Snag dynamic in a mixed Beech forest

Dead tree, which consisting of both standing dead tree and material that has fallen to the ground, is a dynamic resource in forest ecosystem. In order to investigate on falling and dynamic model of snags (standing dead trees) in a mixed beech forest, this research was carried out in compartments No. 112 and 214 in Kheyroud forest, north of Iran. 215 dead trees were measured and then 64 dead trees were randomly selected for analyzing. According to the results, hornbeam snags in a natural forest showed higher breaking height in comparison to beech snags. Investigation on snag dynamic showed that snag falling is higher on steep slopes, however, there is no significant difference between slope gradient and snag falling. Increasing in decay class, caused increasing in sang falling. Also effect of dead wood size, decay stage (quality of dead wood), slop and species were analyzed. Results showed that slop and species have no significant effect on the sang falling, while the effect of deadwood size and decay stage on sang falling is significant

Mapping Brant's oak (Quercus brantii Lindl.) mortality using geostatistical methods in Dasht-e Barm, Fars province

This research was conducted to study the spatial distribution of Brant's oak (Quercus brantii Lindl.) mortality using geostatistical prediction and mapping approaches in Dashte-e Barm, Fars province. Field sampling was performed based on a 500m×500m systematic random grid and 1200 m2 rectangular forest plots. Different geostatistical methods were used for plotting anisotropic empirical semivariogram and surface creation. Results of cross validation showed that ordinary kriging with spherical model achieved superior results. The models were used for wall-to-wall prediction maps with four classes, including 60% mortality. The 25-60%, mortality class occupied the largest area (3827 ha), whereas the 60% tree mortality across the entire study site was shown to be less than 25%. This research concluded that Geostatistical kriging methods could be applied to predict and map missing tree mortality values in forest stands. Our analysis suggests that these methods can be used to generate prediction and probability maps in zagros oak stands for overarching goals such as forest mortality, pest and disease managements

Natural regeneration of oriental beech (Fagus orientalis Lipsky) within canopy gaps and under canopy cover, (Case study: Gorazbon, Kheyroud Forest, Nowshahr)

Establishment of natural regeneration is a crucial process which plays a key role in maintaining the sustainability within the forest stands. This study aimed to investigate the quantitative characteristics of oriental beech regeneration within canopy gaps and under the canopy in Kheyroud forests of Nowshahr in the north of Iran. Two compartments were initially selected, within which a sampling grid featuring 50×50 m distance between plots was established. Regeneration frequency, species and height of seedlings and saplings were measured both within the gaps and under the canopy. Results showed the frequency and mean height of beech regeneration to be higher under canopy layer. Those parameters also significantly differed from those within the gaps. Our findings also show that the reduced light under the canopy is by no means an obstacle to increase the beech regeneration, but it rather contributes to improve the establishment of natural regeneration of beech. This research confirms the previous findings on the shade tolerance of beech and suggests creating canopy gaps in those stands in which beech seedlings are previously stabilized as a mean to support the natural regeneration

Morphological characteristics and health of beech trees by diameter more than one meter (case study, Guilan province)

For investigation of morphological characters of health of beech trees by diameter more than one meter at breast height, 33 trees were selected in Guilan province, Sistan district. Studied morphological characters were crown shape, spiral growth, nodes, collar rot, red wood heart, trees height, trunk height, crown height and trunk decay. Results showed that collar rot had significant correlation with trunk decay in the trees (

Monitoring of Sarsakhti oak reserved forest by aerial photographs and full callipering

Vast areas of Iran are located in Irano-Touranian phyto-geographical region. Exploitation of forests within this region during past decades has changed these valuable forests to fragile ecosystems. Considering the most important ecological function of these forests, namely soil and water protection, the Sarsakhti oak   forest was declared as protected area. In order to study the changes within last 50 years, crown canopy of forest has been studied as main factor using aerial photographs of 1955, 1995 and full callipering of the whole 20 ha stand in 2007. Results showed that the crown canopy density was decreased 6% (from 41% to 35%) between 1955 and 1995 but increased again in 2007 to 40%

Decay dynamics of oriental beech (Fagus orientalis Lipsky) and hornbeam (Carpinus betulus L.) deadwood in mixed beech stands

Due to their significance for carbon sequestration and ecosystem management, information on decay dynamic of deadwood and its total decay time are of great importance to ecologists and forest managers. This study was conducted in Kheirud forest of Nowshahr to study the decay process of beech and hornbeam deadwood. Therefore, 72 beech and hornbeam dead trees were randomly selected. For each sample tree, information on species, diameter, decay classes and slope gradient were recorded. The cubic cut samples with 5 cm length, width and height in two perpendicular aspects were taken from each decaying stump. 30 and 16 years of decaying time were shown to be needed for 95% dry mass of dead beech and hornbeam logs, respectively. In addition, the required periods for passing through all stages of decay for beech and hornbeam dead trees were 27 and 21 years, respectively. A strong relation (R2=0.8) between density and decay stage of dead trees was indicated. Therefore, the density of dead wood was concluded to significantly decline with increased decay stage in both species

Structural diversity of mixed beech stands in the middle stage of succession (Case study: Gorazbon District, Kheiroud Forest of Nowshahr)

To quantify the structural properties of mixed beech (Fagus orientalis) stand in the middle stage of succession, a study was carried out in the Kheiroud forest of Nowshahr in Mazandaran province. To this aim three one-ha sample plots were selected, within each of which a 30×30 m gird was established. A set of structural parameters including the diameter at the breast height, tree height, crown diameter, distance and angle among trees were measured for the closest beech to the intersection points within the grid as reference tree, as well as for other three nearest neighbors to the reference tree. The crown competition coefficient and growth space index of 0.72 and 18.57 were calculated, respectively. In addition, the average distance amongst seedlings was shown to be 60.1cm. Results also showed the average of uniform angle index, species mingling, diameter and height differentiation and neighbors distance to be 0.76, 0.7, 0.31, 0.37, 5 in plots, respectively. Based on uniform angle index (Wi) as well as the distribution pattern of beech is in its middle stage of succession, the distribution of beech trees were aggregated. This showed a high tendency to mix with the hornbeam (Carpinus betulus) trees. Furthermore, Beech was proven to have a maximum rate of inter-competition with hornbeam in the middle stage of succession, which leads to the highest frequency of neighbor distance between 2 to 4 m. According to the results, we concluded that structure of beech stands in the middle stage of succession differ from the late successional stage. This should thus be considered in the envisaged management of such forest stands in northern Iran

Investigation of affective habitat factors affecting on abundance of wood macrofungi and sensitivity analysis using the artificial neural network (case study: Kheyrud forest, Noshahr)

One advantage of artificial neural networks is application in the management and planning of natural ecosystems. Considering the high biological diversity of northern forests of Iran, it is necessary to know forests ecosystems. Thus, using artificial neural networks is important for modeling and forecasting of presence and abundance of wood macrofungi in forests. Fungi samples were collected in summer and fall seasons on oak and hornbeam trees from compartments 110, 207 and 311 in educational and research forest of the University of Tehran. Totally 231 samples of macrofungi were collected that 112 samples of them belong to wood decay fungi. Results showed that the designed artificial neural network, has suitable potential for modeling of abundance of wood fungi. Network with two hidden layers and 11 neurons in each layer with the highest coefficient of determination, show the best performance of topology optimization. The number of inputs and outputs equal to 112 samples with 11 variables including density class 4 or class of fungi. Sensitivity analysis showed the decay stage of tree, tree health status and its condition and stand microclimate have the most effect on presence and abundance of wood macrofungi

Relationship between regeneration of oriental beech (Fagus orientalis Lipsky) and land form

This paper investigates the relationship between land form and location and natural regeneration of beech species. For this purpose, the beech communities over 100 m. above sea level at Namkhaneh district of Educational and Experimental Forest of Tehran University in Caspian region were selected. Based on renegeration condition and distribution at different land forms, data sampling was performed at four different land forms, including slope, valley, ridge and doulin, using 15 sampling strips with equal widths (2m), but different lengths, depends on different environmental circumstances. The strips were selected at 150 m. intervals. Where the longest and the shortest ones were 517 and 40 m., respectively. The doulin land from was selected where the regeneration cover was more than 30%. The doulin forms were divided into four aspects, including north, east, south and west faced directions for precise study of regeneration. Quantitative and qalitative characteristics of natural regeneration of beech (Fagus orientalis Lipsky) were recorded and canopy cover of the beech old-growth stands was estimated. The results showed that there were significant differences between the four landforms in respect to regeneration cover of beech species, where the ridges had the greatest values. The greatest frequency of beech seedlings on ridge and valley and as well as slope and doulin land forms were found at 2 was 0.8 (equal to 8000/ha). 70% of the seedlings were healthy and the rest were not sound

Determining the structural diversity of mixed oriental beech (Fagus orientalis L.) stands in Gorazbon district, Kheyrud forest

Quantification of forest structure and its various components helps to better understand the forest ecosystem and supports its improved management. Here, the Gini index were used as a spatial distribution index for evaluating the structural diversity. The main objective was to analyse the stand structure and determine the necessary factors for the structural heterogeneity and  homogeneity. This study was conducted in compartments 305, 306, 309, 310 and 311 in Gorazbon district, Kheyrud forest by means of a full calipering method. Then Gini index was calculated and finally the Lorenz curve was derived by using frequencies of stems, diameter class, as well as cumulative relative frequencies of trees and their basal area. The results showed Gini index values of 39.5%, 66%, 44%, 82% and 74%  for compartments 305, 306, 309, 310 and 311, respectively. In addiiton, the diameter structure for 305 and 309 compartments was shown to be close to homogeneity, whereas it was close to medium for compartment 306 and close to heterogeneity for compartments 310 and 311. Finally the use of Gini index and Lorenz curve was concluded to he helpful in reclecting the near-real structural diversity in natural beech stands