جستجوی مقالات مرتبط با کلیدواژه « nutrients » در نشریات گروه « جنگلداری »

One of the concerns for the executive organizations to introduce an alternative plan of rest of the Hyrcanian forests is to make decision regarding the exit of coarse woody debris (CWD) volume from the Hyrcanian forests. The research was carried out in the permanent plot with 400 m2 based on the protocols of the comprehensive research plan enacted by Agricultural research Education and Extension organization in Iran. Within each plot beneath the CWDs over than height of 1.5 m and dimensions of 7.5 cm, the organic accumulations resulted from the decay trend were sampled. Besides, the soils mineral layer up to 10 cm depth were sampled after removing the organic accumulations, and were transported to the laboratory. The results of PCA (Principal Component Analysis) showed that beneath the CWDs including higher organic accumulations, amount of the organic carbon and the nutrients were lower in the substrate soil mineral layer. Furthermore, the results of Spearman test indicated that amounts of organic carbon and nutrients in the organic and substrate mineral layers were independent of each other (P > 0.05), and amounts of the organic carbon with Nitrogen were significantly correlated (P < 0.01). Also, the results of two-way PERMANOVA test indicated that interactions of form, species and decay of the CWDs in the study sites were not significantly effective on the organic carbon under the CWDs.

In this study, the impact of boxwood moth pest defoliation on the dynamics of leaf litter and soil nutrients in the Cheshmebolbel boxwood (Buxus hyrcana) reserve was evaluated. A random sampling technique was employed to collect litter layer samples (using a 400 cm2 frame) and soil samples (using a metal cylinder with an 8 cm diameter and a 10 cm depth) from 32 sites in unpolluted and polluted boxwood stands. The results revealed that only soil moisture percentage differed significantly among the soil physical variables, whereas all chemical soil variables showed significant differences between the two polluted and unpolluted boxwood sites. Furthermore, basal respiration (0.14, 0.12), metabolic rate, microbial ratio, and carbon availability index were significantly higher in the polluted sites compared to the unpolluted site, while no significant difference was observed based on the microbial-carbon respiration index. The principal component analysis (PCA) results demonstrated a distinct separation of the two sites, both polluted and unpolluted, along the first axis, based on both litter and soil variables. In this context, nitrogen, metabolic rate, moisture, nitrate, ammonium, and stimulated respiration (0.30, 0.39) exhibited a positive correlation with the first axis, representing the concentration of the unpolluted stand. On the other hand, C/N ratio, potassium, magnesium, calcium, and microbial biomass carbon displayed a negative correlation with the first axis, representing the concentration of unpolluted sites. In general, the findings of this research underscore the substantial influence of defoliation induced by pest outbreaks on an important aspect of forest ecosystem health, performance, and nutrient cycling.

This study was done to investigate the effect of slope aspect and crown dieback intensity on the nutrient status of leaves of Persian oak trees influenced by dieback and site soil in the forests of Ilam province. For this purpose, the Forest area of Melah-Siah was considered and two one-hectare areas on the northern and southern aspects with almost the same altitude levels were selected. In each selected area, 10 trees were sampled in two intensities of healthy and dieback affected. Leaf samples were collected from the four main sides of tree crown and the middle part of the crown and from their terminal branches. Furthermore, from the south side of the selected trees, soil samples were prepared from two depths. Collected samples were transferred to the laboratory for analysis of OC, N, P, K, Ca and Mg.  The results showed that the slope-aspect and crown dieback intensities have significant effects on the amount of phosphorus, calcium and magnesium in Persian oak tree leaves. So that, the amount of leaf phosphorus in the northern site was higher than the southern site. Leaf calcium and magnesium concentrations were higher in the north site than the south site and in dieback-affected trees than the healthy trees. Also, the amount of soil organic carbon was significantly affected by slope aspect. The OC content in depth of 0-20 cm, in the northern site was less than the southern site. The amount of pH, CaCO3 and soil moisture in the depth of 0-20 cm and soil moisture in the depth of 20-50 cm were also changed under the slope aspect. It was concluded that leaf nutrients had more changes than soil elements under the influence of considered factors and the amount of these changes was more attributed to the slope-aspect. The studied Persian oak trees with different crown dieback degrees had a similar situation in terms of soil macro elements, but had different conditions in terms of leaf macro elements. Considering the differences between their habitats in terms of soil moisture and pH, it can be said that the dieback severity of tree crowns is related to physiological mechanisms in trees for absorbing water and nutrients.

Todays, Application of Nanotechnologies in Plant Science is one of the topics of the day. The present study was conducted to investigate the effect of carbon nanotube treatments, calcium chloride 1% and potassium nitrate 1% on leaf nutrients and height growth of Iranian oak seedlings. This experiment was performed in a completely randomized block with three replications in the research greenhouse of Malayer University. For this purpose, the seeds were primed in the first treatment included five levels of concentration of carbon nanotubes (10, 25, 50, 75, 100 mg / l) for six hours, the second treatment of calcium chloride 1% for 48 hours and the third treatment Potassium nitrate for 24 hours and control treatment (non-priming). At the end of a six-month period, the growth rate and nutrient levels of nutrients in the leaves and soil under the seedlings were measured. According to the results, the highest concentration of soil nutrients was observed in low concentrations of nanoparticles. Findings showed that in compared to the other treatments, the greatest effect of potassium nitrate 1% was in increasing soil carbon. Also the Findings showed that the amount of nutrients in the leaves decreased with increasing concentration of carbon nanotubes. According to the results, the use of carbon nanotubes with a concentration of 50 mg / l has good conditions in increasing the concentration of nutrients in the leaves. Also, the use of concentrations of 50 and 75 mg / l of carbon nanotubes increases the height growth of oak seedlings.

The aim of this study was to investigate the effects of shrimp farming effluent on vegetative and reproductive characteristics of grey mangrove in Tiab region of Hormozgan province. For this purpose, two stands, control and another stands next to the shrimp farm as a contaminated to shrimp farming effluent were selected and a three-hectare stand was identified in each of these two sites and sampling was performed by line sampling method. In this way, three 300-meter transects were selected using a random- systematic method in each stand. Also three plots (10×10), 150 meter apart from each other, were selected along the transects and the vegetative and reproductive characteristics of Avicennia marina (Forssk.) Vierh for trees higher than one were measured and analyzed using T-test. Results showed that, in the control site, vitality of trees, and the average quantity of tree height, crown length and the number of seedlings, with the amount of 2.57, 3.53 m, 3.53 m and 8.55 seedlings/m2 were significantly higher than those at the contaminated site. On the basis of the results, in the forest sediment of the contaminated site, the amount of phosphorus and nitrogen were significantly higher than those at the control site. Although more research is needed in order to confirm the factors reducing mangrove growth, this study can emphasize the need for more detailed and specialized studies for correct location selection and also licensing for these farms in order to guarantee and minimize the impact of shrimp farm outputs on mangrove ecosystems.

In this study, the effect of soil and water affected by municipal effluent on the performance of three poplar clones of Populus nigra L. after one year was investigated in a factorial experiment with two factors (1- soil and water in two levels and 2- poplar clones in three levels) based on the completely randomized design with five replications. After one year, in three poplar clones, significant increase in growth and biomass parameters of plants treated by soil and water affected by municipal effluent was observed. In three poplar clones, the significant increase of nutrients and heavy metals in organs of plants treated by soil and water affected by municipal effluent was observed. In three clones, Fe, Cu, Ni, Cr and Pb were mainly accumulated in roots, whereas Zn and Mn showed the highest concentrations in leaves. The three poplar clones did not show statistically significant differences in terms of uptake and accumulation of nutrients and heavy metals in plant organs. The effect of clone on most growth and biomass parameters was significant (p ≤ 0.01). The highest growth and biomass rates were seen in plants of P. nigra 62/154 treated by soil and water affected by municipal effluent. The results of the present study showed that for wood farming in lands affected by municipal effluent, all three poplar clones can be used by prioritizing the P. nigra 62/154 clone.

To investigate the relationship between some physical and chemical properties of soil and tree ecophysiological properties on dieback of Oak trees, 30 square sample plots with 2500 m2 area, in a random systematic grid (200×200) were selected. The percentage of dieback were measured in each sample plot and soil and leaves of trees were sampled. Some soil properties such as texture, electrical conductivity, acidity, bulk density, porosity, Carbon and organic matter and concentrations of Ca, Mg, N, P, K, Na were measured. Also, Peroxidase, Catalase and Ascorbate peroxidase enzymes, MDA, Proline, Chlorophyll a, b, total Chlorophyll, Carotenoid pigment and concentrations of Ca, Na, K, Mg, P and N in leaves were measured. Comparison of variable means showed that there is just significant difference in leaf nitrogen between different dieback classes. In general, the results of this study showed that the soil properties in our study area were not significantly affect on oak decline. On the other hand, the physiological capabilities of trees solely, cannot be the cause of their different dieback.

Salinity stress is one of the most important factors limiting the growth and expansion of plants on the planet. In the world, an area of about 800 million hectares, in Iran about 44 million hectares and in Golestan province more than 75000 hectares of its lands are affected by salinity and has poor vegetation, sparse and exclusively salinity-resistant species. The use of salinity stress-resistant tree species and increasing their yield by adding the required nutrients from different sources to the soil can be effective in establishing vegetation and optimal use of saline soils.

For this purpose, the present study was performed on one-year-old bitter olive seedlings (Melia azedarach) in a factorial experiment with two-factor as a completely randomized design. Salinity stress with irrigation water once every five days in five levels including 0, 5, 10, 15 and 20ds/m and fertilization in four levels including 0, 50, 75 and 100 g of Herbban mineral fertilizer it was applied for each seedling with five replications for 120 days. In order to reduce the adverse effects of displacement and repair of damaged roots, fertilization was performed 50 days before salinity stress. During the period of salinity stress, the rate of vitality quality and survival percentage were measured every five days and at the end of the period, 15 vegetative traits were measured. Data analysis of variance was performed using SPSS software and Duncan test was used to compare the means. Rank data were also analyzed by Kruskal and Ellis tests.

The results showed that salinity stress caused a significant decrease in vitality quality, survival, longitudinal growth, leaf area, number of leaves, average individual leaf area, specific leaf area, leaf fresh weight, leaf dry weight, fresh weight Root and leaf specific gravity increased at 5% probability level. The effect of fertilization caused a significant increase in longitudinal growth and a significant decrease in leaf specific gravity. The highest vitality quality and survival were observed in conditions without salinity stress and fertilizer application. The lowest vitality quality and survival were obtained at 20ds/m and 100 g of fertilizer. Significant increase in longitudinal growth and significant decrease in leaf specific gravity were the only significant effects of fertilization. Comparison of means did not show any difference between the mentioned traits at the control level and 5ds/m. The highest survival percentage at the end of the period at the levels of 10 and 15 ds/m were equal to 100 and 75%, respectively.

Therefore, according to the results, bitter olive easily tolerates salinity of 5ds/m and if suitable fertilizers are used with short stabilization time and high absorption percentage, it can be grown in areas with salinity of 10-15ds/m acted with different goals.

Forest fire and leaf litter is one of the effective factors influencing soil nutrient. Fire intensity and duration can affect the properties of ash and surface soil. The aim of this study was to investigate the physio- chemical properties of ash after the heating of Aleppo oak (Quercus infectoria Oliv.) litter at various temperatures under laboratory conditions. In order to collect litter, Khavmire Abad district in Marivan forest was selected such that litter samples were taken under the crown of the 8 Aleppo oak trees. Trees were selected on a transect parallel to the contour lines, 30 m interval. Leaf litter has milled first and then the samples were prepared in four treatments (milled litter and three treatments heated at 200, 400 and 600 °C). The results showed that the color of ash was dark brown, gray and light gray in temperatures of 200, 400 and 600 °C, respectively. The amount of pH, EC, P, Ca, K and Mg increased significantly with increasing temperature, while OC and TN first increased until 200°C and then decreased significantly. The reduction of nutrient concentrations in the ash of Aleppo oak was: N> C> P> K> Mg> Ca. In sum, temperature can significantly affect the availability of nutrients in ash of Aleppo oak after heating. In addition, different temperatures had significant effects on the amount of nutrients and ash color.

Most of soil physical, chemical, mineral and biological attributes are changed by forest fires. Fire is one of the most important factors of forests destruction in Ilam region and considerable area of the region are annually exposed to fire. Depend on environmental conditions and also fire intensity, different effects will impose on ecological conditions of the environment. Whereas soil is considered as a base for forest’s growth and regeneration, study of fire effects on it’s properties takes an important place.Most of soil physical, chemical, mineral and biological attributes are changed by forest fires. Fire is one of the most important factors of forests destruction in Ilam region and considerable area of the region are annually exposed to fire. Depend on environmental conditions and also fire intensity, different effects will impose on ecological conditions of the environment. Whereas soil is considered as a base for forest’s growth and regeneration, study of fire effects on it’s properties takes an important place.Most of soil physical, chemical, mineral and biological attributes are changed by forest fires. Fire is one of the most important factors of forests destruction in Ilam region and considerable area of the region are annually exposed to fire. Depend on environmental conditions and also fire intensity, different effects will impose on ecological conditions of the environment. Whereas soil is considered as a base for forest’s growth and regeneration, study of fire effects on it’s properties takes an important place.This research was carried out on the effects of fire on soil chemical properties in the three intervals of one, two and three years after a fire. For this purpose, three regional forest fires have been selected considering the similarity in topography and geology conditions. A control region was also selected in the vicinity of the study area (no fire). 40 round sample plots of 100 m2 were taken to Bankool forests. soil samples from a depth of 0-5 cm were collected from below and outside of the crown trees in four study area. Some chemical properties of soil samples were measured. T-test results showed that there are significant differences between chemical variables under and outside crown in the first years of fire and four regions (p