مدلسازی پراکنش گونه گیاهی مورخوش تحت تاثیر عوامل اقلیمی و زیست محیطی دراستان هرمزگان

ABSTRACT
Climate change greatly affects the distribution and existence of the plant species. The proposed study is intended to model and assess the influence of environmental factors on defining the appropriate habitat extent of Zhumeria majdae in the Hormozgan Province, southern Iran. Presence data have been collected using the scientific resources, such as documented field observations and herbarium records (Research Institute of Forests and Rangelands).This data was combined with 19 bioclimatic and topographic variables of WorldClim database.MaxEnt model was used to evaluate the association between the surroundings and the likelihood of the presence of the species. Monthly and seasonal temperature, precipitation, and relative humidity data of synoptic and rain gauge stations of the Ministry of Energy, namely Fin, Sarchahan, and Tashkuiyeh stations, located close to the distribution ranges of the species were utilised to analyse the climatic data in more detail. The outcome showed that the species distribution was most affected by winter precipitation, slope and mean annual temperature. Zhumeria majdae displayed the best development in regions that had 250-350 mm of rain per year, winter temperatures of 8-12 C and summer temperatures of 26-32 C with a shorter growing season. Phenological adjustments like the increase of growing seasons were found in drier areas like Sarchahan and Tang-e Zagh. MaxEnt model showed high accuracy in species distribution prediction and indicate winter precipitation as the most important limiting factor. The study also indicated that Z. majdae is a climatic-sensitive species with a narrow tolerance margin, which needs pronounced seasonal rainfall and moderate temperatures to survive and reproduce successfully.
Extended Abstract
Introduction
Climate change and global warming are among the most critical environmental challenges of the 21st century, profoundly affecting the distribution, survival, and ecological dynamics of plant species. Numerous studies have demonstrated that fluctuations in temperature, altered precipitation patterns, and recurrent droughts contribute to habitat shifts and, in some cases, the extinction of vulnerable plant species. Consequently, both current and historical climatic conditions play a central role in shaping present-day biodiversity patterns and ecosystem functioning. Over recent decades, climate change has substantially influenced plant biodiversity, altering species’ geographic ranges, reducing population sizes, and placing numerous taxa at risk of extinction, which has led to significant modifications in ecosystem structure and stability. Zhumeria majdae is an ecologically and economically valuable endemic medicinal plant species in Iran, restricted to specific mountainous regions of Hormozgan Province and characterized by a narrow distribution range. Due to its wide traditional medicinal applications—including the treatment of digestive disorders, headache relief, and wound healing—the species is also exported to Persian Gulf countries, emphasizing its ecological and commercial importance. Given its limited range, high sensitivity to climatic variability, and narrow tolerance to environmental fluctuations, understanding the key environmental factors influencing its habitat and modeling its potential distribution are essential for effective long-term conservation. The main objective of this study was to model the potential distribution of Zhumeria majdae in Hormozgan Province using climatic and environmental variables and to identify the most influential factors determining its suitable habitat using the MaxEnt model.
 
Methodology
Occurrence records of Zhumeria majdae were compiled from multiple authoritative sources, including the Flora of Iran, Flora Iranica, the GBIF database, the Herbarium of the Research Institute of Forests and Rangelands, and other verified scientific references. All occurrence points were screened for spatial accuracy using ArcGIS and Google Earth to remove duplicates and correct erroneous records. Long-term climatic data—including temperature, precipitation, and relative humidity—were obtained from synoptic and rain gauge stations located in Fin, Sarchahan, and Tashkuiyeh. To model species distribution, 19 bioclimatic variables were considered, encompassing mean annual temperature, annual precipitation, seasonal precipitation, minimum temperature of the coldest month, maximum temperature of the warmest month, and other standard BIOCLIM indices. These variables were sourced from the WorldClim global database at a spatial resolution of 1 km. To assess multicollinearity among predictors, Pearson correlation analysis was conducted in SPSS, and highly correlated variables were excluded from the modeling process. Species distribution modeling was performed using the MaxEnt algorithm, which relies exclusively on presence-only data. Model performance was evaluated using the jackknife test to determine the relative contribution of each variable and the Area Under the Curve (AUC) metric to assess predictive accuracy.
 
Results and discussion
The MaxEnt model indicated that the distribution of Zhumeria majdae is primarily influenced by winter precipitation (BIO19), which accounted for 66.5% of the model’s explanatory power. Other important predictors included slope (12.7%), precipitation of the wettest month (BIO13), and annual temperature range (BIO7). The species exhibited the highest probability of occurrence in areas with winter precipitation of 100–180 mm and mean winter temperatures of 8–12°C. Response curves demonstrated a sharp increase in habitat suitability within these climatic ranges, with further increases in precipitation or temperature having only marginal effects on predicted occurrence. Comparative analyses across three primary habitats—Mount Geno, Sarchahan, and Tang-e Zagh—revealed distinct phenological adaptations. In Mount Geno, where rainfall is higher and temperatures are milder, the growing season was relatively short (~100 days), starting in mid-February and ending with seed dispersal in late May. In contrast, Sarchahan and Tang-e Zagh exhibited longer growing seasons (~120 days), with leaf emergence in late February and seed release by mid-June, reflecting adaptation to drier and warmer conditions. The species showed a clear preference for slopes of 10–35°, where well-drained rocky substrates likely reduce interspecific competition and prevent waterlogging. Habitat suitability declined in flatter areas due to poorer drainage and increased competition. Jackknife analyses confirmed the ecological significance of both precipitation and topography in determining suitable habitats. Model performance was robust, with AUC values of 0.93 for the training dataset and 0.90 for the testing dataset, indicating excellent predictive accuracy. The MaxEnt suitability map further identified central and northern Hormozgan—including parts of Mount Geno, Hajjiabad, and the highlands near Bandar Abbas—as highly suitable habitats under current climatic conditions. These findings highlight the species’ narrow ecological niche and its dependence on specific climatic and topographic conditions, emphasizing the need for targeted conservation measures in these key areas.
 
Conclusion
Despite its medicinal properties and high economic value, Zhumeria majdae is highly vulnerable to future climate change due to its restricted distribution and strong sensitivity to climatic conditions. The results of this study indicate that climatic factors, particularly winter precipitation, play a decisive role in the species’ distribution, and any alterations in rainfall patterns could threaten its natural survival. Variations in the length of the growing season across different regions suggest the species’ capacity for phenological adaptation; however, this adaptation is only possible within a specific range of temperature and precipitation. Therefore, conservation planning, identification of new suitable habitats, and the development of targeted cultivation strategies in climatically similar areas are essential for ensuring the long-term persistence of the species. Furthermore, these findings provide a framework for habitat assessment of other endemic and climate-sensitive species in the arid regions of Iran.
 
Funding
There is no funding support.
 
Authors’ Contribution
Authors contributed equally to the conceptualization and writing of the article. All of the authors approved the content of the manuscript and agreed on all aspects of the work declaration of competing interest none.
 
Conflict of Interest
Authors declared no conflict of interest.
 
Acknowledgments
We are grateful to all the scientific consultants of this paper.