s. a. a. hashemi

Persian oak is the most important forest tree in Fars province (Iran). In order to identify the composition of Alternaria species associated with healthy and declined Persian oak trees in Fars Province, Iran, fungal isolates were recovered from twigs, trunks and leaves of healthy and declining Persian oak trees from early September to late March 2021-2022. Fungal species were identified based on both morphological and as well as molecular characteristics of the DNA sequence data of the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and plasma membrane ATPase genes. In total, 29 Alternaria isolates were obtained, which were identified as Alternaria alternata, Alternaria consortialis and Alternaria chlamydospora. Alternaria alternata showed the highest frequency approximately 51.72% and were isolated from both healthy and declining oak trees. Alternaria chlamydospora and A. consortialis were obtained only from healthy oak trees without declining symptoms with 41.38% and 6.89% frequencies,, respectively. Pathogenicity tests were conducted using all isolates in three replicates. Inoculation of different Alternaria alternata, Alternaria consortialis and Alternaria chlamydospora isolates on Persian oak seedlings did not show any symptoms after 60 days in greenhouse conditions. This is a new report of Alternaria species including A. alternata, A. consortialis and A. chlamydospora as endophytic fungi on Persian oak tree in Fars province of Iran.

Land use optimization is one of the appropriate methods for soil conservation which helps decision makers and watershed planners in order to make the optimum decision among different land uses. The main objective of this research was to find the optimum area of each land use to reduce soil erosion rate as well as to increase the income of stakeholders in Golroudbar watershed located in Semnan province of Iran. The linear programming model was used in three different scenarios including current land use condition without any land management plan, current land use condition with land management plan and the standard land use level. The results showed that in the optimized condition, the orchard land 28.85 percent, rangelands 74.12 percent and irrigated lands 283.78 percent were increased. Additionally, by optimization of the land in standard condition, soil erosion decreased 16.28 percent and the profitability increased 94.58 percent.

In order to quantitatively evaluate the sediment yield in ungauged basins, it is necessary to use empirical models. The EPM model, as a model which is using in Iran, has sometimes been evaluated. Most evaluations have often been conducted by using river's sediment information and direct measurements of dam reservoir sedimentation have been less used, while the sediment measurement method on reservoir is more carefully. 9 small watersheds from Semnan province (Iran) were selected in this research. There is a small earth dam which have been built on the outlet of each watershed in the past years that them age is 10 years. These dams have not been weirs since they have been building to now. Therefore total of sediment yield volumes of each watershed are entrapped in the dam reservoirs. The volume of sediments deposited in reservoir were calculated by surveying. Sediment's apparent specific weights were measured in each reservoir and the volume of sediments transformed into sediments weight. By EPM model the volume and weight of sediment yield were estimated. Values of sediment yield measured in reservoirs were compared with estimated values by t-test. The results showed that at level 5%, there was not any significant difference between sediment yield values estimated in reservoirs by EPM model in comparison with values of volume and weight which were measured. But determination of performance and relative root mean square error showed that EPM model has low efficiency for estimation of sediment yield in the case study of watersheds.