جستجوی مقالات مرتبط با کلیدواژه « Mazandaran » در نشریات گروه « جنگلداری »

The effect of physiographic factors on biodiversity and trees biomass is done in series 4 of Golband (watershed No:45) in Nowshahr by sampling and application of six north-south sample lines (1000-1600 m) and conducting 48 square sample pieces of 4 r on sample lines with 200 m intervals. In each one of sample plots, number and percentage of tree and shrub cover, physiographic factors of slope (three class), direction (three class) and altitude (eight class) were collected. Grass cover was investigated using five 25-square-meter sample plots (four sub-plot plots in the corners and one in the center) inside each plot. Then Simpson diversity indices, Margalef richness and Sheldon uniformity were used to study diversity and biomass estimation is done using allometric equations. The results showed that the differences between all biodiversity indices and biomass were significant in different physiographic conditions. By increasing slope, the average of biodiversity indices increased. The highest value of Simpson diversity indices was observed in the north direction (0.78). By increasing altitude (200-1600 m), the average indicators decreased. Also, the highest amount of biomass was related to the slope class of 30-60%, east direction (220 tons per hectare) and altitude class 1400 meters (268 tons per hectare). Based on the general results of this study, due to the higher humidity, the north direction has the greatest effect on plant diversity and the highest surface vegetation can be seen in the altitude range of beech presence and in the middle slope.Keywords: Elevation above sea level, Simpson, Margalef, Mazandaran, allometric equations.

Collembola are most abundant decomposer soil living arthropoda in forest ecosystems. They are among the best indicators within the soil mesofauna to determine the health and sustainability of forest ecosystems. The Hyrcanian forests, most of which are located in Iran, are among the most valuable forests on Earth, which, despite their climatic diversity, unique plant and animal species, are inscribed on the UNESCO World Heritage List. Despite the very important role of Collembola in ecological processes of forests, including the decomposition of organic matter and nutrient cycles but the role of these small arthropods in the Iranian Hyrcanian forests has not been much studied. The study was conducted to investigate and identify the fauna of Collembola in the forest soils to introduce their importance for forest ecologists in Iran.

The research was carried out at a station in the Samsakandeh mixed forest of Sari as part of the temperate deciduous forests of the Hyrcanian region. For studying collembolan fauna in soil and leaf litter of the forest, in 2016-2017, soil and leaf litter samples were collected from different locations by soil core (depth 10 cm) and pitfall traps. The springtails were extracted by Berlese funnel and were identified after preparing microscopic slides with available keys.

In sum, 25 species belonging to 21 genera from 9 families were collected and identified as species level. The specimens of Lepidocyrtus, Sminthurinus, Neanura, Sphyrotheca and Dicyrtoma identified as genus level.

Six species including Entomobrya obscurella (Brown, 1926), Heteromurus gigans (Mari Mutt & Stomp, 1980), Heteromurus variabilis (Martynova, 1974), Orchesella spectabilis (Stach, 1960), Pseudachorutes corticicolus (Schaffer, 1897) and Protaphorura ombrophila (Stach, 1960) were reported for the first time for Iran fauna. Two species, Neelus murinus (Folsom, 1986) and Pseudachorutes subcrassus Tullberg, 1871, are re-reported to the Samsakandeh mixed forest, 38 years after the first Cox report (1982).

Forest fire is recognized as a significant threat to the safety of human life, infrastructure and the environment. One of the most important steps in reducing the risk of forest fires is determination of the areas with the high probability of forest fire occurrence. Choosing the appropriate methods for modelling of the forest fires is very important. Due to the importance of the issue in this study, first using library studies and expert advices, the most important variables affecting the occurrence of fire in Babolrood basin-Mazandaran province were determined and then the results of three models of dong, artificial neural network and K nearest neighbors were compared in determining the probability of fire occurrence. The results showed that the most important variables affecting the fire occurrence are temperature, rainfall and distance from residential areas. The results of artificial neural network are more reliable than the other two models. According to the results, about 35% of the study area has very high and high potential for forest fire.

Non-implementing of forestry plans across Hyrcanian region in Iran has been one of the one of the important major decisions of forest management sector in recent years. This study was carried out to investigate implementing or non-implementing of forestry plan in the Babol Roud, Mazandaran province. Furthermore, Cochran's relationship was used to determine the number of respondents, whereas Delphi technique was used to adjust questionnaires, which were distributed among 32 people (16 local communities and 16 forestry plan’s staff) for subsequent SWOT analysis. The SWOT analysis was used to analyze the opinions of stakeholders, the process of receiving feedback was purposefully performed. Then, their comments were tested and analyzed. The results of the SWOT evaluation matrix showed that the statistical community demands an aggressive strategy to implement the forestry plan and a defensive strategy in case of its non-implementation. The most important strength of implementing the forestry plan were identified as survival guarantee of the tree stands, whereas non-implementation was assessed to be associated with non-intensive harvest beyond forest capacity. In contrast, the most significant weaknesses were identified as soil and existing hydrological system degradation as well as intense forest invasion (wood smuggling, land use change), respectively. Overall, results generally indicated that in both methods the most majority of the statistical community in the study opposed stopping forestry plans which resulted in ongoing and upcoming economic and environmental problems. Likewise, the major revision of forestry plans’ current condition along with their codification and using alternative management strategies were suggested in order to comprehensively meet the beneficiary needs.

The study was aimed to assess of the Danish and Swiss methods of thinning in 20 years old plantations of Chestnut leaved Oak (Quercus castaneifolia C. A. Mey.) in terms of quantitative and qualitative characteristics of trees, natural regeneration, plant and soil invertebrate diversity. The study area is located in Neka forests, east of Mazandaran province in the Caspian region. This research was conducted under compeletly randomized block design (CRBD) with three replication and three treatments. Also in each sample plot, 3 microsample plot, each 49 m2 were randomly systematic selected. The quantitative and qualitative parameters of trees were measured in each sample plots by full callipering. In each microsample plot natural regeneration was counted. Also, whole plants were recognized in each microsample plot and their coverage percent were estimated. Moreover, in each microsample plot invertebrates were sampled, using core soil samples (81 cm2 cross section) to the depth of 10 cm. The results of this research has been shown that the tree diameter at breast height, the abundance of quality tree and the number of natural regeneration in the thinned areas was more than the control area. Of course, the positive impact of the Danish method was greater than that of the Swiss method. Also this research has shown the control area created a more favorable situation due to the plant species diversity than the thinning areas. However the positive impact of the Danish method was greater than that of the Swiss method. On the other hand the Swiss thinning area created a more favorable situation due to the soil invertebrates' diversity than the Danish method. Overall this research emphasizes that the thinning operation with moderate intensity in Danish method is better than the Swiss method for forestations.

In this research, the fauna of parasitoid wasps (Hymenoptera) was studied in 14 forest regions in Mazandaran province (northern Iran) during 2010-2016. The sampled areas were: Fin Forest Park in Chalus, Dohezar and Sehezar Forests in Tonekabon, Mirza-Kochak-Khan Forest Park in Amol, Dalkhani Forest in Ramsar, Lajim Forest in Sari, Shahid Zare Forest Park in Sari, Khoshroudpey Forest in Galogah, Palang-Darreh in Shirgah, Urim Forest in Savadkooh, Telar Forest Park in Qaemshahr, Asal-Mahalleh in Ramsar, Javarem Forest Park in Zirab, Pahneh-Kola Village in Sari, and Seyed Abusaleh Village in Qaemshahr. In total, 85 parasitoid species within 67 genera and eight families, Braconidae (23 species, 15 genera), Chalcididae (two species, two genera), Chrysididae (four species, three genera), Encyrtidae (six species, six genera), Eulophidae (two species, two genera), Ichneumonidae (41 species, 33 genera), Mymaridae (single species) and Pteromalidae (six species, five genera) were collected and identified. Seven species, Aleiodes pallidicornis (Herrich-Schäffer, 1838), Apanteles parasitellae (Bouché 1834) (Braconidae), Cryptus moschator (Fabricius, 1787), Gelis karakurti (Rossikov, 1904) (Ichneumonidae), Mokrzeckia menzeli Subba Rao, 1981, Solenura ania (Walker, 1846), Solenura nigra (Walker, 1872) (Pteromalidae) are new records for the fauna of Iran.

Forest stand structural development occurs over time and is commonly studied based on initial, optimal and decay developmental stages. The purpose of this study was to evaluate the capability of non-spatial indices for differentiating among developmental stages of beech-hornbeam stand in Haji-Kola- Tirankoli forest of Sari in Mazandaran province. Three sample plots were selected in each developmental stage (totally 9 sample plots). The characteristics of trees with a diameter > 7.5 cm were measured in each plot, including species, diameter at breast height and total height. The results of analysis of variance revealed significant differences amongst the developmental stages for basal area, volume, density, density of large trees, standard deviation of diameter and height, diameter and height of overstory, leaf area index, relative light intensity, species richness of over story, basal area of large to mature trees, modified Frelich-Lorimer index. Nevertheless, other attributes including DBH, density of trees > 100 cm, deadwood diameter, and number of dead wood, Gini coefficient, Doliucort index, Structural Complexity index, and Cox index did not differentiate among the developmental stages. The structure triangle and the Frelich-Lorimer index were shown to properly determine the stage of stand development.

Alnussubcordata is one of the native and the fast growing trees in Hyrcanian forests which its plantation helps to conserve and protect the forest. In this study, for surveying the quantitative and qualitative characteristics of Alnussubcordata with changing the elevation above sea level, four sites were selected in Pahne Kolla forests, Sari, Iran. The systematic random method was used for tree sampling and finally the quantitative and qualitative characteristics of 338 trees were measured. Such characteristics as diameter at breast height, slenderness index (h/d), basal area, trees volume (m3/ha), stem quality, canopy percentage and regeneration in the study area were recorded. The results indicated that average DBH, volume and basal area of trees at elevation 430 (m a.s.l) and average height of trees and slenderness index (h/d) at elevation 600 (m a.s.l) were the highest among other elevations. The comparison of average DBH and height of trees in the sites demonstrated that sites have significant difference whit each other. Therefore, according to the results, altitude is an effective factor in the quantitative and qualitative characteristics of Alnus subcordata.

This study was carried out to evaluate distribution and abundance of Syrphid flies population in Sari-Kiasar forest Region. Data collection was done in five stations including Alikola (1640 metres above sea level, m.a.s.l.), Haftkhal (855 m.a.s.l.), Alamdardeh (396 m.a.s.l.), Pahnekola (175 m.a.s.l.) and one station in Dasht-e-naz region (20 m.a.s.l.). The samples of syrphid flies were collected by set of Malaise trap, window trap, yellow pan trap and white pan trap in each station. The data collection was done every two weeks during spring and summer. Seven species were identified in the study site. The most abundant species was Melanostomamellinum (L.) followed by Sphaerophoriascripta (L.) which was 43.54% and 33.39%, respectively. Results showed that altitudinal gradient affected the species abundance. For example M. mellinum was the most abundant in habitat with altitude 1640m and 855m, S. scripta was the most abundant species in habitat with altitude of 855m, Sphaerophoriarueppellii (Wiedemann) was the most abundant in habitat with altitude 20m, Eupeodescorollae (Fabricius) was the most abundant species in habitat with altitude of 855m and Merodonavidus (Rossi) was the most abundant species in habitat with altitude of 1640m. Also results showed that peak of maximum abundance in studied sites occurred in May.

In the high forests which managing with close-to-nature silvicultural method, the future of forests depends on the stable establishment of saplings planted in the gaps; hence, the current study was done by selection sampling method with the aim of qualitative and quantitative investigation of natural regeneration based on the gap area in two different beech (Fagus orientalis Lipsky) forests: pure beech forest and beech with other species, in three areas of 1.5- 3, 3-5 and 5-10 R, totally amounting to 60 gaps for two different beech types (30 gaps per forest type) in Sourdar Anarestan forest management plan, Mazandaran province, North of Iran. Number of saplings in different gaps was significantly different at 0.01for both forest types. The number of saplings in small and medium area gaps was greater, whereas that of the larger ones was lower. Concerning the mean area of gap with beech forest types, there was significant difference at 0.01.The area of gaps created in the mixed beech stand was more than that in the pure beech forest and according to Duncan's test; maximum gap area was east aspect and then north eastern and west aspects. Also, results showed that as the gap area increased, the number of saplings and their quality decreased for each type. Therefore, maximum the best gap area of 3 to 5 R can be suggested to ensure the future of the planted saplings.

Recreation planning is not only as a tools for enhancing of socio-economy levels of the people but because of its conservational functions can provide a dynamic conditions for conservation of natural resources. With respect to this point that the first step in recreation planning like planning for any activity is the evaluation of land potential for that activity. The aim of this study was to evaluate the potential of ecotourism of Babolrood watershed in Mazandaran province by using of analytical hierarchy process (AHP) and geographical information system (GIS). For this regard، firstly the most important effective criteria and sub-criteria in evaluating of the potential for recreation in the study area were determined by using prior researches، conditions of study area and expert knowledge. After that، some questionnaires were provided and between different experts were distributed. The weight of criteria in each questionnaire was calculated and then the averaged weights were estimated. With applying of AHP method and Expert Choice software the final weight for each criteria and sub-criteria was determined. After that، the needed maps for this evaluation were provided in GIS environment. At the end، with help of Weighted Linear Combination (WLC) technique the final potential map for the ecotourism development of region was provided. The results showed that 19/33 percent of study area has a high potential and 52/81 percent has a good potential for ecotourism. In addition، 23/19 percent has an average potential، 1/84 percent has a weak potential and 2/82 percent is not suitable for recreation land use.

Ectomycorrhizal fungi have an effect on forests stability and preserving trees against phytopathogens. The aim of this research was to collect، identify and compare ectomycorrhizalfungi associated with beech forests in two selected sites include healthy and degraded ecosystems of Mazandaran and Gilan provinces. Sampling procedures was conducted in three one hectare sample plots of different stages of vegetation development (early، optimal and degraded) in Caspian beech forests. Due to the diversity of the fungi and their specific characters، samples were transferred to laboratory appropriately. Overall، 29 genus and 30 species were identified of which 7 species accounted as ectomycorrhizae. The identified fungi are as follows: Boletus edulis*، Cantharellus cibarius*، Helvella crispa*، Laccaria laccata*، Russula rosea*، Scleroderma citrinum*، Scleroderma verrucosum*

This paper lists recent findings of macro fungi of beech stand in Mazandaran province in north of Iran. The list contains data on the occurrence of 100 species of macro fungi، 41 of which are new to Mazandaran province، 24 new Iranian fungusbeech associations، and 11 have not p and previously been recorded from Iran. Russulaces and Polyporaceae are wood inhabiting and 43 grow on soil. Edible and poisonous species are 42 and 10 respectively. Study on macro fungi distribution pattern showed that northern slopes consisting 32% of species diversity had the highest diversity and southern slopes having 13% had the least diversity. Result of this study increases the information about diversity and distribution of macro fungi in beech forests of northern Iran.

August thorn, Ennomos quercinaria (Lep.: Geometridae) has been recognized as an important defoliator of forest trees throughout the world. Several outbreaks have been observed in Mazandaran province during the last decade. Study on the biology of this pest in laboratory conditions revealed that it has six larval instars. Average larval longevity estimated as 46.16±3.74 days. Larvae are green to brown in color and pupate among folded leaves. The pupal period of males and females were 13.85±0.25 days and 12.44±0.16 days, respectively. Males had longer life span (7±0.44 days) compared with the females (5.76±0.25 days). Life cycle averaged 64.52±5.86 days. The flight period was recorded from May through late June. Agust thorn is a univoltine insect and overwinters as an egg among foliage of the host trees. In this study, six spiders, two beetles, three wasps and a fly were identified as natural enemies.

Study on adaptability and productivity of conifer species in different areas of northern forests have been performed by many natural resources researchers and practitioners for the last two decades. In this regard, Picea abies (L) Karsten as a fast growing species have been planted in altitude of over 1000 meters in some of Mazandaran province. Toska Cheshmeh is one of these areas that located in altitude about 1400 meters. The first die back symptoms were detected in 2005 and the present study was initiated during 2008. For evaluation of the disease losses, the trees were measured by full callipering. The result showed severe infestation in the area as 21.93 percent. The infected tree parts were cultured on PDA medium. Pestalotiopsis funerea was isolated and to determine the pathogenicity of the isolated fungus,2-year-old seedlings were inoculated. Management practices should be based on the removal of the dead trees, provide good growing conditions for healthy Norway spruce stands and to keep all the native broadleaf outgrowths in the area.

Fagus orientalis Lipsky accounted for 24 percent of stem number and 30 percent of total volume in northern forests of Iran. The aim of this research is finding the regularity in frequencies of diameter increment, determining the relationship between tree age and fluctuations in radial increment of beech trees. Several hypotheses including stationary, secular trend, cyclic and random variations in data series of the beech tree increment, were examined to find out the main effective factor on variations. Four sound beech trees with mean diameter of 10 cm and maximum age of 350 years were selected. One disk was prepared at breast height from each sample tree. Then rings width was measured and data processed with the Time Series analysis. Results showed that there is more than one trend (model) in radial increment diagram of the sample beech trees. Positive correlation was calculated between tree age and radial increment up to the age of 120 years, where as this correlation turns to negative after this age. The mean and distribution of radial increment differ in periods of tree life. Radial increment of the beech trees is fitted with cubic model along the two age periods. Volume trend of annual increment always is positive and is not inversed. Autocorrelation diagrams show one year periodicity for the fluctuations of radial increments. The other periodicities are irregular and the alterations are not statistically significant.