Northern Forests Of Iran Research Articles

INVESTIGATING THE IMPACT OF DEFORESTATION ON MICROCLIMATE AND INCREASING THE RISK OF HEAT STRESS USING SATELLITE IMAGE PROCESSING (CASE STUDY: FORESTS OF HIRAN AREA)

Abstract. In recent years, the forests of northern Iran, which have a very high value, have been changed and turned into other uses due to various human reasons. Meanwhile, residential and road construction is more visible in these forests. Recognizing the location and investigating the impact of changes in forest extent in any region can greatly help the condition of forests in the past and planning their restoration. In this research, using satellite image processing, the effect of deforestation on the microclimate of the region and its effect on the surface temperature of the region have been investigated. By collecting in situ points in sixty samples including thirty tree areas and thirty pasture and treeless areas, the forest rate was determined using the normalized vegetation cover index. Then the land surface temperature of the studied area was calculated using the single channel method. Finally, by choosing a region as a control region in order to control the impact of global warming, the studied region and the control region were statistically compared. The results of the classification of the region based on tree and non-tree areas showed that during the years 1984 to 2021, about 1400 hectares were deforested. Also, the results of the final Welch T_test statistical test showed that there is a significant difference between the temperatures of the two regions at the 99% confidence level and with a p_value equal to 0.0007. This fact shows the significant impact of deforestation on increasing the temperature of the region.

Flora, Life Forms and Chorotypes of Forest Floor Plants in the Asalem Forests, Western Hyrcanian, Iran

The aim of this research was to introduce the forest floor plants species, their life-forms, and describe their geographic distribution in the Asalem Watershed basin (no.7), Western Guilan province (part of Western Hyrcanian) in northern forests of Iran. The Asalem forest is one of the most important and valuable areas of Caspian forest in Iran. The study was conducted on 91 plots of 400 m2 (20 × 20 m) along 19 transects in the basis of a random- systematic sampling design. Inside each main plot, three quadrates (5 × 5 m) on the diagonal line and internal quadrates (1 × 1 m) were chosen, and all of the floor plants collected. The results revealed that there were 306 species, 181 genera and 54 families. The main family was Poaceae with 36 species and 25 genera (12%). Then, the highest number of species belonged to the Asteraceae with 28 species, Fabaceae with 26 species, Lamiaceae with 20 species, Rosaceae with 14 species, Apiaceae and Cyperaceae each including 13 species, Caryophyllaceae with 12 species, Rubiaceae and Orchidaceae each including 11 species. Regarding to the life forms, Hemicryptophytes with 45% (137 species) were the largest group. The chorological analysis indicated that species belonging to the regions of Euro-Siberian were the most significant ecological groups.

Modeling response curves of European yew (Taxus baccata L.) using HOF models along the environmental gradient in north of Iran

One of the important issues in plant autecology is the analysis and understanding of species-environment relationships and response of species to ecological gradients. Understanding how species respond to environmental variables is useful for predicting the environmental and geographic distribution of species. The main objective of this research is to study the response curve of European yew to identify the most important climatic and physiographic gradient in the northern forests of Iran. In the present study the Huisman–Olff–Fresco function (HOF) was used to study the response curve of the European yew in relation to each of the environmental variables individually and extract the optimum values. In order to select the optimal model, the Akaike Information Criterion (AIC) was used. Based on the results of this study, 41% of the models have either monotonically increasing or decreasing behaviors (models 2 and 3), 27% of the models have a unimodal symmetric behavior and 32% of models have a skewed behavior. European yew in 59% of models has a unimodal response curve. Based on the variables used in the study, it can be said that the European yew is a species that prefers oceanic climates, midlands altitudes, and north-facing slopes for establishment in temperate forests of Iran. Together, these findings advance niche theory about the European yew tree and may be used for generating better predictive models of European yew distributions under future climate change.

Developing a set of key performance indicators for monitoring sustainability of forest functions in the Hyrcanian forests

This study identifies key performance indicators for monitoring the sustainability of forest functions in the northern forests of Iran. This process was conducted in two phases through the Delphi method, and Fuzzy Cognitive Mapping (FCM). The Delphi method classified indicators according to two properties, importance and measurability. These were used to identify four classes: (a) important and measurable, (b) important and less measurable, (c) less important and measurable, (d) less important and less measurable. Indicators placed in groups (a) and (b) were then used to develop a set of key performance indicators using FCM. The FCM enabled the evaluation of the overall cumulative impacts of all indicators within the network, individually and collectively, through their interactions with other indicators. The selected methods and possible application of the key performance indicators could be used to determine how to achieve the sustainable management of a forest area.

Satellite image processing of the Buxus hyrcana Pojark dieback in the Northern Forests of Iran

Pests and diseases can cause a variety of reactions in plants. In recent years, the boxwood dieback has become one of the essential concerns of practitioners and natural resources managers in Iran. To control the boxwood dieback spread, the early detection and disease distribution maps are required. The boxwood dieback causes a range of changes in colour, shape and leaf size with respect to photosynthesis and transpiration. Through remote sensing techniques, e.g. satellite image processing data, the variation of thermal and visual characteristics of the plant could be used to measure and illustrate the symptoms of the disease. In this study, five common vegetation indices like difference vegetation index (DVI), normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI), simple ratio (SR), and plant health index (PHI) were extracted and calculated from Landsat 8 satellite image data from six regions in the Gilan province, located in the northern part of Iran out of 150 maps over the time period 2014‒2018. It turned out that among the aforementioned indices, based upon the results of the models, SR and NDVI indices were more useful for the disease spread, respectively. Our disease progression model fitting criteria showed that this technique could probably be used to assess the extent of the affected areas and also the disease progression in the investigated regions in future.

An introduction to the distribution of carbon stocks in temperate broadleaf forests of northern Iran

Northern forests of Iran are among the most important plant communities in Iran due to their dynamic and diverse vegetation composition and fertile soils. There is little information about carbon stocks of these forests. In the present study, above- and belowground carbon stocks of trees, litter, herbs and soil organic carbon stock at three selected sites of these forests were calculated using random plots and non-destructive sampling. The FAO method was used for carbon estimation of trees and Walkley-Black method was used for soil carbon stock and carbon coefficient was estimated directly. The results showed that both the tree carbon stocks and soil carbon stocks increased from east to west with increasing altitude, showing significant differences. The results also indicate that these forests have a high carbon sequestration potential as a green belt across the northern slopes of the Alborz Mountains, when the contribution of the aboveground section was greater than that of the belowground section (soil and roots) at all sites.

Assessing and Modeling Soil Detachment Capacity by Overland Flow in Forest and Woodland of Northern Iran

Land use has significant effects on the erosion process, since it influences the soil detachment capacity by causing an overland flow (Dc). The effects of different land uses on the rill detachment capacity have not been explained in depth, and the hydraulic parameters providing accurate estimates of this soil property have not been completely identified. This study quantifies Dc at low flow rates in woodland and forestland, compared to two other land uses (cropland and grassland), in the Saravan watershed (Northern Iran), and develops prediction models of Dc and rill erodibility (Kr). Dc was measured on undisturbed soil samples, collected in the four land uses, and characterized in terms of the main physico-chemical properties in a flume experiment, simulating five slopes and five shallow water flows. The results showed that Dc was significantly lower in woodland and forestland compared to cropland and grassland, as the consequence of the changes in the main soil properties and the more developed vegetation cover and structure. Dc was positively correlated to clay and silt contents of soils, and negatively correlated to sand content, aggregate stability, root density, and organic matter. The stream power and unit stream power were found to be very accurate predictors of Dc in woodland and forestland, respectively. Kr values, which assumed the lowest values in woodland and forestland, were provided by interpolating Dc and the shear stress of water flow. Overall, this study has confirmed that vegetation cover and improved soil properties in forestland and woodland may help to reduce erosion in delicate environment ecosystems, such as the forests of Northern Iran.

Management challenges and adaptations with climate change in Iran forests

Nowadays, climate change is one of the global issues. Given the occurrence of climate change in different parts of the world in recent years, a major concern of environmental and forestry activists and policy makers has been to explore the direct and indirect deteriorative impacts of this phenomenon on different facets of forest ecosystem and local communities. The present study run an opinion poll among 315 activists, students, teachers, and experts of environment in Iran during 2019 to find out the extent to which they believed that severe climate change was happening in different forests and how they assessed the performance of environmental resources and forest management practices. The analysis of data exhibited that over 90% of the participants acknowledged the occurrence of severe climatic changes in recent years and almost none of them assessed the present forest management style to be appropriate. On the other hand, the participants suggested that the Zagros and northern forests of Iran have most severely been affected due to climate change by about 53% and 31.7%, respectively. Thus, to reduce destructive impacts of climate and global warming on human and local community, it is recommended to prioritize climate change adaptive management strategies in these regions.

Calculation of the aboveground carbon stocks with satellite data and statistical models integrated into the climatic parameters in the Alborz Mountain forests (northern Iran)

The forest ecosystems of northern Iran in the Alborz Mountains with a wide distribution range have variations in the composition and types of the plants, soil, structure, carbon stocks and climatic conditions. This study investigated the use of a satellite database and climatic parameters in estimating the carbon reserves. Three regions were selected for the distribution range of these forests. The data of 4 climatic parameters (MAP, MHR, MAE and MAT) were modelled based on the relationship with an elevation gradient. 5 spectral vegetation indices (RVI, NDVI, SR, NDGI, DVI and TVI) and near-infrared band (NIR) extracted from the satellite data and the aboveground carbon data of these forests were modelled based on a regression analysis. Finally, the best model of the relationship between the climate variables and the carbon stocks and the satellite indices was obtained from the multivariate linear regression equation and the R2 coefficient. Accordingly, the most influential climatic parameters on the carbon stocks of these forests were precipitation, temperature, and also the most significant indices were NDVI, RVI and NIR band. This research is an attempt to model the calculations of the aboveground carbon in the forests of northern Iran in relation to the climatic parameters using satellite imagery.

Climate change impacts on the distribution and diversity of major tree species in the temperate forests of Northern Iran

This study aimed to assess the impacts of climate change on the distribution of major tree species in the temperate forests of Northern Iran (also known as Hyrcanian forests). We analyzed the current distributions of the eleven major tree species using an ensemble approach involving five different species distribution models (generalized linear model, generalized additive model, generalized boosting model, classification tree analysis, and random forests) and generated the ensemble maps of the current and future distribution of each species. For the future, we used five general circulation models and two representative concentration pathways (RCPs). Finally, we mapped beta-diversity and changes in alpha-diversity of the tree species under climate change. Our analyses showed that generally, the climatically suitable habitats for most of the species tend to shift and shrink in the future. A shift in major trees boundaries will be expected both along an east-west gradient and along an altitudinal gradient under climate change scenarios. The results demonstrated that climate change is likely to exert a strong influence on beta-diversity and richness of the major tree species in northern forests of Iran. In total, beta-diversity of tree species will be higher in the central and eastern parts compared with the western areas under the climate change scenarios and the mid-elevations of the western Hyrcanian forests will likely experience the lowest beta-diversity through time, meaning that the impacts of climate change on these regions are minimal. The impacts of climate change on the distribution of major tree species in the Hyrcanian forests can be considered very severe and pose a high risk of loss in forest functions and services. Forest managers will encounter several uncertainties in the wood productions, plantation, restoration, and conservation plans due to climate change in the Hyrcanian forests.

The importance of coarse woody debris in dynamic phases exposure in the beech (Fagus orientalis L.) stands of Hyrcanian forests

In a natural forest, phases of different dynamics are gradually replaced to create sustainability in the stands. Coarse woody debris is among the most significant structural elements of natural stands that perform an influential position in the identification of dynamic phases. Therefore, the focus of this study is on dead wood conditioning as one of the major structural components in determining the various dynamic phases in the northern forests of Iran as part of the temperate forests. For this study, compartment 326 of Gorazbon District was considered as one of the control parcels of Kheyroud Forest. In this parcel, 25 one-hectare sample plots were selected as permanent plots for a long-term forest structure and succession studies. The coarse woody debris by 100% sampling method was measured. The results showed that there are 8 main phases in this area (gap formation, understorey initiation, stem exclusion, volume accumulation, volume degradation, multiple, lighting, old-growth). The extensive forest area (52%) is located in the understorey initiation and stem exclusion phases. The results also showed that the total average volume of snags and logs was 41.5 m<sup>3</sup>·ha<sup>–1</sup>. Furthermore, the mean dead wood volume in decay classes 1, 2, 3 and 4 was 10.33, 12.22, 9.15 and 83.9 m<sup>3</sup>·ha<sup>–1</sup>, respectively. The average frequency of dead trees in the diameter classes smaller than 25 cm, 25–50 cm and in the diameter class more than 50 cm is 25.79, 6.93, and 4.88. The significance analysis results obtained by ANOVA test showed that there is a significant difference between volume, snag and log stock and the shape of dead wood in various dynamic phases. Therefore, in general, dead wood in the forest differs according to habitat, evolutionary stage (dynamic phases), standing volume and species diversity of the tree species.

The effect of forest management on the frequency of dangerous trees in the Northern forests of Iran

A study of work accidents in forests has shown that dangerous trees play an important role in forest accidents. Despite the importance of safe working environments for forestry operations, the definition of these areas in natural forests is still unclear. Dangerous trees are considered those snagged with broken branches and a canopy or ones with dead trunks and stumps that have a hazard potential to the forest workers. This study investigates the frequency of these trees in the managed and unmanaged forests in the Caspian forests of Iran. In order to do the study, 15 circular plots with a total area of 1,000 square metres in two studied parcels were selected and the trees, according to their dangerous characteristics, were evaluated. The final results indicated that 66 and 50 trees per hectare had signs of being dangerous trees in the managed and unmanaged stand, respectively. A comparison of the average number of dangerous trees in the two studied parcels using the Mann-Whitney test indicated a significant difference so that the average number of dangerous trees in the managed parcel was more than the ummanaged parcel. Trees with broken branches had the highest frequency in the managed stand, while trees with a dead trunk or stump, a broken branch and canopy in the unmanaged forest were more than the other classes. Considering the relative frequency of the dangerous trees in the two study areas, identifying them could be one of the main attempts in logging safety. The existence of hazardous trees with different risk classes in each of the forest stands requires the development of specific safety instructions to deal with the risks of each tree. <br /><br />

Genetic variability and heritability of some morphological and physiological traits in Fagus orientalis Lipsky along an elevation gradient in Hyrcanian forests

Abstract The purpose of the present study was to evaluate the genetic variability and heritability of some morphological and physiological traits in Fagus orientalis Lipsky along an elevation gradient in northern forests of Iran. Beech leaves were sampled from southern and northern crown parts of healthy mature trees along an elevation gradient comprising sites situated at 700 m, 1,200 m and 1,700 m above the sea level. Our statistical analysis showed that the investigated traits differed significantly between the populations. The results indicated the lowest and the highest coefficients of variation for the high (1,700 m) and middle elevation populations (1,200 m) for leaf length, petiole length, leaf area, specific leaf area, dry weight, specific dry weight, leaf index and petiole index traits. With increasing elevation, mean leaf width, distance from leaf base to the leaf maximum width, dry weight and petiole index increased. The plasticity of leaf length, specific leaf area, specific dry weight, petiole index and petiole length peaked at middle elevation, and with increasing elevation, the plasticity of these traits declined. The distance from leaf base to the leaf maximum width had the highest coefficient of genetic (75.5%) and phenotypic (75.5%) variation. The heritability results showed that there were differences in all traits, and that the highest heritability was recorded for the distance from the leaf base to the leaf maximum width (99.95 %). The results suggest that the studied beech populations responded to the environmental changes by changing their leaf traits in different ways at different altitudes.

Influence of land use and land cover change on soil organic carbon and microbial activity in the forests of northern Iran

Land-use changes can alter soil carbon (C) contents, and in particular deforestation has been responsible for a large part of the cumulative human-induced greenhouse gas (GHG) emissions. This study aimed to determine the influence of land-use and land cover change on soil organic carbon (SOC) content, microbial biomass C (MBC) and microbial respiration (MR) in the Hyrcanian forests, north of Iran. We compared an agricultural field (AF), plantations of Alnus subcordata (AS), Acer velutinum (AV), Quercus castaneifolia (QC) and Cupressus sempervirens (CS), and a natural forest (NF). Soil samples were collected at three different depths (0–20, 20–40 and 40–60 cm). Results showed that different land covers significantly affected soil characteristics, and SOC increased by 25% and 1.11% after the conversion of NF to CS and AS plantations respectively, and decreased by 4%, 12.11% and 53% when NF was converted to QC, AV and AF respectively. In all treatments, MBC and MR were significantly higher (p < 0.05) in the 0–20 cm depth, and MR was also correlated positively with MBC and SOC. Microbial biomass was near the half in the agriculture field than in plantations and natural forest in the upper layer, but the effects of land use on microbial biomass C decreased with soil depth. However, we observed considerable amounts microbial biomass C in 40–60 cm depth. Also, results showed that topographical feature, altitude and slope, will affect SOC content. Our results indicated that forest plantation is a key measure to enhance SOC content and mitigate global CO2 emission, especially when soils are degraded and have low soil C content. In particular, afforestation had a crucial effect on elevating SOC content in the Hyrcanian forest, but plantations of oak (QC) and maple (AV) were less effective in terms of soil C increase.

Ecology of wood‐inhabiting fungi in northern forests of Iran

AbstractWood‐decay fungi are important in forest ecosystems and play an important role in nutrient and carbon recycling. The scope of this research was to identify wood‐inhabiting and wood‐decay macrofungi and determine their ecology. We sampled standing trees and dead wood of oak and hornbeam in the northern forests of Iran, specifically in Mazandaran and Golestan provinces. We assessed the influence of field slope, elevation, site direction and the height of fungal sporocarp position on the tree. The species of wood‐inhabiting and wood‐decay fungi belonged to 11 families: Polyporaceae; Stereaceae; Ganodermataceae; Physalacriaceae; Agaricaceae; Xylariaceae; Pluteaceae; Coprinaceae; Strophariaceae; Pleurotaceae; and Hydnaceae. The most common fungal species identified belonged to the Polyporaceae and Ganodermataceae and predominantly grew on trees growing on a slope of 20%, at an altitude of 700–900 m, 0–3 m from the ground a southwesterly site direction and the northern sides of both tree species. These results indicated that field slope was the most important factor in determining fungal sporocarp abundance.

A survey on Entomobryomorpha (Collembola) fauna in northern forests of Iran

A survey on Entomobryomorpha (Collembola) fauna in northern forests of Iran

Investigating the natural structures of Quercus castaneifolia C.A.Meyer in managed tracks in connection with physiographic factors in Northern Iran

The northern forests of Iran have biodiversity and complex structure, which only with the full knowledge of this ecosystem can be expected in the future for optimal and correct management in the future. The long oak tree of Mazoba is the scientific name of the Quercus castaneifolia family of Fagacece and oak species, which is found in the northern parts of Iran from the glacial marshmallows and from the coastal nave to the 1880-meter altitude. The study area is located at a height of 650–620 m above sea level in Shanderman's watershed No. 11 and in the province of Gilan. After turning forests and determining the location of sample parts, four square pieces of one hectare were selected in a square of 100 × 100 in four directions (North, South, East, West) and these specimens were of diameter at the breasts and the quality of the kidney Trees with a diameter of over 7.5 cm were measured 100% and the strips of 10 × 100 m in the north side of each of the parts, in addition to the above, total height, length, crown length, and also inside Restitution bar was studied in classes of diameter 0–2.5 and 2.6–7.49 cm in 5 sections of sample size 2 × 2 to determine the condition of forest regeneration in quantitative and quantitative terms. The study of the distribution range of the number of diagonal and altitudinal classes in the study area showed that the structure of oak masses at relatively large levels is unbalanced to the left, and this adolescence is not created by nature but by the implementation of An incapacitating method has been created. Today, the best kind of management for the northern forests of the country is a single-grain non-uniform gravel method, which is closer to nature in the sustainability of the area. Of course, for the correct application of this type of management, more than anything else, we need to study the natural and less massive masses of the masses, and can be used as a model to guide other oak masses in this area.

The diversity of wood-boring beetles caught by different traps in northern forests of Iran

Varandi HB, Kalashian M, Barari H, Rezaei Taleshi SA. 2018. The diversity of wood-boring beetles caught by different traps in northern forests of Iran. Trop Drylands 2: 65-74. Efficacy of trap types is an important factor for sampling, faunistic survey, evaluation of the population density, seasonal dynamic and monitoring of wood-boring beetles. In the present research, the diversity of Wood-boring beetles (i.e., Buprestidae and Cerambycidae) was studied by using different types of trap (window trap, color pan trap, color sticky trap and Malaise trap) in northern forests of Iran (Mazandaran Province, Iran). Different types of traps employed in five study areas, collected a total of 3120 beetles belonging to 55 species (29 Buprestidae and 26 Cerambycidae). The majority of captured specimens were buprestid beetles (79.87%), while only one-fifth of the specimens were Cerambycidae (20.13%). All of the collected beetle specimens were identified to species's level. One genus (Agrilus spp) and the following five species were the dominant species: Acmaeodera rufoguttata Reitter, Anthaxia hyrcana Kiesenwatter et Kirsch, Anthaxia intermedia Obenberger, Chrysobothris affinis (Fabricius) and Stenoprerus rufus (Linnaeus).

A survey on Entomobryomorpha (Collembola) fauna in northern forests of Iran

A survey on Entomobryomorpha (Collembola) fauna in northern forests of Iran

Modelling of plant species richness along altitudinal gradient: Asalem Watershed basin, temperate deciduous forests in northern Iran

Among the various topographical factors, effects of altitudinal factor on species diversity, richness, composition and biological functions patterns are considerable. This study was done to investigate plant species richness along altitudinal gradient in the Asalem watershed basin, northern forests of Iran. For these purpose, 13 altitudinal transects were established from 100 to 2500 m, according to altitude ranges within 200 m intervals. Data collection was done in 216 circular plots of 1000-m2 area with a distance of 150 m from each other. In total, 576species of 325 genus and 96 families were recorded. The highest number of species was belonged to Asteracese، Fabaceae and Lamiaceae families. The results indicated that forbs with 414 species belong to54 families and ferns with 31 species belong to10 families were the largest and smallest group of plants in study area respectively. In herbaceous layer, the mean number of species was increased along altitudinal gradients (P ≤ 0.005). The lowest and highest value of species number was belonged to 500 and 2500 m altitudes, respectively. Generally, there was a gradual decline of species number at 100 to 500 m. Fitted models indicated that variation patterns at altitudinal gradients were significant and the proposed polynomial model had a high conformity with changes of species richness. The lowest value of species number in woody layer was belonged to 1900 m altitude and 2100 m had the highest value. Three peak points were recorded at the beginning, middle and the end of gradient, respectively. Sinusoidal models showed a correlation between species richness and altitudinal changes by high coefficient of determination. Results of β –diversity indicated that species change rate was fixed at 700 m altitude, but it was decreased by increasing altitude. Fluctuations of β diversity were followed of the sinusoidal models. In the study area, destructive factors including road construction, tourism and over-exploitation are a serious threat for the ecosystem and this study can be considerable to develop targeted strategies for conservation of plant diversity. In addition, study of habitat conditions in each altitudinal gradients is necessary to reconstruction stands with low species diversity and appropriate species selection to establish stands with high density.