Investigation of the effective factors on rate of stemflow for tree species in Hyrcanian forests

The objective of this study was (i) to compare the amount of stemflow in deciduous broadleaved trees (with and without leaves) in accordance with different growth seasons and (ii) to compare the rate of stemflow in coniferous and broadleaved trees in according to the canopy cover area. Stemflow was measured on 20 marked trees using a stemflow collector. Rates were different for the different tree species Beech Fagus orientalis L, Ironwood Parrotia persica L., Alder Alnus subcordata L. and Hornbeam Carpinus betulus L., and were greater in autumn than winter even though trees were then in leaf. The stemflow increased with increasing canopy cover area. Even though canopy cover in conifers (Cupressus sempervirens var. horizontalis) was less than the broad-leaved beech, the rate of stemflow was higher, up to 7 litres per hour with relatively small canopies.Keywords: canopy, seasons, conifers, broad-leaved tree

Morphological adaptation of Cercis griffithii seedlings in response to progressive drought and salinity stresses

The experiment for evaluate the effect of drought and salinity stresses on the morphological behaviours of Afghan redbud seedlings was done in Torogh nursery in Iran country. This study was conducted in a completely randomized design; without stress (tap common water in the nursery- EC 0.8 dS m-1), drought stress (four days a time irrigation) and salt treatment (EC 12.03 dS m-1). During the summer, morphological traits were measured and calculated. Result showed that height seedling after 60th until 70th day significant at the (p<0.05) level and significantly at (p<0.01) levels at the end of growth period under the drought and salinity conditions. Leaf area at the end of growth, leaf area growth and leaf area reduced significantly at (p<0.01) in comparison with control treatment. The result indicated that effect of time × drought interaction for height, diameter, number of leaves and leaf area was not significant. The result indicated that effect of time × salinity interaction for height, diameter and number of leaves was not significant but for leaf area had significant difference at (p<0.05) level. We used four days a time by irrigation and saline water in nursery less than EC 12.03 dS m-1 for economy well water in arid and semi-arid region.Keywords: Afghan redbud, Stress, Growth, Regression model, Repeated Measure

Estimating the carrying capacity of tourism and the necessity of forest stands management (Case study: Darkesh forest, North Khorasan, Iran)

This study focuses on the carrying capacity estimation for Darkesh forest in Northeast Iran. Four factors were used for estimating the carrying capacity including tourist flows, size of the area, optimum space available for each tourist, and visiting time. Results showed that the physical carrying capacity was 2727 ha or 165 visitors day-1, while the real carrying capacity was 2719 ha or 132 visitors day-1. An average of 200 tourists per day visited the park during 2015, which was much higher than the estimated carrying capacity. Development of recreational uses in the study area would also affect the forest production and other benefits in long term. This study suggested that to prevent intense use of the forest area, a plan must be developed. On the other hand, the number of visitors has to be precisely calculated in order to maintain healthy forest stands and to secure the ecological benefits for future generations

Effects of initial spacing on some allometric characteristics of 12- year-old Quercus castaneifolia plantation in central Mazandaran, Iranian Caspian forests

The effects of initial spacing layout on some allometric characteristics of 12-year-old Quercus castaneifolia trees grown in Central Mazandaran, north of Iran were examined. Trees were planted in 5 different layouts (1×1, 1.5×1.5, 2×2.5, 2×3 and 4×4 m). Tree height, diameter at breast height, natural pruning height and the survival of trees were recorded in each sample plot. Tree basal area and H/D ratio and standing volume were calculated for all trees. The results of statistical analysis showed that increasing in spacing level from 1×1 to 4×4 significantly increased the average diameter at breast height from 6.93 to 12.42 cm and survival from 53% to 85%. The average tree basal area per ha decreased from 19.98 m^2 ha^-1 to 6.43 m^2 ha^-1 and H/D ratio from 151 to 77 when the distance between trees increased from 1 × 1 to 4 × 4 m. but spacing regime had no significant effect on tree height and natural pruning height. It can be concluded that on the basis of standing volume, H/D ratio and survival rate, the best plantation spacing in this research station was 2 m × 3 m. Statistically, about 95% of the changes in sediment yield was due to the effect of increased dry land farming area in the basin (R^2= 0.95, α < 0.05)

The acceptable noise level benefit from directionality for listeners with severe hearing loss

Objectives. Directional microphone technology can enhance the speech intelligibility and listening comfort of listeners with hearing impairment. The main aim of this study is to investigate and compare the benefit derived by listeners with severe hearing loss from directional microphone technology with that derived by listeners with moderate hearing loss. Methods. The acceptable noise levels (ANLs) of two groups of listeners with moderate or severe hearing impairment (17 subjects in each group) were measured under unaided, omnidirectional-baseline-aided, and directional-aided conditions. Results. Although the absolute ANL of the listeners in the severe hearing loss group was significantly higher than that of the listeners in the moderate hearing loss group, their derived benefit was equivalent to that derived by the listeners in the moderate hearing loss group. ANL and hearing loss degree were significantly related. Specifically, the ANL increased with the severity of hearing loss. Conclusion. Directional microphone technology can provide the benefits of listening comfort to listeners with severe hearing loss. © 2018 by Korean Society of Otorhinolaryngology-Head and Neck Surgery

Neurology

Contains reports on six research projects.U. S. Public Health Service (B-3055-4, B-3090-4, MH-06175-02)U. S. Air Force (AF49(638)-1313)U.S. Navy. Office of Naval Research (Nonr-1841(70)

Pecking order theory versus trade-off theory : are service SMEs’ capital structure decisions different?

This paper seeks to analyse if the capital structure decisions of service small and medium-sized enterprises (SMEs) are different from those of other types of firm. To do so, we consider four research samples: (i) 610 service SMEs; (ii) 126 service large firms; (iii) 679 manufacturing and construction SMEs; and (iv) 132 manufacturing and construction large firms. Using the two-step estimation method, the empirical evidence obtained in this study shows that the capital structure decisions of service SMEs are different from those of other types of firm. Service SMEs’ capital structure decisions are closer to the assumptions of Pecking Order Theory and further removed from those of Trade-Off Theory compared with the case of other types of firm