zhila ghorbani; Kiomars Sefidi; farshad Keivan Behjou; Mehdi Moameri
Volume 25, Issue 3 , November 2018, , Pages 500-511
Abstract
This study was conducted to assess the effects of different grazing intensities on the biomass amount of Agropyron libanoticum and Festuca ovina in summer rangelands of southern Sabalan, Ardabil province. After determining three sampling areas as different livestock grazing treatments ...
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This study was conducted to assess the effects of different grazing intensities on the biomass amount of Agropyron libanoticum and Festuca ovina in summer rangelands of southern Sabalan, Ardabil province. After determining three sampling areas as different livestock grazing treatments (light, moderate, and heavy grazing), plant sampling was performed by a random-systematic method in 25 plots along 600-m transects. A linear regression was used to determine the relationship between aerial and underground biomass. To assess the effects of different grazing intensities on biomass of these species a one-way ANOVA and Tukey test were used. The results showed that there was a significant relationship between aerial and underground biomass of two species in different treatments. Moreover, increasing the livestock grazing intensity resulted in a significant decrease in the aerial and underground biomass and total biomass of both species. In addition, increasing grazing intensity leads to decreasing aerial biomass in moderate and heavy grazing treatments compared to the light grazing intensity (26.31% and 42.24, , for Festuca ovina, respectively, and 22.04% and 48.76% for Agropyron libanoticum, respectively. Increasing grazing intensity leads to decreasing underground biomass in moderate and heavy grazing treatments compared to the light grazing intensity (25.14% and 42.75 for Festuca ovina, respectively, and 9.39% and 35.30% for Agropyron libanoticum, respectively. Generally, grazing intensity reduced the aerial and underground biomass of Agropyron libanoticum and Festuca ovina.Therefore, grazing control in rangeland management is necessary to prevent the destruction of these species.
Farid Dadjou; Ardavan Ghorbani; Mehdi Moameri; Mahmoud Bidarlord
Volume 25, Issue 3 , November 2018, , Pages 577-593
Abstract
The purpose of this study was to investigate the relationship between rangeland aboveground production based on total aboveground production and life forms of grasses, forbs, and shrubs with 25-year temperature and precipitation data, the year before sampling, and the year of sampling in Hir and Neur ...
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The purpose of this study was to investigate the relationship between rangeland aboveground production based on total aboveground production and life forms of grasses, forbs, and shrubs with 25-year temperature and precipitation data, the year before sampling, and the year of sampling in Hir and Neur rangelands in Ardabil province. To determine the aboveground production, the amount of production was estimated using the harvesting method in one square meter plots (totally 330 plots) in three elevation classes under the range of 1446-2750 meters. Temperature and precipitation were calculated for each plot. Aboveground production maps were prepared in a GIS environment using extracted regression equations. The results showed that over the years, precipitation decreased and temperature increased, and aboveground production also decreased in relation to those climatic factors. Moreover, there is a significant relationship (P<0.01) between the aboveground production of life forms and total aboveground production with climatic factors, and aboveground production of grasses and total have a direct relationship with precipitation; however the maximum aboveground production of forbs was recorded in the middle ranges and maximum aboveground production of shrubs was recorded in the higher ranges of annual precipitation. Grasses and total aboveground production had an inverse relationship with temperature, and the maximum aboveground production of forbs and shrubs was recorded in the middle and lower ranges of annual temperatures, respectively. According to the accuracy of derived regression equations, the maps prepared by climatic data of 1394 and 1395 were better than 25-year climate data. The results of this study can be used for the supply-demand balance of aboveground production, biomass accounts, and ecosystem carbon balance indicator that is potentially an important tool for sustainable development.
Maryam Asadi; Kiomars Sefidi; Mehdi Moameri
Volume 25, Issue 2 , August 2018, , Pages 417-426
Abstract
Livestock grazing is the most common type of rangeland uses that can affect the composition of rangeland vegetation, net primary production, stem to root ratio, and nutrient cycle. This research was conducted to study the impacts of various grazing intensities on nutrient allocation of phosphorus, calcium, ...
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Livestock grazing is the most common type of rangeland uses that can affect the composition of rangeland vegetation, net primary production, stem to root ratio, and nutrient cycle. This research was conducted to study the impacts of various grazing intensities on nutrient allocation of phosphorus, calcium, sodium, and potassium in aerial and underground biomass of Artemisia aucheri in the summer rangelands on the southeast slope of the Sabalan. In this study, a systematic-random sampling was employed. Three parallel transects of 200 m length were established in each grazing intensity. Then along each transect, one square meter plots with 50 m intervals were established to collect the aerial and underground biomass. Analysis of variance revealed that the allocation of phosphorus and calcium of the aerial organs were significantly affected by different grazing intensities. In addition, sodium and calcium of underground organs were significantly different at 1% level. The results of this research and the effect of different grazing intensities on nutrient allocation could be used in the identification and management of livestock grazing and rangelands.