Iranian Journal of Forest and Poplar Research
Year:2006 | Volume:14 | Issue:1 (23)|Papers Count:10

Genetic resources are the most valuable national treasure of a country and it is vital to identify, conserve and use them. The Persian walnut (Juglans regia L.) is one of the most valuable genetic resource in Iran due to its multi benefits (nutrition, wood, environment conservation, genetics and medicine). For this reason, 32 leaf morphological characteristics of 1. regia were studied on nine populations (four native and five cultivated) and 243 individual trees. Leaf sampling was made two years for the native populations and one year for the cultivated populations. The effects of year variation on leaf characteristics and the effects of leaflet numbers on wealth variation of the characteristics within each genotype were studied. The ANOVA analysis showed that there were significant differences between the walnut genotypes in respect to their leaf characteristics (P<0.001). After correction of variance coefficient (C.V.) of each genotype, based on deduction of corrected C.V. within genotype (C.V.G.) according to leaflet numbers (5, 7, 9 and 11 leaflets) from primary C.V., a high real value of C.V. was achieved. The Duncan method was used to compare the means and identify the less variable leaf characteristics, based on C.V.G. and correction of leaflet numbers. Correlation coefficient of leaf characteristics according to each leaflet number groups (5, 7 and 9 leaflets) was investigated. Using cluster analysis (UPGMA method) to classify the 32 leaf morphological characteristics for the 243 trees, resulted in 19 clusters which seven clusters contained one individual members and four clusters contained double or triple members. The results showed that the most important, distinctive and reliable leaf morphological characteristics of J. regia were as follows: length of biggest leaflet, petiollength, leaflet marginal form, Arctangent of average leaflet length to average leaflet width, Arctangent of half leaf width to petiol length.

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 has 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-.

The aim of the study was to investigate some of the ecological factors at natural and planted forests of Haloxylon sp., including climate, soil, accompanied vegetation cover, pest, disease and symbiotic mycorrhizal fungus. For this reason, two districts and 16 sites were selected randomly at Yazd province of Iran, including both the natural and the planted forests. Although the ecological condition of the natural forests was less favourable than the planted forests, but the high growth and longevity of the natural forests are effective and positive indicators at such district which can not be observed at the another district. Natural equilibrium between trees density and site potential and productivity, distribution of Haloxylon trees at various soil textures and salinity rates, few contaminated Haloxylon trees to pests and diseases high diversity of the accompanied vegetation and high diversity and density of the symbiotic mycorrhizal fungi, are the characteristics of the narual forest of Haloxylon in comparison to the planted forests at Yazd province.

The trial was conducted to establish plant cover for the degraded and semi- degraded forests and left water catchments of north Semnan province of Islamic Republic of Iran. The aims of the trials were to conserve soil and water, t100d control, environment rehabilitation and involve the local forest dwellers and rural communities in forest conservation (sharing them in the walnut products income). The trial was conducted under experimental design of split plots with two treatments (walnut seed origins and rainwater catchment systems), each at three levels and three replicates. The results showed that only the effects of rainwater catchment systems and the interaction of the both treatment on height, survival and crown diameter of the Juglans regia were significant. There was not significant difference between the walnut seed origins in their growth performances. The walnut seedlings which were planted under the mulch treatment had the greatest growth and survival performance in comparison to control and crescent banquette methods.

The aim of the study was to compare the quantitative characteristics of two Forest associations (Fagetum and Fageto- Carpinetum) at Kheiroudkenar Forest (Nowshahr, Mazandaran province, Iran), based on data collected from 1980-2003. The applied sampling method was systematic random with constant grid of 200*200 m. The plots (1000 m2) were located over 250 ha (125 ha for each forest association).The results showed that in the Fagetum association there was not significant differences between the quantitative characteristics at different periods, whereas in Fageto-Carpinetum association, the difference was significant. As a result, elimination of some trees species, particularly hornbeam, during trees marking in order to convert the current forest association to pure Fagetum, might reduce the quantitative characteristics in future in comparison to 1980. In Fagetum association, high proportion of the tree's volume belonged to moderate and high stem diameter values, whereas in Fageto-Carpinetum association, high proportion of the trees volume belonged to high stem diameter values. This indicates a moderate aged forest at Fagetum and old aged forest at Fageto-Carpinetum (bell and skew shape volume curve), respectively.

The aim of the study was to introduce the best pine species in respect to growth and wood production for eastern coastal lands of Caspian region of Iran (Mazandaran province). The trial was conducted in 1997 under randomized complete blocks statistical design with three replicates and three treatments, including P. pinea, P: brutia and P. longifolia. Every plot contained 121 seedlings at spacing of 3 x 3 m. The measured growth characteristics were as follows: survival, collar diameter, height, diameter increment, height increment and quality. The growth parameters were evaluated annually end of growth period. After five years, the data were analyzed by ANOVA and Duncan tests, using SPSS and SAS softwares. The results show that although there was not significant difference between the species in respect to survival, collar diameter and diameter increment, but there was significant difference in respect to their height, height increment and quality. The highest and the lowest values of height parameter belonged to P. brutia and P. longifolia, respectively. The most promising species was P. brutia which achieved 159.1 cm total height and 25.91 cm height increment, five years after planting.

This research was carried out at three sites, including lordegan, Ardal and Bazoft of Chaharmahl and Bakhtiari province, where the oak manna (Quercus branttii Lindl.) is the dominant tree species.First of all, forest types were studied, which Q. brantii was the main forest element. Tehn three sites at north west, west and south west of the province, where are the main habitats of Oak manna, were selected and 12 plots of 1000 m2 surface area were allocated at each site, including three land forms (valley, slope and ridge) and four main slope aspects (north, south, east, west). Overall, 36 plots were allocated and site demands, soil physical and chemical properties and tree quantitative and qualitative characteristics were studied at each plot.The results showed that the Oak manna is a light demanding species with highest distribution on south western slopes at 1800 to 2000m. abovesea level. Soilp Hvaried from7.7 at soil surface to 7.85 at deep layers. Total nitrogen and organic matter of soil was good and its salinity was not significant. Most of the Oak trees had a coppice regeneration form (84, 2-78-6 %). Averagely, each tree produced four to five sprouts. This indicates a severe impact of human on Oak forests. Diameter and height of Oak trees varied between 13.8-19 cm and 4.3-5.2 m, respectively due to variation in land form.

Rapid population growth at Iran and subsequent increase in wood and non-wood products demand, resulted in great attention to the fast growing tree species such as the poplars to be used for plantation programs and decrease the wood shortage. A traditional method of cultivating different poplar species and cultivars has been applied centuries ago at northern and western areas of Fars province. These poplars were usually used for wind break establishment and building materials.The poplar plantations cover about 1500 ha land area which their wood product is not enough for the various established wood industries at Fares province. For this reason, it was necessary to identify the fast growing and high yield and quality poplar clones by conducting research programs. The trial of collecting native exotic poplar species and cultivars was conduction a nursery at Fares province in 1990 for three years to introduce the most successful species and clones in respect to growth characteristics, adaptability to environment condition and resistant to pests and diseases. The examined poplar species and clones were as follows:P.ciliata, P.trichocarpa, P.deltoides, P.euramericana, ( Nine clones ), P.alba (Seven clones) and P.nigra ( 42 native an exotic clones ).The data was analyzed by spss computer program. The results showed that the outstanding species and clones were as follows:1- Native and exotic clones of P.nigra: P.n. 69.14, P.n. 69.10, P.n. 69.13, P.n. 42.54, P.n. 56.21 and P.n. 63.135.2- P.euramericana clones: P.e. costanzo, P.e. 561.41, P.e. 154 and P.e. triplo.3- P.trichocarpa