How is climate change impacting net primary production and reference evapotranspiration in the Zagros region of western Iran?

نویسندگان

1 Natural Resources Bureau of Alborz Province, Natural Resources and Watershed Organization of Iran, Karaj, Iran

2 Department of Geography and Environmental Studies, University of Colorado, Colorado, USA

3 Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research (IGSNRR), Chinese Academy of Sciences (CAS), Beijing, China

4 Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran

5 Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran

6 Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran

7 Ahar Colleges of Agriculture and Natural Resources, University of Tabriz, Tabriz, Iran

8 Department of Wood Science and Technology, Faculty of Agriculture and Natural Resources, Karaj Branch, Islamic Azad University, Karaj, Iran

9 Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research (IGSNRR), Chinese Academy of Sciences (CAS), Beijing, China

doi
10.22124/cjes.2024.7692
چکیده

We assessed how climate change may impact net primary production (NPP) and reference evapotranspiration (ET0) from the Zagros region of western Iran covered extensively by oak, -Quercus branti Lindl. forests. The daily meteorological parameters of temperature (T), precipitation (P), relative humidity (RH), wind speed (WS), and sunshine hours were obtained from 20 meteorological stations throughout the region over a 30-year period (1988-2017). Net primary production and ET0 were estimated by the synthetic and the FAO Penman-Monteith models, respectively. A non-dimensional relative sensitivity coefficient was used to examine the sensitivity of NPP and ET0 to changes in the meteorological parameters. The sensitivity analyses were carried out for T, P, and WS within a possible range of ± 10%, ± 30%, and ± 10%, respectively, from the long-term mean. Except for the P with no notable trend, other meteorological parameters exhibited upward or downward trends. The mean NPP and ET0 values were estimated to be 6.5 t ha-1 y-1 and 3.9 mm d-1 across the Zagros region, respectively. Net primary production was found to be more sensitive to precipitation with a sensitivity coefficient of 0.66 and less sensitive to temperature with a sensitivity coefficient of 0.40. The ET0 sensitivity coefficients in response to T changes doubled relative to WS (0.33 against 0.63). Identifying the contributing factors in NPP and ET0 trends is important for understanding the relative impacts of climate change and human activities in arid and semi-arid regions.