IRANIAN JOURNAL OF NATURAL RESOURCES
Year:2001 | Volume:54 | Issue:2|Papers Count:8

In Iran's desert, carrying out research into designating the interrelationship in geomorphological facies, land components and vegetation, as well as efficiently mapping such fields are quite essential. In this research the geomorphological facies, land components and vegetation types of the Mashhadardahal Basin in Kashan have been mapped and compared. The study's results indicate that the boundaries of the mountain geomorphological facies correspond with those of the vegetation types so closely that one can consider them overlapped. However, the land components in the soil map do not enjoy such high overlap because of regional debris as well as the soil being shallow. In the Piedmonts containing fairly thick to thick soil, the boundary of the land components corresponds with that of the vegetation types. In some cases, soil erosion brought about by human factors has resulted in incongruities in the indicated maps. A comparison of geomorphological facie's maps with the vegetation type ones in the research pediments signifies the fact that they show fair congruity with mountain maps. Therefore it is necessary to make a map in which the mountains and piedmonts share the boundary with the vegetation types, and that proves to be efficient. This research points out that one can make such a map through amalgamating geomorphological facies' maps (for the mountains) with the land component ones taking into account geomorphlogists' and pedologists' viewpoints and ideas. Moreover, considering the geomorphological facies as a base and benefiting from pedological views in analysing and amalgamating the facies it is possible to make a map of appropriate use in natural resources.

Khabr National Park and Rouchun wildlife refuge in an overall area of 169200 ha is located in Kerman Province. It has been managed by the departmen of Environment Protection Since 1972. In order to identify the plant species in this region together with a more thorough study of the flora, as well as making known the position of the region within Irans phytogeography, plant species were collected from different parts of the area in the two growing seasons of years 1997,1998. Specifying the biological from and geographycal distribution of the identified species, vegetation spectrum and the regions geography of vegetation were plotted. The identified plants were arranged in the three groups of trees and shrubs; bushes; and, herbs and grass species. A total of 451 species and subspecies of the above  three groups with their respective numbers of  67, 147 and 237 belonging to 29 genera and 74 families were identified. One hundred and eight species and subspecies were recorded for the first time. The most diversification in species with a total of 57 species occurred in the family of composite. The vegetation spectrum indicates a dominant hemicryptophyte biological form with a coverage of 35.9 percent followed by therophyte 24.8%, phanerophyte 19.3%, geophyte 10.4 and chamaephyte 9.1%. A 52.3 percent of the identified plants belong to Irano-Turanian, 12.6 percent Saharo-Sindian and 10.2 percent stand in between. Eight percent of the species represent a joint between Irano-Turan and Mediteranean, whereas the remaining 16.9 either belong to other vegetation regions or constitute joints among several vegetation regions.

A study on the basis of systematic inventory with random start point as well as measuring such factors as diameter and height of trees, length of crown, percentage of storeys with a height less than 1.30 m and more than 1.30 m, as well as herbaceous species in sample plots, show that despite suitable plantation conditions in Shourab (even-aged), Jamand (uneven-aged) district, and control plot, even aged high forest in Shourab district was not fulfilled and it is concluded that applying uneven-aged. High forest method (Selection) in Jamand district was more successful in such a way that mixture and variation of species in regenerations and the number of climax herbaceous species. As well as the number of trees with a crown height less than 50% of half of the tree height and the average of crown and the number of trees per ha. In uneven-age method is more.

The Process of natural regeneration including establishment, of seedlings under dead, and mother trees are, among the most important phenomena in silvics. The aim of this article is to quantify the impact of dead, and mother trees on the density of established seedlings in closed and open parts of a Beech - Hornbeam forest. According to the field observations, parcel no. 9 with closed canopy and no.11 with open canopy, both in Jamaleddinkola district of Caspian forests, were chosen for sampling. Dead trees were taken as the center of sampling plots. Also in a 30-40 m distance from dead trees, 2 or 3 mother trees-same species, D.B.H and height- were seleted as the center of sampling plots. At each of these centers, seedlings were counted in-a circular sample plot (R=10 m). The results show that the seedling density of Beech is higher than that of Hornbeam and other species but there is no significant difference observed between Hornbeam and other species. This result is the same under dead trees as well as mother trees. The seedling density of Beech and Hornbeam established under dead trees, closed stand, is higher than that under mother trees. Other species have the same density under dead, and mother trees of closed stand. Seedling density of Beech established under dead trees in open stand is higher than that under mother trees of open stand but regarding Hornbeam and other species there is no significant difference observed in seedling density.

With respect to extent, Arasbaran forest is one of the limited vegetative regions in Iran. It is located at the southern altitudes of Arass River in north of Tabriz (a city in northwest of Iran). The vegetation cover is composed of various endemic species. The forested area, with more than 5% crown cover density, in this region is about 140,000 has out of which Oak forests are 75%. Two different types of Oak forests (Quercus komarovii A. Camus = Q.longifolia  C.Koch and Quercus  macranthera Fish.et Mey) have been observed in Arasbaran region. There are several obvious differences between the habitats of these two Oak species from physiographic, climatic, geologic and ecological points of view.

Alkaline peroxide mechanical pulping or cold soda process, includes eight steps. Two critical steps are cumulative steaming and impregnating of the chips by a liquor containing sodium hydroxide, hydrogen peroxide, and stabilizing compounds, this having a -determining effect on successful subsequent deliberating and refining steps. In impregnating and saturating the chips, many parameters, including wood species, wood kind, chips dimensions, liquor concentration, temperature, and the duration of impregnation are involved. In this study, by using a solution of sodium hydroxide, as impregnating liquor, the simultaneous effect of different parameters on impregnation, has been studied. The results show that, poplar wood is the most suitable for producing APMP mechanical pulp.

Sodium lignosulphonate, soluble in water, was prepared from kraft lignin, precipitated from black liquor, using Na2S205 or Na2S03 in a plug reactor at 6-7 atmospheres, pH=6.5 and 175 c°: Then, the FT-IR and UV spectra of the product were compared with the spectra of imported lignosulphonate. Also, using gel permeation chromatography (GPC), the average molecular weights of the product and that of imported sample were compared and the results evaluated. It was confirmed that the sulphonation of kraft lignin has occurred and the specifications of the product and those of the authentic sample are reasonably similar.

A part of sampling efficiency depends on the correct selection of plot size and shape. The objective of this study was to compare the sampling efficiency for different plot sizes and shapes in estimation of standing crop on the steppe, high-steppe and semi-steppe regions of Iran. Eight plot sizes (0.25, 0.5, 1, 1.5, 2, 2.5, 3 and 4 square meters) and three plot shapes (square, rectangular and circular) were tested in each region. For each size and shape combination, thirty samples were taken along fifteen transects with random-systematic sampling. The statistical results of this study showed that small plot sizes usually had a non-normal distribution and maximum skewness. Also, the different life forms of low density and scattered pattern had a non-normal distribution and maximum skewness. The weight variances of vegetation from various plot sizes were not homogeneous because these plots sampled different plant communities. The bigger plots usually had minimum coefficient of variation because they contained more variation of vegetation. Analysis of variance showed significant differences among polt sizes but, there were no significant differences among plot shapes. Optimum plot size depends on vegetation patterns, therefore optimum plot sizes were different for each life form. Optimum plot sizes for estimation of standing crop in steppe and high-steppe regions were 1 and 1.5 m2 and for semi-steppe 0.5 and 1 m2.