1- AREEO
Abstract: (4 Views)
Introduction and Objectives: Carbon sequestration in plant biomass and soils that are under this biomass is the easiest way to reduce atmospheric carbon dioxide. Forests play a special role in atmospheric carbon deposition due to the production of large amounts of biomass and are of great interest from the aspect of carbon storage. During the past years, the forest habitats of Zagros have been severely destroyed from quantitative and qualitative aspects, and as a result, the key role of these ecosystems in controlling climate changes has been affected. Evaluating of quantitative changes in above-ground and soil carbon reserves in Zagros forests can show the importance and value of this vital ecosystem from economic and environmental aspects and be useful in sustainable management programs of forest resources. In the present research, the carbon stock was measured and monitored in the permanent sample plots, which has not been done in the west of the country so far. This research is the beginning of long-term monitoring and climate change modeling, which their results can be used in the modeling of carbon deposition and global warming changes. In this regard the present study was conducted with the aim of determining the changes in the carbon stock of above-ground biomass, litter and soil in the standard and standard-coppice Persian oak stands in Dalab forests of Ilam province during the years 2019 to 2022.
Materials and Methods: In this research, first, two Persian oak forest stands with standard and standard-and- coppice forms were selected. A permanent square sample plot of one hectare (dimensions 100 × 100 meters) was selected and established randomly in each forest stand. Quantitative characteristics of all the trees in the sample plots were measured in order to determine the status of each stand and to calculate the biomass and above-ground carbon stock of the stands. Also, in each sample plot, five soil samples were regularly taken from a depth of 0-30 cm in the square and center of the sample plot and carbon, moisture, apparent specific gravity and soil gravel percentage were measured. To estimate the carbon stock of the litter, 10 micro plots of 0.5 square meters were planted randomly in each plot and two groups of fine and coarse litters were collected separately. Fine litters included all leaves, humus layers and all small pieces of wood (less than one centimeter in diameter), and coarse litters included large pieces of wood (more than one centimeter in diameter). Quantitative characteristics of trees were measured in the first year of research and soil and litter sampling was done during 4 years of research. Two-way analysis of variance was used to investigate the changes of quantitative traits related to litter and soil under the influence of sampling year and stand form (sample plot). Independent t-test was used to compare the average of litter biomass and carbon stock between two forest stands. Duncan's test was used to compare the average characteristics of litter and soil between the research years. Statistical analysis of data was done in SPSS version 16.
Results: The results showed that the stand density and canopy cover in the pure standard stand (72 trees/ha) is higher than the standard-coppice stand (55 trees/ha). In the standard-coppice stand, the amount of above-ground biomass and carbon stock (29.93 tons/ha and 14.46 tons/ha, respectively) was less than the pure standard stand (60.17 tons/ha and 29.78 tons/ha, respectively). The average biomass and carbon stock of fine litter in the standard-coppice stand was lower than that of the pure standard stand. The average biomass of fine and coarse litter in the standard-coppice stand was 4.95 and 1.52 tons per hectare, respectively. The average dry weight of fine and coarse litter in the pure standard stand was 6.24 and 1.32 tons per hectare, respectively. The average carbon stock of fine and coarse litter in the standard-coppice stand was estimated as 2.77 and 0.83 tons per hectare and in pure standard stand as 3.81 and 0.72 tons per hectare respectively. The organic carbon percentage of fine and coarse litter in standard-coppice stand was 45.20 and 38.79%, respectively, and in pure standard stand was 44.02 and 39.34%, respectively. The average percentage of organic carbon and soil carbon stock in the standard-coppice stand (respectively 2.01 and 70.11 tons per hectare) was lower than the pure standard stand (respectively 2.09 and 79.67 tons per hectare). The soil moisture in each stand had annual changes and its amount in the standard-coppice stand was lower than in standard stand. The soil carbon stock was significantly affected by the year and its values showed a significant difference between the research years, while the amount of fine litter carbon stock in the research years and the sample plots showed a significant difference, and the coarse litter carbon stock did not show significant changes. In both studied forest stands, the largest share of the stored carbon belonged to the soil, followed by the above-ground carbon stock.
Conclusion: The obtained results indicate that the carbon stock of Persian oak stands in different biological parts is influenced by the quantitative and qualitative characteristics of oak stands and its variations in different years differ depending on the stand characteristics. Based on this, in the standard forest stands, which are less degraded than the standard-coppice stands, they have better ecological performance and this efficiency is shown in the higher amount of above-ground, litter and soil carbon stock. The results of quantifying the amount of carbon stock in different biological parts of oak forests showed that oak forests play a significant role in carbon storage, which is effective in controlling atmospheric carbon dioxide.
Type of Study:
Research |
Subject:
Special Received: 2023/08/15 | Accepted: 2024/01/30