M.a. Hajabbasi, A. Jalalian, J. Khajedin, H.r. Karimzadeh,
Volume 6, Issue 1 (spring 2002)
Abstract
Due to physiography and weak structure, the pasture soils in Boroojen are potentially degradable. Converting pastures to agricultural land accelerates the degradation processes. A study was conducted in 1999 to show the effects of almost 20 years of farming on originally pasture land on soil physical properties, fertility, and tilth index of pastures in Boroojen region in Chahar Mahal and Bakhtiari Province (central Zagrous). Soil texture, clay content, bulk density, organic matter, saturation moisture percent, cone index, plasticity index, mean weight diameter and aggregate size and distribution, nitrogen, phosphorus, and potassium were measured.
After 20 years of cultivation, bulk density increased about 20% while organic matter decreased by 30%. Cone index was lower in the undisturbed pasture but nitrogen and phosphorus contents were higher compared to the disturbed pasture. The undisturbed pasture contained more larger (> 1 mm) aggregates, while the disturbed pasture had more smaller aggregates. Sustainable use of natural resources will lead to their long term workability, while negligence of conservational practices including appropriate farming management practices will result in the destruction of these resources.
E. Zandi Esfahan, S. J. Khajedin, M. Jafari, H. Karimizadeh, H. Azarnivand,
Volume 11, Issue 40 (summer 2007)
Abstract
In order to determine the reciprocal relationship between the important characteristics of soil and the growth of Haloxylon ammodendron (C.A. Mey) plant in segsi plain of Isfahan., ordination method was used. The study was performed through the stratified random sampling and the regions were separated according to the plant age and physical physiognomy, then 10 samples of Haloxylon ammodendron (C.A. Mey) of the same age were selected in each region. Meanwhile, factors such as height, canopy cover area, canopy cover perimeter, canopy cover diameter, and basal area were considered. Also, 30 profiles from viewpoint of growth situations in 10 different regions were dug. Soil characteristics such as : pH, Ec, total soluble Ca2+ and Mg2+, Cl-, CO3--, HCO3-, SP%, CaCO3%, CaSO4%, organic matter%, total nitrogen percentage, phosphorous, Na+, K+, SAR, and hardpan depth were measured. Data was analyzed using ordination method. According to the results, samples of the same age showed significant differences in plant features. Other results showed that physical characteristics such as depth of hardpan from soil surface, SP%, and chemical characteristics such as salinity, alkalinity and total nitrogen had the highest effect on qualities of this kind of plant. In other words, the results mentioned above showed the important role of Haloxylon ammodendron (C.A. Mey) in sharp increase of salinity and alkanity in it's stratum.
M Hemami, F Hazeri, S.j Khajedin,
Volume 13, Issue 48 (7-2009)
Abstract
Population of Persian gazelle has been declining in recent decades and as a result, this species was added to the IUCN list of threatened species in 2006. However, there is paucity of ecological data about this species within its range. Mooteh Wildlife Refuge is one of the best habitats of Persian gazelle in Iran where one of the biggest populations of this species live. Habitat selection by threatened Persian gazelle was studied in three seasons in Mouteh wildlife refuge. Habitat use was related to plant communities and plant vegetation variables using clearance transect pellet group counts carried out every 45th day. The effects of water resources and disturbance by man and livestock were controlled. Habitat selection was significantly different between seasons and plant communities. Salt bearing clay soils with a high diversity of holophyte plants were mostly used particularly over winter, while Artemisia- Zygophyllum community was avoided in all seasons. Minimal models resulting from multiple regression retained a number of vegetation variables in each season including a negative effect of Tamarix sp. and Alhaji camelorum and a positive effect of Halocnemum strobilaceum and Salsola dendroide in autumn and winter. It is concluded that selection of habitat by Persian gazelle changes by seasons and that salt-bearing soils and Artemisia-Salsola community are the most important habitats for gazelles in Mouteh Wildlife Refuge.
