University of Tehran Press Iranian Journal of Soil and Water Research 2008-479X 57 3 2026 05 22 Distribution and Morphological Characteristics of Microplastics in Surface Soils of Four Climatic Regions of Fars Province Distribution and Morphological Characteristics of Microplastics in Surface Soils of Four Climatic Regions of Fars Province 725 749 107292 10.22059/ijswr.2026.412332.670114 FA Shekoufeh Forouzan Department of Soil Science, College of Agriculture, Shiraz University, Shiraz, Iran 0009-0008-7688-7580 Ali Akbar Moosavi Department of Soil Science, College of Agriculture, Shiraz University, Shiraz 0000-0003-0305-2829 Sajjad Abbasi Department of Earth Sciences, School of Science, Shiraz University, Shiraz, Iran 0000-0002-5194-9334 Majid Baghernejad Department of Soil Science, College of Agriculture, Shiraz University, Shiraz, Iran 0000-0002-4935-741X Journal Article 2026 03 30 Microplastics (MPs) pose a serious threat to soil ecosystem sustainability and human health. This study investigated the distribution and morphological characteristics (shape, color, size) of MPs in surface soils from four climatic regions of Fars Province, Iran (Darab, Arjan Plain, Sepidan, and Sarvestan). Twenty-seven soil samples were collected, and MPs were extracted using density separation with ZnCl₂ solution. Identification was performed via stereomicroscopy, and polymer composition was determined by Raman spectroscopy. Of 128 identified particles, fibers dominated across all regions (91.41%). Sarvestan exhibited 100% fibrous particles, while Darab had the highest proportion of film-like particles. Black particles prevailed in Arjan and Sarvestan, whereas Sepidan showed dominance of blue-dark blue particles and polyamide polymer (66.67%), reflecting its rangeland-tourism land use and high-rainfall climate. The 250–500 µm size class was most abundant in Sepidan (46.30%), while larger particles (≥1000 µm) were mainly observed in the barren lands of Sarvestan. Raman spectroscopy confirmed polyamide as a prevalent polymer. Although no direct significant correlation was found between MP abundance and climatic factors (temperature, precipitation), climate indirectly influences MP size and morphology through processes such as runoff, surface erosion, and sediment dynamics, interacting with local land use. Therefore, tailored management strategies aligned with specific climatic and land-use conditions are essential, particularly in high-rainfall areas like Sepidan and arid regions like Sarvestan. Microplastics (MPs) pose a serious threat to soil ecosystem sustainability and human health. This study investigated the distribution and morphological characteristics (shape, color, size) of MPs in surface soils from four climatic regions of Fars Province, Iran (Darab, Arjan Plain, Sepidan, and Sarvestan). Twenty-seven soil samples were collected, and MPs were extracted using density separation with ZnCl₂ solution. Identification was performed via stereomicroscopy, and polymer composition was determined by Raman spectroscopy. Of 128 identified particles, fibers dominated across all regions (91.41%). Sarvestan exhibited 100% fibrous particles, while Darab had the highest proportion of film-like particles. Black particles prevailed in Arjan and Sarvestan, whereas Sepidan showed dominance of blue-dark blue particles and polyamide polymer (66.67%), reflecting its rangeland-tourism land use and high-rainfall climate. The 250–500 µm size class was most abundant in Sepidan (46.30%), while larger particles (≥1000 µm) were mainly observed in the barren lands of Sarvestan. Raman spectroscopy confirmed polyamide as a prevalent polymer. Although no direct significant correlation was found between MP abundance and climatic factors (temperature, precipitation), climate indirectly influences MP size and morphology through processes such as runoff, surface erosion, and sediment dynamics, interacting with local land use. Therefore, tailored management strategies aligned with specific climatic and land-use conditions are essential, particularly in high-rainfall areas like Sepidan and arid regions like Sarvestan. https://ijswr.ut.ac.ir/article_107292_529547f7d09f047cf430aefcd204cd00.pdf