جستجوی مقالات مرتبط با کلیدواژه « maximum entropy model » در نشریات گروه « اکولوژی »

Drought is one of the natural disasters that can occur in any climate. In recent decades, Iran has been continuously affected by severe and widespread droughts and has imposed harmful effects on various economic sectors, including the country's water resources. One of the needs for the growth and development of every country is water. On the other hand, due to the lack of permanent or even seasonal surface water flows in many plains of the country, one of the most important sources of water harvesting is the use of underground water reserves. Therefore, it is very important to investigate the status of these resources and determine the influencing factors on them. In this research, it has been tried to identify the areas that are exposed to severe groundwater drought and the impact of the factors affecting groundwater drought using the maximum entropy model and using MaxEnt software in the basin. The Jiroft plain watershed should be identified. To implement the maximum entropy model, 70% of the data were used for model training and 30% for model testing. The results of this study, based on the jackknife test, showed that the most important factors affecting groundwater drought are altitude, distance from the river, and soil moisture, and the model shows the most sensitivity to these parameters. gave Also, the results showed that the model has an acceptable accuracy in identifying groundwater drought, so that the accuracy of the model was estimated at 0.76.

Plants producing nectar and pollen, producing abundant nectar and pollen strengthen the pollinator population and increses biodiversity and honeybee products. Teucrium and Thymus kotschyanus are among the most important species to produce vegetable nectar in Iran. These plants play a major role in producing honey and pollen in rangelands. In the present study, the potential distribution for T. kotschyanus and T. polium was assessed by using the MaxEnt model.  Firstly, 19 bioclimatic variables were extracted from chelsa data collection for evaluating the current weather condition and was modeled by max software. According to the results, the organic carbon content in the soil profile (orc) is the most important variable affecting the distribution of both species. In. T. kotschyanus not only the soil organic carbon but also the amount of sunlight (solar), deriest month (BIO14) and aspect are the most influential variable. In addition to the amount of aspect, annual rainfall (Boio12) and the weight percentage of sand particle are also considered to be the most important environmental factors in the distribution of T. polium and Thymus kotschyanus species. The results of this study can provide valuable information to identify the priority of areas and possible future shelters for the protection of T. kotschyanus.  T. polium. Species.

Predicting the effect of climate change on the distribution of valuable and endangered plant species is essential for their conservation and management. In this study, the MaxEnt model and 10 environmental variables were used to predict the current and future distribution of E. amoenum and E. italicum in response to climate change. Also, to predict the effect of climate change in the future (the 2050s and 2070s), two climate scenarios of RCP 2.6 and RCP8.5 were used under the CCSM4 general circulation model. Evaluating the accuracy of the models based on the AUC index indicates their excellent performance (<0.9). Resutls  of this study reveal that the most important variables affecting the distribution of E. amoenum species are slope (38.8%), annual temperature range (11.5%), and precipitation in the driest season (31.9%) are. Also, the solar radiation (37.6%), slope (36.4%), and the average temperature of the coldest season (11.5%) are the most important environmental factors affecting the distribution of E. italicum. In addition, the results show that the distribution of the studied species will decrease in response to climate change and under RCP2.6 and RCP8.5 in the 2050s and 2070s. Therefore, the results of this study emphasize the need to develop  conservation strategies to prevent the extinction of these species.