جستجوی مقالات مرتبط با کلیدواژه "پتاسیم" در نشریات گروه "جنگلداری"

Most of the biological nitrogen fixation rate among forest species is related to the symbiosis of Frankia actinomycetes with actinorhizal plants such as Alder. In the present study, we investigated changes in vegetative characteristics, biomass and nutrients of Alnus subcordata  and Alnus glutinosa affected by three treatments including: symbiosis with Frankia nodes (T1), symbiosis with Frankia nodes and fertilization with urea fertilizer equivalent to 50 kg per hectare (T2), symbiosis with Frankia and fertilization with Urea fertilizer equivalent to 100 kg ha (T3) and without symbiosis with Frankia and without fertilizer (control) for 60 days in research greenhouse of faculty of natural sciences of University of Guilan. At the end of the study, the collar diameter and height of the seedlings were measured and biomass of their different parts was calculated by drying in the oven. The percentage of nitrogen, phosphorus and potassium in the components of the plant were also calculated using Kjeldahl, extraction and colorimetric methods, respectively. According to the results of analysis of variance, significant differences were observed between vegetative characteristics, biomass and nutrients of the species under different treatments. Comparison of means with Turkey’s test showed the best performance of 50 kg / ha fertilizer treatment among the treatments. In addition, the performance of Alnus subcordata in the most of cases was better than Alnus glutinosa. The results of the present study indicate the positive effect of nitrogen fertilization on alder seedlings in early stages of growth and in nursery environment and for alder species, 50 kg urea fertilizer per hectare is sufficient. Of course, considering the environmental considerations, the use of nitrogen-containing organic fertilizers is preferable if fertilization is required.

Dendrochemistry is the science of analyzing the elements of tree rings that identify the biochemical changes of a tree under environmental changes. In order to investigate the change in the concentration of some of the chemical elements in the wood of declined trees compared to healthy ones, three healthy and declined Iranian oak trees (Quercus brantii Lindl.) in forests close to Khorramabad were cut and a disk was prepared from each tree. Then the vegetative rings of the last 35 years were cut into three five-years and two 10-years-old cuttings and extracted by the wet digestion method and the concentration chemical elements were measured using the atomic absorption apparatus. The results showed that potassium concentration in the wood of declined trees was higher than healthy ones while calcium and copper concentrations in the wood of healthy trees were less. Also, the ratio of sodium and calcium to potassium concentration in the trees of the two communities was significantly different. Correlation between elemental concentration and radial growth of healthy trees was not significant, whereas in declined trees there was a negative and significant correlation between calcium and lead content and radial growth. According to the results, the effect of climatic factors seems to be the most effective among several factors.

According to the positive role and symbiosis of ectomycorrhizal fungi for absorbing water and nutrition and transferring to trees, identification of them are of great importance. The aim of this study was to investigate the relationship between recognized ectomycorrhizal fungi and some soil chemical properties in the Flourd series of Farim forests, Mazandaran province. Forty five beech trees were measured in three elevation classes (1200-1500, 1500-1800, and 1800-2100m a.s.l.) and samples were taken from the root tips at a depth of 10 cm. ITS nrDNA was replicated and sequenced using ITS1F and ITS4B or ITS4 primer pairs, then was corrected by BioEdit software and studied in NCBI. After specified the desired tree for sampling root tips, a sample was taken next to the same tree at a depth of 10 cm to examine of soil chemical properties. The results of this study showed that 10 different families were identified that the most symbiosis was in the Russulaceae and Cortinariaceae families. The results showed that edaphic factors such as soil pH, N, P, K, and C in the first elevation were higher than two other elevations. Moreover, the results of statistical analysis showed that P, K, and pH had a significant difference. Our results suggested that forest site conditions and tree diversity can influence on soil properties and the richness of ectomycorrhizal fungi and consequently on forest ecosystem dynamic.

In order to evaluate the role of different regimes of soil humidity and light intensity on allocation pattern of nutrients in the organs of wild pistachio sapling, this research was carried out in Albroz Research Complex (Karaj, Iran) during 2014 summer. One year pot based wild pistachio saplings were treated by soil humidity (including 100%, 50% and 20% of field capacity) and artificial shading (including 0%, 30% and 50% of full sunlight) factors in a split plot experiment based on a randomized complete block design with 3 replicates and 10 saplings per plot. After more than 4 months seedlings were pulled out from the pots and N, P, K and Zn contents were measured in their root, stem and leaves. Results showed that drought, shade and their interaction had no effect on concentration of studied elements in root. Zn content is the only stem variable which is affected and decreased by water deficit. Water deficit significantly decreased N and Zn content of leaves as well. Interaction of shading and drought stress had significant effects on N and K content of leaves, so that increasing the amount of shade caused increase of these elements concentration for moderate and severe shade and decreased them for without stress treated saplings. In general we concluded that shade is helpful for drought induced wild pistachio saplings and improves nutrients transportation process from root to shoot.

The aim of the study was to investigate the effects of different species and clones of poplar on beneath soil properties and their differences in amount of nutrient elements in their litters. Soil (0-20 cm depth) and litter sampling was made under the randomized complete blocks design with three replicates and five treatments of 18 year old poplar species and clones، including four exotics; Populus euramericana triplo، Populus deltoides 69/55، Populus deltoides 63/51، Populus euramericana 45/51 and one native: Populus caspica (control) planted at 4 x 4 m. spacing. The measured soil and litter chemical properties consisted of: Organic carbon، total nitrogen، phosphorus and potassium. The measured poplar characteristics consisted of: total height، stem diameter at breast height (dbh) and crown diameter. Results showed that there were significant differences (ρ<0. 05) between the poplar species and clones in respect to the soil and litter chemical properties، except potassium in soil. Furthermore، the highest and the lowest amount of nutrient elements in the litter belonged to P. d. 63. 51 and P. caspica، respectively and Populus deltoides 63/51 achieved the greatest stem and crown diameter and total height. It can be concluded that Populus deltoides 63/51 in addition to its proper growth، has a positive effects on soil nutrients due to its better litter quantity and quality production in comparison to the other species and clones.

In this experiment, soil nutrients, amount of autumn litterfall and nutrients recycling via litterfall into forest floor and their relationships to each other were studied in three stands (Elm, Maple and Ash) at Darabkola Experimental Forest of Sari Agricultural Sciences and Natural Resources University (North of I.R. Iran). Soil samples were made from 0-15 cm depth of soil surface and their chemical properties (pH, EC and the concentrations of N, P, K, Ca and Mg) were tested. Three litter traps (50×50 cm) were randomly placed in each stand and litter was collected at monthly intervals in autumn. Because leaves usually form a significant percentage of litterfall amount, they were collected from each litter-trap at different months of autumn, dried and sieved and finally analyzed. Results showed that there was significant difference (p<0.05) between the tree species in terms of soil nutrient concentration,except P and K contents). The lowest amount of soil N, P, K, Ca and Mg belonged to Ash plantation. Overall, the greatest and the lowest amount of litterfall belonged to Maple and Ash species, respectively. The results showed that the stands were able to change th soil properties to some extent. It might be concluded that these changes are consistent with the differences observed in respect to the recycled nutrients at each stand.

Salinity limits production of agricultural and natural resources crops of the world. Plant production decreases in areas containing saline soils or irrigated with saline water. Because most soils in arid and semiarid areas are alkaline and saline and Populus euphratica Oliv is a well-adapted plant in such soils, identification of its tolerance salinity is very import, particularly in Iran. In order to evaluate the effect of salinity on growth and chemical composition of leaves, stems and roots, a glasshouse trial was conducted, using statistical design of randomized complete blocks (RCBD) with three replicates. The rooted cuttings of P. euphratica were inserted in Hogland soil-less culture and after 15 days were treated with five leaves of NaCl and CaCl2 (0, 0.27, 0.54, 0.81 and 1.08% or 1.3, 6.1, 10.5, 13.5 and 18 ds/m) at 4: 5 ratio, respectively. The measured variables were survival, leaf appearace, height, leaf number and area, dry weight of leaves, stem and roots, and percentage of Na+, Cl -, Ca++, Mg++, K+ and N - at leaves, stem and roots. The results showed that salinity did not significantly affect leaf and stem dry weight at 6 ds/m of salinity but over 6 ds/m the root dry weight decreased significantly. Althoush leaf number decreased significantly by increase in saline levels, but root dry weight and seedling's height have not been influenced by salinity, significantly. Increase in saline levels, increased N- and K+ in leaves and Na+, K+, Mg++ and Cl- in branches. The root elements have not been influenced by salinity, except Cl-.