Alireza Amolikondori; Mohammad Feizian
Abstract
Introduction: Diverse gap sizes have formed in temperate Hyrcanian forests as a result of different silvicultural operations. Understanding the consequences of these practices on forest stand dynamics can help in deciding the choice of silvicultural methods. Therefore, the purpose of this study was to ...
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Introduction: Diverse gap sizes have formed in temperate Hyrcanian forests as a result of different silvicultural operations. Understanding the consequences of these practices on forest stand dynamics can help in deciding the choice of silvicultural methods. Therefore, the purpose of this study was to investigate the effect of canopy gaps on the carbon stock of beech trees and compare it with the adjacent stand and also the interaction between tree attributes and their carbon stock. Material and methods: The created gaps from single-tree cutting were classified in three classes of small, medium and large area with five replicates for each. Trees were also identified in the adjacent forest to each gap at a distance of 20 m from four directions of them. Tree height, DBH, surface area, volume, length, diameter of crown and carbon stock of trees were measured. One-way analysis of variance was used to compare the average carbon stock index of beech trees in canopy gaps and in different situations as well as for large diameter trees. Independent t-test was applied to compare the average carbon storage in the height classes of the trees and also between the adjacent forest stands with the canopy edges. Pearson correlation coefficient was used to determine the correlation between the index of carbon stock amount with some structural features of beech trees in the edge of the canopy gaps and the adjacent forest stand.Results and Discussion: The findings revealed that the carbon stock of beech trees along the gaps' edges differed significantly (p≤0.05). No significant difference in carbon stock was observed for beech trees among different directions at the edge of the gaps (p≤0.05). There was no significant difference between the mean value carbon storage of trees at the edge of the gaps and the adjacent forest (p≤0.05). The highest mean of carbon was observed in the large-sized trees (3725.28 ± 584.49) at the large gaps. The results of correlation showed that with increasing DBH, height, length and diameter of the crown and the volume of the crown, the amount of carbon storage of trees increased at the edge of the gaps and also in the adjacent forest (p≤0.01). Conclusion: Findings indicate the effect of canopy gap area resulting from the implementation of single-tree selection method in beech forest. The correlation between the structural characteristics of beech trees such as DBH, height and crown area with carbon stock shows that when applying silvicultural methods (tending and logging) in Hyrcanian forests, structural characteristics Beech trees, especially the abundance of large-sized trees, should be considered with more carbon stocks in them.
Hadi Dordaneh; Kambiz Abrari Vajari; Zia-aldin Badehian
Abstract
Introduction: The Zagros forests, which are one of Iran's most important forest ecosystems, contain a diversified vegetation that includes trees, shrubs, and herb-layer species. Identification and precise knowledge of their ecological role in this ecosystem can help in natural resources protection and ...
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Introduction: The Zagros forests, which are one of Iran's most important forest ecosystems, contain a diversified vegetation that includes trees, shrubs, and herb-layer species. Identification and precise knowledge of their ecological role in this ecosystem can help in natural resources protection and sustainable development. In order to study the effects of physiographic factors (aspect, slope, and elevation) on the woody plants species diversity and also soil carbon stock in the central Zagros, the maple tree (Acer monspessulanum Var. cinerscens) forest in Hashtadpahlu region which is located in Lorestan was selected. Material and methods: Within the forest, 37 circular plots, each measuring 1000 m2, were placed systematic-randomly for this purpose. Richness and diversity indices were calculated for woody species within plots. Soil samples were taken from a depth of 0-30 cm to measure the quantity of carbon stock in the soil and the value of soil organic carbon and bulk density for soil samples were measured.Results and discussion: In this forest, 11 different woody plant species (trees and shrubs) from seven different families were investigated. The results showed that the highest diversity of shrub species was observed in the northern aspect and the lower slopes (class of 5-20%), while the elevation has no significant effect on the shrub diversity. Also, the physiographic factors had no significant effect on shrub species richness and tree species diversity and richness. The most soil carbon stock was measured in the eastern aspect while the other physiographic factors had no significant effect on the carbon stock. The reduced carbon supply on the northern slopes relative to the rest of the slopes could be a result of heavy grazing, low density and poor vegetative quality of woody species, reduction of tree litter and other plant species and climatic conditions in this slope. As a result, the most important factors impacting the number of species diversity indices in the Acer forest are the aspect and slope.Conclusion: The richness and diversity of woody species in the Acer sp. forest are appropriate and physiographic factors have played an important role in the values of their indices. Physiographic parameters have an impact on the carbon stock of the soil. As a result, environmental variables should be considered in the management of Zagros forests due to its extensive distribution.
