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مرکز اطلاعات علمی SID1
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    1
  • End Page: 

    9
Measures: 
  • Citations: 

    0
  • Views: 

    203
  • Downloads: 

    113
Abstract: 

This study was carried out to introduce wood-inhabiting fungi and their relationship with hosts in forests of Middle Zagros, Lorestan province, Iran. For this study, at first, the location of the infected trees were recorded with GPS and then, following factors were recorded comprising physiographic factors (altitude, slope and aspect), the frequency of fungi, fungi establishment aspect on trunk, breast diameter height of tree, distribution on standing or fallen trees, seed or sprouted individual, crown dieback of host trees along Sarabe-Navehkesh river. Then, identifying wood-inhabiting fungi was performed using studies and the use of valid keys. The results indicated the presence of two species of Trametes trogii and Trametes versicolor on willow trees. Also, investigations on T. trogii fungus on willow showed that the highest frequency of fungi was observed at a diameter of 20-40 cm, standing trees and die back at 1/3 of crown. In addition, the highest percentage of T. trogii presence was on <0. 5m height class. Investigating the decay relationship with some of site factors, ordinal logistic regression was used and was determined that crown decay variable had significant effect on decay class of trees (p≤ 0. 01). The establishment of wood-inhabiting fungi on decayed trees, dead trees and remained stump in forest can contribute to soil improvement, but in areas where young and healthy trees are infected need to control. Therefore, in this area to protect river-side trees, good management of forest protection is necessary to protect and preserve in order to inhibiting T. trogii fungi distribution.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    10
  • End Page: 

    19
Measures: 
  • Citations: 

    0
  • Views: 

    153
  • Downloads: 

    117
Abstract: 

The present study was conducted to evaluate the spatial variability of forest soil chemical features in Bandpeye Sharghi forest in Babol. In order to conduct this study, after a field visit in the district of Afrabon, an area with a concentrated livestock presence was identified. In order to investigate the chemical variables, a network of 50×50 meters was selected in a randomizedsystematic manner in our case area (livestock place) toward the forest; then, 73 samples from a depth of 0-10 cm were taken from the centers of network to study variables like soil PH, organic carbon, lime, nitrogen, phosphorus and potassium in the laboratory. Six soil chemical variables were investigated and a plot of their kriging estimation was drawn using GS+ software (version 9). The results showed that only changes in soil PH and nitrogen are the same in various directions and a square grid can be used to study them. The analysis of variogram revealed that the soil PH and nitrogen variables had a spatial pattern which led to a strong structure considering the ratio of ceiling to the component effect of 0/90 and 0/83, respectively. The amount of these two variables is of lowest value in the eastern direction (livestock place). The accuracy of the estimates, the mean absolute error and the squared mean of errors for the two variables of soil PH and nitrogen were calculated as 0/163, 0/560, 0/195 and 0/221 respectively; the results indicated a high accuracy of the estimates of soil PH and nitrogen.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    106
  • End Page: 

    113
Measures: 
  • Citations: 

    0
  • Views: 

    147
  • Downloads: 

    93
Abstract: 

The Arasbaran vegetation community is an important source of biodiversity and one of the biosphere reserves in the northwest of Iran, which is influenced by different climates and special importance due to variations in altitude. Since an altitude is an environmental characteristic that affects the habitat of plant species, this study aimed to investigate the ecological role of altitude on the quantitative characteristics of caucasian oak trees (Q. macranthera Fisch. & C. A. Mey. ex Hohen. ) and determine the best range for the natural growth of this species in Arasbaran forests. Three oak stands were selected in three altitude ranges including low (1200-1400 m a. s. l. ), middle (1400-1600 m a. s. l. ) and high (1600-1800 m a. s. l. ) altitude. At each altitude, three plots were sampled with one-hectare area, and the quantitative characteristics of all trees, including diameter at breast height, basal area and trees canopy diameter were measured. Normality of data was verified by the Kolmogorov-Smirnov test, and the comparison of the mean of the characteristics was done using one-way ANOVA at a probability level of 0. 05 and Duncan's test. The results showed that there was a significant difference in diameter of the trees, the height of the trees and basal area per hectare among the three altitudes, but density per hectare had a significant difference between the first and second altitudes. In addition, the canopy coverage had no significant difference among the three altitude ranges. The middle altitude was more favorable condition stand in terms of its quantitative characteristics. Therefore, the results of this study indicated that the middle altitude (1400-1600 m a. s. l. ) is a more suitable habitat for caucasian oak species in Arasbaran forests, and doing more protection of the stands in this altitude can be created a seed bank for the production of high quality seedlings and forest plantations in the region.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    114
  • End Page: 

    122
Measures: 
  • Citations: 

    0
  • Views: 

    265
  • Downloads: 

    107
Abstract: 

Chestnut as an indigenous and valuable forest species exists in some forests of Guilan province, which the area of its stands is decreasing due to the lack of natural regeneration and socioeconomic problems as well as ink and blight diseases; therefore, chestnut’ s asexual propagation through tissue culture methods can be effective in protecting this species and preventing its extinction. The aim of this study was to use the micropropagation method in order to produce complete chestnut plantlets by identifying the best explants and plant growth regulators. For this purpose, seeds were collected from Visroud site, sterilized, soaked in boiling water and cultured on B5 medium, and then explants were taken from germinated seeds. Leaf, stem and root explants from in vitro seedlings of chestnut were cultured on B5 containing cytokinins (TDZ and BA) with concentrations of 0. 02, 0. 2, 1 and 2 mg/l and auxins (IBA, NAA, and IAA) with concentrations of 0. 1, 0. 2, 1 and 2 mg/l. Results showed that the best response was obtained from the leaf explants and TDZ (0. 2 mg/l) and IBA (2 mg/l) had the highest percentage of callus-shooting (32. 4%) and rooting (80%), respectively. The survival of seedlings outside the laboratory was 80%. Considering the importance of chestnut species in economic and environmental terms, the present study can be useful for the implementation of reclamation management to protect, develop and prevent extinction of this species.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    123
  • End Page: 

    132
Measures: 
  • Citations: 

    0
  • Views: 

    381
  • Downloads: 

    171
Abstract: 

Indigenous knowledge refers to a set of skills, values, beliefs and methods of a social group that has been inherited in various areas of life through the experiences and approval of generations of generations. A great number of villagers have been living on the outskirts of the valuable Hircanian forests of northern Iran for hundreds of years. This research was carried out with the aim of the role of indigenous knowledge in employment, income of local people and conservation of forests of Vaz, city of Noor. The research was a survey and information gathering method in this documentary-field study and data gathering tool was questionnaire and interview. To determine the validity of the research, experts' opinions were used and to determine its reliability was applied the Cronbach's alpha (0. 8) and SPSS software. The statistical population consisted of residents of the area of Vaz (800 people) and the sample size (260) was randomized using Cochran sampling method. In order to prove the hypotheses, inferential statistics such as Spearman Correlation Coefficient (for quantitative data), chisquare’ s test, one-variable regression and one-sample t-test were used. The results showed that there was a significant correlation between the educations, the duration of the presence in the area, the employment, monthly income and the type of income earned by the individuals in the area with native knowledge (p≤ 0. 05). This is while there was not a significant relation between of gender, age, place of residence, and the time of employment and income of individuals with indigenous knowledge. The results also revealed that familiarity with native knowledge creates employment and income and improves the protection of forests in the region.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    133
  • End Page: 

    141
Measures: 
  • Citations: 

    0
  • Views: 

    218
  • Downloads: 

    101
Abstract: 

Computation of tree biomass, leads to a clear understanding of production potential of natural and artificial forest habitats. Measuring the biomass of trees is possible by direct-cutting and estimation methods. The present study was performed to evaluate the accuracy of allometric equations in estimation of poplar (Populus alba L. ) biomass in Koran village of Chaharmahal and Bakhtiari province. For this purpose, 30 number of trees in the study area were randomly selected and their quantitative characteristics including diameter and height of trees were measured and recorded. Then, the biomass of selected trees was calculated by using allometric power equations and applying a diameter at breast height. Then, all selected trees were cut down, sectioned, weighted and sampled and by deducting the percentage of moisture calculated for the samples and extending it to the whole of each section, the biomass of the different organs of the trees was calculated and the results of the cutting method were compared with the estimated biomass of the allometric equations. The results of paired samples t-test showed that the highest biomass of the trees belonged to trunk, branch, twigs and leaf, respectively. Also, results of comparing the two methods showed that there were no significant differences between two methods in calculating the trunk biomass (P 0. 387), shoots (P 0. 093) and leaves (P 0. 082). But for branch biomass, there was a significant difference between the two methods (P: 0. 007). The results of this study showed that allometric equations have high accuracy (90%) in estimating the biomass of poplar trees and can be used in related studies instead of destructive and costly cutting off method.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    142
  • End Page: 

    151
Measures: 
  • Citations: 

    0
  • Views: 

    219
  • Downloads: 

    131
Keywords: 
Abstract: 

Tree species through litter fall have the most important effect on soil properties and play a fundamental role in the carbon cycle and nutrient release. This study aimed to investigate the corelation between tree species and changes in carbon sequestration and some soil properties in the forest types of central Zagros The tree species features in the Persian oak, Aleppo oak, and Wild pear forest types were measured by 24 plots of 500 m2 (20×25 m) and soil properties were determined (at two depths of 0-10 & 10-30 cm) by 48 combined sample. Data on tree features, soil properties, and carbon sequestration variables were analyzed and compared by one-way ANOVA. Based on the results, unlike crown height and tree density, canopy area showed no significant difference. Significant differences among forest types were also observed in carbon sequestration, soil texture, N, OC, K, pH, and saturated humidity in the 1st sampling depth but the T. N. V, C/N ratio, EC, Ca, bulk density, and saturated humidity showed no significant differences in the 2nd sampling depth. The most values of clay, silt, and pH, were seen in both Wild Pear and Aleppo oak forest types while Persian oak forest type had the most values of carbon sequestration, sand, K, N, OC, and saturated humidity in the 1st sampling depth. The crown height was the most important variable that showed significant correlation with the changes of carbon sequestration, K, pH, and saturated humidity. It is concluded that the changes in carbon sequestration and soil nutrients in Zagros forest types is mostly affected by forest types and crown height. It is suggested that to estimate carbon sequestration by remote sensing in Zagros forest, the Lidar data that able to measure crown height be applied.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    152
  • End Page: 

    162
Measures: 
  • Citations: 

    0
  • Views: 

    170
  • Downloads: 

    93
Abstract: 

The spatial distribution pattern is an important attribute of forest communities. Comprehending latent processes in the spatial pattern of tree communities is an important aim in forest ecology. Ecological processes in forest ecosystems directly affect the spatial pattern of various forest species. The spatial distribution pattern of species of different forest species affects ecological processes of forest ecosystems and plays an important role in comprehending forest ecosystem dynamics. This study aims to determine the spatial pattern of trees and shrubs, Pistacia mutica, Acer monspessulanum, Amygdalus scoparia, Cotoneaster Kotschyi Klotz, Daphne mucronata, Berberis integerrima, Nerium oleander in forest habitat of Cheltan Dehbakri in Bam county, Kerman province. The attributes recorded in the field includes: species type and geographic position for individual trees and shrubs within a 15 ha area. We used three methods, Nearest Neighbor, Ripley's K function and O-ring function for determination of species-specific spatial distribution pattern as well as the spatial pattern of total woody species across the study. Despite existing differences in the intensity of aggregation, the results showed that all woody species are distributed in an aggregated pattern. According to the results of the nearest neighbor method, the distribution pattern of Berberis integerrima species is random, but other species are aggregated Results of this study proved the ability of mentioned indices to determine the true spatial pattern of woody species in the study area and can provide useful information for describing the sustainability of this valuable ecosystem and monitoring conservation and restoration activities. Regarding the goal and available circumstances, can be applied from each one of indices in future studies.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    163
  • End Page: 

    174
Measures: 
  • Citations: 

    0
  • Views: 

    217
  • Downloads: 

    159
Abstract: 

Hyrcanian (Caspian) area is one of the most important vegetation areas in Iran, which due to its antiquity, has a high ecosystem value. On the other hand, this ecosystem is involved in multiple fires every year and loses a significant level of vegetation, so the use of scientific methods to predict places with potential fire risk is very important. This can be used for the conservation management of Hyrcanian forests. Many real-world systems are used in terms of pattern recognition, so proper use of machine learning methods is essential in practical applications. However, the use of clustering-based methods is emphasized as an effective method due to its approach in pattern recognition and output discovery. The purpose of this study was to evaluate the ability and compare the performance of Fuzzy C-Means and k-Medoids clustering in modeling forest fire occurrence with emphasis on the performance capabilities of the algorithm. Due to the existence of periodic fires, the mentioned algorithms were used to improve the level of coding in MATLAB software in order to improve studies in the field of forest fire risk prediction. Model input criteria in this study are recorded fire points, distance to agricultural areas, distance to the road, distance to the river, air pressure, solar radiation, slope, aspect, wind speed, forest type and percentage of canopy density. The results obtained from the fire hazard prediction map of both algorithms show their high ability to predict the fire occurrence model. Also, based on the results of the confusion matrix table of the comparison of the two algorithms, the FCM algorithm showed better performance than the kmedoids algorithm in predicting places with potential fire risk. Therefore, the use of FCM algorithm is suggested as one of the effective methods in differential clustering for future studies.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    175
  • End Page: 

    184
Measures: 
  • Citations: 

    0
  • Views: 

    140
  • Downloads: 

    103
Abstract: 

Carbon storage by natural forests, plantation forests, pastures and soils is the best way to reduce atmospheric carbon. This study was conducted in 2018 with the aim of evaluating the effect of spate irrigation on the biomass and carbon storage in various organs of Eucalyptus camaldulensis and Acacia salicina plantation at the Kowsar station located in Gare-Bygone Plain. After truncating the trees, trunk, branches and leaves were separated. In addition, the amount of litter produced under the trees was also collected and weighed. Afterwards, the dried samples were powdered by electric milling and the carbon content in the samples including trunk, branch, leaf and litter was measured by electro-ash method. Data were analyzed using randomized complete block design and the means were compared by Tukey test at P<0. 05. The results showed that leaves had the lowest amount of carbon storage and trunk had the highest amount of carbon storage. In eucalyptus stand (first strip), the highest carbon content of 187. 56 t/ha was stored as living tissue including trunk, branch and leaf litter. Given that each ton of carbon equals 3. 67 tons of carbon dioxide gas, it can be concluded that the amount of 688. 34 tons of carbon dioxide gas in the air in different organs of the plant and in litter stored as organic matter. In acacia, however, the amount of carbon stored was 72. 81 t/ha and the equivalent of stored carbon dioxide was 267. 21 t/ha. The economic-environmental value of this amount of stored carbon was calculated to be $137619. 05 and $5333. 33 per hectare, respectively. With respect to 32 years of spreading water in these areas, each hectare of eucalyptus and acacia trees averages 21. 51 and 8. 35 tons of carbon dioxide gas have been stored as organic matter per year, respectively. In this respegt, the eucalyptus plantation has played a greater role in reducing air pollution. The economic value of the oxygen produced in the forests of eucalyptus and acacia ($11190. 5 and $1774. 28, respectively) is also adds to the economic value of reducing carbon dioxide, and their economic performance value reach to $148809. 52 and $55238. 10, respectively. Therefore, the development of eucalyptus afforestation toghether with spate irrigation method in similar prone areas is more economically justified and recommended from a carbon storage perspective.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    185
  • End Page: 

    195
Measures: 
  • Citations: 

    0
  • Views: 

    157
  • Downloads: 

    117
Keywords: 
Abstract: 

Forest fire is recognized as a significant threat to the safety of human life, infrastructure and the environment. One of the most important steps in reducing the risk of forest fires is determination of the areas with the high probability of forest fire occurrence. Choosing the appropriate methods for modelling of the forest fires is very important. Due to the importance of the issue in this study, first using library studies and expert advices, the most important variables affecting the occurrence of fire in Babolrood basin-Mazandaran province were determined and then the results of three models of dong, artificial neural network and K nearest neighbors were compared in determining the probability of fire occurrence. The results showed that the most important variables affecting the fire occurrence are temperature, rainfall and distance from residential areas. The results of artificial neural network are more reliable than the other two models. According to the results, about 35% of the study area has very high and high potential for forest fire.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    196
  • End Page: 

    206
Measures: 
  • Citations: 

    0
  • Views: 

    177
  • Downloads: 

    116
Abstract: 

Canopy cover is an important forest structure parameter with many applications in ecology, hydrology and forest management. This study aimed at investigating the capability of Landsat 8 satellite OLI data for modeling and estimation of forest canopy in a part of the Zagros forests. First the images were evaluated in terms of geometrical and radiometric errors. Required processing such as Vegetation Indices, Principle Component Analysis (PCA), and Tasseled Cap transformation were performed on the images of the study area. To measure aboveground canopy cover using hemispherical photography method, 60 sample plots were designed with a square dimension of 45 × 45 m. The spectral values of the corresponding sample plots were extracted using a polygon map of sample plots. Forest canopy cover was modeled using stepwise multiple linear regression and the accuracy of the model was evaluated via the k-fold cross validation technique. The results of multiple linear regression between canopy cover with main and computational bands showed that the model obtained from SR vegetation index and band 8 with R2 = 0. 662 and RMSE (%) = 15. 24 was the best model. Overall, this study demonstrated that the estimation of forest canopy cover is cost-effective and requires low computation power using Landsat 8 satellite.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    20
  • End Page: 

    29
Measures: 
  • Citations: 

    0
  • Views: 

    206
  • Downloads: 

    121
Abstract: 

This study was conducted with the aim of economic, social and environmental evaluation of organizing plan of livestock exit from forest in the central part of Rezvanshahr city of Guilan province. The present quantitative research that was conducted in 2018, in terms of collecting data is descriptive-survey. The sampling method used in the research is also a simple random stratified. In order to evaluate the plan, a researcher-made questionnaire was used, the validity of which was confirmed by a group of experts and its reliability was confirmed by theta coefficient (0. 87). The two groups were compared using independent t-test and U-test. Prioritization of conditions and effects of the plan was done by consulting local experts and the Analytical Hierarchy Process (AHP). The results of the research showed that there are no significant differences between the two groups in terms of individual properties-professional, income rate, production rate, creation of second job, trust in authorities, feeling of frustration and addiction. But other economic, social and environmental conditions of the two groups are significantly different. Also, from the perspective of the participants in the plan, more access to health-welfare facilities, providing appropriate educational conditions and promoting public participation are the main effects of the project. According to the results of the research, financial support, the development of rural industries and home-based businesses, the establishment of forest conservation organizations, the holding of periodic meetings among beneficiaries of the plan and carrying out various cultural-social activities is suggested.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    207
  • End Page: 

    218
Measures: 
  • Citations: 

    0
  • Views: 

    173
  • Downloads: 

    99
Abstract: 

Quantitative structure description can be used as one of the most important tools in forest management. The study of the structural characteristics of unique species such as Stinking Bean Trefoil (Anagyris foetida L. ) has a high priority and its conservation is essential. Therefore, Current research is attempting to scrutinize the structural properties of this species. The study area with 930 hectares located on 7 kilometers east of Gilan-e Gharb city from Kermanshah province. For this study, the target range was first determined and then bounded using GPS. Subsequently, sampling was prepared by systematic-random sampling. Species type, diameter, height, canopy including main canopy and minor canopy were sampled. Furthermore, the distance and azimuth of each tree were calculated and recorded. The results showed that the most important tree species were Stinking Bean Trefoil, Oak, Fig and Hawthorn with 62. 1%, 27. 6%, 5. 7% and 4. 84% respectively. The cross section for Stinking Bean Trefoil is about 0. 2 m3/ ha, for other species it is 0. 5 m3/ha and for total stand about 0. 74 m3. ha-1. Stinking Bean Trefoil, Persian oak and other species is 65. 55%, 26. 2% and 8. 25%, respectively. Most of the indices showed clustered spatial pattern.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    219
  • End Page: 

    227
Measures: 
  • Citations: 

    0
  • Views: 

    192
  • Downloads: 

    144
Abstract: 

Forest logging prohibition is one of the most important challenges in the management of Hyrcanian forests that it has diffrent consequences. The purpose of this study is identifing, weighting and prioritizetion the positive and negative consequences of the forest logging prohibition from economic and social aspects in forests in the east of Mazandaran province (forests managed of the department of natural resources and watershed of Mazandaran province (Sari). The statistical population of the study consists of a group of 60 people including experts and specialists, faculty members specialized in this field and rural communities living in the margins of managed forests. In the study we used the Delphi method for identifing the consequences of the forest logging prohibition, the entropy technique used to calculate the weight of them and the preferences technique based on the similarity to the ideal solution (TOPSIS) used to prioritize them. The analysis of the research findings identified 6 positive and 17 negative consequences from economic and social aspects for the forest logging prohibition based on 55 questionnaires received. The results of consequences weighting showed that among the positive consequences, the consequences of increasing the economic values of forest environmental services and the tendency towards wood cultivation with weights 0. 200573 and 0. 200426 respectivly, and from the negative consequences, increasing wood smuggling 0. 05163 and reducing employment 0. 0513133 have the most weight. The results of prioritization of consequences showed that among the positive and negative consequences, changing the dependent management of wood to multiple management forest and increasing wood smuggling have the highest priority among other consequences. Also the results showed that in positive consequences, economic perspective and in negative consequences, social perspective gained more weight. Therefore, we are suggested that in order to implement the forest logging prohibition plan, programs considered for accurate, continuous monitoring and budget allocation for increaseing forest protection and reduce wood smuggling and create job opportunities by the government.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    30
  • End Page: 

    40
Measures: 
  • Citations: 

    0
  • Views: 

    234
  • Downloads: 

    104
Abstract: 

Diameter at the breast and height of trees are the most important components in the forest inventory. Measuring the diameter of trees is simpler and less costly than height; hence, some equations are used to predict height by diameter of trees. In the present study, the ability to use different diameter-height models for estimating the height of beech trees (Fagus oriantalis Lipsky) in uneven age and mixed stands in Hyrcanian forest, North of Iran. In this study, a systematic-randomly sampling method with 150 × 200m network (0. 1 ha) was used. Diameter and height of the thickest and nearest trees (690 individuals) to the center of circular sample plots (345) was measured. 70% of the data was used for modeling and the remaining 30% was used for evaluating estimated models. Using 20 nonlinear regression models including 11 two-parameter models and 9 three-parameter models, the relationship between height as a dependent variable and diameter as an independent variable was considered and analyzed. In order to evaluate the models and select the best model, the validity of the statistical models was evaluated using RMSE and BIAS. The results of the model evaluation criteria did not differ significantly. Korf, Ratkowsky, Naslund and Weibull models with root mean square error of 4. 17, 4. 19, 4. 21, and 4. 23 and BIAS of 0. 17,-0. 38,-0. 55 and-0. 1, respectively had a good ability to accurately estimate the height of beech trees. According to the region conditions, these models can be used to estimate the height of beech trees in broadleaved and mixed forest of northern Iran.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    41
  • End Page: 

    48
Measures: 
  • Citations: 

    0
  • Views: 

    168
  • Downloads: 

    134
Abstract: 

Today, Zagros reforestation is more than ever felt due to human presence and its destructive activities. To do this requires observing the scientific principles of silviculture. Of essential restoration activities in these forests can be mentioned the seed planting of indigenous species within their range of development. In this regard, the present research was conducted with the aim of investigate the germination and emergence status of Quercus persica, Pistacia atlantica and Acer cineracens seeds planted in Dalab Ilam forests in 2018. For this, three sites on the northern slope and approximately the same height of 1380 to 1410 meters above sea level were selected. In each site, three trees were considered for each of Q. persica, P. atlantica and A. cineracens species. Under each tree, three holes were drilled between the trunk and the end of the crown for each crown side, and a total of 12 holes. In drilled holes under the trees, the corresponding seeds were planted in the winter 2017. The results of the sampling in the spring 2018 showed that the seeds of Q. persica had the highest emergence rates (22%). The seeds of P. atlantica gained the second rank in terms of germination and emergence (18%). The seeds of A. cineracens had the lowest amount of emergence (0. 3%) and the number of emerged seedlings was rare. The highest occurrence rate of Q. persica seedlings was on the northern side of tree crown (32%) and in for P. atlantica was on the southern (32%) and western (30%) sides of the tree crown. The highest rate of seedling emergence of Q. persica (48%) and P. atlantica (51%) was found at nearest distance to tree trunk. Despite planting the seeds of these three tree species in the same conditions in terms of topography, position under the crown and distance from tree trunk, similar results were not obtained which the reason of this can be attributed to their seed characteristics such as seed size and seed vigor.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    49
  • End Page: 

    61
Measures: 
  • Citations: 

    0
  • Views: 

    132
  • Downloads: 

    103
Abstract: 

Land degradation and environmental heterogeneities are factors that affect forest ecosystems worldwide and their characteristics. Despite the significant role of soil seed bank to the rehabilitation of degraded plant communities, the floristic studies in many terrestrial ecosystems have focused only on aboveground vegetation. This study carried out to investigate the effect of land-use change from forest to agriculture and long-term and short-term abundance of this disturbance on aboveground vegetation and soil seed bank in Cheghasabz forest park in Ilam County. A total of 66 sample plots (1 m × 1 m) were established using a random systematic method to measure the aboveground vegetation. For soil seed bank, around each of the sample plots, a sample 20 cm × 20 cm area to a depth of 10 cm randomly collected. The seedling emergence method (in greenhouse) and the Braun-Blanquet cover-abundance scale was used to study of soil seed bank and vegetation, repectively. The results showed that in all three studied areas, the number of species in the soil seed bank decreased compared to aboveground vegetation. The dominant life form in the three studied areas were therophytes for both the soil seed bank and aboveground vegetation. The phytocorya distribution of plant species in all land uses also showed that the elements of Irano-Turanian and Iran-Touran-Mediterranean are dominant for both soil seed bank and aboveground vegetation. The density of soil seed bank decreased significantly in agricultural land use. Along DCA axes, based on soil seed bank and aboveground vegetation two distinct vegetation composition separated. The first group includes plots of the soil seed bank and aboveground vegetation in long-term abandoned lands and forest stands, and the second group consisted of seed bank and vegetation of short-term abandoned lands. Long-term abandonment from agriculture as a management measure and relying on the seed bank can be efficient in restoration of vegetation and returning to pre-disturbance conditions.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    62
  • End Page: 

    74
Measures: 
  • Citations: 

    0
  • Views: 

    207
  • Downloads: 

    112
Abstract: 

Forest structure, as measured by the physical arrangement of trees and their crowns, is a fundamental attribute of forest ecosystems that its measurement can serve as indicators in ecosystem management. In this research, the horizontal and vertical structure of a part of the northern Zagros forests was studied. For this purpose, conventional region forests of Havarekhol village in Baneh city was selected and sixty 20×20 m2 plots in a grid of 200×300 m2 by randomized-systematic method were established in an area of about 345 ha. In each plot, diameter at breast height of all trees and coppices thicker than 1 cm, height of trees and coppices, two crown diameters, crown height and spatial locations of all trees and coppices were measured. SVS software was used to display the horizontal and vertical structure of the forest, and stand statistical indices were analyzed using SPSS software. Distribution of trees and coppices in the height classes showed a two-three storied forest structure in Havare-Khol with the highest abundance in the middle story and the lower abundance in the overstory. The highest distribution of trees and coppices in Havare-Khol forest were within 2-4 m height class and more than 84% of stems had less than 4 m height. Most trees and coppices were less than 10 cm in diameter, indicating a young forest for Havare-Khol with a low diameter distribution range, and a low abundance of thick and old stands in the forest. The horizontal structure of the forest showed large vacant patches and discontinuities of the canopy in the nearest villages that the amount of these empty spots is gradually diminishing as they approach the conventional region border. Also, the vertical structure of the forest shows that in the areas closer to the center of the village the trees and coppice shoots are more concentrated in the middle story and understory, and the greater the distance from the center of the village, the higher the presence of trees in the overstory. Overall, drawing the forest structure showed that with increasing distance from the center of the village, the diameter at breast height, height and area of canopy cover and coppice shoots increased.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    75
  • End Page: 

    85
Measures: 
  • Citations: 

    0
  • Views: 

    135
  • Downloads: 

    94
Abstract: 

Human demand for food and energy has led to major changes in the level of active nitrogen (N) released to the atmosphere. N addition experiments are a reliable way for investigating the effect of extra N deposition on target ecosystems. The present study was carried out to investigate in the effects of an artificial N deposition on the soil biochemical properties of a 20-year-old oak (Pinus radiata) plantation in Hyrcanian forests in the north of Iran. Twelve plots of (20 m × 10 m) were established in the study area. Four N treatments were considered: zero (control), 50 (low), 100 (medium) and 150 (high) kg N ha− 1 year− 1. N in the form of NH4NO3 solution was manually sprayed onto the plots monthly for one year. Analysis of variance showed that soil characteristics at nitrogen treatment and different seasons and interaction of season and treatment had significant differences (P value <0. 01). In this regard and at the end of the simulation period, the lowest soil pH was observed in high treatment (6± 0. 3) and highest in control treatment (6. 8± 0. 3). The highest amount of total nitrogen was observed at high N treatment (0. 55± 0. 02). But in relation to K and P concentrations, the control treatment (368± 2. 7) (12± 1. 6) had highest and high N treatment (266± 3) (6. 6± 0. 7) had lowest concentration of P and K, respectively. In this study, due to the increase in nitrate content obtained by adding ammonium nitrate in the nitrogen simulation process, nitrate becomes saturated in the soil and mobile in the soil, and then leaching with base cations and decreasing soil pH.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    86
  • End Page: 

    96
Measures: 
  • Citations: 

    0
  • Views: 

    162
  • Downloads: 

    121
Abstract: 

One of the most important issues in the Zagros forests of Ilam is the dieback of oak trees, and the purpose of this research is to analyze the temporal-spatial analysis of the relationship between oak trees dieback and occurred droughts. In order to identify the dry areas of oak, using the method of determinationof. the training samples in geographic information system (GIS) and satellite images of modis were used. For temporal and spatial analysis of drought in Ilam province, NDVI index from MODIS satellite images in the statistical period of 2000 to 2018 was used. For spatially analysis of relationship between oak forest dieback and droughts, Moran spatial autocorrelation model, one of the spatial pattern distribution models, was selected. Coincidentally, a 30-square-meter GPS device was used to find the coordinates of the dried droplets and the number of dried oak trees at each point, and a map of oak tree dieback distribution was prepared using GIS software. The results of combining drought zoning from NDVI index with oak dieback distribution map in two time series from 2000 to 2009 and 2010 to 2018 in the analysis of Moran index showed that oak dieback has a cluster pattern and the decline of oak trees is spreading in a mass. Also there was a significant relationship between drought trend in spatial and temporal dimensions and oak dieback in recent years in different parts of Ilam.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    9
  • Issue: 

    17
  • Start Page: 

    97
  • End Page: 

    105
Measures: 
  • Citations: 

    0
  • Views: 

    288
  • Downloads: 

    108
Abstract: 

Forests have great potential for moderating climate changes and contain the most carbon storage in the world. Therefore, any kind of threat and change in this ecosystem may lead to changes in vegetation composition, reduced diversity, and ecosystems service on local, regional, and global scales. The main purpose of this study was to compare the climate parameters changes in a forest ecosystem vs urban area. The minimum and maximum temperature, precipitation, and radiation by using ofLARS-WG model were evaluated for the past and the future periods in a forest climatic station at Kaleybar (settled in Arasbaran forest)and Tabriz as an urban station. The results of the study in the past period showed that all the climate parameters had a significant difference (p≤ 0. 05) between forest and urban areas. The minimum temperature, maximum temperature, and radiation have a lower amount but the average rainfall has a significantly higher amount in the forest station (p≤ 0. 05). In addition, all climatic parameters will increase except the minimum temperature in the future. The comparison of the future climate condition in the Arasbaran forest showed that minimum temperature and radiation will increase significantly, but maximum temperature and precipitation will not show a significant difference. Eventually, the present study showed that the climate change trend of the forest ecosystem was less than the urban environment, and it refers to the role of forest ecosystem in climate change mitigation.

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