Vegetation dynamics under long-term protection in arid and semiarid ecosystems– A case study of the Karkheh River Watershed (SW Iran)

<title>Abstract</title> <p>Vegetation restoration in arid and semiarid ecosystems is crucial for mitigating ecological degradation and contributing to global climate change mitigation and ecosystem recovery. These regions present exceedingly challenging conditions for plant growth and development. Only a relatively limited number of plant species are capable of surviving in such environments. Therefore, identifying these flora is highly important. The current research aims to analyze changes in the vegetation cover of a semiarid ecosystem during a 20-year enclosure period. In this study, the plant species were identified via a field survey in the fenced and protected areas. Also, long-term changes in soil moisture and vegetation cover were investigated via Landsat satellite images. We found that in this region in 2005, a total of 23 plant species, 11 families, and one plant community type were reported, while in 2025, this number increased to 70 species, 29 families, and six distinct vegetation types, indicating a significant increase in floristic richness.The findings reveal a complex interaction between vegetation recovery and the persistence of water stress in protected rangelands. This study highlights the importance of developing targeted conservation strategies to promote sustainable management, mitigate land degradation, and enhance the resilience of fragile arid and semiarid ecosystems.</p>