The Yozyovon Sand Massif as a proposed Important Plant Area in the Fergana Valley: floristic value, habitat loss, and threats

Lowland sand ecosystems are among the most vulnerable and least represented habitat types in area-based conservation frameworks, particularly in the arid landscapes of Central Asia. Despite their high ecological specialization and endemism, these ecosystems remain poorly integrated into national and regional conservation planning. In this study, the applicability of the Important Plant Area (IPA) framework to arid lowland sands was assessed, and the Yozyovon Sand Massif in the Central Fergana Valley (FV), Uzbekistan, was evaluated as a proposed IPA. Floristic surveys conducted between 2023 and 2025, supplemented by herbarium and documentary records, yielded an integrated inventory of 296 vascular plant taxa belonging to 175 genera and 44 families; historical but unconfirmed records were flagged separately and excluded from the IPA trigger-species assessment. The application of 14 Criterion A trigger taxa of high conservation importance, whereas the habitat-based assessment under Criterion C revealed greater spatial discontinuity and a marked reduction in the extent of continuous sandy habitats. Anthropogenic pressures were evaluated using an IUCN-aligned threat assessment approach, which identified irrigated agriculture, hydrological modification, and substrate disturbance as the dominant drivers of ecosystem degradation. To quantify long-term habitat dynamics, Random Forest classifications were applied to Landsat imagery for 1991, 2000, 2015, and 2025 and evaluated using held-out, spatially separated reference data. Within the fixed 416.24 km2 study extent, the mapped Sand area declined from 125.95 km2 in 1991 to 54.79 km2 in 2025, corresponding to an overall reduction of 56.50%. The integration of floristic evidence, standardized threat assessment, and validated land-cover classifications provided a more comprehensive basis for applying the IPA framework in data-poor arid lowland environments. The results support the proposal of the Yozyovon Sand Massif as an IPA. If formally recognized, the site would represent the fourth IPA in the FV and would address a major gap in the regional IPA network. More broadly, this study highlights the need to explicitly incorporate desert sand ecosystems into biodiversity conservation strategies and provides an evidence-based approach for conservation prioritization in arid regions.