Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
10.22059/jfwp.2025.392721.1344
Abstract
The Zagros forests in Ilam Province, covering 0.64 million hectares, have been in decline for over two decades, with the index of consecutive dry days (CDD)—a key climate change indicator—identified as a contributing factor. We analyzed 35 years (1988–2022) of daily meteorological data from the Ilam synoptic weather station using the Mann-Kendall non-parametric test to assess trends in precipitation and CDD. The mean annual precipitation was 544 mm (SD = 173 mm) with no significant trend (ZMK = 1.46), though a notable decrease occurred from 605 mm before the onset of decline to 497 mm afterward (t = 1.98). On average, 313 (±12 SD) dry days occurred annually, with about 70% during spring and summer. Each year, 27 (±4 SD) dry spells were recorded, mostly under 30 days, but two typically exceeded that threshold (30 days). A significant rise in dry spells longer than 30 days was observed after the decline began (ZMK = +3.12). The mean maximum annual CDD reached 150 days, peaking at 219 days in 2021. These findings indicate that reduced precipitation and prolonged dry periods linked to climate change play a critical role in the ongoing decline of the Zagros forests in Ilam Province.
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Mirzaei, S. , Attarod, P. and Mostafanezhad Nesheli, K. (2025). The effect of long-term trends of precipitation and consecutive dry days on Zagros forests decline in Ilam Province. Forest and Wood Products, 78(1), 1-10. doi: 10.22059/jfwp.2025.392721.1344
MLA
Mirzaei, S. , , Attarod, P. , and Mostafanezhad Nesheli, K. . "The effect of long-term trends of precipitation and consecutive dry days on Zagros forests decline in Ilam Province", Forest and Wood Products, 78, 1, 2025, 1-10. doi: 10.22059/jfwp.2025.392721.1344
HARVARD
Mirzaei, S., Attarod, P., Mostafanezhad Nesheli, K. (2025). 'The effect of long-term trends of precipitation and consecutive dry days on Zagros forests decline in Ilam Province', Forest and Wood Products, 78(1), pp. 1-10. doi: 10.22059/jfwp.2025.392721.1344
CHICAGO
S. Mirzaei , P. Attarod and K. Mostafanezhad Nesheli, "The effect of long-term trends of precipitation and consecutive dry days on Zagros forests decline in Ilam Province," Forest and Wood Products, 78 1 (2025): 1-10, doi: 10.22059/jfwp.2025.392721.1344
VANCOUVER
Mirzaei, S., Attarod, P., Mostafanezhad Nesheli, K. The effect of long-term trends of precipitation and consecutive dry days on Zagros forests decline in Ilam Province. Forest and Wood Products, 2025; 78(1): 1-10. doi: 10.22059/jfwp.2025.392721.1344
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