P Dehghan Rahimabadi - P.h.D. Candidate in Combat Desertification, Faculty of Natural Resources, University of Tehran, Tehran,Iran
E Heydari Alamdarloo - P.h.D. in Combat Desertification, Faculty of Natural Resources, University of Tehran, Tehran, Iran
H Azarnivand - Professor, Faculty of Natural Resources, University of Tehran, Tehran, Iran
J Barkhordari - Professor; Agricultural and Natural Resources Research and Training Center of Yazd Province, Yazd, Iran

One of the main topics of scientific research in the field of climate change impact assessment is thestudy of carbon cycle changes in rangelands and Net Primary Production (NPP) is an important component inthis cycle in terms of carbon storage and a key indicator for assessing ecosystem function. In this study, usingMann-Kendall test and linear regression, the trend of NPP changes in the rangelands of Alborz Province from۲۰۰۱ to ۲۰۲۰ was investigated. The results of Mann-Kendall test showed that NPP has increasing trend innorth and some parts of the south of the study area. In the central parts, NPP is generally decreasing. In theseareas, the population density is higher than other areas. The results of regression analysis indicated that in thenorthern, especially the northwest, central and southern regions have higher intensity of changes, on the otherhand, the eastern regions and most of the southern regions have less intensity of changes than other regions.According to the results of this study, the human role is evident in NPP changes in Alborz province.

NPP; MODIS; Mann-Kendall; Regression