Document Type : Complete scientific research article
Authors
1
PhD student in Forestry, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
2
Associate Professor, Department of Forestry, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
3
Assistant Professor, Department of Forest Sciences, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran.
4
Professor, Department of Forestry, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
5
Professor, Department of Forestry and Forest Ecology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
Abstract
Background and Objective: Understanding the variations in leaf area index resulting from forest management practices and harvesting, and comparing them to those of unmanaged stands, offers valuable insights into forest stands that are crucial for informed decision-making, future planning, and sustainable forest management. This study aims to assess and compare the leaf area index, volume, tree density, and Basal Area in managed and unmanaged stands, both overall and by species, within the uneven-aged broad-leaved stands of the Shast Kalateh forests.
Materials and Methods: The study area is located in a part of Series One (managed stand) and Series Two (unmanaged stand) within Dr. Bahram Nia's forestry plan. Systematic sampling was conducted using a grid measuring 200×150 meters on the ground. Data on diameter at breast height, species type, and height of selected trees were collected for each sample plot. Additionally, a leaf litter trap measuring 60×60×20 centimeters was installed in each sample plot. Leaves were collected on a monthly basis for one year after installation and then transferred to the laboratory. After determining the specific leaf area and dry weight of leaves per species in the trap, the leaf area index was calculated for each species and subsequently for all species within each sample plot. The characteristics of volume per hectare, the number of trees per hectare, and ground area per hectare were also calculated for each sample plot. The total leaf area index for both managed and unmanaged stands, as well as volume per hectare, the number of trees per hectare, and ground area per hectare, were compared and evaluated using an independent t-test.
Findings: The results of the descriptive statistics indicated that the leaf area index was higher in the managed stand (6.63) compared to the unmanaged stand (6.03). The average leaf area index by species for, F.Oreintalis Lipsky, C. betulus L, P. persica and A. Velutinum Boiss in the managed stand was 1.76, 2.01, 1.87, and 1.63, respectively, while in the unmanaged stand, these values were 2.41, 1.44, 1.38, and 1.16, respectively. The independent t-test results showed a statistically significant difference in the overall leaf area index between the managed and unmanaged stands at a 95% confidence level (p < 0.05). However, there was no significant difference at a 95% confidence level in the standing volume, tree density, and basal area between the two types of stands (p > 0.05). Furthermore, there were statistically significant differences in the leaf area index of, F.Oreintalis Lipsky, C. betulus L, P. persica species between the managed and unmanaged stands at a 95% confidence level. However, there was no statistically significant difference in the leaf area index of A. Velutinum Boiss between the two stands (p > 0.05).
Conclusion: The results of this study show that forest management and harvesting have a significant impact on the leaf area index. Therefore, by implementing proper management and precise harvesting techniques, it is possible to enhance the leaf area index, leading to increased production, carbon storage, and photosynthesis.
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