Masome Narouei; Morteza Khodagholi; Razieh Saboohi
Volume 31, Issue 3 , September 2024, , Pages 284-300
Abstract
Abstract Background and objectives:Knowing the effective environmental factors in the establishment of vegetation can help the proper management of pasture ecosystems. A suitable habitat has a significant effect on the survival and reproduction of species. Revealing changes in climate ...
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Abstract Background and objectives:Knowing the effective environmental factors in the establishment of vegetation can help the proper management of pasture ecosystems. A suitable habitat has a significant effect on the survival and reproduction of species. Revealing changes in climate parameters indicates that climate changes have started in Iran and it is necessary to determine the potential habitats of indicator species, now and in the coming years, under climate warning models. With the advancement of statistics and geographic information system, it has become possible to predict the habitat of plant species using modeling methods. Therefore, this research was conducted with the aim of preparing a forecast map of Platychaete aucheri habitats based on the climate forecast model in Sistan and Baluchestan province.Methodology:First, using 8 synoptic stations inside and nearby areas, the database including precipitation variables, night temperature, daily temperature and average temperature, from the year of establishment of each station until 2019, and 19 climate parameters were calculated. Also, three physiographic variables, including slope, direction and height, were prepared using a digital height model with an accuracy of 30 meters. Then, by using the updated maps of the ecological zones recognition plan and field visits, the presence and absence points of P.aucheri species were determined. The basis of the analysis used in this research is logistic regression, which is based on environmental values related to the presence and absence of species. Using logistic regression, the growth behavior of this species in Sistan and Baluchestan region was determined and the map was modeled and the relevant equations were calculated in the current conditions. After ensuring the efficiency of the model, the climate data predicted by the general circulation model MRI-ESM2-0 were used under the scenarios 4.5 and 8.5, and by using the current equations and placing the data extracted from the database, Worldclime, the future distribution map of the species P.aucheri was produced for 2050 under RCP4.5 and RCP8.5 climate scenarios. In this way, at the stage of defining the logistic regression model in ArcGIS, instead of the map of the climate variables that exist in the model, the maps of the same variables predicted for the year 2050 were placed.Results:The results of the potential maps showed that the current distribution of the species, P.aucheri, had a more colorful presence in the central and southern parts, and the percentage of the presence of the species decreased by moving towards the northern regions. The area of suitable habitat (probability of occurrence greater than 75%) of P.aucheri species in the province is equal to 12873269 hectares, approximately 71%. The evaluation of the model was done using the data of the presence and absence of the species and using the Kappa statistical coefficient. In this connection, the value of the Kappa statistical coefficient was obtained as 0.85, which according to the presented classification of the Kappa coefficients, the model has good and acceptable accuracy. It is acceptable. The maps resulting from the prediction of the logistic regression model show that the habitat area of P.aucheri species will increase significantly in 2050 under both RCP4.5 and RCP8.5 scenarios, and it is observed that the habitat area of P.aucheri species is more than 75% more likely to occur. In the province, it will be equal to 15506391 and 17788376 hectares, respectively, which will occupy a surface equivalent to 85.3 and 97.85%, respectively. Under the RCP8.5 scenario, the probability of the presence of the species will increase greatly, and it can be seen that the probability of the presence of this species in the lower floors reaches 50% to zero. Conclusion:In general, climate change and the consequent increase in temperature indicators will preserve the current habitat, increase the probability of the presence of the species in the entire province, and the vertical expansion of the P.aucheri species and its movement to higher latitudes along the altitude gradient of the region. Therefore, the expected upper limit of the vegetative range of P. aucheri species will undergo changes during the next three decades.
Saeedeh Nateghi; Morteza Khodagholi; Mahshid Souri
Volume 31, Issue 3 , September 2024, , Pages 301-322
Abstract
Abstract Introduction Rangeland ecosystems are very important and sensitive to changes in environmental factors. Small changes in temperature and rainfall regime or other climatic events can fundamentally reduce the composition, distribution and dispersion of plant species as well as ...
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Abstract Introduction Rangeland ecosystems are very important and sensitive to changes in environmental factors. Small changes in temperature and rainfall regime or other climatic events can fundamentally reduce the composition, distribution and dispersion of plant species as well as their production. To better understand future climate change, it is essential to determine the current and future distribution of species. Species distribution modeling is currently the only tool that can be used to assess the number of changes in the distribution of multiple species in response to climate change. Therefore, considering the importance of climate in the distribution of plant species, this research examines the distribution of plant species in the future, taking into account the relationship between the important pasture species in Alborz province and the climate factor. Materials and methods In this research, four plant species including Stipa arabica, Ferula ovina, Bromus tomentellus and Artemisia aucheri were investigated in Alborz province. In order to determine the amount of precipitation and temperature, the data of the synoptic stations, which were analyzed by the Man-Kendall method, were used. Using the maps of the Ecological Zones Recognition Plan of the Forestry and Rangeland Research Institute and ArcGIS, the vegetation cover map of the province and the current distribution of species, the presence and absence of species were drawn and recorded. In order to prepare the environmental information layer, 19 bio-climates for the present were calculated and downloaded from the WorldClim.org site for 2050 with an accuracy of 30 seconds. These data were obtained for two scenarios RCP4.5 and RCP8.5 for the future period. Then, the values of environmental variables were entered as independent variables and species presence and absence information as dependent variables in SPSS software, and the logistic regression statistical model was obtained from the presence of selected species. This statistical model was defined in the ArcGIS software environment and the potential species map was prepared. Kappa statistical coefficient was used to validate the resulting potential habitat maps model using 22 independent variables and with the help of error matrix. Results The results showed the rising temperature trends in all stations, and 65.76% of the trends were significant. In the northern and eastern heights of Alborz province, the increase in average temperature, especially in the early spring, late autumn and winter seasons, will cause early snow melting in the region, and due to the decrease in precipitation in the mountainous regions, it will cause many problems in water storage. According to the predictions of the logistic regression model, Stipa arabica species, 68626 hectares equivalent to 13% of the province, Bromus tomentellus, 298842 hectares equivalent to 58% of the province, Ferula ovina, 195465 hectares equivalent to 38% of the province, and Artemisia aucheri, 232539 hectares equivalent to 45% of the province have the probability of occurrence of class 75-100 The percentage is for the presence of these species. The evaluation of regression model using Kappa coefficient for Stipa arabica, Bromus tomentellus, Ferula ovina and Artemisia aucheri species was equal to 86, 85, 82 and 79 respectively, which are models with good accuracy according to Koch and Smith classification. 19 bio-climatic maps were prepared under two scenarios 4.5 and 8.5 for the year 2050. The current situation is similar to the 4.5 scenario, but in both models, we will see a decrease in the probability of the floor occurring by 75-100 percent in 2050. Also, the average of all temperature parameters in Karaj station will increase by 1.9 degrees Celsius by 2050 and the amount of precipitation will decrease by 1.33 mm. Discussion and conclusion The researchers reported that although there have been no significant changes in rainfall over the past 50 years, the decrease in rainfall in April and the increase in rainfall in December and July can indicate possible climate change in these areas in the future, and the climate in Iran, especially in spring is warming, which confirms the results of the present study. The minimum and maximum height in which the Stipa Arabica species is present is 1400 and 2400 meters, respectively, and the modeling results in 2050 show this minimum and maximum height in the 4.5 scenario, 2400-2100 meters and in the 8.5 scenario, respectively. It shows 2900 meters. The minimum and maximum altitude where the Ferula ovina species is present is 1850 and 2600 meters, respectively. If the modeling results in 2050 show this minimum and maximum height unchanged in the 4.5 scenario and 2800-3000 meters in the 8.5 scenario, respectively. The Bromus tomentellus species is currently located at an altitude of 1600-2700 m, while in scenario 4.5 (equilibrium conditions) and scenario 8.5 (pessimistic scenario) it is at an altitude above 2500 m, which indicates that this species of There is not much difference in altitude opinion. The minimum and maximum altitudes where Artemisia aucheri is present are 1600 and 2800 meters, respectively. Slope and temperature are the two main parameters affecting the distribution of this species and so that the slope affects the depth of the soil and thus has an effect on the establishment of the roots. Due to heat compensation in pessimistic conditions, this species has moved to higher altitudes, i.e. around 3000 meters, which confirms the results of other researchers. With the increase in temperature due to climate change, the extent of habitat of the species under investigation will decrease and they will move to areas that are higher and therefore have lower temperature.
Mohammad Khosroshahi; Zahra Saeedifar; Khosro Shahbazi; Samira Zandifar; Sakineh Lotfinasabasl; Azadeh Gohardoust; Fatemeh Dargahian; Maryam Naeemi; Tahereh Ensafi Moghadam; Leila Kashi Zenouzi; Zohreh Ebrahimi Khosefi; Morteza Khodagholi
Volume 30, Issue 4 , February 2024, , Pages 521-541
Abstract
Background and objectivesWind erosion and dust phenomenon are considered as one of the important processes of land degradation and a serious challenge in Iran. This phenomenon occurs due to the interaction between weather and terrestrial processes. The purpose of this research is to investigate and analyze ...
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Background and objectivesWind erosion and dust phenomenon are considered as one of the important processes of land degradation and a serious challenge in Iran. This phenomenon occurs due to the interaction between weather and terrestrial processes. The purpose of this research is to investigate and analyze the trend of temporal and spatial changes in the number of dusty days in Iran and to investigate the role of climate in its spread. MethodologyIn this research, after receiving hourly and daily statistics of dust events (through 148 synoptic and climatology stations) and parameters of precipitation, evaporation, temperature as key climatic elements (from 171 stations) in 22 provinces located in arid and semi-arid regions of Iran, The spread of dust was investigated and the correlation between climate and dust was determined. After calculating the number of dust days in Iran, the information was called in the GIS environment and a map of the spatial changes of the parameter of the number of dust days in the three decades of 1987-1996, 1997-2006, 2007-2016 was prepared. In the following, the spatial analysis of this parameter and its expansion over three decades were investigated. Next, the climate parameter that had the highest correlation with the number of dusty days was selected and after preparing a map of its spatial changes in the GIS software environment, the spatial compatibility of the desired parameter with the expansion of the number of dusty days was investigated. In the next step, after performing the homogeneity test on the dust occurrences, the partial square regression model was used to determine the contribution of the three mentioned climatic elements as independent variables and the number of dust days as a dependent variable. ResultsThe results showed that the number of dusty days and the area of its occurrence have increased in Iran, so that in the last decade under study (2007-2016) compared to the previous two decades, the dustiest event occurred in Iran. This increase has been more intense especially in the western and southwestern regions of the country, which were also affected by extra-local dust events. These dust events have spread to the central regions of the country with greater frequency. The homogeneity test in many provinces showed a common change point (year 2007-2008) in the number of dusty days, which could be related to the beginning of severe droughts and climate changes from this year in Iran. The study of climatic parameters (temperature, precipitation and evaporation) on changes in the number of dust days in Iran showed that during recent years, temperature had the highest significant correlation level (0.58) with the occurrence of dust. The temperature gradient map in the last decade (2007-2016) compared to the previous decade (1997-2006) also showed the increasing trend of temperature, especially in the western and southwestern regions as well as the southeastern regions of Iran. Modeling the effect of climatic parameters of temperature, precipitation and evaporation on the parameter of the number of dusty days showed that the contribution of the studied climatic parameters to the occurrence of dusty days is about 33% and other effects can be related to things such as human factors or soil characteristics, type of vegetation, solar radiation, etc. ConclusionIn general, the results of examining the trend of changes in the number of dust days and climatic indicators for nearly 3 decades indicate a significant increase in the number of dust days in most parts of Iran and the conditions for this increase have been provided and if the trend of changing these indicators in the coming years is according to the current trend, the risk of environmental problems in the country can be expected to increase.
Farzad Heidari moorchekhortei; Mohammad Khosroshahi; Razieh Saboohi; Morteza Khodagholi; Leila Kashi Zenouzi
Volume 30, Issue 2 , September 2023, , Pages 196-213
Abstract
Background and objectivesResearch has been done on different materials to control and reduce wind erosion. Among them, we can mention the performance of agar gum biopolymer in reducing dust production at different concentrations of 0.5, 1.0, and 1.5%. Its results showed that the addition of biopolymer ...
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Background and objectivesResearch has been done on different materials to control and reduce wind erosion. Among them, we can mention the performance of agar gum biopolymer in reducing dust production at different concentrations of 0.5, 1.0, and 1.5%. Its results showed that the addition of biopolymer improves the water-holding capacity, increases the surface and compressive strength of the soil, and decreases dust production. In another study, agar gum biopolymer significantly improved soil mechanical properties. This study investigates the effect of polymer nuclei (M19) on controlling sand dunes. This research investigates the effect of nucleos (M19) mulch on reducing wind erosion and controlling sand dunes and dust. MethodologyThis research was carried out in Segazi Plain, a study and implementation priority due to its proximity to urban areas, military facilities, transportation, as well as industries and workshops located there, from the aspect of preventing wind erosion and desertification. After choosing the field, two plots of 500 square meters with the same conditions (an active hill with an area around it with natural and hand-planted vegetation) were selected. To determine the effect of soil cover, the area of each plot was determined by wooden stakes. In addition, the surrounding sand dunes were staked to measure their displacement. A pump sprayer mulched the measuring plot with nucleos (M19) mulch. Following the soil moisture changes, information including seedling survival and growth rate, soil cover's ability to control sand dune displacement, and compressive stress was examined during different months. Finally, the effectiveness of soil cover was compared with the control treatment using the T-test. Results The results of examining the changes in humidity and the effect of soil cover on it showed that the highest humidity in the area was after rain. No clear difference was observed between the drying process of the control plot and the mulched plot. It was also found that this mulch positively affects seedling growth rates. During the research period, the control sand dunes moved about 0.75 to 2.5 meters depending on the season and wind direction. In contrast, the mulched sand dunes remained stable. On the other hand, with time, the mulched field's surface became flaky, and signs of wear and tear were observed.ConclusionThe first point about using this polymer as a soil cover is its two phases during transportation and storage until mulching. In such a way, the two layers can be clearly distinguished. As a result, mixing is necessary for the uniformity of the polymer during the preparation of the final emulsion. This can be considered as one of the negative characteristics of the used polymer. This mulch positively affected soil moisture changes and increased soil moisture retention. On the other hand, the comparison of the growth of the seedlings in the mulched field and control also shows its effect on the growth of the seedlings. This soil cover's only positive and critical feature is its high flexibility after mulching in such a way that it is possible to drive on it with caution. Finally, after a year, cracks were first detected in the research field. Gradually, the number and depth of cracks increased, which caused the mulched field surface to become flaky. Following this complication, instability and signs of wear and tear were observed in the mulched area. However, no movement or change in location was observed in the mulched hill. It should be noted that with time, more destruction occurs on the surface of the mulched area. Following more flaking, the mulched surface may be destroyed, and hill erosion may begin. Considering these cases, mulching in this and similar areas is not recommended.
Razieh Saboohi; Farzad Heidari Mourchekhorti; Morteza Khodagholi; Somayeh Salehpour
Volume 28, Issue 2 , June 2021, , Pages 280-295
Abstract
The use of polymers to control wind erosion has been considered in recent years. However, before recommending them as mulch, their effects on the environment and reduction of wind erosion should be investigated. In this paper, the effect of Imen Asia polymer in stabilizing quicksands and reducing wind ...
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The use of polymers to control wind erosion has been considered in recent years. However, before recommending them as mulch, their effects on the environment and reduction of wind erosion should be investigated. In this paper, the effect of Imen Asia polymer in stabilizing quicksands and reducing wind erosion in both laboratory and field sections in the Lower Jargooiyeh region was investigated. For this purpose, first, an emulsion of polymer in water with a ratio of one to three (one-part polymer in two parts water) was prepared and to investigate its effect on reducing erosion, a volume of emulsion containing 80, 100, and 120 kg of polymer in 25 m2 plots Sprayed with three repetitions. The results showed that the wind erosion threshold speed after mulching increased from 3.5 to more than 11 m / s in all treatments. The study of the environmental effects of the polymer showed that the concentration of mulch did not affect the germination of native plants and the lifestyle of insects and rodents in the area. The effect of polymer on the physical and chemical properties of soil, including changes in the number of toxic elements and heavy metals on the soil before and after mulching, also confirms that it does not have a negative effect on these properties. Economically, the cost of using this polymer per hectare was evaluated. Based on the net present value (NVP) of this material and its internal rate of return (IRR), the economics of using it and investing in the use of this polymer as mulch are justified. Due to the lack of harmful effects on the environment and the ability to reduce wind erosion and economical to oil mulch, the use of this polymer as mulch is recommended
Morteza Khodagholi; Morteza Akbarzadeh
Volume 23, Issue 1 , June 2016, , Pages 118-127
Abstract
This study was conducted to demonstrate the growth behavior of Andrachne fruticosus L, Artemisia sieberi Besser، Euphorbia decipiens Boiss and Buhse، Noaea mucronataForssk، Scariola orientalis Sojak، Stachys inflate Benth، Stipa arabica Trin & Rupr and annual species in the Soh rangelands of ...
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This study was conducted to demonstrate the growth behavior of Andrachne fruticosus L, Artemisia sieberi Besser، Euphorbia decipiens Boiss and Buhse، Noaea mucronataForssk، Scariola orientalis Sojak، Stachys inflate Benth، Stipa arabica Trin & Rupr and annual species in the Soh rangelands of Meimeh, Isfahan during 2008 to 2010. To determine the production and consumption of the study species, a number of eight individuals for each species were selected for all months of growing and grazing season within the exclosure area as well as in the grazing area. Results showed that different years and months had significant effect on production of the study species (p < 0.01). According to the results recorded during the experiment, the average production of six perennials and annuals was calculated to be 255.9 kg dry forage per hectare. The highest production rate was obtained for Artemisia sieberi and annuals, 38.2% and 32.9% of total forage production, respectively. Production changes were totally affected by changes in the volume and distribution of rainfall and the correlation coefficient between them was statistically significant in all species except Euphorbia decipiens. The production of the study species showed high fluctuation in response to the most severe drought in 2008. Forage production of the study species in the high-production year was 4.5-20 times higher as compared with the low-production year. For all species, the highest forage production was obtained in May. The consumption rate varied in different years and the highest consumption was recorded in 2009 for all species except Euphorbia decipiens. As well, the highest consumption rate was recorded for annuals during the three study years.
Zahra Pakzad; Mahmoud Raeini Sarjaz; Morteza Khodagholi
Volume 20, Issue 1 , June 2013, , Pages 199-212
Abstract
To investigate the effect of climatic factors on distribution of Astragalus adscendens in rangelands of Isfahan province, 57 climatic variables with most importance in terms of ecology of this species were selected. Data were tested by factor analysis in SPSS 16. The maps of Isfahan climatic factors ...
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To investigate the effect of climatic factors on distribution of Astragalus adscendens in rangelands of Isfahan province, 57 climatic variables with most importance in terms of ecology of this species were selected. Data were tested by factor analysis in SPSS 16. The maps of Isfahan climatic factors in the factor analysis were drawn and integrated with the map of vegetation types and digital elevation map to identify the habitat of Astragalus adscendens. According to the results, the first three factors could explain 90.2% of total variance in selected variables as follows: temperature, precipitation, and radiation and wind, with 47.4, 30, and 12.8% of variance, respectively. The three climate factors were compared with the average of climate elements in the habitats of Astragalus adscendens and the areas without this species. Results showed that the areas with an altitude of 2400 m which have approximately 50% relative humidity, with more than 400 mm of rainfall per year and relative radiation are considered as the main habitat for Astragalus adscendens. The tolerance of this species to climatic factors is limited.