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.

Non-timber forest products (NTFPs) contribute to local people’s livelihood in many regions around the world. This article investigates the types of NTFPs collected, processed, and traded in the Arasbaran region of Iran, the roles of these products in household economies, and the potential contribution to rural household economies through the collection, processing, and marketing of NTFPs. Data were collected using household and community surveys as well as through secondary sources on the role of NTFPs within Arasbaran forests in Iran. The main NTFPs harvested by local people were fruits. The fruits from 14 woody species, including trees and shrubs, were harvested by local people. The average share of forest-harvested fruit to household income was 27 percent. The mean annual income derived from the harvest and sale of sumac and reddish blackberry in the sample rural household incomes was USD 1822 and USD 142, respectively. In regard to processing efficiency, plum, cornelian cherry, and sumac exhibited the highest processing efficiency. Better policy support would be needed along the whole value chain, starting with the forest management plans, to include fruit species. In addition, measures to support processing facilities as well as to promote trade and marketing beyond the local area would be highly important to develop the potential of forest fruits and other NTFPs. Besides technical and financial support, measures should include regulatory revisions as well as information, training, and awareness raising.

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.

This study examined the spatial variability of throughfall (T_f) and its implications for sampling throughfall during the leafless period of oak trees. To do this, we measured T_f 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 T_f amounted to 85.7% of gross rainfall. The spatial coefficient of variation (CV) for rainstorm total T_f volumes was 25%, on average, and it decreased as the magnitude of rainfall increased. During the leafless period, T_f 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 T_f under the canopies of Brant’s oaks during their leafless period. We may also conclude that the 29 T_f collectors used in the present study were sufficient to robustly estimate tree-scale T_f values within a 10% error of the mean at the 95% confidence level. Given that a ±10% uncertainty in T_f 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 T_f collectors, and their expected level of confidence, when measuring tree-level T_f of scattered oak trees and those in forest stands.