NATURAL ECOSYSTEMS OF IRAN
Year:2016 | Volume:6 | Issue:4|Papers Count:8

Arid and semi-arid rangelands are formed the most areas of Iran, hence it is necessary to be tolerant the plants of this region against drought. Using of resistant species to drought is vital for improving and developing of the rangelands. In this study, we evaluated the effects of drought stress onHelichrysum globiferom and Helichrysum aucherigermination properties. Seeds of two species were collected of Qushchy rangelands in 70 kilometers of the old road of Urmia–Karabakh. A factorial experimental design with four repeats and four salinity levels (0-50-100-150 mM PEG) in Seed Ecology laboratory of Sari Natural Resource Faculty was chosen.Results showed that drought stress had a significant subtractive effect on percentage and speed of germination, stem, and plant and root length in two Species. About all studied traits, the species ofHelichrysum globiferom had more reduction properties thanHelichrysum aucheri species. The ratio of Root to shoot length (allometric coefficient) also was the highest inHelichrysum globiferom. So the highest decrease in both species was observed in germination in treatment 100 and 150 mM because in this treatment no seed is germination. Therefore, as the species ofHelichrysum globiferomis more resistant than another one, it is suggested to use it for improving and developing of rangelands.

To shed light on the relationship between vegetation and soil will help to identify rangelands potential and functions. As an integral part of rangelands, woody plants play a substantial role in constituting soil properties. The present study was aimed to investigate the effects of woody plants on rangelands functions in Parvar region, Semnan province. According to landscape function analysis method (LFA), the number of eleven soil features on three woody plant structures (closed, semi- closed and open canopy) with three transects were studied along which five replicates on per patch as well as bare soil considered. Then factors measured on three parameters of stability, infiltration and nutrient cycling were classified as per each structure. The results showed that woody species with closed canopy have more contributes in improving rangeland function indices, including stability, infiltration and nutrient cycling compared to those relatively closed and open. On the other hand, the shorter woody species have greater contribution in soil stability.

The availability of land use information permits decision-makers to develop plans in short to long-term period for the conservation, sustainable use and development of natural resources and watersheds. In this study, ETM+ image (2006), GPS and GIS were used for image interpretation, field data collection and land use mapping.Preprocessing and required correction have conducted. Initially, field visit have been conducted and different land uses have been defined. In the second step, image was visually interpreted and then training area has selected and using the maximum likelihood algorithm image was classified. According to the lack of the capability for detecting river beds and residential areas in digital image processing, integration of visual and digital interpretation (supervised classification) and object-based image analysis were used. Results show that, in visual interpretation, there is almost no capability to discriminate rangeland from dry farming land uses; however garden, residential areas and riverbeds are discriminated. Results of supervised classification show that there are problems to detect and discriminate different land uses; however, by integration of digital and visual interpretation, it is possible to use Landsat data to discriminate different land uses in the areas such as Kaftareh watersheds and Arshagh region of Ardabil province. The results of the evaluation of object-based classification accuracy showed the highest overall accuracy. In the future studies, according to the importance of land use map in the studies such as natural resources, watershed managements and agriculture, it is better to use high spatial imagery and object-based methods.

Indicator plants are the easiest instrument to understanding ecological conditions in Environment. This research investigates indicator plants species in six natural site of endangered species Populus caspica Bornm. In three Northern provinces of Iran with two goals; evaluate the current status of these habitats and indicator plant performance in the expression present status in habitats. Sampling was preformed systematic randomly with 100*150 (m) sampling network and sample plot with an area of 400 m2 (20*20) and 9 microplot with an area of 4 m2 (2*2). Floristic list of all plant species were provided and Indicator plants species were identified with referring to the valid research and studies. Fundamental climate parameters (mean annual precipitation, annual temperature, etc....) and habitat characteristics (soil, destruction) were evaluated to assess Reagent indicator plants. According to the results, representing a total of 43 species was identified. There destroyed indicator plants, indicator plants of alkaline and poor acidity soil and Wetland Indicator plants are most striking feature of Populus caspica habitats. Humid and semi-humid climate, calcareous soil and widespread destruction were the most striking features of this endangered species site in Hyrcanian forest. Overall results of this study confirm the efficiency of valuable Indicator plants in the expression ecological conditions of habitats showed necessity of applying Indicator plants in biological resources management and advises considering the most effective and efficient arrangements ex situ and in situ management to restore and preserve these archaeological and endangered species sites.

The goal of this study is to investigate the relationship between rangeland area, the number of exploiter, and animal unit to Range Management plan. First, the list of summer range of Isfahan plans was prepared. Then, rangeland area, the rangeland yield, the number of exploiter, and the animal unit were pulled out from the Range plans. Next, the number of existing animals in rangelands was counted. The number of samples was determined 90, among 226 Summer Range Management Plans, using Cochran's formula. Samples contain 45 plans of one exploiter and 45 plans of the group (plans which had more than one exploiter). Finally, the relationship between the rangeland area, the number of exploiter and animal unit (separately and commonly) and rangeland's yield were analyzed in both one exploiter's rangeland and group rangelands. Then, yield in two group's rangeland was compared. Also the number of existing animal and animal unit in each group (separately) were compared.Results indicated that a negative significant relationship was found between the yield and the rangeland area in both one exploiter rangelands (P£ 0.01) and group rangelands (P£0.05). A significant relationship was found between rangeland the yield and theanimal unit in each two group's rangeland (P£0.01). There is no significant difference (P£0.05) between yields in two group's rangeland. Finally, a significant relation was found between the number of existing animal and animal unit in each two group's rangeland. Hence, sustainable rangeland management can be achieved by the selection of the number of animal unit based on rangelands area and yield.

Rangeland ecosystems are considered as one of the most complex ecosystems and there are the close relationships between its components. This implies that rangeland resources in every area, be evaluated properly for each kind of utilizations and also land suitability is specified for each land use. The aim of this study was determining ranges suitability for sheep grazing in Baqeran watershed, South Khorasan that has been performed using the FAO method in GIS. In this study three factors, including forage production, water resources and sensitivity to erosion were considered among physical and vegetation factors which have been provided as three sub-models. The final model of range suitability shows that high slope and distance from water resources are the most important factors to decrease land suitability for this land use.It was also observed the 32.63 % of rangelands were grouped in the S2 class (medium), 21.13 % were grouped at S3 class (low- suitability) and 18.06 % of N class (non– suitable).

The aim of present the study was assessing the relationship between Dorema aucheri dispersion. At first, 60 sites were selected in Delfan County. In each site 3 transects with 100 m length and 10 4-square meter along transects was established and canopy cover and species density then studied. Then at the first, mid and end of transect, soil samples were collected in 0-30 cm depth. Height, slope, aspect and some soil properties, including texture, electrical conductivity, acidity, organic matter, phosphorus, potassium and nitrate were determined. Cluster analysis, independent t test, discriminant function and principle component analysis were used for analyzing the data. The results of cluster analysis indicated that the sites were separated into two main groups. Also the results showed that studied species have the most presence in height of 2345 m, at the slope more than 80 percent, southwestern and western aspect, temperature more than 10 degrees, precipitation 498 mm, soils with 1.63 percent organic matter, and less sand, and more silt and clay. The results of discriminant function and principle component analysis indicated that at the first level height, precipitation, temperature and some soil parameters like sand, silt and organic matter and at the second level aspect and other soil characteristics like pH and potassium are effective in the studies species dispersion. According the results of the present study, this fact is documentable that the studied species is suitable for restoration in rangeland.

Earth Plant ecosystem offers different services, given the current conditions Earth and excessive pollution atmosphere, carbon sequestration to soil by plant communities is one of the most important services in long time. The present study was aimed to assess the effect of exclosure on carbon sequestration and soil physical and chemical properties in rangelands Chaharmahal and Bakhtiari Province. In each region, seven homogenous sites (grazed and non-grazed) were selected in terms of environmental conditions and vegetation and soil sampling were achieved in the each site. The vegetation sampling was done in rangeland with the establishment of transects and install a four-square-meter plots. The soil samples were done to a depth of 30 cm in each plot at the each site. Aerial biomass and litter in each plot were collected and weighed. The results of analysis data showed that the amount aerial biomass, soil carbon, and total carbon sequestration in semi-steppe rangelands with dominated grasses respectively, with 1.9 t/ha, 51.75 t/ha, and 53.02 t/ha were significantly estimated more than semi steppe shrubland rangeland. The results also showed that the average total carbon sequestration and soil in both study areas in treatment exclosure had a significant difference in grazingland treatment.