تحقیقات جنگل و صنوبر ایران (Jun 2005)
Abstracts
Abstract
Qualitative and quantitative evaluation of natural regeneration in gaps within beech (Fagus orientalis Lipsky) stands of Caspian Region Abstract According to few recent studies, regeneration was favourably established in few natural gaps at beech stands located in Golband Forest of Caspian region of Iran (Jamand district), whereas in other gaps, weeds including Rubus sp. and ferns were established. The aim of the research was to investigate the effects of natural parameters, including climate, soil and topography; human and livestock activities and inappropriate gap size caused by removal of trees in the upper storey. For this reason, 13 natural gaps were selected as sampling plots, depending on their regeneration condition and their distribution within the forest. After that, the seedlings age, height and diameter (at collar and breast height) were measured. The results showed that the seedlings of F. orientalis occupied highest area of the gaps (75%) in comparison to other species. There was not significant difference between the beech seedlings in respect to their age (6-8 year old). The gap size had negative effect on seedlings density and positive effect on seedlings height. The branching mode of beech indicates that most of the saplings were forked. Overall, an increase in the gap area, increased the number of the forked and broom shaped saplings. The results showed that cuttings should be made in a way to prevent large gaps. In contrast, the small and medium gaps provide an appropriate area for regeneration, quantitatively and qualitatively. Keywords: Fagus orientalis, gap size, regeneration, beech, sapling. Investigation on production of ten most important and well worth native hardwood species at forest nurseries of Caspian region of Iran Abstract Development and rehabilitation are two major factors in the Comprehensive Project of Caspian Forest Conservation of Iran which can be reached by standard seedlings production. Due to importance of these forests, productive afforestation and subsequently seedling production at nurseries in respect to tree species and their quantitative and qualitative characteristics, have a special value in that project. The data related to seedling production at 21 nurseries located at Caspian Region of Iran for five year period (1998- 2001) were recorded and analyzed. The results showed that 57 species were produced in the nurseries, including 31 hardwood and 26 soft wood species and total seedling production was about 30 m/year. From the 31 hardwood species, the proportions of natives and exotics were 95% and 5%, respectively, whereas the proportions for the softwood species were 84% and 16%, respectively. Four of the native hardwood species, including Acer velutinum, Alnus subcordata, Fraxinus excelsior and Quercus castaneifolia which have high quality industrial woods, covered more than 50% of the total nurseries seedling production, from which A. velutinum and A. subcordata covered the highest proportion of these four species. Based on economical evaluation of the species wood values, A. velutinum gained the highest value and the other three species achieved the second rank. Keywords: CaspianForests, hardwood, softwood, nursery, native, exotic, seedling. Investigation on adaptation and performance of Olive (Olea europaea L.) cultivars seedlings at Qom area of Iran Abstract The aim of the study was to investigate adaptability of 12 olive cultivars at Maroon station of Qomprovince of Iran. The trial was conducted under Randomized complete Blocks Design with three replicates. The seedling performances, including height, collar diameter, survival and crown cover diameter were recorded and analyzed for three years. In order to study the resistance of the olives to wind and determine their shade area, other parameters including collar diameter/height and crown cover diameter/height ratios were calculated. The statistical analysis of the third year data showed that the effects of olive cultivars on the whole seedlings performances were significant (P