جستجوی مقالات مرتبط با کلیدواژه "مدل سازی پراکنش گونه" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

Identification of habitats potential of endemic species can facilitate conservation planning and rehabilitation programs in watershed. The purpose of this study is modelling the distribution of Artemisia aucheri habitats in watershed of Baladeh Nour city, Mazandaran province. For achieve of this objective, environmental map variables (physiographic, soil and climate parameters) was prepared with geographic information systems techniques in cell size of 10 x 10. Also; 60 site as well as the presence or absence of species were recorded by sampling classified – random. For each sampling site were recorded information about the presence or absence of species and environmental variables, and the relationship between species distribution and environmental factors was determined by using logistic regression (LR), and forecast maps the distribution of the Artemisia aucheri Boiss was produced in the study area. According to LR results, between 14 environmental variables: Slope, pH, Sodium Absorption Ratio, Silt and Annual Mean Temperature were the most important environmental factors influencing the distribution of the species. Evaluate the correctness statistical models were performed by using the kappa coefficient and ROC area under the curve plots. Value indices respectively are 0.5 and 0.75 for the logistic regression model; their values indicated the logistic regression method can to create potential habitat map on local scales. This model, therefore, can be applied to recognize potential sites for rangeland reclamation projects.

The climate change is the greatest environmental challenge facing the world today. The prediction of the effect of climate change on the distribution of sensitive and valuable plant species is considered important in the management and conservation of them. Onosma L. as a very rich taxa from Lithospermeae Dumort. tribe in Boraginaceae family including 52 species in Iran wich more than half of them are endemic to Iran. The Onosma sabalanica Ponert. and Onosma cornuta H. Riedl. are the rare and endemic species of Onosma L. in Iran. Objective of the present study was to predict the effects of the climate change on the spatial distribution of these plants at future. In this regard, with using species distribution model's tool (SDM), different algorithms (GLM, GAM, GBM, RF, CTA, FDA, MARS, ANN, SRE) in different optimistic (RCP2.6) and pessimistic (RCP8.5) scenarios predicted the future spatial distribution of this species for 2050 by an ensemble model in R statistical software. The results showed that the performance of all models based on TSS index was excellent and modeling of the distribution of the species had been done with high statistical reliability. The results also represented that the distribution of these species in both optimistic and pessimistic scenarios of 2050 had been significantly reduced which requires to apply strategies for protecting of this valuable plants.