crude protein, metabolistic energy, and dry matter digestibility is supplied in summer rangelands during vegetation period. However, during the flowering and seeding periods, the livestock will probably face shortage. It is therefore necessary to carefully plan the feeding and use of nutritional supplements during these vegetation periods in an attempt to supply the livestock needs for the maintenance mode.

As the most significant greenhouse gas in the atmosphere and the main cause of global warming and climate change in the past century, carbon dioxide should be absorbed and sequestrated from the atmosphere using the possible ways. Biotic carbon sequestration, including the absorption of extra atmospheric carbon by means of phytomass, is the easiest and most inexpensive way to reduce the consequences of climate change. Natural and artificial rangeland ecosystems have a great ability in enhancing the carbon sequestration potential. Artificial rangeland ecosystem (ARE) results from the conversion of low-yield dry farms to hand-planted rangelands. In an attempt to compare the phytomass carbon sequestration potential of the natural and artificial rangelands, the amount of the sequestrated carbon in the aerial and underground parts of two dominant species (i.e. Astragalus hypsogeton and Onobrichis cornuta) in the natural rangeland ecosystem and Medicago sativa species in artificial rangeland ecosystem of Meydan mountainous regions in the highlands of the North of Esfarayen were determined, per area unit. The results of the mean comparison of phytomass carbon sequestration in these two ecosystems, which was carried out using independent t-Test, indicated that at P<0.01 its amount was significantly (i.e. 6.5 times) greater in the artificial ecosystem compared to the natural one. In addition, no significant difference was observed in the average of the total phytomass carbon sequestration, per area unit, between these two ecosystems. The results of the independent t-Test at P<0.05 revealed that establishing an artificial ecosystem in place of an annual dry land cropping ecosystem, not only preserves the basic ecological resources but also increases the stable carbon sequestration from almost 0, per area unit, to the amount observed in the natural rangeland.

By encompassing various natural potentials, rangelands are considered as a significant resource for livestock and crop production. Accordingly, implementing proper and relevant managerial plans in the rangelands requires the evaluation of the vital activities of various different plant species. The purpose of the present study is examining various phonological stages of Stipa hohenackeriana in an attempt to achieve a proper management plan for the region under study and other similar regions. For so doing, an experiment was carried out in the semi-steppe rangelands of Kordan region in Alborz province over a four-year period (2007-2010). Ten bases were selected from the plant species and the date of the occurrence of the critical stages of the plant including the vegetation and vegetative growth, flowering, seed maturation, and plant death stages along with the information about plant height in centimeter were recorded in special forms during a four-year period over the growth season. This was carried out in 15-day intervals for the growth stage and weekly for the reproduction stage. Moreover, the meteorological statistics and information, regarding each of the four years, including the average monthly heat and the monthly rainfalls were obtained from the closest meteorological station in the region. On the basis of this information, the dry period curves were separately drawn for these years (2007-2010) in an attempt to adapt the data with the phonological stages of the species under study. The results indicated that the species starts growing on different dates in different years, depending on the local weather conditions, particularly the temperature of the environment (degree centigrade per day).

Nodushan region with an approximate area of 109400 hectares is located in 80 km NW of the city of Yazd in Yazd province. The average annual rainfall of the region over a ten-year period (1998-2007) is 98mm. The analyses indicated that the region under study contains 30 plant species, 15 of which are aromatic and 20 ones are medicinal and aromatic plants belonging to 46 genera and 21 families. The most frequent species were Lamiaceae family with 18 species, Asteraceae family with 9 species, Apiaceae with 7 species, Brassicaceae with 6 species, and Rosaceae with 5 species, respectively. Regarding the life forms, 46% of the species were Hemicryptophytes, 20% were Phanerophytes, 14% were Therophytes, 11% were Chamaephytes, and 9% Geophyte. Regarding the geographical distribution, the plants under study included: 63.1% Irano-Turanian, 9.2% Irano-Turanian and Mediterranean, 7.7% cosmopolitan, 6.2% Irano-Turanian and Saharo-Sindian, 4.6% Irano-Touranian and Mediterranean and Saharo-Sindian, 4.6% Irano-Turanian and Euro-Siberian, 3.1% Irano-Touranian and Mediterranean and Euro-Siberian, and 1.5% Irano-Touranian and Mediterranean and Euro-Siberian and Saharo- Sindian. Of the 65 identified medicinal and aromatic plants, 8 ones are endemic species of Iran andHymenocrater yazdianus, among them, is endemic of Yazd. By collecting information from related resources, the important medicinal properties of the plants under study were identified and briefly addressed in this article.

The present experiment was carried out in an attempt to evaluate the genetic diversity in different populations ofBromus Tomentellus species following the studies on total protein electrophoresis and a comparison of their relation with the ecological factors. For so doing, the protein patterns of 80 genotypes from eight populations of Bromus Tomentellus species were examined to determine the degree of genetic diversity. On the basis of the results of SDS-PAGE, 24 reproducible bands, i.e. protein peptides were recorded for evaluating the genetic diversity. The percentage of polymorphism in the total bands varied from 52% to 19%. The correlation matrix of genetic and geographic distances was not proved in the Mantel test and no statistically significant correlation was found between them (P=0.400, R ^ 2=0.0049). This indicated the absence of an environmental gradient among the diversity of the total proteins. Given that Iran is the centre of various Bromus Tomentellus species, it is not surprising to observe such a high degree of diversity in various properties of this plant. Therefore, it is suggested that the Bromus Tomentellus modification programs should be extended to include diverse parents in the breeding program. A considerable genetic increase for the modification of Bromus Tomentellus can be achieved through the systematic application of germplasm which has a different protein pattern and higher qualitative properties.

Soil is one of the crucial components in any pasture ecosystem. Any disruption in soil nutrient cycle may reduce the fertility and eventually the destruction of the soil in long terms. Hence, in an attempt to evaluate the effect of livestock graze on phosphor, potassium, and pH of the soil, a study was carried out in Dijing rangeland in the suburbs of Taftan in Khash. After the field visit, three symbolic regions regarding grazing intensity (i.e. reference, key, and critical) were identified. Afterwards, soil sampling was carried out in all of the regions following the random-systematic method. Soil samples were obtained from two horizons of soil profile (0-10 cm, 10-30 cm), over three time-periods during the grazing season.20 soil samples were taken from each horizon. After collecting and checking the normality of distribution in the data, an analysis was carried out using split–split plot design. The analysis of variance and Duncan test indicated that the amount of phosphor, potassium, and pH of the soil was higher in the critical region in comparison to the other two areas. In addition, the difference between the above-mentioned horizons was significant. That is, the amount of potassium and phosphor in the first horizon was more than the second one, but the amount of pH in the second horizon was more.