The use of artificial neural network to evaluate the effects of human and physiographic factors on forest stock volume

Increase in human factors coupled with physiographic factors will impact stock volume in forest ecosystems. The scale of this process and critical information in forestry management provide an incentive for the development of model to predict the forest stock volume. In this paper, we use data derived from Siahrood, Guilan Province, Iran using Field inventory by cluster sampling in a network (1 × 1 km) with 90 clusters and 900 circular plots (1000 m2). To evaluate modeling approaches for stock volume responses to changing condition. The relationship between the standing volume and human factors and each physiographic factor were examined using Pearson and the Artificial Neural Network method. Based on Field  observations it was observed that  different stock volume exhibit in specific  physiographic response to population density, livestock density, distance from village, aspect, slope and elevation. Results show that Multilayer Neural Networks with 12 nodes can predict the forest stock volume with the lowest RMSE (48.76m3). In addition, the artificial neural network designed for the buffer of three populations with 85.5%  accuracy was selected as the best model to predict the volume based on the mentioned components. The results suggest ANN is an effective approach to predict exact forest stock volume and human factors in certain topography conditions and provides  useful information for the acceptable amount of standing inventory using the present human population in future experiment.Keywords: stock volume, human factors, physiographic factors, neural network Corresponding autho

Processes of forest products and production costs in Guilan forests, Iran

This research was conducted in the west forest of Guilan, northern Iran. Data from various harvesting methods for 20 years were collected. Results showed that, productivity rate of round wood, pulp wood and fuel wood has had an upward trend, while rate of traditional products (lumber, sawn wood, charcoal, etc.) has had a downward trend. Production cost has been investigated in this research. The results showed that, the main cost is the opportunity cost. Due to the disability of competition between the domestic wood price with the imported wood price, domestic wood industries will face serious investment difficulty in the future

Road effect on diameter growth of trees in Caspian forests of Iran

Forest roads are the most important elements of forestry projects, the management, supervision, care, and only access way to the forest for mechanized harvesting and using other services of forests. The aim of this study was to compare the current annual increment of basal area in different distances from the road in northern forests of Iran. For this purpose, 50 plots were established in 5 distance classes (0-10, 10-20, 20-30, 30-40, and 40-50 m) on the 10 perpendicular transects to the forest road. In each plot current annual increment of basal area of 6 trees were measured by trunk core samples. Results of ANOVA test showed that there is no significant difference among the current annual increment of basal area in different distance classes from the roads. The results also showed that with increasing of distance from the roads into forest interior, current annual increment of basal area were reduced. The UNIANOVA test showed that there was a significant difference between interaction distance classes and diameter classes on current annual ring and diameter increment (p = 0.00)

Modeling human population patterns on tree density

In order to evaluate the possible correlation between the tree density and the human population density, the forested area in Nav Asalem district located in Guilan Province was selected. The descriptors of tree number and basal area per hectare as well as the stand density index were used to determine the tree density, which was conducted from a 2014 forest inventory including 62 cluster (558 plots) systematically scattered over 30 % of the forest area. In addition, to determine the density of the human population, circular buffers at intervals of 1 to 7 km from the center of each cluster was considered and population density of each layer was calculated using buffering functions. Statistical results showed that the average basal area, average number of trees and the average stand density index was 23.16 m2/ha, 243 per ha and 178.25 respectively and also different human population density in each buffer. Using Pearson correlation test indicated a significant negative correlation between the stand density index and basal area (DBH≥ 15 cm) with human population density. There was no significant relationship between the number of trees per hectare and the human population density except at 7 km. This findings support studies regarding the disturbance has strong correlative with the number of residents per unit area at up to 7 km from clusters and greater control on anthropogenic interventions should be the main priority of sustainable forestry in Hyrcanian forests of northern Iran. Due to the existence of an effective relationship between the components of the tree density and human population in the forest, policy-makers and planners of natural resources could benefit management patterns appropriate to above components to achieve sustainable management

Wound healing rate in oriental beech trees following logging damage

Beech is the most important commercial species in the Caspian forests of Iran. Selective cutting and harvesting methods may adversely impact the quality of the residual trees, as the injuries make the trees prone to future disease, insect infestations or timber defects. Although attempts to better understand how wounds affect the residual trees have been made in many different contexts, there are still few investigations on uneven-aged forests. In this study the key objectives were to determine and model the healing rate for different wound parameters (width, length, and area of wound); to analyse the relationship between wound healing rate (WHR), tree diameter growth and tree height growth; to analyse the WHR in relation to wound position on the stem; and to analyse the relationship between WHR, width and area of wound in DBH classes and social classes, with the aim of enabling the prognosis of logging wounds. Wounded beech trees were examined immediately after selective logging and after a 5-year period. The WHR was 31.2 ±7.7 cm2 year-1. The wound width healing rate (18.4 ±3.4 mm·year-1) was significantly higher than the wound length healing rate (4.5 ±1.6 mm·year-1). Only 12% of wounds were completely closed after a 5-year period, and 15 years are necessary for the complete closure of 80% of total wounds. The ratio of wound area to stem area at wound height (RWS) showed a more pronounced effect on diameter than on height. Regression analysis showed that WHR was correlated negatively with wound area and width and positively with tree diameter growth, but no significant relationship was found between height growth and WHR parameters. The WHR was significantly higher at an upper position than at a lower one, and statistical tests showed that the tree vertical layering classes had a significant effect on WHR. Finally, it was shown that WHRs in upper-storey trees are significantly higher than in the middle and lower storeys

Wound healing rate in oriental beech trees following logging damage

Beech is the most important commercial species in the Caspian forests of Iran. Selective cutting and harvesting methods may adversely impact the quality of the residual trees, as the injuries make the trees prone to future disease, insect infestations or timber defects. Although attempts to better understand how wounds affect the residual trees have been made in many different contexts, there are still few investigations on uneven-aged forests. In this study the key objectives were to determine and model the healing rate for different wound parameters (width, length, and area of wound); to analyse the relationship between wound healing rate (WHR), tree diameter growth and tree height growth; to analyse the WHR in relation to wound position on the stem; and to analyse the relationship between WHR, width and area of wound in DBH classes and social classes, with the aim of enabling the prognosis of logging wounds. Wounded beech trees were examined immediately after selective logging and after a 5-year period. The WHR was 31.2 \ub17.7 cm2 year-1. The wound width healing rate (18.4 \ub13.4 mm\ub7year-1) was significantly higher than the wound length healing rate (4.5 \ub11.6 mm\ub7year-1). Only 12% of wounds were completely closed after a 5-year period, and 15 years are necessary for the complete closure of 80% of total wounds. The ratio of wound area to stem area at wound height (RWS) showed a more pronounced effect on diameter than on height. Regression analysis showed that WHR was correlated negatively with wound area and width and positively with tree diameter growth, but no significant relationship was found between height growth and WHR parameters. The WHR was significantly higher at an upper position than at a lower one, and statistical tests showed that the tree vertical layering classes had a significant effect on WHR. Finally, it was shown that WHRs in upper-storey trees are significantly higher than in the middle and lower storeys