Document Type : Research article
Authors
1
Corresponding author, Assistant Prof., Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
2
Prof., Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
3
Associate Prof., Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
4
Assistant Prof., Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
5
Associate Prof., Research Division of Natural Resources, Chaharmahal and Bakhtiari Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Shahr-eKord, Iran
6
Assistant Prof., Research Division of Natural Resources, Fars Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Shiraz, Iran
7
Associate Prof., Research Division of Natural Resources, Lorestan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Khorramabad Iran
8
Assistant Prof., Research Division of Natural Resources, Kurdistan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Sanandaj, Iran
9
Assistant Prof., Research Division of Natural Resources, Khuzestan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Ahvaz, Iran
10
Assistant Prof., Research Division of Natural Resources, Kohgiluyeh and Boyer-Ahmad Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Yasuj, Iran
11
Assistant Prof., Research Division of Natural Resources, Kermanshah Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Kermanshah, Iran
12
Assistant Prof., Research Division of Natural Resources, Lorestan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Khorramabad, Iran
13
Assistant Prof., Research Division of Natural Resources, Ilam Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Ilam, Iran
14
Assistant Prof., Research Division of Natural Resources, West Azerbaijan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Urmia, Iran
15
Faculty member
16
Researcher, Research Division of Natural Resources, Kermanshah Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Kermanshah, Iran
10.22092/ijfpr.2024.364224.2135
Abstract
Background and objectives: Reproduction (regeneration) is a fundamental process that drives the dynamics of a forest, occurring continuously in a healthy and natural forest with a specific spatial and temporal pattern. Natural regeneration poses significant challenges in Zagros forests, Iran. This research was undertaken to examine and analyze the current state of reproduction of tree and shrub species in the monitoring sample plots of Zagros forests. This study, while scrutinizing the species composition, origin, distribution curves, and health of seedlings and saplings, explores the interrelationship between reproduction and nurse species. It will serve as the foundation for long-term studies that determine the temporal changes in reproduction and its characteristics in the Zagros forests.
Methodology: This research was conducted in the permanent monitoring plots of Zagros, spanning from West Azerbaijan to Fars province. A total of 120 sample plots of 100 square meters were studied within these plots. Each province had 30 studied sites in the typical forests, with 10 of them located in the protected forests. The variables studied included reproduction density by species, origin and type of reproduction, nurse species, height of seedling, terminal bud, and health status of reproduction. A height of 0.5 meters was set as the criterion to distinguish reproduction. The t-test was used to compare parametric data in two groups, while the Kruskal Wallis and Mann-Whitney U tests were employed for non-parametric data.
Results: In the studied area, the reproduction of 20 forest tree and shrub species was recorded, and the density of seedlings and saplings was calculated to be 366 plants per hectare. However, the reproduction was not uniformly distributed, with 37% of the sample plots lacking reproduction. The abundance distribution diagram in the height classes revealed a decrease in the number of oak (Quercus spp.) and hawthorn (Crataegus spp.) reproduction with a height of less than 5 cm. Of the total number of recorded reproduction, 72.5% originated from seeds and 25% were shoots. Overall, 66% of reproduction was dependent on nurses, with oak, hawthorn, stone, and rock playing the greatest roles as nurses. Stones and rocks played a more significant role in the revival of seedlings. Cerasus microcarpa (C.A.Mey.) Boiss., Q. infectoria Oliv., and Q. libani Oliv. had the highest dependence on the nurse, while Pyrus spp., Daphne mucronata Royle, and Crataegus spp. had the least dependence on nurse species. Reproduction sheltered by nurses was significantly healthier than those without nurses. Also, reproduction sheltered by stones and rocks had a higher health rate than reproduction sheltered by trees, although this difference was not significant. Lonicera nummulariifolia Jaub. & Spach, Fraxinus angustifolia Vahl, and Acer monspessulanum L. had the worst condition in terms of reproduction. Despite the presence of mature trees, they had no reproduction (L. nummulariifolia and F. angustifolia) or had very low reproduction (A. monspessulanum). The results showed that the number of reproduction in protected sites was higher than non-protected sites. Although this difference was not significant, the reproduction in the protected sites was significantly healthier.
Conclusion: The results indicated that the reproduction in the Zagros forests is not in a normal situation. However, given suitable spatial and temporal conditions, reproduction occurs and establishes. Although in conditions of disturbance and overgrazing, reproduction attempts to survive by taking shelter near stones, pits, or under thorny shrubs, the conservation of the forest stand by maintaining the tree canopy (oak, hawthorn, and other species) and the forest’s natural structure provides the best conditions for the establishment and survival of reproduction, thereby ensuring the sustainability of the ecosystem.
Keywords
Main Subjects
)