فصلنامه استراتژی راهبردی جنگل
پیاپی 10 (زمستان 1398)

Biological activities are underlying strategies against dust storms. The leaves, because of the larger surface in comparison with other parts of plant organs, are considered important for atmospheric dust filtration. The purpose of this study was to compare the amount of dust deposited on the leaves surface of Ziziphus spina Christi and Albizia lebbek in urban areas of Ahvaz city, south west of Iran. Leaf samples were randomly collected from different heights of individual trees in four main directions and washed and dust particles of the solution were dried in an oven and weighed. The leaf area was measured by Image J software. The results indicated that the amount of dust per unit leaf area of Z. spina-christi (11.74 mg/cm2 ) was significantly different with those of A. lebbek (9.11 mg/cm2 ). The results of this study will open up an avenue for identifying suitable trees for dust filtration in the southwest of Iran.

The use of natural resources in the international space, the use of different places in cities, having a high position, raising the price of air, and so on. . All reputable experts are in favor of Sava and can change you, so ask for support as they can visit. From the ways presented and the assessment of the damages, the position of the village is decided before the accident. By using natural resources, holes and gaps in the solitude provided to you have been able to power the crown of God and can use wind, storm and snow. That way you can have limited views. He also pointed to tomography as a method of providing unobstructed inspection of the trunk. In this case, you can buy other materials using the tomography technique along with various assessment methods and the ability to diagnose the physical defect of the trunk. In this way, given the limited velocity of the sway wave of the trunk machine, a color image of the trunk cross section can be obtained. In this image it is possible to use large marker colors and positioning troubleshooting such as rot, cavities, gaps, etc. You can do this using human resources. In this case, you can use the risks and potential damages to the elderly to correct and repair them, and you can use them.

Widespread tree mortality events have recently been observed in several biomes. To effectively quantify the severity and extent of these events, tools that allow for rapid assessment at the landscape scale are required. Past studies using high spatial resolution satellite imagery have primarily focused on detecting green, red, and gray tree canopies during and shortly after tree damage or mortality has occurred. However, detecting trees in various stages of death is not always possible due to limited availability of archived satellite imagery. In Iran, forest inventory information has been essential with respect to land management because 10% of Iran is composed of forests. Therefore, accurate forest information such as tree counts, height, DBH, and volume are critical for forest management. While such data traditionally have required labor intensive and time consuming field measurement, new technologies such as remote sensing have supplemented and supplanted some of these field measurements. Although different types of sensors have been used to extract individual trees information, WorldView2 (WV-2) has been used recently to extract surface information because WV-2 have high spatial and spectral resolution. In this study, object base classifiers (with KNN way) were used to classify WV-2 satellite and do assessment accuracy with UAV image in study sites. The study indicate that the classification accuracy of Object-based algorithm was best for extraction of dry trees. This study is conducted to evaluate the possibility of WV-2 data to extract forest characteristics from identifying and measuring individual trees. Our results demonstrate that WV-2 data, NDVI with object based classification can be used to detect tree mortality resulting from numerous causes and in several forest cover types.