mashaallah mohammadpour; Mohammadreza Tatian; Reza Tamartash; Jafar Hoseinzadeh
Volume 28, Issue 1 , April 2021, , Pages 34-54
Abstract
Rangelands beneath the forests of Dalab in the northwest of Ilam are grazed from May to November. To investigate the grazing behavior and determine the dependence of livestock on forage resources, three goats and three Kurdish sheep were randomly selected from three herds in the ...
Read More
Rangelands beneath the forests of Dalab in the northwest of Ilam are grazed from May to November. To investigate the grazing behavior and determine the dependence of livestock on forage resources, three goats and three Kurdish sheep were randomly selected from three herds in the area, and by installing a GPS device on them, information on the distance and movement time of livestock were recorded every month. Maps of geological formation, slope, altitude, land use, and landform were prepared, and monthly GPS information was combined with the maps. The evaluation of forage production was carried out in 27 plots of forest floor and 25 samples of trees and shrubs. The results showed that the goat had an average daily mobility of 7.7 km and a distance of 2.6 km for grazing; but these figures for sheep are 7.8 and 1.9 km, respectively. It was also found that goats were more present in the altitude of 1400 to 1500 m and sheep in the elevation of 1300 to 1400 m. Livestock were more prone to grazing on the forest floor, and they preferred slopes of less than 30%, hill form, and Pabdeh geological formation. Comparison of grazing, moving, and stopping times showed no difference between the types of grazing in terms of grazing behavior, but there were differences between the types of activity (movement, stopping, and grazing) in different months. Examination of the grazing behavior of the livestock using video recording revealed that the livestock spent about 33 to 36 minutes on grazing, three to five minutes on stopping, and 12 to 14 minutes on grazing without movement. Finally, it was found that about 50% of the relative forage production was from forest floor grasses, 34% forest trees, and 10% sub-forest farms; therefore, livestock ration dependence on forest floor grasses is about 61 %, forest trees 25 %, and forest floor farms 7 %.
Jalag Abdollahi; Hossein Naderi; Alireza Khavanin Zadeh; Mohammad Sadegh Farmahini
Volume 22, Issue 2 , August 2015, , Pages 251-265
Abstract
In this research, the effects of important environmental variables on vegetation diversity were determined in Nodoushan-Yazd. For this purpose, 46 various land unit tracts (LUT) were studied. To collect vegetation data, the number and optimum size of sampling plots were determined using the statistical ...
Read More
In this research, the effects of important environmental variables on vegetation diversity were determined in Nodoushan-Yazd. For this purpose, 46 various land unit tracts (LUT) were studied. To collect vegetation data, the number and optimum size of sampling plots were determined using the statistical and minimal area methods, respectively. For each sampled unit, one composite soil sample was collected according to plant root depth. Soil properties included: gravel, texture, saturation percentage (S.P), calcium carbonate, pH, EC, soluble ions (Na+, Mg2+ and Ca2+) and S.A.R.The study of diversity indices was performed based on species canopy cover, the presence or absence of species and the use of three diversity indices (richness, Shannon-Wiener and Simpson). Then, the relationship between environmental variables and biodiversity indices was investigated using RDA ordination. According to the obtained results, altitude had the most impact on vegetation diversity. The species diversity indices were also significantly correlated with some of the soil variables, including Na, T.N.V, saturation percentage (S.P) and soil texture. The trend of changes in species diversity in the study area had significant correlation with the type of geological formation.