Zelkova carpinifolia reservoir from Hyrcanian Forests, Northern Iran, a new sacrifice of Ophiostoma novo-ulmi

Abstract

Zelkova carpinifolia belongs to the Ulmaceae. It is the only species from Zelkova genus that has been distributed and is native to Iranian forests. This tree species is one of the valuable species that is comprised of endangered plants. Nevertheless, the most of reservoirs of this species have been faced to problems that fungal disease is one of the important and lethal disturbance. This study was conducted to identify the main disturbance which has been resulted in Z. carpinifolia decadence in Daland forest reservoir, North of Iran. The study has ensured that O. novo-ulmi is the fungal pathogen in this forest reservoir. It can be reminded that this pathogen had been previously found in Ulmus genus which has been created devastating event in these noteworthy reservoirs. Some symptoms which were observed in field comprising flagging and wilting of leaves. Bark beetle galleries and occlusion of xylem vessels were the other evidence of fungal disease. In light of laboratory results, the fungi colony was fluffy, light-colored and fast-growing. The different shapes of fungi growth like white fibrous and flower shape or dark petaloid shape were observed. Mean colony diameters of O. novo-ulmi were 3.72 ±0.16 mm/day in the dark at 20 °C. Simultaneously, Microscopic analysis of sexual and asexual systems of O. novo-ulmi using a light microscope, a stereo microscope, and a scanning electron microscope revealed that it had morphological features of sporothix, pesotum, yeast-like and perithecium synanon morphology.

Independent Evolution Has Led to Distinct Genomic Signatures in Dutch Elm Disease-Causing Fungi and Other Vascular Wilts-Causing Fungal Pathogens

“…In the case of Dutch elm disease (DED), which was first described in the early 1920s [ 8 ], the pathogens O. ulmi and O. novo-ulmi caused two successive pandemics that impacted several of the elm species in the forest, agrarian, and urban environments on several continents [ 68 , 69 , 70 ]. Within 100 years, an estimated 1 billion adult elm trees were killed [ 71 ], and the ongoing pandemic caused by O. novo-ulmi is threatening the survival of the iconic species Zelkova carpinifolia [ 72 ].…”

Climate-Triggered Insect Defoliators and Forest Fires Using Multitemporal Landsat and TerraClimate Data in NE Iran: An Application of GEOBIA TreeNet and Panel Data Analysis

“…Alternatively, this study proposes testing the capabilities of new data such as Sentinel-2 with higher spectral, spatial, and swat width that can produce dense time series, which are more appropriate for monitoring near-real-time insect infestation. There have been increasing reports about the outbreaks of other biotic agents such as bark beetles and pathogens in the Hyrcanian forests [52,53,54]; therefore, further investigations are required for identifying the spatial extent of these agents and exploring their triggers. Furthermore, separating mortality induced by insect defoliators from bark beetles or pathogens should be scrutinized.…”

“…The stages of moderate to extreme tree mortality events showed a significant association with the high intensity of forest water content deficit derived from the MODIS–NDWI; however, the severe defoliation only showed a significant relationship with the intensity of forest greenness loss derived from NDVI in NE Iran [49]. In addition to climate hazards, drought, and forest fires, there has been rising concerning reports about the outbreaks of some insect defoliators such as Lymantria dispar , Erannis defoliaria , and Operophtera brumata [50,51] as well as pathogens [52,53,54] throughout Hyrcanian forests during recent years. Therefore, this study used TreeNet to delineate insect-infested forests from non-insect-infested forests using numerous Landsat 8 OLI-derived object features, topographic-derived features, and tree species types in Hyrcanian forest, NE Iran.…”