Physiological responses of three populations of Artemisia sieberi Besser to drought stress during early growth stage

Introduction: Iran, characterized by arid and semi-arid climates, faces challenges in plant biodiversity due to limited rainfall and extreme temperature fluctuations. To counter desertification and enhance ecosystem sustainability, conservation and restoration efforts are crucial. Native plant species, well-adapted to these harsh conditions, offer a promising solution for rehabilitation. However, overgrazing and land-use changes pose significant threats to these species, leading to a decline in biodiversity (Kamali et al., ۲۰۲۱a). Arid and semi-arid regions, characterized by their vulnerability to drought, face significant ecological challenges. Limited water availability and extreme temperature fluctuations disrupt plant physiological processes, leading to reduced growth, biomass production, and overall vegetation degradation. Delayed seed germination and hindered seedling establishment further exacerbate these issues. To effectively address these challenges and promote vegetation sustainability in these regions, a comprehensive understanding of plant responses to drought stress is crucial for developing sustainable management strategies (Hoekstra et al., ۲۰۰۱). Artemisia spp. occupy millions of hectares of natural habitats in the country and is considered the largest rangeland ecosystem in Iran. The dependence of various plant and animal communities on these habitats confirms their high capacity, and comprehensive management in these habitats is of utmost importance. Planning in the field of rangeland ecosystem management requires basic information in these areas. According to the results, Artemisia species are distributed in about ۳۴ million hectares of steppe and semi-steppe regions of Iran, covering about ۲۱% of the country's land area. Artemisia sieberi and Artemisia aucheri are the most abundant Artemisia species in Iran. Unfortunately, in recent years, the drying up of Artemisia spp. has been observed in many parts of the country, mainly due to overgrazing and successive droughts. These habitats are very sensitive and fragile due to the harsh habitat conditions. Climate change, overgrazing, and land-use change are very important in determining the fate of these habitats. Artemisia sieberi, a species of paramount genetic value to Iran, is predominantly propagated through seeds. Its high nutritional value for livestock and exceptional tolerance to the rigors of desert and semi-desert environments make it a highly prized species. Artemisia sieberi is extensively found in the desert plains of the country, either as a monoculture or as a dominant species within rangeland communities. As a shrub well-adapted to harsh desert conditions, it serves not only as forage in winter pastures but also demonstrates remarkable resistance to heat, drought, and erosion (Kamali et al., ۲۰۲۱b). Zheng et al. (۲۰۰۵) reported that Artemisia sphaerocephala is widely used for the restoration of semi-arid regions in China. However, the study revealed that seed germination of this species, particularly with aerial seeding, is low. Furthermore, drought conditions negatively impacted seed germination, with few seeds germinating at a water potential of -۱.۴ MPa. Based on the findings, mid-May was determined to be the most suitable time for seeding from a climatic perspective. Additionally, the results indicated that light was a limiting factor for germination, while temperature had a positive correlation with seed germination. This study aimed to investigate the germination behavior of different populations of Artemisia sieberi under drought stress. As a drought-tolerant species, Artemisia sieberi holds significant potential for the restoration of arid and semi-arid regions. Given the critical role of seed germination in species survival and vegetation development, a thorough understanding of the germination process of Artemisia sieberi can contribute to improving restoration techniques and sustainable management of these areas.

کلیدواژه ها:

Artemisia sieberi ، drought stress ، plant biodiversity ، ecosystem sustainability ، seed germination ، vegetation sustainability