OICC Press Journal of Rangeland Science 2423-642X 16 3 2026 09 30 Impact of Plant Species Diversity on Aboveground Biomass and Carbon Sequestration in the Peri-Urban Rangelands of North western Tehran, Iran 10.57647/jrs.2026.1603.24 EN Tara Mousivand Department of Natural Resources and Environment, SR.C., Islamic Azad University, Tehran, Iran Zahra Azizi Department of Geoinformation and Geomatics Engineering, Shahid Beheshti University, Tehran, Iran https://orcid.org/0000-0001-8572-7134 Mohammad Mehdi Dehshiri Department of Natural Resources and Environment, Bo.C., Islamic Azad University, Borujerd, Iran Lobat Taghavi Department of Natural Resources and Environment, SR.C., Islamic Azad University, Tehran, Iran Mahdi Ramezani Department of Natural Resources and Environment, SR.C., Islamic Azad University, Tehran, Iran Journal Article 2026 09 30 Urban expansion is reshaping peri-urban ecosystems, including the rangelands of northwestern Tehran. This study aimed to examine whether plant species diversity enhances above-ground biomass (AGB) and, by extension, carbon storage within three rangeland sites that define the analytical area of interest (AOI). In 2022, field sampling recorded 1,558 specimens representing 38 plant species. The dominant taxa included Bromus tectorum and Astragalus belgheisicus, whereas Henrardia persica and Melica persica were rare. AGB was quantified via direct harvest and standard laboratory procedures, and organic carbon was inferred from organic matter. Diversity indices (e.g., Shannon–Wiener, Simpson, Margalef, Menhinick, Pielou) were computed. Most of the indices were positively related to AGB. Shannon (r ≈ 0.63; p <0.05) and Simpson (r ≈ 0.42; p<0.05) exhibited significant positive relations with AGB; other richness/evenness metrics showed consistent but weaker trends, whereas Hill’s number showed no clear effect. Sentinel-2 (2018, 2022) imagery supported land cover mapping using supervised Maximum Likelihood Classification (MLC). Accuracy assessment was performed within the AOI, and Normalized Difference Vegetation Index (NDVI) aided vegetation characterization. Vegetation cover had decreased significantly (34%) between 2018 and 2022. Findings indicated that, within the studied rangeland AOI, higher plant diversity is related to greater AGB and carbon potential.