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

Arbuscular mycorrhizal fungi, due to their very beneficial effects in the growth and development of plants through supplying the water needed by plants, especially in drought stress conditions and increasing their tolerance to salt stress and in general, helping the plant to overcome living and non-living tensions, they are the focus of many researchers. This research was conducted during 2020-2022 with the aim of investigating the effect of flood spreading, vegetation type on the abundance and diversity of mycorrhizal fungi in Kowsar Station.

In spring and autumn, in different land covers, including planted Eucalyptus and Acacia forest, planted pasture with Atriplex bushes with 37 years old and natural pasture in two situations with flood spate irrigation and without spate irrigation. Three samples were prepared from roots less than 1 mm of trees and dominant plants (Heliantemum, Dendrostellera, and Artemisia) in the pasture and the rhizosphere soil up to a depth of 20 cm. After separating and staining the roots, their microscopic examination to determine the presence of symbiosis in the root tissue and to determine the extent of root colonization with mycorrhizal fungi and the extent of mycorrhizal symbiosis based on the extent of root contamination with structures of mycorrhiza was done. The soil passed through a 2 mm sieve was used to separate the spores, and the genus and species of mycorrhizal fungi were identified based on the morphology of the spores using identification keys and information available in scientific sources.

The results showed that the spore density of mycorrhizal fungi in both sampling seasons was higher in areas with flood spreading than areas without flood spreading. The highest spore density in the field of flood spreading in the autumn season is related to H. lippii with the number of spores 50.20 per gram of soil and the lowest with the number of spores 18.80 per gram of soil related to this species in the field without flood spreading in spring. So that the difference between the two was statistically significant with Duncan's test at the 5% level. Also, in all land uses, spore density was higher in autumn than in spring. The highest percentage of root colonization or the percentage of symbiosis was related to Acacia with 61.81% in the field without flood spreading in spring season and the lowest value was related to Eucalyptus with 12.26% in the field without flood spreading in autumn season. In this research, 21 species belonging to 9 genera Acaulospora, Claroideoglomus, Diversispora, Entrophospora, Funneliformis, Glomus, Rhizophagus, Scutellospora and Septoglomus were identified in with and without flood spreading areas. Septoglomus constrictum was the most abundant with 100.0% frequency. Glomus heterosporum and Rhizophagus aggregatum were in the second category with a frequency of 50.0% and Funneliformis mosseae, Glomus ambisporum, Glomus intraradices and Rhizophagus fasciculatus were in the third category with a frequency of 33.3%.

Considering the fact that the identification of mycorrhizal fungi in the rhizosphere of tree plants and pasture bushes in dry areas and their use can be a fundamental step to reduce the negative impact of various stresses, including drought stress, it is suggested the active and effective species of these fungi may be identified and propagated and used as inoculum (biofertilizer) to restore rangelands in these areas.

Eucalyptus species are one of the most suitable tree species in terms of wood production for pulp and paper industry and leaves for pharmaceutical industry. This study aims to determine the wood and foliage production in coppiced Eucalyptus species. This study carried out on four Eucalypts species including Eucalyptus camaldulensis 9616, E. melliodora, E. stricklandii and E. Salubris with 4 treatments (1, 2, 3 shoots per stumps and control) and were planted at 1.5×  2 m spacing as statistical split plot design with 3 replications at Shooshtar Research Station, Khuzistan province.  At the end of first year, seedlings were cut 10 cm above the ground and coppice shoots treatment was applied. Survival percentages, diameter at breasts height (dbh), and height were measured yearly during dormancy on all trees. After four years of growth, all shoots were cut and stems and branches were weighed separately, and finally the biomass was recorded. The growth results of four years after the shoot treatment showed that the highest average wood yield was in the E. camaldulensis species and in the control and 3-shoot treatments with 45.4 and 38.9 tons per hectare per year, respectively. The average foliage biomass under different shoot treatments showed that in the 3-shoot treatment of  E. camaldulensis species with 10.3 ton/ha/yr. had the highest value  and was placed in the first group. Also, total of wood and foliage yield of E. camaldulensis in control and 3-shoot treatments with 50.8 and 49.9 tons per hectare per year respectively, were placed in the first group.

Knowing the qualitative and quantitative characteristics of plantation is principal of forest management. Laleh Natural Park in DEZFOUL, with a total area of 9.31 hectares, is located 11 km far from Dezful. The 23-year old stands in the studied park were Eucalyptus and Prosopis. In order to study the number of trees, according to the small levels of the studied stands (pure Eucalyptus 1.9 hectare and mixed with Prosopis 1.7 hectare), the full calipering inventory method was selected and the certain characteristics such as diameter at the breast height and height of all trees. According to the results, the average number of trees in the pure Eucalyptus stand is equal to 110.5 trees per hectare, the average diameter at breast height of stand is 25.22 cm and the average total height is 12.10 m. Also, the average number of species in the mixed Eucalyptus and Prosopis stand is 70.6 trees per hectare, the average diameter at breast height is 27.32 cm and the average total height is 9.57 m. In order to study the effect of Eucalyptus and Prosopis on the soil of the area, 50 soil samples were taken at 2 depth of 0-10 and 10-20 cm from pure and mixed stands and some soil characteristics including texture, moisture and acidity were studies. Soil texture of both stands in this study was loam. There was no significant difference between the two populations in terms of total relative humidity. In terms of acidity, there was a significant difference between two soil depths of 0-10 and 10-20 cm soil in the pure stand which was higher at depth of 10-20 cm.

Eucalyptus species are used for afforestation in different ecological areas due to their rapid growth and high genetic diversity. The industrial performance of some species and provenances of Eucalyptus was evaluated.

The experiment was a factorial experiment based on randomized complete block design (RCBD) with two factors: 1) genotype at 6 levels and 2) time at 3 levels in four replications. Irrigation was carried out using the treated wastewater of Qom city. Selected genotypes were including six provenances of Eucalyptus camaldulensis Dehnh., E. Microtheca Muell. and E. rubida Deane & Maiden. Growth traits including: tree height, trunk diameter, height growth, diameter growth and height to diameter ratio were measured. Because of evergreen eucalyptus trees, vegetative traits were recorded in two stages yearly, one in early autumn (after summer heat stress) and the other in spring (after winter cold stress).

Statistical analysis such as analysis of variance and comparison of mean traits between genotypes and different years showed that the effect of treatment (species and provenances), replication and year effect on tree height were significant. Mean comparisons showed that species and provenances were classified into five distinct groups and one common group; E. camaldulensis 41ch was in the highest group. Trees were grouped according to the diameter of trunk, E. camaldulensis 41ch and E. camaldulensis Qom were in the first and second groups. In addition, E. camaldulensis 41ch and E. camaldulensis Qom were in the first group and E. microtheca 62 and E. rubida 166sh respectivelygroups. The diameter trunk of E. camaldulensis Qom was in the first group and E. rubida 166sh in the last group. In terms of trunk height to diameter ratio, the species were divided into two distinct groups and three common groups, based on these results, E. camaldulensis 41zh was the first group with the highest height to diameter ratio.

In general, the results showed that E. camaldulensis had the highest ratio of survival and establishment, it had the highest growth and diameter growth and E. microtheca was in the next place. E. camaldulensis seems to have a higher performance for wood production than other species and provenances, E. camaldulensis Qom was also ranked first in terms of diameter and height growth, this due to seed origin (Qom) and adaptation to regional conditions. Overall, the results showed that E. camaldulensis had the highest rank in height and diameter growth, followed by E. microtheca.

Many species used in forestation could survive even in severe conditions, but considering the growth and economic efficiency is also important. Eucalyptus species are important sources for the production of wood, paper, fuel, and oils that are commonly used for planting the forests in the tropics. The purpose of this study was to evaluate the growth of adaptable species and cultivars, industrial and fast growing eucalyptus, for planting in inefficient lands of dry areas in Ilam province. For this purpose, the vegetative growth of eight species and varieties of eucalyptus including E. camaldulensis (from four origins), E. sargentii, E. microtheca, E. melliodora and E. saligna were investigated in a five-year period.in a randomized complete block design with three replicates in Mohsenab research station of Mehran, Ilam. The data analysis was performed using ANOVA and Duncan's multiple range tests in SAS software. The results indicated that there is a significant difference between species and cultivars in terms of indicators of height, trunk diameter, and canopy. E. camaldulensis is superior regarding to vegetative growth index in this study compared to other species. Three varieties of this species has an annual production of between two to five cubic meters per hectare, Shafarood variety has shown annual yield of more than 35 m per ha.

The different species form the genus Eucalyptusspp. are amongst the most important fast growing tree types of Oceania which have been planted in Iran for more than 50 years. In particular, the Eucalyptus trees were vastly planted in the southern parts of the country, from which the old-growth trees are still found in Lorestan (e.g. Malavi region) and Fars provinces. The applications to produce wood pulp, paper and leaf oils are amongst the motivations for future industrial and medicinal uses. In this study, the adaptation and performance of different industrial Eucalyptus ecotypes in Lorestan province were tested. A range of species including E. globulus (spp. bicostata), E. globulus (spp. maidenii), E. nitens, E. viminalis (spp. cygnetensis), E. camadulensis (var. obtus)and E. suggrandis (spp. suggrandis)were planted with 3 m distance within a complete randomized block design in a 2-ha field and were monitored for a 7-year period. The comparison of means by Duncan test showed the E. camadulensis (spp. obtus) and E. globulus (spp. maidenii)to be superior regarding the majority of their investigated properties in 99% confidence level.

A large area of world soil have salinity problem. Salinity affects establishment، germination and emergence of plants. Planting salt tolerant species and cultivars is a very convenient and economical way to overcome the problems associated with soil salinity. Various species of Eucalyptus introduced as salt tolerant trees and have widely used around the world. The most important elements dissolved in saline soil that inhibit the growth and crop production are reduced sodium chloride and calcium chloride. In this study has been investigated the effect of calcium chloride as a salt stress on germination and seedling growth of three species (E. camldulensis، E. microtheca and E. saligna) in two substrates، sand and MS medium. The results showed that seed germination has continued until 250 mmol of salinity in both substrates in E. microtheca while the species E. camaldulensis and E. saligna، germinated respectively until 200 and 150 mmol. The maximum and minimum total mean germination (percent and speed germination and seed vigor) and seedling growth (root and shoot length) characteristics in both substrates belong to E. microtheca and E. saligna. Thus، according to the results of this research E. microtheca can be introduced as a more resistance species to salt stress than two other species، E. camaldulensis and E. saligna in germination and primary growth stages.

Salinity is one of the most important abiotic stresses that according to its negative effects on plant growth، reduces lands’ potential productivity. Seed germination is the first stage of plant development، in which plant encounters salinity of soil. Thus، study of plant response to salinity in this stage can have an important role in determination of plant salinity resistance. The salinity resistance of plant can be determined in short time. In this study، in order to identify salinity resistance of three Eucalyptus species (E. microtheca، E. camaldulensis، E. saligna) in germination and initial growth stages، using MS media culture in vitro condition and using completely randomized factorial experiment with3 replications their seeds were exposed to 6 salinity treatments، including 0، 50، 100، 150، 200 and 250 Mm NaCl in laboratory condition. Germination percent، germination speed، seed vigor، root and shoot length، root and shoot fresh weight، root and shoot dry mass and total biomass were measured and used as salinity tolerance index (STI). E. microtheca was more salinity tolerant than E. camaldulensis and E. saligna. In order to achieve more confident results seeds of these 3 species were planted in different salinity classes of natural soil. After comparison، it was determined that results were quite consistent.

Lead is one of the most important environmental pollutants which disturbed nutrient uptake by plant. Present study was conducted with the aim of evaluation of some biotic factors potential in lead (Pb) phytoremediation and nutrient uptake by eucalyptus in Pb-contaminated soil. Treatments include three levels of bacteria (B0, Ba105 and Ps36), two levels of mycorrhiza (M0 and M1) and three levels of Pb (0, 50 and 100 mg/kg). Bacterial isolates were pseudomonas and bacillus and fungi was Glomus moseae. Results showed that increasing in soil Pb concentration improved Pb uptake by plants. Inoculation with Ba105 caused significant increase in shoot Pb uptake and this treatment caused in 55 and 19.5% increase in Pb uptake compared to control (without inoculation) and inoculation with pseudomonas Ps36. Also, mycorrhizal inoculation resulted in 23.7 and 44% increase in shoot and root Pb uptake compared to control. The greatest phosphorous uptake occurred in 0 mg/kg Pb. As Pb concentration in soil is increased, shoot and root phosphorous uptake by eucalyptus significantly. Inoculations with Ps36 and Ba105 along with mycorrhiza caused increase in shoot and root phosphorus and potassium uptake. Association of soil beneficial microorganisms (bacteria and fungi) with fast-growing and high biomass producer tree species like eucalyptus could cause improvement in phytoremediation efficiency under heavy metal stress.

Due to Eucalyptus potential as a fast growing species, its utilization for afforestation and industrial and medical purposes is very important. E. maculata Hook. is an important species among the other eucalypts in respect to some chemical components production and medical utilization. Sexual and asexual propagation of this species is difficult, for this reason the trial was conducted to investigate its propagation by tissue culture, using micro mature stocks.The produced explants from the mature stocks, were placed on MS medium (Murashige and Skooge) treated by ½ nitrate and various growth regulators such as Kin (Kinetin), BAP (Benzylamino purine), IBA (Indole-3-acetic acid), 2ip (2-Isopentyladenine), TDZ (Tidiazorun) and NAA (Naphtalen Acetic Acid) at different levels of concentration. After two months, growth indexes, including shoot number, shoot height, root number, root length, bud number and greenness rate were measured and recorded. Results showed that the best shooting treatment was IBA (0.01 mgl-1), BAP (0.3 mgl-1) and 2ip (0.5 mgl-1), in which average shoot number, shoot height and greenness rate were 4.63, 2.73 cm and 3.75, respectively, whereas the best rooting treatment was NAA (0.5 mgl-1) plus IBA (0.5 mgl-1), in which root length was 0.2 cm. Finally, the micropropagated plantlets were transferred to greenhouse to pass their adaptation process.

World anxiousness to earth global warmness brought a special attention to soil's potential for carbon sequestration. The purpose of the trial was to investigate effects of tree plantation on carbon sequestration at arid lands. For this reason, a site at forest park of Dehloran area in Ilam province of Iran was chosen where three tree species, including Eucalyptus camaldulensis, Prosopis juliflora and Ziziphus spina-christi had been planted before. Based on random systematic statistical method, 6- 10 sampling plots of 10 x 10 m. size were allocated for each species at planted and unplanted (control) parts, separately. Soil sampling was made in center of each plot at 0-20cm depth after removing the organic layer of the soil surface to measure carbon sequestration, N, P, K, pH, moisture, bulk density, silt, sand, clay and gravel amount. Results showed that carbon sequestration rate under the trees cover was 117.7 ton per hectare which was about five times more than the control plots (24.82 T/ha). Furthermore, only average carbon sequestration rate under P. juliflora plots was significantly more than under Z. spina-christii plots (p< 0.005). In addition, only average carbon sequestration at high density plots was significantly more than at low density plots under E. camaldulensis species. There was only significant difference between plots outside and inside crown cover of Z. spina-christii in respect to carbon sequestration rate. Overall, it might be concluded that forest plantation at Dehloran area played an important role in reducing atmospheric pollution and its area should be increased at high extent.

Trees as alive components of an ecosystem are able to convert some of the environment contaminants to unharmful substances and store some of them in their tissues and reduce their density and intensity in the air and soil by breath، root absorption and photosynthesis and other biotic functions. Trees function in such condition is completely related to environmental and habitat circumstances and their physiological potential. At beginning، five research sites at Khuzestan and Bushehr provinces were selected among the contaminated area by the Gulf War. At each site، soil sampling was made from three levels of depth (0-20، 20-40 and 40-60 cm). Soil physical and chemical characteristics test was made to measure nine metal elements and 12 other soil properties. The eucalypt species consisted of: E. camaldulensis، E. camaldulensis 9616، E. microtheca and E. sargentii which were planted under the Randomized Complete Blocks statistical design with three replicates. Before sampling the trees for determining the contaminant elements. Three individual trees were selected at each plot per one replicate to make sampling for leaf (four specimens per tree at four mean geographical directions). The data were analyzed under the variance analysis and Duncan test programs، using Excel and SAS computer soft wares. Overall، amount of the contaminants in different sites and at three levels of depth was not significantly different. The best eucalypt species and the best sites for absorbing the contaminants in their leaves are respectively as follows: 1- E. camaldulensis، E. microtheca، E. sargentii and E. camaldulensis 96162- Dezful، Isvand، Shooshtar، Karkheh and Kaki. The species which made the best performance in relation to their site interaction are respectively as follows: 1- E. microtheca firstly at Karkheh and shooshtar sites and secondly at Dezful and Isvand sites. 2- E. camaldulensis 96163- E. camaldulensis and E. sargentii.

Afforestation with native or non-native species affects understory vegetation. These effects, besides of edaphic and climatologic factors, also depend on the species of the plants which are used. In the present study, the allelopathic effects of two species of Eucalyptus (E. camaldulensis Dehnh. and E. microtheca F.Mull.) and one species of Acacia (A. salicina Lindl) on the understory vegetation in Shiraspary region, Mamasani (Fars province) were studied. Aqueous extraction of leaves of these species was prepared in the laboratory; the effects of different densities of these extractions on the vegetative factors of Avena fatua L., Lolium perenne L., were investigated. The maximum inhibitory effect was on radical length and the minimum inhibitory effect was on seed germination. 5% density of these extractions had a stimulatory effect on the seed germination. The highest inhibitory effect on Lolium perenne was on E. camaldulensis, A. salicina, while the least inhibitory effect was on E. microtheca. The highest inhibitory effect on Avena fatua germination was on E. camaldulensis; the least inhibitory effect was after exerting A. salicina. 5% density of E. camaldulensis showed a stimulatory effect on radical growth. The 5% density of extractions increased the plumule length. The maximum inhibitory effect on the length of Lolium perenne was on A. salicina, E. camaldulensis, while the minimum inhibitory effect was on E. microtheca. The maximum inhibitory effect on length of Avena fatua was on E. camaldulensis, and the minimum inhibitory effect on radical length was on E. microtheca, A. salicina. The minimum inhibitory effect on plumule length originated from A. salicina. Compared with the control, the allelopathy effect of two Eucalyptus species was more than that of the Acacia. Both the stimulatory and inhibitory effects coincide with each other, indicating the presence of both types of allelochemicals which are capable of enhancing and suppressing at the same time. However, toxic allelochemicals are more volatile in nature than the stimulatory allelochemicals. This increased the competition ability of eucalyptuses and caused them to dominate forests and woodlands. Eucalyptus should not be cultivated in sensitive and especially arid ecosystems, so that the allelopathic effects of this species can be minimized.

In this research, the adaptation and establishment of several industrial provenances of Eucalyptus was studied during a five year period. Climatic, edaphic and floristic data were primarily collected. In this trial, 15 species and provenances of Eucalyptus were planted under Complete Randomized Blocks design with 3×3m spacing. Factors including survival, height, diameter and crown cover of the rees were assessed annually. Based on Duncan’s test, E. camaldulensis 15195, E. camaldulensis15272, E. camaldulensis 20709, E. camaldulensis 15023 and E. maidenii 300-sh ranked in the higher class in terms of survival, but they achieved the middle class with regard to height and diameter parameters. E. globulus ssp. bicostata 16731 and E. camaldulensis 41-ch were classified in the lowest class in terms of survival, despite exhibiting excellent height and diameter growth.

Studying the soil and eucalypt relationships is essential for eucalypts plantation and avoidance of their negative effects on soil productivity. For this purpose, eucalypt species trial consisting of six species (E. camaldulensis, E. macarthurii, E. maidenii, E. rubida, E. saligna, and E. viminalis) planted in 1983 was conducted. Randomized Complete Blocks with four replicates at 2 x 2 m spacing and total number of 100 seedlings at each plot was used for this research. At each plot, three trees were randomly selected and leafsampling was done for each tree at 1/3 of upper height at the end of summer. The aim of the study was to investigate the nutrients of six eucalypt species planted at Guilan province, Iran. The results showed that there was not significant difference among the replicates regarding the amount of N, P and K, but there was significant difference between the eucalypt species in respect to amount of N. There was significant correlation between K% and P% of eucalypt leaves and some soil characteristics.

The aim of this study was to investigate the positive or negative effects of eucalypt plantation on different soil properties. For this reason, an eucalypt trial consisting of six species: E. camaldulensis, E. macarthurii, E. maidenii, E. rubida, E. saligna, E. viminalis which were planted in 1983 in Sheikh-Neshin state of Shafarud Company in Guilan province under experimental design of Randomized Complete Blocks with four replications at 2×2 m spacing and total number of 100 seedlings at each plot, was used for this research. Soil samples were taken from each plot, including four control ones by auger up to 60 cm. depth (totally 28 samples). Soil morphology was studied by digging three soil profiles at the eucalypt site and two adjacent parcels, including poplar plantation and the oak forest. Soil samples were taken from four soil horizons of each profile (totally 12 samples). Results showed that the species have differed significantly in respect to only few soil properties, including silt percentage, litter dry weight, bulk density, penetration resistance, pH and phosphorous amount. The soil profiles at the eucalypt site and the two adjacent sites of poplar plantation and oak forest consisted of four horizons, including A, AC, B and C. Root development at eucalypt, poplar and oak sites limited to 100, 85 and 150 cm soil depth, respectively. Overall, eucalypt plantation was able to improve soil structure and porosity, particularly at topsoil. Although there was intensive livestock traffic in the eucalypt site, but soil compaction was significantly less than the control plots and there was not significant difference between the eucalypt species in response to penetration resistance. Eucalypt plantation after 22 years reduced soil pH, but it was less than one unit.