نوع مقاله : مقاله پژوهشی
نویسندگان
1 نویسنده مسئول، استادیار، گروه علوم و مهندسی جنگل، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران
2 استاد، گروه علوم و مهندسی جنگل، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران
3 دانشیار، گروه میکروبیولوژی، دانشگاه مازندران، بابلسر، ایران
4 مربی، گروه علوم مهندسی، دانشگاه ملی مهارت، تهران، ایران
5 استادیار، گروه صنایع کاربردی، دانشگاه ملی مهارت، تهران، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: The Flord District represents a managed forest stand under the supervision of the Farim Wood and Paper Company, where three marking cycles have been conducted to date. Within a forest ecosystem, fallen deadwood functions as a microhabitat that plays a crucial role in shaping the species diversity and abundance of wood-inhabiting fungi. macro wood-inhabiting fungi occuring on fallen logs are among the primary and most effective decomposers within forest ecosystems. Owing to their distinct climatic characterictics, parts of the Hyrcanian forests of the northern Alborz region harbor not only a rich vegetation cover but also a highly diverse fungal flora. Identifying the wood-inhabiting fungal flora in each region provides valuable insights into the complexity of forest ecosystem biodiversity. The present study aims to investigate the abundance and species diversity of wood-inhabiting fungi on fallen beech logs and to examine their relationship with the volume of deadwood.
Methodology: Following preliminary forest surveys, sampling was conducted in the beech stands of the Flord District, Farim Forest (Pol Sefid, Mazandaran Province), located within an altitudinal range of 1200–1800 m a.s.l. A total of 15 fallen beech logs, randomly selected at intervals of more than 200 m apart, were examined. For the collection of macro wood-inhabiting fungi, whenever a fruiting body was observed, the specimen was carefully harvested in an intact, complete, and suitable form for morphological identification. All collected fungi were numbered, labeled, and transferred to the mycology laboratory for taxonomic determination based on macroscopic and microscopic features. The obtained data on species diversity were entered into SPSS v.16, where normality was assessed using the Kolmogorov–Smirnov test. Species diversity and clustering analyses were performed using individual-based and sample-based rarefaction curves in PAST software. To further evaluate species segregation, Principal Component Analysis (PCA) was applied. Rarefaction, as a statistical approach, estimates the expected number of species in a randomly drawn subsample of n individuals (where n < N), thereby providing an answer to the fundamental question of how many species are likely to occur in a given subsample. In addition, multivariate relationships among samples were visualized using the Convex Hulls method, which constructs a set of polygons enclosing the points within a dataset. Furthermore, ternary plots were employed to display the relative distribution of three variables, where each variable is represented on one side of a triangular diagram, and their proportions determine the position of sample points.
Results: In total, 15 fallen beech logs were examined, yielding 26 species of macro fungi belonging to 22 genera and 16 families. Among these, Trametes versicolor, Trametes hirsuta, Bjerkandera adusta, Galerina autumnalis, Ganoderma lucidum, and Stereum hirsutum were the most frequently encountered taxa, whereas Crepidotus mollis, Ganoderma applanatum, Pluteus cervinus, Trametes gibbosa, and Tremella mesenterica exhibited the lowest occurrence. Within this assemblage, the family Polyporaceae showed the strongest association with fallen beech logs, with deadwood volume estimated at 1.46 m³ per hectare in the managed beech stands of the Flord forest. Among the 26 identified wood-inhabiting fungal species, the families Polyporaceae, Phanerochaetaceae, Ganodermataceae, and Hymenochaetaceae were the most abundant, whereas Crepidotaceae, Pluteaceae, and Tremellaceae represented the least frequent taxa. Results of the PCA revealed that species diversity resulted in the segregation of fungi into two main groups, with only Trametes versicolor being distinctly separated from all other taxa, while the remaining species clustered within similar groups. Furthermore, the rarefaction analysis indicated that T. versicolor exhibited a different pattern compared with other fungi, and the response pattern of each species varied across different elevation.
Conclusion: One of the fundamental principles of close-to-nature silviculture is the retention of fallen deadwood within forest ecosystems. These elements contribute to the formation of diverse microclimates within habitats and influence the responses of living organisms to forest management practices and silvicultural systems. An assessment of the Flord managed forest revealed that, due to timber harvesting over the past three decades, the volume of fallen deadwood in this district is considerably lower compared with natural beech stands of the Hyrcanian forests in other regions. Fallen deadwood represents one of the most important habitat substrates for wood-inhabiting fungal flora, underscoring the increasing necessity of retaining them within managed forests. Therefore, it is recommended that sustainable forest management and conservation strategies pay special attention to the ecological role of fallen deadwood as a key habitat substrate for wood-inhabiting fungi. A purely economic perspective toward fallen deadwood may threaten natural regeneration processes and subsequent regeneration within the forest ecosystem cycle.
کلیدواژهها [English]
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