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.
morteza Khodagholi; Razieh Saboohi; Mina Bayat; Parvaneh Ashouri; Javad Motamedi (Torkan)
Volume 29, Issue 4 , January 2023, , Pages 530-541
Abstract
Understanding the environmental factors affecting the establishment of vegetation, can help in the proper management of rangeland ecosystems. Optimal habitat has a beneficial effect on the survival and reproduction of species. With the advancement of statistical science and GIS, it has become possible ...
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Understanding the environmental factors affecting the establishment of vegetation, can help in the proper management of rangeland ecosystems. Optimal habitat has a beneficial effect on the survival and reproduction of species. With the advancement of statistical science and GIS, it has become possible to predict the habitat of plant species using modeling methods. Therefore, the present study was conducted with the aim of preparing a forecast map of B. tomentellus habitats based on the climate forecast model in South Zagros (Fars province). First, using 29 synoptic stations inside and adjacent areas, a database including variables of precipitation, night temperature, daily temperature and average temperature was formed and 19 climatic measures were calculated. Also, using a digital height model with an accuracy of 30 meters, three physiographic variables including slope, direction and height were prepared. Then, using updated maps of ecological zones and field visits, the presence and absence points of B. tomentellus were identified. Using logistic regression, the growth behavior of this species in the South Zagros region was determined and the model map and the corresponding equations were calculated in the current conditions. Using current equations and placement of data extracted from the Worldclime database, the future distribution map of B. tomentellus for 2050 was generated under the RCP4.5 and RCP8.5 climate scenarios. The results showed that B. tomentellus species will migrate to higher altitudes of 170 and 260 m, respectively, in the RCP4.5 and RCP8.5 scenarios. Also, the area of suitable habitat areas, from 26.8% of the area of South Zagros rangeland habitats in the current conditions, to 8.5% under the RCP4.5 scenario and 1.7% under the pessimistic scenario (RCP8.5) in 2050 Will be reduced.
leila kashi zenouzi; Shahram Banedj Schafiee; Hosein Saadat
Volume 23, Issue 1 , June 2016, , Pages 150-160
Abstract
This research was aimed to investigate the relationship between the distribution of range species including: Astragaluss microcephalus, Bromus tomentellus, Onobrichis cornuta and some soil physicochemical properties. After overlaying the maps of land-use, slope percentage, and geology, and forming the ...
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This research was aimed to investigate the relationship between the distribution of range species including: Astragaluss microcephalus, Bromus tomentellus, Onobrichis cornuta and some soil physicochemical properties. After overlaying the maps of land-use, slope percentage, and geology, and forming the homogenous land units in the Zilber Chay Watershed, 35 soil samples were taken by stratified random sampling method. Soil physicochemical properties including texture, pH, EC, lime, and organic matter were measured. The soil factors related to each of these range species were obtained by overlaying the maps of range species distribution with land unit maps. First, the relationship between the presence of these range species with soil factors was investigated using logistic regression method. Then, the vegetation density map was prepared using Landsat satellite images and NDVI index for the land units in which the range vegetation type As.mi-Br.to-On.co was found. The values of area density percentage for the vegetation cover related to the range type As.mi-Br.to-On.co were calculated using area density model. According to the results of paired samples test, there was no significance difference among the measured values at 0-15 and 15-45 cm soil depths, except for soil acidity and electrical conductivity. The statistical analysis of the relationship between soil physiochemical properties at 0-15 and 15-45 cm soil depths was performed using multiple linear regression method. The determination coefficient of multiple linear regression model was calculated to be 0.24, 0.31, 0.32, 0.42 and 0.69, respectively, for the vegetation densities of 30, 50, 65, 85 and 100% at 0-15 cm soil depth. In addition, the regression coefficients of soil acidity and electrical conductivity were calculated to be 0.24, 0.31, 0.32, 0.42, and 0.69, respectively, for the vegetation densities of 30, 50, 65, 85, and 100% at 15-45 cm soil depth. This result indicated that the vegetation density of As.mi-Br.to-On.co was affected by the amount of organic matter, pH, and soil texture at 0-15 cm soil depth in the study area.
Zeinab Jafarian; Hossein Arzani; Mohammad Jafari; Ghavamedin Zahedi; Hossein Azarnivand
Volume 19, Issue 3 , December 2012, , Pages 371-381
Abstract
This research was aimed to investigate the relationships between dominant rangeland species and environmental factors in the Rineh rangelands located on the southern slope of Damavand Mountain. Stratified random sampling method was applied and the study area was classified to 37 sample units based upon ...
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This research was aimed to investigate the relationships between dominant rangeland species and environmental factors in the Rineh rangelands located on the southern slope of Damavand Mountain. Stratified random sampling method was applied and the study area was classified to 37 sample units based upon elevation, slop and aspect.
In the study area, 750 plots 1m2 and 75 plots 25m2 were established. One hundred and fifty soil samples were dug at the depth of 0-30 cm and 16 soil properties including pH, CaCo3, bulk density, particle density, total phosphorus, total nitrogen, absorbed potassium, organic matter, saturation moisture, soil texture, field capacity, permanent wilting point, available water capacity and water holding capacity were measured in laboratory. After collecting the climate data, 16 climate factors including average relative humidity, average rainfall, average temperature, average minimum temperature, average maximum temperature in spring, summer and annual as well as annual frost days were selected to reconstruct the missing data. IRS images including red and near-infrared bands and PAN band as well as combined bands derived from RVI, NDVI, and PCA were selected. Regression equation was developed for each species using logistic regression. Results indicated that most of the factors including slop, aspect, average minimum temperature in spring, number of frost days, average daily temperature in summer, and most of the soil factors were entered in regression models. Also, satellite data were used as effective tools in showing the presence of plant species.
Mohammad ali Zare Chahoki; Marjan Shafizade
Volume 15, Issue 3 , January 2008, , Pages 403-414
Abstract
The aim of this research was to study the relationships between presence of plant species and environmental factors in Chabeyki region of Yazd province. After delimitation of the study area, sampling was performed using randomized-systematic method. Within each type 5 parallel transects with 500 m length, ...
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The aim of this research was to study the relationships between presence of plant species and environmental factors in Chabeyki region of Yazd province. After delimitation of the study area, sampling was performed using randomized-systematic method. Within each type 5 parallel transects with 500 m length, each containing 50 quadrates (according to vegetation variations) were established. Quadrate size was determined for each vegetation type using the minimal area method. Soil samples were taken from 0-30 and 30-80 cm in starting and ending points of each transect. Measured soil properties included gravel, texture, available moisture, saturation moisture, organic matter, lime, gypsum, pH, electrical conductivity and soluble ions (Na+, K+, Mg2+, Ca2+, Cl-, , and ). Logistic regression technique was used to analyze the collected data. The results showed that the vegetation distribution is mainly related to soil characteristics such as gravel, saturation moisture, EC, pH, and lime. The presence of Cornulaca monocantha andCalligonum comosum has negative relation with saturation moisture and positive relation with gravel. Haloxylon aphyllum has also positive relation with pH. While, the presence of Seidlitzia rosmarinus has positive relation with Lime. EC has positive relation with the presence of Tamarix ramosissima.