مجله مرتع
سال چهارم شماره 4 (پیاپی 16، زمستان 1389)

Mentha mozaffarianii Z.Jamzad is traditionally used from ancient times for diarrhea, stomachache, meteorism, and headache and as coolness. This study was carried out to determine some ecological characteristics of Mentha mozaffarianii Z.Jamzad in Hormozgan Province. The study sites were selected based on our field observations and also the spatial distribution of major habitats of the species in study area. The climatic factors were obtained from the nearest climatology station to selected sites. The growth parameters of the species were studied using 20 transects, each 50 m in length. Every 10 m along each transect, we selected the nearest individual and measured plant height, plant diameters (the largest and the smallest), and also plant cover. In addition, we took two soil samples (depth of 0-30 cm) from each studied sites and determined physico-chemical properties of the soil in the lab. One-way ANOVA followed by Duncan multiple comparison tests (=0.05) was used to test for the significant differences between studied sites. Results showed that this species is mainly distributed in river beds of mountainous areas which ranged in elevation from 250 to 2400 m a.s.l. and have a moderate and dry desert climate regime. Also, the main soil types in major habitats of this species were loam, loamy-sand and sandy-loam ranged in PH from 7.27 to 8.10 and EC from 1.01 to 4.45 ds/m.

In order to assess forage quantity and quality of various populations of Festuca ovina L. under irrigated and non-irrigated conditions, seeds of 11 populations were sown using a completely randomized blocks design with three replicates during 2006 - 2007. The results showed significant differences for many traits in various populations of this species. The population of 1779 and 1049 (with an average yield of 450 and 533 Kg/ha, respectively) and the population of 2213b and 599 (with an average yield of 211 and 218 Kg/ha, respectively) had the higher yield under irrigated and non-irrigated treatments, respectively. In addition, population of 1569a (Gorgan) and 2213b (Zanjan) had the highest forage quality under two treatments and therefore suggested for sowing practices in dry farming areas of Tehran province. Correlations between different traits showed that: dry matter yield was positively related to seedling emergence rate and water soluble carbohydrates positively correlated with digestibility and negatively with crude protein of foraged produced by different populations. Consequently, the relationships among digestibility and fiber components (ADF) were negatively significant.

This study aimed to investigate the effect of grazing intensity on ecological indicators, using qualitative rangeland health model in Chaharbagh semi steppe rangelands. Three functional attributes (soil and site stability, hydrologic function and biotic integrity) of rangeland health were evaluated using 17 ecological indicators in health model. According to results, Increasing in grazing intensity resulted in changes of ecological indicators. Also three functional attributes of rangeland health in key area were evaluated in healthy category in compression to reference area. Degradation occured in critical area because of grazing intensity between basal areas (inter patches). Grazing intensity also affected plant structure characteristics and elimniate perennial species. Results showed that three functional attributes of rangeland health was at risk in critical area in comparison with reference area. In rangeland health assessment of studied sites, the most sensitive indicator was biotic indexes and the least sensitive indicators were rill erosion, gully and wind.

The importance of native cool-season grasses in rangeland ecosystems is due to high adaptability of these species and also their roles in soil conservation, livestock grazing and forage production. For such species, study of seedling emergence and establishment, as critical phases of plant growth, is essential for rangeland improvement and recovery practices, in particular in arid and semi-arid regions. The main objective of this research was to evaluate seedling emergence and establishment of seven cool - season grasses under field conditions in Sisab site located at Northern Khorasan. The field seed sowing experiment was carried out using a completely randomized block design with four replicates. For each species, the emergence rate and status of seedling establishment were assessed during one growing season. ANOVA analysis showed a significant differences between various species for seedling emergence, growth and establishment rates (p<0.05).The highest seedling emergence rates on all sites, were recorded for large-seeded grasses such as Agropyron elongatum and Secale montanum, (25 and32%, respectively) while the lowest rates were recorded for small-seeded grasses such as Festuca ovina, Dactylis glomerata (1 and 1/8%, respectively). Our findings suggest that seed size might be as the most effective factor on the seedling emergence and establishment of such grasses.

The distribution of Artemisia fragrans was studied in 10000 ha of Halichal Amol rangelands. Six key areas within three different altitudes (534-1240, 1240-2160, 2160<) were selected. In each selected area, three transects were established and canopy cover of all species were estimated in 180 plots along the transects. Soil was also sampled in the cores adjacent to the roots of species in two different depths: 0-10 and 10-30 cm. Soil texture, pH, EC, Ca, K and C/N of all soil samples were measured in the laboratory. TWINSPAN was used to separate the ecological groups, then, CANOCO and PC-ORD programs were used to perform Canonical Correspondence Analysis and Detrended Correspondence Analysis. Finally, ANOVA and post-hoc tests were used to compare A. fragrans cover and edaphic factors in the studied sites. The results showed that the most important factors affecting pattern and distribution of plant communities were altitude, pH and K in upper layer of soil. The cover percentage of A. fragrans was variable along the altitudinal gradient and its variability was related to EC and pH of upper soil layer.

Autecological studies provide information necessary for ecologically sound rangeland management and improvement. This research was aimed to study autecology of Artemisia turanica Krasch. in the winter rangelands of the Northern Khorasan Province. The study was conducted via field visits and laboratory measurements accordingly. A. turanica grows on flat or rolling plains, 1000-1500 meters a.s.l., and 0-60% slopes. The average annual rainfall and temperature in its natural habitats are between 200-300 mm and 8-16 ºC isolines, respectively. Geological formations were marl, conglomerate, and sandstone. Soils were silty loam, weak alkaline, medium saline, and poor in N and organic carbon. A. turanica started its yearly growth at late March, flowering in late July and seeding in late September; seed shedding is completed by December and January. The highest forage quality was in the early stage of growth, but it reduced to the lowest level by the seeding stage. Forage quality decreased from the beginning towards the end of growth season i.e. a decrease in crude protein but increases in the ADF, NDF and dry matter percentages. During the grazing season, November-January, metabolic energy in the A. turanica textures was lower than the critical level (8 Mj/kg); therefore this species may not provide a full diet for the grazing livestocks, in the winter rangelands. However, higher palatability and crude protein contents, plus adaptations to the saline soils are advantages of A. turanica as compared with the other Artemisia species in the study area.

This research aimed to investigate changes in plant diversity as affected by environmental factors in an area of 74,000 ha of East Semnan rangelands. Vegetation in each site was studied using 15 quadrates (with appropriate size) located along 3 transects, each 750m in length. In each quadrate, all species were recorded and their vegetation cover estimated separately. In order to determine soil properties, soil samples were taken at the beginning and at the end of each transect from two depths of 0-20 cm and 20-80 cm. Finally, physiographic parameters such as slope and elevation were recorded for studied sites. For data analysis, species richness and evenness were calculated using different diversity indices and the differences between various vegetation types were tested using one-way ANOVA followed by a multiple comparison test. The results for all calculated diversity indices and richness, except for the Manhinak index, showed that vegetation type of Artemisia aucheri- Astragalus spp-Bromus tomentellus is the most diverse type whereas the vegetation type of Halocnemum strobilaceum is the less diverse one. Based on Kamargo and Simpson indices, vegetation type of Halocnemum strobilaceum had the largest evenness index while the vegetation type of Sidlitzia rosmarinus had the lowest evenness index. In addition, the results showed that species diversity in various vegetation types was mainly affected by soil properties such as soil texture, EC and also the gypsum, lime and gravel content of the soil.

Drought stress is one of the most important factors controlling plant growth in arid and semi arid regions. Super absorbent polymers has introduced for absorbing seasonal rain to decrease moisture stress. As a result of over population and industrialization, water shortage is pronounced in dry or semi arid areas; hence use of waste water for some crops is being important. This study aimed to evaluate the multiple effects of municipal wastewater and super absorbent polymer on Nitraria schoberi growth under greenhouse conditions. In this study factorial complete randomized design with four replications was used. The treatments used included: two types of soils (clay and sandy), three level of super absorbent (0, 4, and 8), irrigation at two levels (wastewater and Tap water) and two irrigation regimes (5 and 15 days). The results indicated that the number of established seedlings, plant height and root length, plant dry weight were affected by different quantities of super absorbent and wastewater. According to results, application of polymers significantly increased water holding capacity especially in sandy soils. Therefore using polymer can increase the success chance of seedling establishment in rehabilitation projects.

This study aimed to evaluate effects of clipping on some growth characteristics of Panicum antidotale. A completely randomized design with 4 treatments including once a week (frequent), every two weeks (moderate), every four weeks (low) and control (unclipped) was carried out in 11 replicates. Shoots were clipped at a height of 7 cm in all treatments. The result showed no significant effects of clipping treatments on total biomass, above-ground and below ground biomass and also number of shoots and roots. Therefore, this species can be considered as tolerant to clipping.

For detecting the trend of land use and vegetation changes in southern part of Neka, two sets of Landsat data including MSS (1977) and ETM+ (2003) were analized. Different image processing and enhancement techniques such as re-sampling, color composite, band-rationing and PCA were used. NDVI and bands 5 and 7 were selected as the best band set with use of optimum index factor (OIF). To produce a base map for field surveying, unsupervised classification was done on the ETM+ images. Then, supervised classification was done on both ETM+ and MSS images, using maximum likelihood classifier. Stratified random sampling (500×500 m2) was designed and type of land use was recorded in 291 points. Six different land use classes including: forest, agricultural area, dry land, urban area, bare land and degraded area were distinguished. According to the results forest, agricultural and bare lands areas were decreased urban area and degraded area were increased and during these years. The size of urban areas had the most changes (25%) in this period. Overall accuracy and Kappa for MSS images are 85.96% and 80% and for ETM+ images are 86.36% and 83%, respectively.

Nitrogen fixation and drought stress effects is different in species of annual medics according to productivity and soil fertility. Chosen for experiment are six species of annual medics such as: Medicago orbicularis, M. polymorpha, M. radiate, M. littoralis, M. rigidula and M. truncatula which can survive in different climates, produce sufficient forage, and fertilize the soil effectively. The experimental designed as a factorial employing Randomized Complete Block (RCB) with four replications. Nutrition source irrigated with nutrition solution that was without nitrogen and in quartz culture. Plants inseminated with Sinorhizobiam meliloti. Drought stress was conducted with four levels of field capacity, 100, 75, 50 and 25% respectively. The results showed that there is significant difference in the diverse species by reason nitrogen fixation. Minimum amount of nitrogen fixation was 68/45 Kg/ha by Medicago radiata and the most was by M. truncatula 132/27 Kg/ha. So enough potential of nitrogen biological production by annual medics that is important based on economic view point. Annual medics can have effectiveness utility in rain feed cereal production system which affect on rangeland and agriculture land to sustainable system. Species such as M. littoralis and M. truncatula have maximum of nitrogen fixation and can used those in suitable area and Ley-Farming systems. The least effect of drought stress on shot dry weight was for M. rigidula amount 1891 Kg/ha. The most plant height was for M. littoralis 40/71 centimeter. The most root dry weight was for M. rigidula amount 798/8 Kg/ha. The most ratio of shot dry weight to root dry weight was for M. orbicularis amount 4/68. Thus, M. rigidula is the best species for cultivation in drought stress situation.

In the recent years, range management plans have played an important role in preventing rangeland degradation and improving their conditions. The principal essence of any range management plan is to involve those people who exploit the range resources, without which range management efficiency will be negligible. Accordingly, this study aimed to investigate factors influencing participation of pastoralists in range management plans in Tafresh County rangelands. This study designed as a correlation-descriptive research. A sample of 55 out of 95 pastoralists in the study area were selected, using “systematic random sampling” method. The findings revealed that the extent of satisfaction of plan, stakeholders awareness, motivation for participation, extent of mass media use, effectiveness of extension methods, livestock ownership, ownership of rain-fed land, ownership of sheep and goats, number of livestock permit number, and the periods that livestock is maintained in village had positive significant correlation with the extent of participation in range management plans. In addition, extents of participation of pastoralists groups were significantly different in terms of types of plans. In conclusion, people participation should be taken into account in all stages of designing and implementing range management plans, hence the effectiveness of these plans can be guaranteed.