Ghader Karimi; Hasan Yeganeh; hasan barati
Abstract
Rangelands have been composed of different plant species that emergence of phenological stages in every one of them will be influenced by environmental and genetic factors. In order to exploit the time and achieve acceptable performance in each plant species, it is necessary that the emergence of biological ...
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Rangelands have been composed of different plant species that emergence of phenological stages in every one of them will be influenced by environmental and genetic factors. In order to exploit the time and achieve acceptable performance in each plant species, it is necessary that the emergence of biological phenomena are recorded and studied. The objective of the present study is to survey the different phenological stages of Bromus tomentellus in order to achieve proper management programs in the study area and similar areas. For this purpose, this study was conducted in semi- steppe rangelands of Kordan located in Alborz province for a 4-year period (2007- 2010). Among the plant species under consideration, ten plant bases were selected and recorded in special forms, during 4 years in the growing season, in 15-day intervals at the vegetative stage and in weekly intervals at reproductive stage, occurrence date of plant critical stages including the stages of the growth and vegetative growth, flowering, seed maturation and drying of the plant, along with the information related to the total height of plant in centimeter. In addition, the meteorological data and information relevant to a four- year study include; average monthly temperature and monthly rainfall from the meteorological station closest to the study area were prepared, and by noting the dry period, the Ombrothermic curves for the years 2007-2010 were separately drawn to adapt to the phenological stages of the study plant. The results indicated that this plant species begins its growth by noting the weather conditions, especially environment temperature (degree-day), in different years of the study period. Different phenological stages also have almost constant temperature demand (GDD), which the emergence of the stages is observed after obtaining the required temperature
Ghader Karimi; Hasan Yeganeh; Hasan Barati; Farhang Ghasriani
Abstract
Due to the growing trend of rangelands degradation, study effects of different harvesting intensities on species in order to gain a more fundamental utilization of ranglands can be effective for reclamation and improvement. The purpose of this research was to study effects of different harvesting intensities ...
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Due to the growing trend of rangelands degradation, study effects of different harvesting intensities on species in order to gain a more fundamental utilization of ranglands can be effective for reclamation and improvement. The purpose of this research was to study effects of different harvesting intensities on key species Ajuga chamaecistus.This species has a forage value in the study area. In this first region and a key area of one hectare in area Kordan and in the first year and was grazed, and fencing. Selected and removed from any of 0, 25, 50, 75% and control is exercised (a basic 10 treatments). Monthly by the clipper and the area is grazing season. Effect of harvest was study with the changes in the characteristics the species treated, including; forage and seed production, vitality, mortality and growth of shoots. Finally, production data the combined analysis of data with a split plot design and seed production, vitality, mortality and growth of shoots data in SAS software was analysed. Results of studies of the effects on forage production and harvest of Ajuga chamaecistus species showed the effect of different levels, different years, and their interactions on the production level is a significant percentage. This shows that in different years with different weather conditions of production are different. Also results of the analysis data showed seed production, vitality, mortality and growth of shoots are affected different levels of harvest and weather conditions. In general according to results indicated the negative effects harvesting at the level 75% was observed. In other words, heavy grazing has a negative impact on the species treated. So harvesting up 75% endangering the survival of these species and in fact, harvesting 50 percent it is not a serious problem.
