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

The utilization of flood and its spreading on flat plains is a reclamation approach for natural resources in most countries such as Iran. But existance of information about moisture condition in the different parts of spreading area and its impact on tree species is necessary. Therfore، this project was performed in Qarecharian spreading station (Zanjan province) during five years (2005-2009). Four seedlings from each tree species of Elaeagnus angustifolia، Amygdalus communis and Robinia pseudoacacia were planted at four locations considering moisture condition at the three spreading canals first، third and fifth in three replications for each. The vitality of each seedlings were noted after flooding and drought periods. The height and diameteric growth were also noted. The results showed، the third canal with the vitality of 63، third location with 72، and E. angustifolia with 91 seedlings were the best.

Whereas more than 90 % of Iran is located in arid and semi-arid area, water is one of the most important factors that can prevent from sustainable development in all of agricultural subjects. Thus, the water can play an important role in ecological condition changes especially for plants. In this research, it was attempted to survey the water harvesting and its spreading impact on plant composition changes in a flood spreader. The study area is located in the part of the Zanjan plain, in north-west of Zanjan city and between two rivers Sorhain and Qarecharian, which is include rain fed and released lands that, has been occupied by quaternary deposition. For this purpose, the amount of rainfall and diverted floodwater to the station monitored and measured during all flooding time. In order to evaluate the plant composition changes in three sites in spreading area and one in control site, totally 11 permanent transects (9 in spreading area and 2 as control) were stabilized and using Line Intercept Method, the canopy cover percentage of all species were noted and all species were distinguished. This study showed that some species under impact of floodwater spreading omitted, some increased or decreased, and some new species observed for first time. Increasing of the vegetation cover and appearance of palatable plants in last year showed that the floodwater spreading can improve the foliage production. Considering to life form of observed species, although perennial forbs increased, but the floodwater spreading in the case of establishment of perennial grasses did not operate successfully. Therefore, shortage of studying period (8 Years) and changes on amount of harvested floodwater make correctitude of these obtained results rather less valid.