Spatial and Temporal Changes of Net Primary Production (NPP) and Their Relationship with Climatic Factors from 2000 to 2014 in Isfahan Province

The aim of the present study was to evaluate the spatial and temporal changes of NPP in different biomes of Isfahan province from 2000 to 2014 and their response to climatic factors. For this purpose, the NPP data of the MODIS satellite were collected and the map of climatic variables was produced using various interpolation methods. The investigation of the spatial and temporal variations of NPP was carried out by combining these data. The results indicated that the spatial distribution of annual NPP changed significantly, with higher NPP in the west and southwest and the lower NPP in the east of the province. The mean annual NPP values for rangeland, forest, desert, Haloxylon forest and agricultural lands were 16.7, 58.77, 1.66, 5.76 and 51.43 grCm-2yr-1, respectively. The temporal changes of the NPP annual average during 2000-2014 had no significant trend. In 82.14% of the total area, the slope of changes was less than zero and in 17.86%, the value of this index was more than zero. The highest and lowest changes in the slope were observed in the biomes of forest and desert, respectively. The amounts of NPP of biomes in rangeland, desert and Haloxylon forest were influenced by precipitation, while the temperature was the main controlling factor in the forest and agriculture biomes