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Humus forms are good indicators of environmental conditions and thus important in forest ecological processes. Altitudinal gradients are considered as natural laboratory for evaluating soil ecological processes and humus form distribution. The objective of this study was to evaluate the macromorphology of humus forms along an altitudinal gradient (0-2000 m asl) covered with plain forest, mixed and pure forests and forest-grassland ecotone, in Alborz Mountains in northern Iran. In total, 225 humus profiles were evaluated. Forest stand variables including tree density, basal area, crown density, and height, forest floor and soil physico-chemical properties along with biological features were measured. We found that altitudinal gradient
In order to understand the distribution models of corticolous mosses (epiphytes growing on trees barks) and variations in the their abundance related to altitudinal gradients, southern forests of nowshahr were selected along a longitudinal transect from 0-2500 m.a.s.l. These forests consisted of three dominant forest types and within each type, 100 trees were selected as mosses substrata. By using parametercdiversity indices and a variety of abundance distribution models, the extent of species abundance variation and diversity of the species have been studied along the altitudinal gradient. Results showed that, in the middle layers of Hyrcanian forests, which has more precipitation, Fagus orientalis-Carpinus betulus forest types were signif
Soil organic matter (OM) stratification and macro and micro fauna are both good indicators for the evaluation of soil ecological functioning, which is interrelated with nutrient cycles. To the best of the authors’ knowledge, responses of the degree of OM stratification with soil depth expressed as a ratio, and belowground biota to forest degradation and land cover changes have received little attention, particularly in northern Iran. In this study, five land covers were selected: virgin natural forest dominated by Carpinus betulus and Parrotia persica (natural forest), mono-species oak stand (plantation), land including Citrus sinensis and Citrus tangerina trees (garden), land dominated by Brachypodium pinnatum and Carex sylvatica (rangel
Over the past four decades, management plan based on the Boolean Ecological Capability model has caused major problems in the management of the Hyrcanian Forests. The aim of this study is to evaluate ecological capability of five proposed sites including Golestan National Park, Afra Takhteh Yew Forest, Kojoor Forest, Cypress Woodland of Hassanabad-e Chalous, Lomer forest along the Hyrcanian region from east to west, using both Boolean and fuzzy logic and to compare these two models. A total of 10 important factors including slope, aspect, elevation, soil types, soil erosion, soil transformation, canopy cover, the value of species, distance to streams and climate were investigated in this study. The results show that elevation, slope and asp
Aims: Natural regeneration will guarantee forest future and sustainability. Ecological factors (soil and physiology) may influence regeneration process and provide a variety of sites favorable for seed generation and establishment of different plant species. The present study aimed to evaluate effect of environmental factors on Fagus orientalis regeneration in Kojoor Forest, one of Hyrcanian inscribed sites on UNESCO's Natural World Heritage List.Materials & Methods: After determination of high valued and undisturbed stands of F. orientalis Lipeskey on the vegetation map, sampling was carried out with 2.5% of statistical intensity (the surface area of each plot was 0.1 ha and statistical network dimension was 200? 200m 2). The effects of ab
The objective of the present study was to evaluate how altitudinal gradients shape the composition of soil bacterial and fungal communities, humus forms and soil properties across six altitude levels in Hyrcanian forests. Soil microbiomes were characterized by sequencing amplicons of selected molecular markers. Soil chemistry and plant mycorrhizal type were the two dominant factors explaining variations in bacterial and fungal diversity, respectively. The lowest altitude level had more favorable conditions for the formation of mull humus and exhibited higher N and Ca contents. These conditions were also associated with a higher proportion of Betaproteobacteria, Acidimicrobia, Acidobacteria and Nitrospirae. Low soil and forest floor
Persian honey locust(Gleditsia caspica Desf.) is an endemic tree in the northern forests of Iran and southeastern Azerbaijan, which has low seed germination because of water impermeability of seed. In this research, effects of hot water at 70 ?C and 100 ?C (5, 10, 15 and 20 minutes), dry heat at 60 ?C, 80 ?C and 100?C (15, 30 and 60 minutes) and sulphuric acid treatment at two concentrations of 70% and 98% (at immersions of 5, 20, 40 and 60 minutes) were studied on the characteristics of seed germination of this species. Experiment was carried out based on completely randomized design in three replicates. No germination was observed in the seeds treated with hot water (100 ?C), dry heat and control, while the seeds?treated with?semi-hot wat
Hyrcanian forests are one of the most valuable forests in the world, dating from about 25 to 50 million years old. Climate variation, unique plant and animal species accompany with habitat diversity have made these forests one of the most unique ecosystems on Earth and worthy of being listed on the UNESCOchr ('39') s World Heritage List. Therefore, the main purpose of this study is to use both Delphi and Ideal Point methods to identify effective criteria and prioritize proposed habitats for inscription on the UNESCOchr ('39') s World Heritage List. For this purpose, five habitats from east to west of the Hyrcanian forests including Golestan National Park, Afra Takhteh Yew Forest (Golestan Province), Zarbin Hassanabad Chalus Forest, Kojoor F
Wild almond (Amygdalus scoparia) is a dominant shrub species in mountain forests of the Irano-Turanian region. Dieback and decline symptoms of wild almond shrubs were first observed in Harat protected forest (Yazd, Iran) in the autumn of 2014. Since then, the incidence and severity of the disease have increased. To study the aetiology and estimate losses from the disease, field studies were conducted in 2016 and 2017. For this purpose, eight stands were selected, in which 24%-99% of the trees were wild almond in their species composition. In total, 50 cankers and 50 infected twigs of wild almond shrubs were collected. Fungal isolates were identified based on morphological and cultural characteristics, as well as sequence data of ITS1 + 5.8
Land cover changes are recognized to affect the organic matter fractions and other soil properties with a consequence for microbial and enzyme activities involved in nutrient cycling. The topsoil (0–10 cm depth) C, N, and P microbial [i.e., basal respiration (BR), substrate inducted respiration (SIR), microbial biomass-C, -N, and -P (MBC, MBN and MBP)] ratios, enzyme (i.e., urease, invertase, acid phosphatase and arylsulfatase) activities, as well as the fractions of particulate organic matter (POC and PON) and dissolved organic matter (DOC and DON) were measured in a virgin natural forest dominated by Carpinus betulus and Parrotia persica (natural forest), mono-species Quercus castaneifolia stand (plantation), land including Citrus sin
Wild almond (Amygdalus scoparia) is a dominant shrub species in mountain forests of the Irano‐Turanian region. Dieback and decline symptoms of wild almond shrubs were first observed in Harat protected forest (Yazd, Iran) in the autumn of 2014. Since then, the incidence and severity of the disease have increased. To study the aetiology and estimate losses from the disease, field studies were conducted in 2016 and 2017. For this purpose, eight stands were selected, in which 24%–99% of the trees were wild almond in their species composition. In total, 50 cankers and 50 infected twigs of wild almond shrubs were collected. Fungal isolates were identified based on morphological and cultural characteristics, as well as sequence data of ITS1?+
Changing land use is one of the most important human interactions in natural ecosystems that affect ecosystem processes, especially soils. In the present study, the effects of forest (natural forest and oak plantation) and nonforest (garden, rangeland and agriculture) land sues on the variability of soil quality indices and carbon dioxide emission dynamics have been considered. In each of the proposed land uses, 16 soil samples (0-10 cm depth) were collected and transferred to the laboratory. According to the results, the highest amounts of soil organic matter were allocated to forest habitats and the highest bulk density was belonged to rangeland and agricultural areas. However, the variation of soil particle density among the various land
Humus systems are the largest part of organic carbon stock and play an important role in forest ecological processes. Elevation by influencing on the biological and non-biological properties of the forest ecosystem is an important factor for assessing the changes in the trees and distribution of humus systems. In this study, the morphological and chemical characteristics of humus forms in three altitudinal levels (500, 1000, and 1500 masl) and three transects which were 1000 meters apart were investigated. In each transect, 3 plots with 400 m 2 area were sampled, and in each plot 5 profiles of humus (in total of 135 profiles) were examined in the central Hyrcanian forest. Humus and samples were taken and transferred to the laboratory for ch
Background and Objective: Dead trees are an important factor for structure and activity controlling in forest temperature. For the sake of survey role of dead trees in the regeneration of trees species, regeneration density of environs dead trees in Lalis forests, Nowshahr was studied. Method: For a sampling of snags by circle plots (500 m2 area) and snag in the center, and also in the logs used of along plots into width four-meter and dead trees length. Decay classes of dead trees, topographic position and canopy gap area due to dead tree inscribed according to average diameter of canopy opening. In this study gaps were divided into five groups, including close canopy, very small (2), small (50-150 m2), medium-size gap (150-250 m2) and lar
In recent years, the negative impacts of climate change on forest trees has intensified ([40]), thus exposing forests to increasingly stressful conditions, such as heat and drought ([23]). The most alarming outcome of climate change is the increased number of trees dying off because of drought. During recent years, many trees have been lost in the forests of the Zagros Mountains, located in the western provinces of Iran (Ilam, Lorestan, and Kermanshah), as a result of decreased precipitation and increased temperature in the region. The Zagros forests cover an area of 5 million hectares (about 40% of all Iranian forests), and represent the widest forest region of the country ([1]). Persian oak (Quercus brantii Lindl.) is the dominant tree sp