جستجوی مقالات مرتبط با کلیدواژه "تکثیر طبیعی" در نشریات گروه "کشاورزی"

Nesarud and Kheyrud rivers are important rivers in Mazandaran province that are important in terms of having special populations of fish, spawning of migratory species and feeding of estuarine fish. The aim of this study was to evaluate the microbial quality of water in Nesarud (shilling) and Kheyroud (natural reproduction) rivers from April to August 2018 and microbial factors including total bacteria, total coliform, fecal coliform and fecal streptococcus were evaluated. For this purpose, 4 stations along the route of Nesarud and Kheyrud rivers were selected and monthly for sampling of river water was performed for 4 months (April, May, July and August). Based on the obtained results, the maximum changes in the average total bacterial count of Nesarud (20250 CFU/ml) and Kheyrud (21250 CFU/ml) were achieved in May and the maximum changes in the average total coliform of Nesarud (45 CFU/ml) per month. May and Kheyrud (50 CFU/ml) were reported in April and the range of mean changes in fecal coliforms in different months in Nesarud rivers (10 CFU/ml) in May and Kheyrud (8.5 CFU/ml) per month April was variable. According to studies, the water quality of the Nesarud and Kheyrud rivers is suitable for shill formation and natural reproduction in terms of bacterial indices and the number of bacteria was in the standard range.

This study aimed to identify the silvicultural characteristics, geological structure, soil and climatic characteristics, and to form a table for the ecological needs of the Tecomella undulata (Roxb.) Seem.. Six T. undulata habitats in southern Iran were selected following specification of their range of occurrence. The results indicated the distribution of T. undulata in warm and southern Iran, from the coast of Persian Gulf at a height of 10 meters a.s.l in Moqdan (Bushehr) to 1612 meters a.s.l in Esfandaghe (Jiroft). Annual rainfall of the study area is 100 to 200 mm with an average annual temperature of 5 to 50 °C. The habitats had mostly light to moderate and more sandy to loamy sandy soil texture with low water storage capacity. The soil was rich in potassium, yet very poor in nitrogen and organic matter, the average acidity of saturated sand was 7 to 8 and its conductivity was 0.5 mm/m, which predominantly lie on sediments of the Quaternary and Tertiary periods. The average density of T. undulata per ha in the six habitats was 75. In addition, results showed the maximum height of 10.2 m and the mean diameter of 47.35 cm. The mean canopy area was 13.2 m2 (ranging between 1 and 20.5 m2). The flowering stage of T. undulata species usually starts in late march to the middle of May. Furthermore, seed ripening occurs in late June and early May in the habitats associated with the best acorn production (Dasht-e kooch- Jiroft).  Natural propagation of T. undulata is carried out through the seeds and roots sprouts. The results of this study provided useful information about autecology of T. undulata.