University of Tehran Journal of Range and Watershed Managment 5044-2008 69 3 2016 11 21 Net Primary Productivity in Kouhdasht, its Spatio-Temporal Patterns and Relation to Meteorological Variables Net Primary Productivity in Kouhdasht, its Spatio-Temporal Patterns and Relation to Meteorological Variables 561 574 61497 10.22059/jrwm.2016.61497 FA Moslem Borji Hassan Gavyar M. Sc. in Watershed Management, Faculty of Natural Resources, University of Tehran, Karaj, I.R. Iran. Hadi Eskandari Dameneh PhD Student in Combating Desertification Faculty of Natural Resources, Hormozgan University, Bandar Abbas, I.R. Iran. Hassan Khosravi Assistant Professors, Faculty of Natural Resources, University of Tehran, Karaj, I.R. Iran. Journal Article 2015 08 04 Nowadays, temperature increase, rainfall decrease and its effect on the time dynamics of carbon fixation cycle still are faced by many uncertainties. Net Primary Production (NPP) is one of the main factors of carbon cycle; precipitation and temperature measurement are known as two useful tools to study different ecosystems stability and resilience in terms of climate. Hence, in this study, NPP distribution affected by climate parameters of temperature and precipitation have been investigated in four ecosystems of forests, grassland, irrigated agriculture and rain fed agriculture during the period of 2003-2010. Considering climate conditions of biomes, NPP estimation at regional scale was done based on the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) MOD17 NPP product. The results showed that the regression relation was weak between NPP and rainfall for four studied ecosystems, in the other words, low coefficient between these two variables has caused no justified relationship between them. The regression relation between temperature and NPP in forests, pastures and rain-fed agriculture ecosystems follows quadratic <em>equations</em> with determined coefficient over 0.55. The results of this study show that the forest ecosystem resilience to water and temperature tensions is more than other ecosystems, and irrigated agriculture has the least resilience Nowadays, temperature increase, rainfall decrease and its effect on the time dynamics of carbon fixation cycle still are faced by many uncertainties. Net Primary Production (NPP) is one of the main factors of carbon cycle; precipitation and temperature measurement are known as two useful tools to study different ecosystems stability and resilience in terms of climate. Hence, in this study, NPP distribution affected by climate parameters of temperature and precipitation have been investigated in four ecosystems of forests, grassland, irrigated agriculture and rain fed agriculture during the period of 2003-2010. Considering climate conditions of biomes, NPP estimation at regional scale was done based on the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) MOD17 NPP product. The results showed that the regression relation was weak between NPP and rainfall for four studied ecosystems, in the other words, low coefficient between these two variables has caused no justified relationship between them. The regression relation between temperature and NPP in forests, pastures and rain-fed agriculture ecosystems follows quadratic <em>equations</em> with determined coefficient over 0.55. The results of this study show that the forest ecosystem resilience to water and temperature tensions is more than other ecosystems, and irrigated agriculture has the least resilience https://jrwm.ut.ac.ir/article_61497_d4cabd546a161c1147b7590b7ee390e4.pdf