Mashaallah Ghonchepour; Majid Sadeghinia; Naser Baghestani; Ahmad Pourmirazee; Mohammadreza Kodouri
Volume 30, Issue 1 , April 2023, , Pages 152-163
Ebrahim Atarod; Naser Baghestani; Jalal Barkhordari; Ali Beman Mirjalili
Volume 25, Issue 2 , August 2018, , Pages 289-297
Abstract
This study was carried out in the Serizi- Bafq flood water spreading area of Yazd province. Vegetation sampling was performed in four flood spreading areas and the adjoining area as control in a completely randomized design. In order to investigate the vegetation changes, the transect-quadratic ...
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This study was carried out in the Serizi- Bafq flood water spreading area of Yazd province. Vegetation sampling was performed in four flood spreading areas and the adjoining area as control in a completely randomized design. In order to investigate the vegetation changes, the transect-quadratic method was used and three transects with a length of 100 meters were established. On each transect, 10 plots of 5×5(m2) were used. Collectively, 120 plots were installed inside the flood spreading area as well as in the control area. The parameters of canopy cover, density and presence of the plants in the flood and control areas were measured. The data were analyzed using t-test in SPSS software. The results showed that the percentage of canopy cover, density and presence of Hammada salicornia, Seidlitzia rosmarinus as well as the percentage of total canopy, total density and total species presence showed a significant difference at the 1% level. A significant difference was also found for litter coverage at the 5% level. The total percentage of annuals, Zygophyllum europterum, Salsola yazdiana, and Artemisia seiberi in the flood and control areas was not statistically significant. Flood water spreading operations have led to the presence of Zygophyllum europterum, Salsola yazdiana, and Artemisia seiberi. The vegetation percentage of these species is low in the current situation, but with repeated water logging in the flood spreading area, there may be significant changes in the long-term vegetation composition.
Naser Baghestani Mebodi; Mohammad Taghi Zare; Mohammad Fayyaz
Volume 20, Issue 4 , March 2014, , Pages 809-818
Ali beman Mirjalili; Ghasem ali Dianati Tilaki; Naser Baghestani
Volume 15, Issue 3 , January 2008, , Pages 295-303
Abstract
Five distance sampling techniques used to estimate density for Artemisia aucheri and Cornulaca monacantha species in this survey include: point center quarter, closest individual, nearest neighbor, random pairs and angle order methods. Sampling was conducted within 3 (40 m ×100 m) sampling areas ...
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Five distance sampling techniques used to estimate density for Artemisia aucheri and Cornulaca monacantha species in this survey include: point center quarter, closest individual, nearest neighbor, random pairs and angle order methods. Sampling was conducted within 3 (40 m ×100 m) sampling areas selected in TangLaybid. 30 points were selected equidistant apart along 10 randomly located 100-m transects for measurement of distance within each sampling area. Density obtained by each method was compared to the total count in a randomized complete design and Duncan’s test. Hopkines and Eberhardt indices were used to detect dispersion pattern of plants. The point center quarter method provided a reliable estimate of density for Cornulaca monacantha in the community with density of 0.38/ and a clumped distribution. The nearest neighbor method gave a reliable estimate of density for Artemisia aucheri in the communities with density of 1.8/ and 2.9/ and a tendency toward uniformity. Results showed that the point center quarter method can give reliable results in shrub communities with cover around 10% and a clumped pattern while the nearest neighbor method can give a reliable estimate in communities with cover between 16-20% and a uniform pattern.
Hosein Gharadaghi; Hosein Arzani; Hasan Ebrahimzadeh; Mohammad reza Ghnnadha; Naser Baghestani
Volume 14, Issue 1 , January 2007, , Pages 19-32
Abstract
Rangelands are one of the important natural ecosystems in our country that were deteriorated during recent decades because of many causes especially earlier and intensive grazing. Grazing management need to determine beginning of grazing season and intensity in rangelands. It is very important to know ...
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Rangelands are one of the important natural ecosystems in our country that were deteriorated during recent decades because of many causes especially earlier and intensive grazing. Grazing management need to determine beginning of grazing season and intensity in rangelands. It is very important to know much about physiological and phenological status of rangeland species. Total nonstructural carbohydrates (TNC) and their changes during seasonal growth is one of the important physiological parameter in perennial plants. Also these reserves are primary source of energy in respiration, growth and survival of perennial plants during their quiescence and growth season and regrowth after grazing or cutting. In this research seasonal changes of TNC reserves in three perennial and desirable grass species(Bromus tomentellus, Festuca ovina, Dactylis glomerata) were studied in Polor summer rangelands(altitude, 2600m; annual precipitation, 535mm; with cold mountain climatic) at the north of Tehran province. Samples were collected in ten stages of plants phenology stages with three replications from above and underground matter (canopy and roots). Samples were oven dried at 70◦C during 48 houres. TNC concentration were measured by phenol-solpheric method (mg per gr dry matter). Data of all attributes were analyzed in the frame of rondomized compeletly block design by using Minitab software, and ANOVA one and two ways. Seasonal changes of TNC reserves in any of studied species and also their root and canopy were shown in annual curves. The results indicated that all species have distinct seasonal changes and they had the lowest TNC reserves at early spring and end of the seasonal growth and then increased. The results showed significant differences in TNC reserves between phenology Stages in root and canopy during seasonal growth (P= 0.05 & 0.01) and all species had higher amount of TNC reserves in root than canopy (P=0.01). The rate of TNC restoration was different between studied species. These differences were related to phenology and seasonal growth along. So in this area Dactylis glomerata is more sensitive to grazing and Bromus tomentellus conversely is more resistant to grazing. At the end we concluded that critical period for all species in relate of their TNC reserves is from starting growth in early spring till early May and at the end of seasonal growth, mid August. Beginning of grazing season from late may until early August is recommended for this area.
Jalal Abdollahi; Hosein Arzani; Naser Baghestani; Mohammad Hasan Rahimian
Volume 13, Issue 3 , February 2006, , Pages 162-171
Abstract
Remote sensing is a method to produce updated information in vast area. Describing the model for utilization and processing satellite data in regard to developing a method for mapping forage production of arid regions were the purpose for this study. For this purpose Landsat ETM+ data used at Nodushan ...
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Remote sensing is a method to produce updated information in vast area. Describing the model for utilization and processing satellite data in regard to developing a method for mapping forage production of arid regions were the purpose for this study. For this purpose Landsat ETM+ data used at Nodushan area in 2002 . The study area covers about 60000 hectares and the annual precipitation is about 140-300 mm. in order to correct the necessary data 50 sites with different vegetation types using 25 quadrant of 1*2 m size and then awareged were used. To study the dependent variable of vegetation relations with independent variables of satellite data, vegetation indices and environmental factors; multiple linear regression analysis were manipulated using SPSS software. Then a suitable model was selected which caried predict the vegetation properties of the study area. Finally, production map was produced using ILWIS software. According to the results, mapping of forage production via remote sensing is possible even when its vegetation cover is less than 25%.
Jalal Abdollahi; Hosein Arzani; Naser Baghestani; Fakhr.... MirAskarshahi
Volume 13, Issue 2 , February 2006, , Pages 74-81
Abstract
An optimal planning system for managing the range and maintaining it’s vegetation is highly influenced by the humidity and rainfall of the range. In this research, the reactions of the seidlitzia rosmarinous species to the fluctuation of precipitation and under ground water were studied at Chah-Afzal ...
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An optimal planning system for managing the range and maintaining it’s vegetation is highly influenced by the humidity and rainfall of the range. In this research, the reactions of the seidlitzia rosmarinous species to the fluctuation of precipitation and under ground water were studied at Chah-Afzal in Ardakan-Yazd. Regarding the amount of collecting data after five years, by applying Minitab software, using linear regression, an equation between the amount of the production and precipitation was obtained with a high correlation coefficient (r=0.93). The results showed that the variation of the plant production was due to the fluctuation of the annual precipitation. Moreover, result of another analysis was demonstrated a lack of agreement between the cover and density of the se.rosmarinous species with the amount of precipitation. In addition, the results state that the downward trend in the percentage of canopy cover and the density of the se.rosmarinous species in the region are highly influenced (r=0.94 and r=0.99 respectively) by the discharge of ground water table. Thus, the gradual decrease of this source in the coming years might bring out negative effects on the cover, density and finally on the condition of the range in Chah-Afzal. Also, Interaction between the effect of ground water table changes on the amount of forage production was not significant.