جستجوی مقالات مرتبط با کلیدواژه "زنده مانی نهال" در نشریات گروه "جنگلداری"

In dry areas, the lack of rainfall, inappropriate seasonal distribution, and high evaporation and transpiration, and on the other hand, high water supply costs, cause the loss of seedlings, especially in the critical period of establishment. In the present study, the effects of different moisture storage treatments on the quantitative and qualitative growth of Cercis siliguastrum L., Celtis caucasica Wild., Elaeagnus angustifolia L. and Amygdalus scoparia Spach plantations were studied in the Semnan University. This experiment was conducted in a completely randomized design with five treatments: i) soil texture modification, ii) use of hydrogels, iii) zeolites and iv) straw with crushed stone and v) control (natural soil of region) with five replications and totally 300 seedlings of the species. The height, collar and crown diameter, number and length of lateral branches were measured at the beginning and the end of the growth period and survival rate of all seedlings were recorded at the end of growing period.  In Cercis siliguastrum, the highest growth of collar diameter, crown and length of lateral branches were measured under straw treatment.. In Amygdalus scoparia, the highest quantitative growth values were observed in straw treatment. In Elaeagnus angustifolia and Celtis caucasica , different treatments had no significant effects on growth parameters. Different storage treatments had no effect of survival of investigated species. The lowest survival rate (with a range of 80-88%) was related to Amygdalus scoparia seedling and no significant difference was observed in this factor amongst other species. The type and efficiency of moisture storage methods are different according to the type of species used, the straw and crushed stone treatment was effective in the growth of Celtis caucasica and Amygdalus scoparia seedlings. In contrast, Celtis caucasica had the highest growth in the natural soil. On the other hand, none of the investigated moisture storage treatments had no effect on the vegetative characteristics of Elaeagnus angustifolia seedlings. Furthermore, the use of hydrogel and zeolite had no positive effect on the growth and establishment of the investigated species.

This study was carried out in the researching forest of the UPM University of Malaysia. In order to enrichment the forest artificially and in four different ways, make artificial gap in four 1 ha (100×100) plot. 9 micro plots 10m×10m made in 2 plots and 5 micro plots 10m×10m and 20m×20m in 2 other plots, totally 28 micro plots. In these micro plots was planted far from others in 2.5m×2.5m, seedlings of 3 species of Shorea assamica, Shorea platyclados, and Mersava anisoptera, (totally 812 seedlings). Species, number, diameter, length of stem with out branches, length, diameters of crown, survival percentage of seedlings and light intensity in each micro plot was recorded. The light intensity classified in 3 classes (Class 3: 17% - 23%, Class 2: 10% - 17%, and Class 1: 4% - 10%). Results showed that seedlings which are in Class 2 of light have more Height and Diameter growth and have more Chances of survival. M. anisoptera had the highest survival rate, and S. assamic had the less. M. anisoptera had the highest diameter growth and S. platyclados had the less. In Class 2 and 3 the diameter growth was more than in Class 1. S. platyclados had the highest growth rate in Class 2, and S. assamic had the fewer rates in Class 1. The S. platyclados had the highest crown diameter, and the S. assamica had the less. Crown diameter in Class 2 and 3 are the same and was the maximum rate, and in Class 1 had the minimum rate. M. anisoptera had maximum stem length and S. assamica had minimum and in different Light Classes had non-significant. Interaction between species and Light class had non-significant effect on height and diameter growth and had significant effect on crown diameter and stem length.

Populus caspica Bornm. is an endemic and fast growing tree distributed in northern Iran, considered as endangered species without proper sexual reproduction in natural conditions. In contrast to other poplar species, knowledge about regeneration of this species is little. The tree yearly disperse plentiful of short-lived tiny seeds that need the suitable conditions and substrates to germinate and grow. Usually, the required conditions are not available in its natural habitats. The study was carried out to consider the mentioned problem. Therefore, for mass production of seed-born seedlings and broadening genetic basis of the species, matured capsules were collected from 25 single trees, distributed at different sites in Golestan, Mazandaran, and Guilan provinces at early April 2010. Sixteen trees of the 25 trees produced suitable and enough seeds. After well sifting, 30 seeds of each tree were sown per pot at three different soil treatments including: i) only nursery soil, ii) combination of nursery soil and fine sand (wind shifting sands), and iii) only fine sand, as well as three light aspect treatments including: 1) Eastern aspect, 2) Southern aspect and 3) Western aspect for 16 provenances. The experiment design was factorial model based on Completely Randomized Block Design with three replications. Pots were kept in large basins and irrigation was done daily in basin and pots. Weed control was done at different dates during growing season. Height of all seedlings was recorded at the end of growing season. Results of analysis of variance showed significant differences among all of the sources of variance. Soil treatments caused 113, 57 and 0 centimeters in seedling height, respectively. Significant differences were observed among the mother trees based on their seedling height. The results indicated that the progenies of Zarringol 2, Zarringol 3, Kenesy and Golestan 4 trees revealed 111.4, 98.9, 98.9 and 94.3 centimeter in height, respectively as the longest one, so that 11 groups were specified among the 16 mother trees. Significant differences among the direction treatments were observed, so that the seedling height of 87.6, 87.3 and 81.4 centimeters were recorded for eastern, southern and western aspects, respectively. As a main result, the study shown significant differences for height in soil, mother trees and light aspect treatments. Therefore, mass seed-born seedling production for the species would be possible using the best treatments of the study.