جستجوی مقالات مرتبط با کلیدواژه « بوم شناسی » در نشریات گروه « جنگلداری »

Forests are dynamic systems that are constantly undergoing permanent changes. Understanding elements in the forestland ecosystem and factors affecting it will help preserve this ecosystem, as preservation of species diversity will help protect the ecological values of the ecosystem. By studying various environmental factors such as vegetation and topography, soil and climate, we can understand the stability of plant communities and the correlation between these factors and vegetation. This is very important and practical for forest community development and regeneration. The importance of biodiversity and its management especially based on the protection and sustainable use of ecosystem resources is one of the main objectives of natural resource management.

The present study examined unique species and rich specie reserves in the forestland region of Neimour in Iranian Noshahr, aiming to evaluate the vegetation of the edges surrounding the Khezr Nabi swamp. Simultaneously with survey, based on the homogeneity or heterogeneity of the vegetation units in relation to the distance from the marsh, ultimately, the zonation of marsh plants was carried out in three zones and sampling was done. Using the Braun-Blanquet method, samples were gathered by taking 1×2 meter frames in eight geographical directions. Plant species diversity in the growing season was examined using the Simpson and Shannon-Weiner indicators, and the richness and uniformity of the species were measured using menhinick and margalef richness indicators.

The results of this study, taken from biodiversity indicators, suggested that the most species diversity and richness pertained to the east, north and northeast, with the swamp directions noting no statistical differences; but a statistical difference(p<0.05)was observedin menhinick and margalef richness indicators. The soil texture, including sandy clay loam (62.5%), sandy loam (25%) and loam (12.5%).The clay(p<0.01), organic matter(p<0.01)  and soil acidity (p<0.05) characteristics have significant differences. The study also found that in terms of the number of the species, most species pertained to the beech trees, while in herbal and fauna species, the Gramineae family and soil ant family were seen most in the northern direction.

As the findings suggested, the cover tree, fauna, and the edaphic cover were affected by the Khezr Nabi swamp, which formed a sub-habitat with a special micro-climate.

With sufficient knowledge regarding the presence of fungi and the significance of biodiversity, the forest's management objectives can achieve their sustainability goals. Therefore, in order to properly manage the forest, it is necessary to establish indicators that provide adequate information on biodiversity and monitor changes resulting from management activities. This study aims to identify various macroscopic fungi and investigate their biodiversity in their habitat, i.e., deadwood.

Fifteen specimens of deadwood fungi were randomly selected in Darabkola forest. All macroscopic fungi were numbered and collected, then transferred to the mycology laboratory for identification. The biodiversity of the fungi was calculated using Shannon-Wiener diversity index, Simpson diversity index, richness index, and uniformity index with PAST software

The obtained results revealed that there were 37 species of macroscopic fungi belonging to 27 genera and 16 families. Trametes versicolor, Daldinia concentrica, Trichaptum biforme, and Fomes fomentarius were the most abundant, while Hericium coralloides, Ganoderma resinaceum, Ganoderma adspersum, and Trametes trogii were the least abundant species. Additionally, the families Polyporaceae, Xylariaceae, Ganodermataceae, Pleurotaceae, and Schizophyllaceae were the most abundant, whereas Pezizaceae and Hericiaceae were the least abundant. Most fungi were present in the final stages of decomposition. The results indicated that the mean diversity index for Shannon-Wiener species diversity was 3.24, Simpson species diversity index was 0.95, Margalef's richness index was 6.11, Menhinick's index was 1.95, and uniformity was 0.69. The analysis of the Shannon-Wiener diversity index showed that Trichaptum biforme and Trametes versicolor had a higher diversity value with a score of 1.46.

The results of this study indicate that for the management of fallen deadwood habitats with the aim of increasing the biodiversity of fungi, it is recommended to preserve these fallen deadwood areas within the forest. This preservation would contribute to the revitalization and completion of the ecosystem cycle.

Maintaining the structure and biodiversity of ecosystems is considered to be one of the most important goals of modern forestry. For this purpose, the tools are needed for forest management, to have the lowest cost and time to check the current status, as well as the changes caused by development of forest management activities. Indicators of nearest neighbor have advantages that their application gives priority to direct measurements of biological diversity. Because in addition to the study of species diversity, it investigates the locations of trees. Also nearest neighbor indices provide valuable information about ecological interactions of trees in forests. Therefore, this study was aimed to introduce and apply important indices based on nearest neighbor analysis to study ecological relationships of trees in beech-hornbeam stands in Nave Asalem- Gilan forests.
In order to do this research, seven 1-ha plots with homogeneous environmental conditions were inventoried in a Fageto-Carpinetum association in Nave Asalem- Gilan. In each plot, distance and azimuth of all trees on the plot with more than 7.5 cm diameter at breast height from the center of sampling area and species, and diameter at breast height were recorded. The spatial pattern and species diversity were then investigated using the uniform angle, mean directional, species mingling and segregation indices. The amounts of each of the mentioned indices were calculated for each sample individually. The average of the values obtained for each sample were calculated for the Fageto-Carpinetum.
The results showed in seven 1-ha plots of Fageto-Carpinetum, Fagus orientalis, Carpinus betulus, Acer cappadocicum, Acer velutinum and Alnus subcordata had the maximum density per hectare. The values of uniform angle and mean directional indices were 0.53 and 2.02, respectively, showing a spatial distribution between random and clustered. In terms of species diversity, the Fageto-Carpinetum association with an average of 0.47 and 0.25 for species mingling and segregation indices, respectively, presenting a medium level of species mixing. The amount of species mingling indices indicated low level of mixing of beech species and high level of mixing of other species. The segregation index showed a pair of trees or nearest neighbor reference trees belonged to different species.
In general, the results of this study indicated the efficiency of nearest neighbor indices to study the structure of Fageto-Carpinetum associations and the results can be used for planning to revitalize the structure and status of biodiversity in degraded Fageto-Carpinetum associations.