Iranian Journal of Forest and Poplar Research
Year:2008 | Volume:16 | Issue:1 (31)|Papers Count:20

This research was conducted to determine genetic variation and estimate heritability for one mountainous population of wild service tree (Sorbus torminalis (L.) Crantz), named Ashak (2100 to 2300 m.a.s.l) were specified on central Mazandaran forests (Farim). Seeds were collected from twenty healthy mother trees and planted in Orimalek nursery (1550 m.a.s.l). To perform the progeny test, thirty seedlings were used from each one of the mother trees and planted in a randomised complete block design with three replications at beside the Orimalek nursery of Farim Corporation Wood. Ten seedlings from each one of the mother trees were randomly allocated to each replication on a row. Establishment, vigour, collar diameter, height growth and number of branches were recorded on the progenies during the two years period of the experiment. The results indicated that different between genotypes was statically significant (p<0.01) both in first and second year in their progeny collar diameter and height growth. Genetic variance and heritability of height growth was higher than another traits. Heritability of height for the two years were nearly constant. Based on these results according to high heritability of progenies height growth, the genetic variation was high in Ashak population and height would be regarded as more suitable characteristic for increasing the genetic gain by selection in mother trees.

The combination of panchromatic band with multispectral data is known as data fusion operation, which increases ground resolution of multispectral data. The results of the application of this method on the accuracy level of forest type classification were investigated. The multispectral data and PAN band from the ETM+ sensors belong to forest district located in "Azarrood" forestry plans in "Savadkooh" were used for the sake of this survey. The bands were controlled according to Radiometric and geometric error separately. Band 1, was omitted because of the existence of radiometric error and its less importance in vegetation cover study. Geometric correction was performed by 22 round control points with DEM, up to orthorectification level, with up precision of least than half pixel. Fusion operation was performed by PC method. The supervised classification was performed with using basic and synthetic bands (ratio, principle Analysis), with maximum likelihood, minimum distance, parallelepiped algorithm. The highest overall accuracy was 34.12% and kappa coefficient 23.15% for separability six vegetation type. The result shows the reduction of data correctness in compare with the result of produced forest type map without fusion. That as the reasons, we can indicated are, selected method type for fusion operation, heterogeneous area. Therefore, the repetition of this operation in another area with using other fusion methods is proposed.

The Zagros forests, covering approximately 5.2 million hectares of area, are considered as vital part of natural resources in Iran. Regulated and precise management plans to manage the Zagros forests is crucial regarding to its economic and social circumstances. Applying the local forestry, involving people’s participation in a near future, can be rewarding provided by making the possibility of its implementation. In this study, in order to find a transient policy to preparing the Shoul Abad area (Located in Lorestan Province) for the participatory forestry, tribal (local) forestry is considered as the best tool that can help to record, revise, and correct this kind of forestry. A number of three districts including Kamargap (where the tribal forestry is being implemented), Hiyye (where the tribal forestry is not being implemented) and Darre-Dang were selected and analyzed by FAO criteria (e.g. investigating the forest resources, biodiversity etc.). The forest sustainability was calculated by analyzing the data (regeneration, canopy coverage and biodiversity) gathered from the districts, using SAS software. Comparing the mean groups was carried out using SNK test. The results showed that the forest sustainability is higher in Kamargap district. Hence, applying the tribal forestry is now proposed to manage the forests located in Shoul Abad-Lorestan.

In order to compare adaptability and growth of Pinus elliottii and P. radiata, the trial was conducted in 1995 at Chamestan-Noor Forest and Rangeland Experimental station (Caspian Sea of Iran). The seedlings of two species were planted in separate groups. Each stand area was 7500m2. In addition, determination of survival and measurements of quantity accomplished (for five years). After 10 years, parameters such as survival, quantity and quality are determined. Finally, data with T-test method in SPSS are analyzed. Species comparisons showed that P. elliottii survival (75%) is more than P. radiata survival (57%) in the studied area. The mean diameter at breast height (D.B.H) of Slash pine and Monterey pine was 15/4 and 15.5 centimeters, respectively. Also mean height of Slash pine and Monterey pine were 11.1 and 9.5 meters, respectively. Analysis of mean height and diameter demonstrated that there were no significant difference for diameter growth between P. elliottii and P. radiata. However, there was significant difference for height growth between two species. Furthermore, volume per ha for P. elliottii 190 sylve and for P. radiata 91 sylve were determined. Comparison of two pines revealed that Slash pine (P. elliottii) grows faster and is more resistant than Monterey pine (P. radiata) in the Chamestan region. Thus, Slash pine for plantation with aim of wood production and using of fast growing species is proposed.

Poplar trees are the fastest growing trees in the northern hemisphere and it woods is suitable for a variety uses and they are the most important resource of wood production. For this reason they are best plant for wood culture. Geographical and climate diversities have important effect in height and diameter growth. This study was established at Esfahan, Fozveh Experiment Station (EFES) in 1370 in order to evaluate the height, diameter and wood production of 14 clones Poplar containing 5 P. euramericana, 4 P. deltoides, 3 P. alba and 2 P. simonii and  P. ciliata. The highest value of survival (100 %) tends to P. alba var. nivea P. d. 72/51 and P. e. 45/51 while the least value of survival (0%) tend to P. d. 69/55. The highest height tends to P. e. I 214 (18.1m), P. d. 72/51 (18m) and P. e. triplo (18m) and the least height tend to P. simonii (9.6m) and P. ciliata (11.7m). The highest diameter tend to P. d. 72/51 (25.6cm), P. e. I 214 (25.2 cm) and P. e. vernirubensis (24.9 cm) and least diameter tend to P. simonii (14.6 cm), P. alba var. nivea and P. ciliata with 16cm. The highest total wood production tend to P. d. 72/51 with 265 m3/ha, P.e. I 214 with 255.4 m3/ha and P. e. vrnirubensis with 250.2 m3/ha and least wood production tend to P. simonii (43.3 m3/ha), P. ciliata (70 m3/ha) and P. alba var. nivea with 74.2 m3/ha.

In order to study the effects of logging on plant species diversity, two compartments of logged and unlogged of beech forests in the Shafaroud region in western Guilan were selected. Inventory procedure was systematic- random method. Sampling plot area was 50´50m to survey woody species and for herbaceous species, 8´8m nested plot sampling was obtained. Regeneration (seedlings) was studied at 10´10m subplots. Data analysis was carried out by Shannon – Wiener and Pielou’s evenness indices and Jaccard’s similarity index. Results showed that species richness for trees, shrub and herbaceous were obtained 7, 8 and 28 in the logged forest, whereas they were 6, 4 and 18 in the unlogged forest, respectively. The diversity value in the unlogged forest was found higher than in logged forest in tree layer, while in the seedling, small sapling, large sapling, shrub and herbaceous layers were higher in the logged than unlogged forest. In addition, the evenness values in all vegetation layers were found higher in the logged than unlogged forest. Jaccard’s similarity index for tree, shrub and herbaceous layers were 62.50, 50.00 and 60.71 percent in the studied forests, respectively.

In order to select the optimum interplant distance and determination the best species for biological sand dune fixation, this study was carried out on sandy hills of  (Khouzestan province) located in southwest of Iran. There are about 350,000 ha of sandy dunes and sandy lands in Khouzestan. During the past 40 years, different physical, chemical and biological operations were applied to stabilize these lands and the results were all satisfied. This experiment was conducted in 1999 under rain fed conditions and statistical method of split plots and Fully Randomized Design Complete Blocks, with three replicates. The main treatments consisted of three levels of spacing (3´3m, 4´4m and 5´5m), and the secondary treatments consisted of three species (Prosopis juliflora, Acacia victoriae and A. farnesiana) in form of pure and mixed (50%) in six levels. The measured characteristics were: survival, mean height, crown diameter and the effect of interplant distance. In this study, a petroleum mulch cover was applied to stabilize the sandy dunes against wind erosion. After five years, the data were analyzed. The results showed that the greatest survival rate belonged to the species of P. juliflora and A. victoriae with 73 and 62 percent, respectively. The species of P. juliflora attained to the highest mean height in pure plantation with 4.9 meter followed by A. victoriae and A. farnesiana with 3.69 and 1.84 meters respectively. The highest crown diameter (5.28 m) achieved by P. juliflora in mixed plantation with A. farnesiana and the least (1.9 m) in all treatments was measured by A. farnesiana.

Siyahkal forest in Guilan province consists of industrially valuable hardwood species such as Beech (fagus orientalis) and Hornbeam (Carpinus betulus), which have significant economic value. This research evaluated the damages caused by felling operation and log extractions in uneven aged hardwood forest of Siyahkal, where silvicultural selection method was practiced. In 31 felling gaps 113 trees were marked and felled and then examined. In this research the complete enumeration forest mensaration method was used to evaluate the amount of damages to forest stand in each felling stages and extraction stages from stump to side of skidding routes in felling gaps and load collection area. Weight averages was used in order to evaluate the overall damages in area of the study, because of differences in sizes of the felling gaps and extraction routes. The results of this study showed that the damages to forest stand in extraction routes were 42.5% where as in felling gaps were 17.5%.Assessment of the scars to tree trunks showed that the scars caused by extraction operation were bigger in size than felling operation. Also the scars were present more at height of two meters from ground level and were mostly deep scars i.e. damages to cambium. Analyzing the scars of forest stand in felling gaps showed that the damages increase with increase in intensity of harvesting.

Due to encroachment and intense utilization, natural ecosystems of Zagros lost their normal trend and have converted to fragile and sensitive ecosystems. There are dense human populations that live in these forests which are depended on these forest resources. One of the most important utilizations in northern Zagros is Galazani (pruning) and using of oak limbs as fodder. This kind of use leads to prominent changes in forest structure and its physiognomy in some region (for example Alot in Kurdistan province) which can be a hazard for forest sustainability. Regarding to this problem and having no regeneration from seed, qualitative characteristics of Gall oak acorns, that is one of the most prominent species in these forests, was investigated in three untouched and pruned sites. Totally 60 Gall-oak trees (10 trees per site) and 6000 acorns (100 acorns per tree) were collected. Primary moisture of acorns in untouched sites was a little more than in pruned sites but there was no significant difference between them. The weevil Curculio gladium and Balaninus gladium were the insect species that predated the acorns collected from our sites. There were significant difference (in level of 95%) in the infestation rate among untouched and pruned sites of Blake, however in Ghole-shir and Mir-Yousef sites were no significant differences between insect-infested acorns. The weight of thousand acorns was significantly more in untouched sites; probably because of having more time to storing enough nutrients in their cotyledons. Germination percent and germination index data were analyzed by simple One Way ANOVA, and their averages were compared by Duncan test. There were no significant differences between germination percent of untouched and pruned sites. Comparing means indicate that, Blake site with 96.75 germination percent was placed in group A, Ghole-shir and Mir-Yousef sites were placed in group B with 90.78 and 88.75 germination percent, respectively. Germination index of untouched and pruned sites had no significant differences and in Duncan grouping they placed in one group. The values for germination index in Mir-Yousef, Blake and Ghole-shir sites were 13.18, 12.83 and 12.36, respectively.

Response of Haloxylon's root to soil moisture content was studied at Yazd, Shahid-Sadooghi Control Desert Research Station adjacent to manual Haloxylon spp. plantations. Nine lysimeters (120 cm diameter and 170 cm depth) with four hatchways at different depths (30, 60, 90 and 120 cm.) were made to sampling of soil and plant's root. Haloxylon's seedlings were planted in lysimeters after preparation of them. Moisture treatments contain: Pot capacity (control), 1/3 pot capacity and dry stress down after a year nursing of the seedlings. All experiments were conducted in a completely randomized design (CRD) with three replications. Water requirement content to reach the soil moisture to optimum level, provided by weighting of lysimeters weekly. Irrigation was avoided at dry stress treatment when plants were established completely. Treatments were continued for two growth seasons and the effects of them on root development (length viewpoint) were evaluated. After removing, washing and drying up the roots from lysimeters, total root weight was measured in each lysimeter separately and then, the effects of different treatments on it were studied. Results showed that moisture treatments have significantly affected the root weight (p=0.1%). Different soil depths have also significantly affected the dry root weight at the same statistical level, whereas the effect of soil depth was not significant on root length.

The present study is focused on the evaluation of FCD (Forest Canopy Density model) for the estimation of forest density in northern forests of Iran using Landsat 7 satellite data. The model was developed as a semi-expert system in Asia-Pacific region that estimates forest canopy density without any training areas. In this study, an ETM+ image dated July 18th, 2000 was analyzed. After preprocessing the satellite image, four basic indices of FCD model (Vegetation Index, Bare Soil Index, Shadow Index and Thermal Index), were calculated. Vegetation Density Index and Advanced Shadow Index were then calculated and forest density map (derived from FCD model) was finally extracted. The forest density map was classified according to the form presented by Forest, Range & Watershed Management Organization of Iran (7 classes), and another form (5 classes). In order to assess the accuracy of classified forest density map, a ground truth map of the entire study area was generated using aerial photos - at the scale of 1:10000 dated August, 1999. In this way, at first, the geometric correction of digital photos was implemented and the mosaic of photos was generated. Then, the Ground truth map was produced using on-screen digitizing method based on visual interpretation and applying stereoscope and printed photos. In this study, the highest overall accuracy and kappa coefficient - were obtained in classification in five classes - equal to 61% and 0.38, respectively. The overall accuracy and kappa coefficient in case of classification in 7 classes were less than those calculated in case of classification in 5 classes. This is because of the spectral similarity among the lower density classes. Hence, it could be concluded that in such forests, the potential of the model in separating high density forests, was relatively acceptable whereas the model could not correctly separate the lower density classes.

We compared land use maps of 1988 and 2004 of northern mountainous forests of Iran that have been extracted from landsat images in 15 years period and investigated on boundary changes and calculated deforestation areas as well. This information is essential for afforestation and forest extension in the deforestation areas of upper border of the mountainous forests. For this reason, we used landsat TM and ETM+ images in 1988 and 2004 for providing land use maps and also collected information from 2960 sample plot (90´90m) using systematic random sampling. Based on extracted maps, 121528 ha of northern mountainous forests of Iran has been deforested in 15 years period. The deforestation area were estimated 8101 ha per year.  It is 0.45 percent of the northern forests. The percentage of deforestation area in terms of provinces (Guilan, Mazandran and Golestan) was estimated 1182, 4647 and 2272 ha per year or annually 0.21%, 0.49% and 0.69%, respectively. The results showed that the maximum deforestation percentage occurred in the Golestan and the minimum in the Guilan province.

The spatial structure of a forest stand plays a key role in its dynamics. It also determines the chance of establishing seedlings and the renewal capacity of the stand. However, this relation between spatial pattern and forest dynamics is two sided and information can refine our understanding of natural processes. Regarding to importance of seedling establishment in forest dynamics, the aim of this study was to investigate on spatial pattern of gaps in managed and unmanaged forests. The study site is located in Kheiroudkenar research forest – Noshahr. For this purpose, two sites in beech stands with similarity in physiographical condition were selected and the position of all gaps in each site was surveyed. Also, some quantitative parameters were recorded in each gap. Then, Ripley's M function was used to obtain the spatial structure of gaps. The null hypothesis is a random distribution of gaps which was tested by using of Monte Carlo technique. The results showed that frequency of gaps in managed area is more than unmanaged area. Regarding to average area of gaps (235 m2 in managed area and 210 m2 in unmanaged area), gaps cover 9% of the study area in managed and 4% in unmanaged stand. It means that silvicultural practices intensity was high and it could not be suitable for develop stand structure. Also, spatial pattern of gaps are regular for both area in 60m and 80m radius, respectively. Based on this trend, spatial structure is regular within each stand and random among them.    

The asexual reproduction of Juniperus excelsa along with its sexual reproduction is a great importance of matter because of its some problems in natural regeneration. The identification and application of efficient treatments in rooting of Juniperus excelsa cutting will be useful in production of seedlings. The objective of this study was asexual reproduction of Juniperus excelsa by means of cutting which conducted in a 4 years period. Cuttings (short and long) were obtained from young and old Juniper tress in Sirachal station and Alborz research centre. Cuttings were treated by hormones (IBA and NAA with different concentrations), willow extract (with and without hydrogen peroxide 1%) and planted under various condition including light (white, red and blue) and bed composition (fine and harsh). Forty nine cuttings were planted in split plots. Statistical data were gathered from 25 cutting in each plot. Statistical data were analyzed by SAS method and tested by Duncan test. Results indicated that hormones, light and bed composition treatments were significant (1%) and cutting size (5%) in rooting. According to Danken test, the average of rooting in white light, fine bed composition and 200 ppm of IBA was 37.32% that belonged to a group.