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This study examined the spatial variability of throughfall (Tf ) and its implications for sampling throughfall during the leafless period of oak trees. To do this, we measured Tf under five single Brant’s oak trees (Quercus brantii var. Persica), in the Zagros region of Iran, spanning a six-month-long study period. Overall, the Tf amounted to 85.7% of gross rainfall. The spatial coefficient of variation (CV) for rainstorm total Tf volumes was 25%, on average, and it decreased as the magnitude of rainfall increased. During the leafless period, Tf was spatially autocorrelated over distances of 1 to 3.5 m, indicating the benefits of sampling with relatively elongated troughs. Our findings highlight the great variability of Tf under the canopies of Brant’s oaks during their leafless period. We may also conclude that the 29 Tf collectors used in the present study were sufficient to robustly estimate tree-scale Tf values within a 10% error of the mean at the 95% confidence level. Given that a ±10% uncertainty in Tf is associated with a ±100% uncertainty in interception loss, this underscores the challenges in its measurement at the individual tree level in the leafless season. These results are valuable for determining the number and placement of Tf collectors, and their expected level of confidence, when measuring tree-level Tf of scattered oak trees and those in forest stands.
Omid Fathizadeh; Seyed Sadeghi; Iman Pazhouhan; Sajad Ghanbari; Pedram Attarod; Lei Su. Spatial Variability and Optimal Number of Rain Gauges for Sampling Throughfall under Single Oak Trees during the Leafless Period. Forests 2021, 12, 585 .
AMA StyleOmid Fathizadeh, Seyed Sadeghi, Iman Pazhouhan, Sajad Ghanbari, Pedram Attarod, Lei Su. Spatial Variability and Optimal Number of Rain Gauges for Sampling Throughfall under Single Oak Trees during the Leafless Period. Forests. 2021; 12 (5):585.
Chicago/Turabian StyleOmid Fathizadeh; Seyed Sadeghi; Iman Pazhouhan; Sajad Ghanbari; Pedram Attarod; Lei Su. 2021. "Spatial Variability and Optimal Number of Rain Gauges for Sampling Throughfall under Single Oak Trees during the Leafless Period." Forests 12, no. 5: 585.
The charcoal disease agents, Biscogniauxia mediterranea and Obolarina persica are two latent, ascomycetous oak pathogens in the Middle Eastern Zagros forests, where they have devastating effects, particularly during drought. Under greenhouse conditions, we investigated the effects of the two charcoal disease agents individually and in combination with drought on survival, growth, foliar gas-exchange, pigment content, oxidative stress and the antioxidant response of Quercus infectoria and Q. libani, two of the dominant tree species in this region. Commonly, the strongest negative effects emerged in the drought–pathogen interaction treatments. Q. infectoria showed less severe lesions, higher survival, more growth, and less leaf loss than Q. libani under combined biotic and abiotic stress. In both oak species, the combination of pathogen infection and drought resulted in more than 50% reduction in foliar gas-exchange parameters with partial recovery over time in Q. infectoria suggesting a superior defense system. Indeed, enhanced foliar anthocyanin, total soluble protein and glutathione concentrations imply an upregulation of the antioxidant defense system in Q. infectoria under stress while none of these parameters showed a significant treatment response in Q. libani. Consequently, Q. infectoria foliage showed no significant increase in superoxide, lower lipoxygenase activity, and less electrolyte leakage compared to the highly elevated levels seen in Q. libani indicating oxidative damage. Our findings indicate greater drought tolerance and pathogen resilience in Q. infectoria compared to Q. libani. Under future climate scenarios, we therefore expect changes in forest community structure driven by a decline in Q. libani and closely associated organisms.
Ehsan Ghanbary; Omid Fathizadeh; Iman Pazhouhan; Mehrdad Zarafshar; Masoud Kouchaksaraei; Shahram Jafarnia; Ghasem Parad; Martin Bader. Drought and Pathogen Effects on Survival, Leaf Physiology, Oxidative Damage, and Defense in Two Middle Eastern Oak Species. Forests 2021, 12, 247 .
AMA StyleEhsan Ghanbary, Omid Fathizadeh, Iman Pazhouhan, Mehrdad Zarafshar, Masoud Kouchaksaraei, Shahram Jafarnia, Ghasem Parad, Martin Bader. Drought and Pathogen Effects on Survival, Leaf Physiology, Oxidative Damage, and Defense in Two Middle Eastern Oak Species. Forests. 2021; 12 (2):247.
Chicago/Turabian StyleEhsan Ghanbary; Omid Fathizadeh; Iman Pazhouhan; Mehrdad Zarafshar; Masoud Kouchaksaraei; Shahram Jafarnia; Ghasem Parad; Martin Bader. 2021. "Drought and Pathogen Effects on Survival, Leaf Physiology, Oxidative Damage, and Defense in Two Middle Eastern Oak Species." Forests 12, no. 2: 247.
Throughfall (TF) makes up the majority of understory rainfall and thereby plays an important role in controlling the amount of water reaching the forest floor. TF under a single Quercus castaneifolia (C.A.Mey, chestnut-leaved oak) tree in Northern Iran was measured during the leafed and leafless periods. TF quantity under the Q. castaneifolia canopy made up 69.3% and 88.0% of gross rainfall during leafed and leafless periods, respectively. Phenoseason influenced TF distribution patterns as TF temporal patterns during the leafed period were slightly more stable than during the leafless periods. The minimum number of TF collectors needed to yield a representative mean TF with accepted errors of 10% at 95% confidence level was twenty-six and twelve TF collectors for leafed and leafless periods, respectively. We conclude that phenoseasonality significantly affects TF spatiotemporal variability and presented the required number of collectors necessary for sampling TF under an individual Q. castaneifolia tree.
Omid Fathizadeh; Seyed Mohammad Moein Sadeghi; Curtis D. Holder; Lei Su. Leaf Phenology Drives Spatio-Temporal Patterns of Throughfall under a Single Quercus castaneifolia C.A.Mey. Forests 2020, 11, 688 .
AMA StyleOmid Fathizadeh, Seyed Mohammad Moein Sadeghi, Curtis D. Holder, Lei Su. Leaf Phenology Drives Spatio-Temporal Patterns of Throughfall under a Single Quercus castaneifolia C.A.Mey. Forests. 2020; 11 (6):688.
Chicago/Turabian StyleOmid Fathizadeh; Seyed Mohammad Moein Sadeghi; Curtis D. Holder; Lei Su. 2020. "Leaf Phenology Drives Spatio-Temporal Patterns of Throughfall under a Single Quercus castaneifolia C.A.Mey." Forests 11, no. 6: 688.
Interception represents a significant component of the water budget of forests, diverting significant quantities of precipitation away from soil moisture, transpiration, and surface and groundwater recharge. There are several physically-based models of forest interception but their utility across seasonal variability is limited because few studies have collected field data of both the growing (leaf on) and dormant (leaf off) seasons and explored how seasonality affects parameters of simulations. Rainfall partitioning modelling using the Reformulated Gash Analytical Model (RGAM) for Brant’s oak (Quercus brantii) forest plots in the Zagros forest, Iran, simulated interception values close to the observed, with an underestimation of 4.0% and 7.5% for the leafed and leafless periods, respectively. Model parameters varied seasonally: free throughfall coefficient, canopy storage capacity, canopy saturation point, and ratio of mean wet evaporation rate to mean rainfall intensity were ∼0.60, 1.0 mm, 2.6 mm, and 0.15 in the leafed period and ∼0.80, 0.1 mm, 0.5 mm, and 0.04 in the leafless period, respectively. In this application, the RGAM was highly sensitive to change in the ratio of mean wet evaporation rate to mean rainfall intensity, and less sensitive to canopy cover and canopy storage capacity, especially in the leafless period. Therefore, canopy structure is less important for rainfall interception predictions by RGAM.
O. Fathizadeh; S.M. Hosseini; R.F. Keim; A. Darvishi Boloorani. A seasonal evaluation of the reformulated Gash interception model for semi-arid deciduous oak forest stands. Forest Ecology and Management 2018, 409, 601 -613.
AMA StyleO. Fathizadeh, S.M. Hosseini, R.F. Keim, A. Darvishi Boloorani. A seasonal evaluation of the reformulated Gash interception model for semi-arid deciduous oak forest stands. Forest Ecology and Management. 2018; 409 ():601-613.
Chicago/Turabian StyleO. Fathizadeh; S.M. Hosseini; R.F. Keim; A. Darvishi Boloorani. 2018. "A seasonal evaluation of the reformulated Gash interception model for semi-arid deciduous oak forest stands." Forest Ecology and Management 409, no. : 601-613.