جستجوی مقالات مرتبط با کلیدواژه « Persian Oak » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

Dust storms are increasingly threatening the forest ecosystem in Western Iran. Due to its coverage of vast area of Zagros forest, the Quercus brantii is at the front line of the attack. Most tree deaths in this forest are from this species. This study aims to investigate the effect of simulated dust on wood development and leaf stomata from seedlings of Persian oak. The oak seedlings were put in a chamber and dusted from 9 a.m. until 6 p.m. at three different days with an interval of 12 days. They were under three increasing concentrations of dust (5000, 7000, and 9000 mg/m3). Leaf and wood samples of about 10 seedlings were collected, and the leaf stomatal features, growth ring and vessel features of both treated and untreated seedlings were examined. The results showed no variations in stomatal features except for pore aperture. As for wood features, growth ring, vessel number and diameter considerably changed. In treated seedlings, the growth ring and vessel diameter were smaller and the number of vessels was higher than in the untreated seedlings. No detection of differences in stomatal features could be tracked due to the short-period of treatment. The usual seedlings’ annual growth could be altered by treatment affecting on both annual growth ring and vessel features. To sum up, it can be concluded that dust storm has strong effect on seedling’s growth as can limit wood formation

Zagros forests are one of the important natural ecosystems in Iran with high plant diversity and variety of plant communities. In recent decades, fire events have frequently occurred in some of these ecosystems. The purpose of this research is to investigate the composition and diversity of herbaceous species after nine years of fire occurrence in the forests of Zagros in western Iran. For this purpose in 2015, an area of 40 ha that had burned in 2006 was selected and compared with the unburned area (control area). In both areas, 80 plots were selected. The optimal size of plots was determined based on Whittaker's nested plot sampling and minimal area method. Then, vegetation cover percent of each herbaceous species was estimated according to Van der Marel criterion in each plot. The results showed that the fire reduced the diversity, evenness and richness indices, but this decrease was not significant between Shannon-Wiener (P= 0.57) and species density index (P= 0.06). Species Avena fatua with 21.51 and 18.56% had the highest coverage in the burned and control areas, respectively. In addition, the average of herbaceous percent cover was significantly higher in the burned area (P<0.05). Also, Fabaceae, Asteraceae and Poaceae families were the most important families in both areas. The overall results of this study revealed that many species are able to restore their primary conditions over time.