Dead wood characteristics influencing macrofungi species abundance and diversity in Caspian natural beech (Fagus orientalis Lipsky) forests

Aim of study: This study aimed to examine the dead wood inhabiting macrofungi communities occurring on dead beech and hornbeam trees in Caspian forests.Area of study: The Kheiroud forest in the north of Iran.Material and Methods: Data from 205 sampling dead tree were analyzed by means of Generalized Linear Models (GLM) to test the effects of decay stage, DBH, Length or Height on macrofungi diversity.  Additionally, tree species, dead wood size, log position, decay stage  were used as predictor factors for the number of sporocarps species (NSS) as a fungal species richness and diversity in each dead log using analysis of varianceMain results: The number of sporocarps species (NSS) varied in different dead wood size and decay classes. The different stages of decay and the different size classes of dead wood had significantly different species richness of macrofungi. Deadwood in the high-decayed stages contained the highest diversity of fungi. Most of fungi identified on both logs and snags belonged to Basidiomycetes and Ascomycetes. The highest value for richness and evenness indices calculated in large diameter dead wood in decay class III. The results indicated the size and decay class of dead wood describe the greatest variance of the model that means the highest number of sporocarps species inhabited on the large dead wood in advanced stage of decaying.Research highlights: Macrofungi diversity varied significantly across pieces of dead wood with downed logs, larger pieces, and wood in later stages of decay having the highest macrofungi diversity. Keywords: Caspian forest; coarse woody debris; down woody debris; Iran

Dead wood characteristics influencing macrofungi species abundance and diversity in Caspian natural beech (Fagus orientalis Lipsky) forests

Aim of study: This study aimed to examine the dead wood inhabiting macrofungi communities occurring on dead beech and hornbeam trees in Caspian forests. Area of study: The Kheiroud forest in the north of Iran. Material and Methods: Data from 205 sampling dead tree were analyzed by means of Generalized Linear Models (GLM) to test the effects of decay stage, DBH, Length or Height on macrofungi diversity. Additionally, tree species, dead wood size, log position, decay stage were used as predictor factors for the number of sporocarps species (NSS) as a fungal species richness and diversity in each dead log using analysis of variance Main results: The number of sporocarps species (NSS) varied in different dead wood size and decay classes. The different stages of decay and the different size classes of dead wood had significantly different species richness of macrofungi. Deadwood in the high-decayed stages contained the highest diversity of fungi. Most of fungi identified on both logs and snags belonged to Basidiomycetes and Ascomycetes. The highest value for richness and evenness indices calculated in large diameter dead wood in decay class III. The results indicated the size and decay class of dead wood describe the greatest variance of the model that means the highest number of sporocarps species inhabited on the large dead wood in advanced stage of decaying. Research highlights: Macrofungi diversity varied significantly across pieces of dead wood with downed logs, larger pieces, and wood in later stages of decay having the highest macrofungi diversity

Snag dynamic in a mixed Beech forest

Dead tree, which consisting of both standing dead tree and material that has fallen to the ground, is a dynamic resource in forest ecosystem. In order to investigate on falling and dynamic model of snags (standing dead trees) in a mixed beech forest, this research was carried out in compartments No. 112 and 214 in Kheyroud forest, north of Iran. 215 dead trees were measured and then 64 dead trees were randomly selected for analyzing. According to the results, hornbeam snags in a natural forest showed higher breaking height in comparison to beech snags. Investigation on snag dynamic showed that snag falling is higher on steep slopes, however, there is no significant difference between slope gradient and snag falling. Increasing in decay class, caused increasing in sang falling. Also effect of dead wood size, decay stage (quality of dead wood), slop and species were analyzed. Results showed that slop and species have no significant effect on the sang falling, while the effect of deadwood size and decay stage on sang falling is significant

Survey of wildfire simulation using FARSITE model (case study: Yeylagh Gasre Dagh, Meshgin Shahr Municipality)

Wildfire as a natural hazard is a major problem for forest and rangeland ecosystems of the world. In the Semi-Steppe Rangelands of Ardabil Province, severe wildfires can account for the adverse impacts on the ecosystems. These fires are the result of the combination of weather conditions, dry fuels, and topography effects. The Ghasre Dagh Yeylagh fire is an example of a severe wildfire that occurred with extreme environmental conditions, which was ignited on August 16, 2015, in the Meshgin Shahr municipality. In this study, weather conditions, fuels, and topography factors that strongly affected the fire will be accurately analyzed. The fire spread and behavior data including the observed final fire perimeter and fire arrival to the northern border of the fire perimeter (firefighting point) collected during the event will be also compared with the results of fire simulation obtained by FARSITE model. The average simulation accuracy for the burned area, as measured by the Sorensen coefficient and Cohen Kappa Coefficient was 0.84. Simulation overestimation of flanking fire spread areas was expected and observed, since suppression activities that contained the fire spread were not considered in the model, due to the lake of this information. The main goal of this paper is to thoroughly study the behavior of a recent fire, to learn from it, and lessen the potential mistakes or hazardous fire-fighting operations in similar environmental conditions. Furthermore, a crucial point is to teach the fire crews not to be threatened by severe or abrupt fire behavior under extreme environmental conditions

Investigation on dead trees effects on natural regeneration of oriental beech and hornbeam in a mixed beech forest.

The process of natural regeneration including establishment of seedling under dead and mother trees ensure sustainable productivity in the forests. Qualifying the impact of dead trees on the density of establishment seedling in closed and open canopy in a mixed beech forest was studied. According to the field inspection, compartments 112 and 214 in Kheiroudkenar forests were chosen for sampling. Dead trees were considered as the center of sampling plot with different radius. Also in a 20-30 meter distance from dead trees, sound mother trees of same species were chosen. At the center of each plot, seedlings were counted in a circular sample plots with diffident radius. The results show that number of beech seedlings is higher than that of hornbeam and there is significant difference between establishments of seedling between dead and sound trees in an open canopy. Seedling density in open stand is higher than that under mother trees. Frequency of seedling around the dead trees was maximum. The higher decay class, the higher is the establishment of seedling. Also the number of seedlings is higher in small sample plots (100m2) which are closer to the dead trees. The results showed that the maintenance of dead trees is important and effective in establishment of natural regeneration in mixed beech forest

Decay dynamics of oriental beech (Fagus orientalis Lipsky) and hornbeam (Carpinus betulus L.) deadwood in mixed beech stands

Due to their significance for carbon sequestration and ecosystem management, information on decay dynamic of deadwood and its total decay time are of great importance to ecologists and forest managers. This study was conducted in Kheirud forest of Nowshahr to study the decay process of beech and hornbeam deadwood. Therefore, 72 beech and hornbeam dead trees were randomly selected. For each sample tree, information on species, diameter, decay classes and slope gradient were recorded. The cubic cut samples with 5 cm length, width and height in two perpendicular aspects were taken from each decaying stump. 30 and 16 years of decaying time were shown to be needed for 95% dry mass of dead beech and hornbeam logs, respectively. In addition, the required periods for passing through all stages of decay for beech and hornbeam dead trees were 27 and 21 years, respectively. A strong relation (R2=0.8) between density and decay stage of dead trees was indicated. Therefore, the density of dead wood was concluded to significantly decline with increased decay stage in both species

Population Structure and Regeneration Status of Woody Plants in Relation to the Human Interventions, Arasbaran Biosphere Reserve, Iran

Proper understanding of the diversity and natural structure of woody species and the impacts of human interventions are prerequisites for maintaining the remaining forests as well as restoration of deforested and degraded areas. This research was conducted to document the impact of human interventions on the population structure and the species diversity in the Arasbaran biosphere reserve in Iran due to the limited research and insufficient knowledge. The study area was divided into three adjacent sampling areas of low, medium, and high destruction intensity. Thirty fixed area 0.1-hectare plots were sampled to evaluate the composition, diversity, and species richness. Oak (Quercus macranthera), hawthorn (Crataegus meyeri), and maple (Acer campestre) were the top three dominant tree species at all the sites. The relative dominance of the top three species comprised 87.8% of the basal area of all species. The relative abundance of the top three species accounted for 68.1% of the species. The mean density and basal areas per tree across all three destruction statuses were 145 ± 59 stems ha−1 and 0.01 ± 0.005 m2 ha−1, respectively. The mean height of trees was different at low and high disturbance sites (4.6 ± 0.96 m and 3.37 ± 1.74 m, respectively). Due to the impact of human interventions on forest structure, composition, and diversity, conservation programs are recommended for implementation and in collaboration with local communities to employ management aimed at providing services for local people while restoring these forests. Basic ecological studies such as this study are the foundation to begin developing policies and management that meet multiple ecological and social goals

Late successional stage dynamics in natural Oriental beech (Fagus orientalis Lipsky) stands in northern Iran (Case study: Gorazbon district of Kheiroud-Kenar experimental forest)

To study the beech stand dynamics followed by the definition of developmental phases in natural mixed beech stands, three sample plots, each covering 25 ha, were inventoried in undisturbed natural mixed beech (Fagus oreintalis Lipsky) stands in Kheiroud-Kenar experimental forest in the north of Iran. The plots were subdivided into 25 one-hectare subplots. Within each mail plot, the subplots were numbered from 1 to 25, within which a number of stand parameters including diameter, canopy gaps properties, natural regeneration and dead trees were recorded. In terms of late successional stage, three stages and eight phases were recognized. According to those, development of beech stands occur in three main stages including early, middle and late characterized by volume growing up, volume accumulations and volume transition terms. Various phases within those stages were recognized. The Growing up stage embraces gap forming, understory initiation and regeneration phases. As for the volume accumulations stage, volume stability, lightning and stem exclusion phases were recognized. Subsequently, the decline stage includes gap making, old growth and volume degradation phases. Some of those phases could be subdivided into small-scale cycles e.g. pre or late volume stability. Furthermore, the intermediate stage includes mixed phases which are mainly created by small-scale and frequent disturbances. The F. orientalis stand were covered to a major extent by phases of stem exclusion, volume stability and understory initiation. In other words, the beech stands are currently in the middle stage of development. Here, we attempted to prepare quantitative characteristics of each of the recognized phases. Finally we illustrated the developmental pattern of beech stands as well as related silvicultural pathways. Dynamics of oriental beech stands begin by formation small-sized gaps (often created by the fall of a single gap maker tree). This fact shows that the single tree selection method is a near-to--nature method within this area. Our findings emphasize that silvicultural methods and related treatments must be regulated based on stand developmental phases. This can lead to decrease the intensity of human intervention and to choose the most appropriate, timely treatments e.g. tree marking

Natural regeneration of oriental beech (Fagus orientalis Lipsky) within canopy gaps and under canopy cover, (Case study: Gorazbon, Kheyroud Forest, Nowshahr)

Establishment of natural regeneration is a crucial process which plays a key role in maintaining the sustainability within the forest stands. This study aimed to investigate the quantitative characteristics of oriental beech regeneration within canopy gaps and under the canopy in Kheyroud forests of Nowshahr in the north of Iran. Two compartments were initially selected, within which a sampling grid featuring 50×50 m distance between plots was established. Regeneration frequency, species and height of seedlings and saplings were measured both within the gaps and under the canopy. Results showed the frequency and mean height of beech regeneration to be higher under canopy layer. Those parameters also significantly differed from those within the gaps. Our findings also show that the reduced light under the canopy is by no means an obstacle to increase the beech regeneration, but it rather contributes to improve the establishment of natural regeneration of beech. This research confirms the previous findings on the shade tolerance of beech and suggests creating canopy gaps in those stands in which beech seedlings are previously stabilized as a mean to support the natural regeneration

Quantitative and qualitative assessment of deadwood in natural stands of Hyrcanian forests (Case study: Gorazbon district of Kheyrud, Nowshahr)

The conservation value of Coarse Woody Debris (CWD), as critical microhabitat component, in forest ecosystems led to increasingly expand interests in researches about it. The scientific CWD information had gradually considered by decision-makers for implementing forestry planning. In this study, due to evaluate qualitative and quantitative characters of CWD and its proportion to live standing trees, full callipering method was applied. Data were collected from an unmanaged parcel (parcel no. 37, Gorazbon district, Kheyrud forest) situated in southern slopes of Caspian beech forests. The study site has never been under wood exploitation. The data of CWD (middle diameter ≥ 10 cm) and stand (D.B.H ≥ 7.5 cm) were measured using full calipering method. The results of this study illustrated the average number of live standing trees, snags, and fallen trees were 357, 8, and 26 per ha, respectively. Between all species, hornbeam had the highest volume proportion both in live standing trees and CWD. One fifth of total CWD volume was accounted to sangs and stumps and about half of the total volume was exposure in low degree of decomposition. CWD volume amounted 3.5% of total yield of site study. In summary, total CWD volume is lower than optimal value considered for CWD in temperate forests which sets alarms that any removal of CWD could bring irrecoverable consequences in site study