Bazrmanesh Azade, Soltani Saeid, Esfahani Mostafa Tarkesh, Jafari Reza
Department of Natural Resources, Isfahan University of Technology, Isfahan, 8415683111, Iran.
Sci Rep. 2025 Jul 9;15(1):24743. doi: 10.1038/s41598-025-09629-0.
Drought substantially affects ecosystem structure and function, shaping vegetation dynamics and influencing long-term environmental sustainability. This study examines drought effects on forest and rangeland ecosystems across three bioclimatic zones in the Hyrcanian region of Iran. MODIS-derived Leaf Area Index (LAI) data (2001-2022) and Standardized Precipitation Index (SPI) were used with a generalized linear model (GLM) to assess vegetation responses. The findings indicate that rangeland ecosystems, especially in Zones II and III, are susceptible to drought, with SPI accounting for over 80% of the observed LAI variability in these regions. Forests better withstand dry conditions, with SPI explaining about half of the changes in LAI Zone III, with high elevation and snow-dominated precipitation, is drought-sensitive. Zone I near the Caspian Sea has higher humidity and more stable conditions. Zone II, with a semi-humid cold climate, exhibits the largest LAI fluctuations due to its strong dependence on moisture. Elevation, vegetation type, and climate critically influence drought responses. Targeted land management, including water optimization and conservation, is essential. Future research should integrate additional factors such as soil moisture, land cover change, and anthropogenic pressures such as deforestation, overgrazing, and environmental degradation alongside predictive modeling to enhance ecological sustainability.
干旱对生态系统的结构和功能有重大影响，塑造着植被动态并影响长期环境可持续性。本研究考察了伊朗里海地区三个生物气候区干旱对森林和牧场生态系统的影响。利用中分辨率成像光谱仪（MODIS）得出的叶面积指数（LAI）数据（2001 - 2022年）和标准化降水指数（SPI），结合广义线性模型（GLM）来评估植被的响应。研究结果表明，牧场生态系统，尤其是在二区和三区，易受干旱影响，在这些地区，SPI解释了超过80%观测到的叶面积指数变化。森林更能抵御干旱条件，在三区，SPI解释了叶面积指数变化的约一半，三区海拔高且降水以降雪为主，对干旱敏感。靠近里海的一区湿度较高且条件更稳定。二区具有半湿润寒冷气候，由于对水分强烈依赖，叶面积指数波动最大。海拔、植被类型和气候对干旱响应有至关重要的影响。针对性的土地管理，包括水资源优化和保护，至关重要。未来的研究应将土壤湿度、土地覆盖变化以及森林砍伐、过度放牧和环境退化等人为主导压力等其他因素与预测模型相结合，以增强生态可持续性。
