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.
Parvaneh Ashouri; Behnam Hamzeh; Adel Jalili
Volume 27, Issue 3 , October 2020, , Pages 385-395
Abstract
The ecological model of productivity-species richness relationships states that maximum species diversity occurs when species production is moderate, and there is a humped-back pattern between production as ecosystem energy variable and species richness. The discovery of this ...
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The ecological model of productivity-species richness relationships states that maximum species diversity occurs when species production is moderate, and there is a humped-back pattern between production as ecosystem energy variable and species richness. The discovery of this relationship leads to an understanding of the processes of biodiversity formation in ecosystems. To test this model, species production and richness were measured in the semi-steppe ecosystem of Gharebough in the Anguaran wildlife refuge in Zanjan province. Correlation and linear and nonlinear regression analysis were used to examine the relationship between species richness as a dependent variable and productivity as an independent variable. A total of 41 plant species were identified in 30 plots. The average species richness per plot per square meter was calculated as nine species. The relative production percentages were 15% for shrubs, 16% for forbs, and 69% for grasses. The highest percentage of presence in the plots was allocated to Stipa lessingiana, Poa bulbosa, Astragalus stevenianus, and Bromus tomentellus. The total production of the species was calculated to be 83 g/m2. Shrub production and forbs showed a significant linear regression relationship with species richness. Also, the shrub production had a significant nonlinear regression relationship with species richness, showing a humped-back pattern. The findings of this study showed that increasing production increases species richness and according to the values of the coefficient of explanation of regression relations (R2), in addition to the production factor, other important factors play a role in species richness. Therefore, this hypothesis cannot be confirmed on a local scale.
Mohammad Phayaz; Hasan Yeganeh; Houshmand Safari; Hamzeh Ali Shirmardi; Rasoul Mirakhorli; Seyed Hamid Habibian; parvaneh Ashouri Sanjabi
Volume 20, Issue 4 , March 2014, , Pages 686-694
Saeid Rashvand; Hoshmand Safari; Parvaneh Ashouri sanjabi
Volume 19, Issue 2 , September 2012, , Pages 355-369
Abstract
In this study, sustainability of forage production in some rangeland species of mountainous rangelands of Alamut Qazvin was investigated. These mountainous rangelands are located in the highlands of North-Eastern city of Qazvin as a part of south basin of central Alborz Mountains. The rainfall of these ...
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In this study, sustainability of forage production in some rangeland species of mountainous rangelands of Alamut Qazvin was investigated. These mountainous rangelands are located in the highlands of North-Eastern city of Qazvin as a part of south basin of central Alborz Mountains. The rainfall of these natural environments is 400 mm per year. Long dry season is considered as the main characteristics of the natural environments of these ecosystems. Production per hectare of 24 species was studied during four years. Combined analysis of variance for dry forage production (kg/ha) showed significant differences (p>0.01) among species and the years. According to the results of mean comparisons (Duncan’s multiple test) and cluster analysis (Ward method), Eryngium billardieri, Cousinia esfandiari, Artemisia aucheri, Verbascum speciosum, Agropyron intermedium, and Cirsium haussknechtii had higher forage production. Interaction effect of species * year was significant at 1% probability level and sustainability parameters were calculated based upon average forage production. Parameters of CVi, S2di and R2 had similar trends in introduction of sustainable species and most of them showed low forage production based upon these parameters. Parameters of Bi, W2i and S2i also showed the same trend in expression of sustainability and on the basis of these three parameters, an average forage production was recorded for most of sustainable species. In general, Cousinia esfandiari and Artemisia aucheri showed appropriate production sustainability based upon most sustainability parameters. Agropyron intermedium and Cirsium haussknechtii were not sensitive to adverse conditions while Verbascum speciosum and Eryngium billardieri were sensitive to adverse conditions. Therefore, Agropyron intermedium and Artemisia aucheri could be introduced for range improvement programs.