نشریه حفاظت زیست بوم گیاهان
سال یازدهم شماره 2 (پیاپی 23، پاییز و زمستان 1402)

Today, one of the most important issues in economic, social planning and future decisions in an area is the awareness of vegetation rates and its spatio-temporal variations. The purpose of this research is to investigate vegetation changes in Central Zagros using MODIS Terra satellite data with spatial resolution of 250 m (2001 - 2018) and NDVI index. At the same time, DEM and DSM models and bilinear interpolation method were used to resampling. These data were processed to analyze vegetation changes in the interior and exterior of anthropogenic activities in the Central Zagros. The results showed that the NDVI index has increased in these altitudes and within mountain passes and valleys and in areas and lowlands adjacent to the slopes to the southwest, especially the Khuzestan plain. At the same time, the temporal trend of vegetation changes in the Central Zagros shows the increase of the NDVI index in this period. In the Central Zagros in January, the vegetation index at low altitudes, especially towards the Khuzestan plain, has a significant increase compared to higher altitudes; Therefore, nomads migrate to winter settlements. Meanwhile, in May, it is possible to establish nomads at higher altitudes and use high rangelands, resulting in nomadic summer migration. Spatial changes of vegetation within the interior and exterior of human activities showed that the increase of the average positive part of the vegetation index within the 5 km around of the cities is due to the expansion of gardens, agriculture and green area in this region. The relatively noticeable trend outside of that is also caused by temperature changes and the general trend of increasing vegetation index in central Zagros. The increase in the vegetation index in the 1km around of the communication roads and villages , as well as the areas outside it, can be related to the increase in temperature due to global warming and the reduction of winter snow-covers and due to the expansion of fields and gardens around the villages, roads and green area created in the around of roads and villages.

The evaluation of rangelands needs some studies about the physical effects and climatic factors on the changes of rangelands during different years. Evaluating changes in crown cover, plant composition, production rate, status, capacity and trend of rangelands during different years is very important. beneficiaries are often faced with unpredictable climate and natural condition changings, which rangelands of this group of experimental farmers is necessary for sustainable management and ecological health. The goals of this research are to investigate the understanding of climate change from the point of view of farmers in Rineh, Polour, Kangarchal and Poshtkoh regions in Mazandaran province. And its effect is on the beneficiary’s efforts and it will provide suggestions to reduce the effect of climate change and increase production of rangelands. In this regard, some questions were formulated and asked to the local users through a questionnaire, and SPSS software was used to determine users' opinions and compare their views in four sites. Also, four index including plants, herbal production, rangeland’s ecosystem (situation, soil and wild life), livestock and grazing systems, herd management and livelihood system were evaluated in four sites. The results of the average comparison showed that a large number of operators, about 41.7% believe that climate change which has occurred in these sites are happened in recent years. Also, the reduction of snowfall, the production of rangelands, the number of livestock shows that 37.7% of the respondents agree with the increases of immigration. For this purpose, in order to reduce the negative effects of climate changes are essential for a comprehensive education, proper planning and providing financial services and implementing plans for the proper use of water resources to deal with climate changes.

A Acer velutinum Boiss. (Persian or velvet maple) is one of the industrial and important species of Hyrcanian (Caspian) forests with wide distribution. This species is rarely seen in the forests of other parts of the world and has only been reported from the forests of the Caucasus. Therefore the information about this species is very limited. This research aims to investigate the response of A. velutinum seedlings to drought stress as one of the consequences of climate change. Seedlings of velvet maple were analyzed in terms of height, basal diameter, leaf area (LA), specific leaf area (SLA), biomass, photosynthesis pigments, relative water content RWC), free proline, malondialdehyde (MDA), superoxide dismutase(SOD), and peroxidase(POD) activities to drought stress. One year old of Potted plants were exposed to four water supply regimes (100, 75, 50, and 25% field capacity (FC); performed as a control, mild, moderate, and severe water stress. The results showed that drought reduced all aspects of growth in the velvet maple. It negatively affected on growth and reduced plant height, stem diameter, biomass, and leaf area, but SLA significantly increased under moderate treatment. Drought stress reduced chlorophyll content, however, no significant difference was found for carotenoids. RWC reduced significantly just under severe drought stress. Proline and MDA content increased significantly when plants were exposed to moderate and severe drought stress. Drought stress induced POD and SOD activity under drought treatments, although the highest activities were measured under mild and moderate treatments. Our data demonstrate that A. velutinum seedlings have relative drought resistance. They used drought avoidance and tolerance mechanisms through changes in morpho-physiological characteristics. The results of this research briefly showed the mechanisms of drought tolerance in A. velutinum and will provide essential information for more research in the future.

Many parks and green spaces in Tehran are located in polluted areas in order to reduce some air pollution; however, sometimes the plants themselves are damaged which cannot be easily recognized. The studied ornamental plants were collected, their pollen were separated from the anthers, and their purification was done by Erdtman's acetolysis method. They were stained with methylene blue and Lugol's solution and the pollens prepared for microscopic observations. Morphological changes of pollens with regional depressions (shrinking), changes in the size of the space between the exine and intine, tearing, asymmetry and deformation of pollen were observed. In the anatomical results some pollen grains were vacuolated and larger than normal, and some others were starchy and contained accumulations of contaminated particles. All these changes damage the pollen performance. Dahlia variabilis Dest. 97% and Tagetes patula L. 83% experienced the most anatomical damages and Rosa hibrida L.  46% and Datura innoxia Miller 24% underwent the most morphological damages.

This study was carried out with the aim of investigating and knowing the chemical and physical characteristics of Astragalus parrowianus Fischer and the relationship of these characteristics with soil and topographical characteristics in Jalamabadan rangeland of Joveyn city. At first, the studied area was divided into four places where A. parrowianus was present for sampling. In July and August of 2019, the study area was visited to take samples of tragacanth and then by using of scientific resources and the guidance of local operators, 4 different sites with the presence of A. parrowianus were identified. Then, in each of the places, the tragacanth was extracted from the plant bases and A profile was dug at a depth of 0-60 cm in order to prepare a soil sample. Quantitative characteristics of tragacanth, including production, ash, viscosity, and qualitative characteristics of Tragacanth, including potassium, calcium, phosphorus, and sodium elements, arabinose, galactose, fructose, glucose, sucrose sugars, and proline, serine, and valine amino acids were measured. In the collected soil samples, the factors of electrical conductivity, percentage of sand, silt, clay, pH, soil water saturation percentage, potassium and organic matter were determined in the laboratory using standard methods. Also slope, aspect and elevation maps were prepared in order to determine the topographic characteristics. Then, using one-way analysis of variance, the difference between the sites was investigated in terms of quantitative and qualitative characteristics of tragacanth and soil characteristics. Finally, using the Redundancy Analysis (RDA), the relationship between the environmental characteristics and the characteristics of tragacanth was investigated. Among the soil characteristics, the amount of organic matter, the percentage of clay, sand, the amount of gravel and electrical conductivity have significant differences in the studied sites. While potassium, pH and percentage of silt have no significant difference among the studied sites. Except for valine, magnesium, sucrose and galactose, the physical and chemical characteristics of tragacanth have significant differences among the investigated sites. Site 1 has the lowest amount of viscosity, calcium, sodium, fructose, proline and the highest amount of product and ash. Site two has the highest amount of potassium, phosphorus, arabinose, glucose, and proline. The third site has the highest viscosity, calcium and serine and the lowest sucrose and galactose. Site four has the lowest amount of ketira, potassium, phosphorus, arabinose, glucose, ash, serine and the highest amount of sodium and fructose. Also, about 90% of the changes are justified by the first axis of the RDA diagram and the variables of height above sea level (72%), soil alkalinity (42%), slope direction (36%), electrical conductivity (34%) and slope percentage (33%) were the most important effective factors in differentiating the different growth locations of A. parrowianus in Jalmabadan region. According to the results, the characteristics of tragacanth gum are influenced by environmental factors, and each of the characteristics of tragacanth gum are affected by certain environmental characteristics. From this, for various industrial purposes that certain characteristic of Katira gum is important, it is necessary that the effected environment in which the species grows or its gum is harvested should be in optimal conditions.

Floristic studies are one of the most effective methods for managing and Protection of biological reserves of vegetation, and it plays an important role in controlling erosion and rehabilitating destroyed areas. Destructive conditions have caused the reduction of valuable plant species in the flora of the region. Therefore, the aim of this research was to investigate the floristic composition, geographical distribution, biological spectrum and and identifying endemic species in the Kordan watershed in the Kurdish watershed in Alborz province of Iran. The flora of the region was studied by field trip between 2019 and 2021 in different plant phenological stages. In total, 151 species of flora belonging to 28 families and 115 genera were surveyed and identified in several field trips during the study period from 201 to 2021. Based on the number of species, Asteraceae (35 species and 24 genera), Poaceae (17 species and 13 genera), and Lamiaceae (15 species and 13 genera) were the most important families. The largest genera were Astragalus, Centaurea, Bromus, Salsola, Cirsium and Alyssum. In this study, the life-form spectra were classified on the basis of Raunkiaer's system. Then, the 𝜒2 test was used to compare the biological spectrum with Raunkiaer's normal spectrum and with those in other floristic studies conducted in the near the study area.  The results showed that the life-form spectrum in the present study w::as char::acteristic of a cold dry and mountainous climate region with hot and dry summer and relatively cold winter and dominated by hemicryptophytes (46% of the recorded species), followed by therophytes (32% of the recorded species). Findings also indicated that the effects of climate, and human activities such as overgrazing caused a reduction in phanerophytes from around 46 to 5%, increases in therophytes from about 13 to 32% and hemicryptophytes from 26 to 46% in comparison with Raunkiaer's normal spectrum. It can be concluded that hemicryptophytes and phanerophytes usually comprise the highest and lowest percentages of life forms in studies conducted in the Irano-Turanian growth zone.

Soil macrofauna plays a critical role in the development of soil structure and provides a variety of ecological functions. The present study aims to compare the biological index of soil macrofauna in broadleaved, coniferous, and mixed stands during growing and resting seasons in Geno protected area, Hormozgan Province, Iran. After a half-hectare broadleaved stand, a half-hectare coniferous stand, and a half-hectare broadleaf-coniferous (mixed) stand in the Geno protected area were selected to identify the soil macrofauna and measure the physical, chemical, and soil properties and their relationship with soil macrofauna, 10 soil samples were randomly collected from different soil depths including under the canopy to a depth of 15 cm, during the growing and resting seasons. The macrofauna were isolated from the soil samples and were then submitted to a laboratory for chemical analysis. Data were analyzed using SPSS26 software. Richness, evenness, and biodiversity indices were compared using t-test, and then ANOVA and Duncan tests were used to compare physical and chemical properties of macrofauna soil in growing and resting seasons. The results showed a significant difference biological index of macrofauna in broadleaved, coniferous, and mixed stands in the growing and resting seasons.Tperesence of macrofauna the soil, their great diversity and activity as one of the key factors in the supply of nutrients and soil fertility can play a constructive role in the health of ecosystems and maintaining its balance

The present research aimed to investigate the crown dieback of Persian oak trees in relation to their individual and site characteristics, evaluated the changes in crown health of trees during the years 2019 to 2022 in Meleh-Siah forest in the northern half of Ilam province. Two sites were identified in the northern and southern aspects and 100 oak trees were marked in each site. The characteristics of each tree, including the diameter at breast height, tree height, max and min crown diameter and tree origin were measured and recorded. The dieback condition of tree crowns was evaluated and divided into four classes of crown dieback. The evaluation of crown dieback of trees was done during four years and in September. The results showed that the highest abundance of trees in the northern site is in the classes of declining and crown dieback up to 50%, and in the southern site is in the class of crown dieback more than 50%. The number of trees leaving the healthy and declining classes was higher, respectively, which were transferred to the higher crown dieback classes. The healthy and declining classes were associated with decreasing changes and the crown dieback less than 50% class was associated with increasing changes. dbh, height and crown area of ​​healthy trees were lower than those of other crown dieback classes. The frequency of crown dieback was higher in denser stand. The rate of crown dieback was higher in coppice trees than in standard trees; in addition, the temporal changes of crown dieback were more in coppice trees. It was concluded that individual and social traits and environmental conditions had a considerable impact on the crown health of oak trees and how they reacted to recently happened droughts.

This study aimed to evaluate the structural characteristics of natural forests and providing the possibility of studying the changes in the structural characteristics of these stands over time, in order to plan and manage the forest in the Tang Dalab To achieve this, all trees were calipered in two one-hectare plots. Additionally, the structural characteristics were measured using the nearest neighbor’s method. To measure several indices like nearest neighbor distance index (density of trees), uniform angle index Clark and Evans index (variety of location), Mingling index (species mixture), diameter and canopy differentiation indices (dimensional differences of trees), and complex structural diversity index (tree diversity) were used. The results of uniform angle (south site 0.44 and north site 0.48) and Clark and Evans indices (Southern aspect 1/07 and Northern aspect 1/09)indicated a random spatial pattern of trees. According to the Mingling index, the northern aspect has relatively moderate mixing (0.31) and no mixing (0) in the pure southern aspect). The mean distance to the neighbors was 8.12 m in the northern stand and 5.81 in the southern aspect. The results of the diameter and canopy differentiation index indicated a low difference in diameter (0.24) and canopy (0.24) in the southern aspect an average difference in diameter differentiation (0.41) and a high difference in canopy differentiation (0.51) in the northern aspect complex structural diversity index, indicated more diversity in the northern aspect (0.38) compared to the southern aspect (0.18). The indicators used in this research can be used to describe the structure and ecological characteristics of different tree species in order to increase ecosystem stability and planning to create heterogeneity in the structure of the stand and help forest managers in planning and making appropriate decisions. However, the effectiveness of these indicators in some situations is doubted by some researchers.

Ferula assa-foiteda L., as one of the most significant medicinal and export plants in Iran, plays a role in the livelihood of stakeholders and the pharmaceutical industry. Over exploitation of this plant habitats and recent droughts will reduce plant density and eventually the extinction of this species in the near future. This study was conducted to identify potential habitats of this species in Isfahan province using modeling species distribution. For this purpose, during 3 years of field surveys, data of the studied species were collected from 88 presence points. Physiographic information (slope, elevation, aspect) and 19 bioclimatic variables were used in the modeling process. The potential species distribution map was produced using maximum entropy model and Geographic Information System. The results of model evaluation showed the proper performance of the model with the AUC value equal to 0.962. Analysis of variable importance using Jackknife test, showed that slope, temperature annual range, annual precipitation and precipitation of coldest quarter were identified as the most important environmental factors influencing the species distribution. Regarding the response curves to environmental factors, Ferula assa-foiteda is more likely to occure in areas with a slope of more than 70%, temperature annual range from about 37 to 43 °C, annual precipitation and precipitation of coldest quarter about 70 and 40 mm, respectively. Based on the obtained results, about 7% of the habitats of Isfahan province especially in the semi arid and steppe areas are suitable for the growth of Ferula assa-foiteda which is very important in management of rehabilitation and develop cultivation.

The Zagros forests are the largest forest area in Iran, and the Iranian oak (Quercus brantii Lindl.) is the most extensive and abundant tree in this forest habitat. The green oak leaf roler, Tortrix viridana L is one of the key leaf-eating pests of oak trees in this growing region. The outbreak and spread of this leaf-eating insect has many negative and economic consequences. The host trees of this pest are only Darmazo species (Q. infectori) and Iranian oak (Q. branti). This research aims to investigate the changes in the biochemical and physiological parameters of oak leaves in the areas attacked by the green oak leaf roler, in the three regions of Gurkesh Durood, Kohman El Shatter and Garit of Lorestan province, using a systematic random sampling method with a grid size of 200 x 150, 30 A sample piece of 10 AR was made with dimensions of 40 x 25 (1000 square meters). The results of this study showed that between the amount of biochemical and physiological parameters, such as cellulose, pectin, lignin, phenolic, gallotannin, proanthocyanidin, flavonoid, protein, proline, soluble nitrogen, total nitrogen in the leaves of trees with green oak leaf roler outbreak and the amount of leaf eating.

The wood quality in forest trees largely depends on their self-pruning and forest management pays attention to the pruning factor to achieve high quality of wood products. Therefore, this study aimed to determine the relationship between self-pruning index in Oriental beech trees and some of their structural attributes. For this purpose, 186 beech trees were randomly selected in Alandan, Sari and the self-pruning index along with other structural features were measured. The correlation results showed that there is a significant positive correlation between self-pruning index with DBH, crown length, area and crown volume and also a significant negative correlation with symmetry and crown ratios. No significant difference was observed in the height classes of beech trees in terms of self-pruning index (Sig.=0.164). The highest mean value of the pruning index belongs to the class of 75-46 cm in diameter (Sig.=0.002). The analysis of variance results showed that the highest mean value of the index was present in the groups of three trees. With increasing the stubbiness ratio, the self-pruning index increased (p=0.009). A significant interaction was observed between stubbiness ratio with crown length, crown area and volume, DBH and height of beech trees in site. In general, the results showed that self-pruning in large-sized beech trees was performed according to forest conditions and this important index was related to the structural attributes of trees such as height, DBH, surface area and volume of the crown and it is also necessary to consider the pruning of forest trees in intermediate-cutting operations to increase the wood quality.

In a rangeland ecosystem, it is important to pay attention to environmental factors and their effect on the distribution and establishment of plants in order to plan exploitation. The purpose of this research is to investigate the relationship between the cover of some species and environmental factors in the north of West Azerbaijan province. For this purpose, in the period from mid-May to the end of June 2021, sampling of vegetation in eight rangelands sites with different vegetation combinations in Chaipareh and Khoy Counties in a systematic-random method with the establishment of transects and plots one square meter was done. In each of the rangeland sites, the percentage of rangeland species coverage was recorded. Topographical factors including elevation above sea level, slope percentage and geographical aspect of the range were recorded for each site. Soil samples were taken from each of the sites at five points from 0 to 20 cm depth and taken to the laboratory to measure soil parameters. The results of the use of detrended correspondence analysis (DCA) showed that the importance of the axes based on the specific value decreases from the first axis to the second and third axis, and as a result, the major contribution of changes in the distribution of plant species is related to the first and second axis. The results of DCA showed that the specific value of the first axis is (0.36) and the second axis is (0.23). Changes in species distribution due to soil and topography factors were investigated using the linear redundancy Detrended Analysis (RDA) method. The results of the redundancy analysis showed that the four axes explain a total of 83% of the variance of species composition changes by environmental factors, and therefore this indicates that the investigated parameters have a direct effect on the distribution of species, but because the first axis, it has the highest value (0.295) and is related to different soil parameters, and this indicates that the contribution of soil on the distribution of species in the study sites is more than the topographical parameters. The general results of this study showed that the distribution of rangeland species in the study sites is influenced by soil and topographical factors. It seems that the higher the altitude, organic carbon, saturated moisture, percentage of sand, silt and clay, the slope and direction of the range and calcium in the rangeland site, the more frequent the presence of some species such as Artemisia fragrans Willd, Antemis koteschyana Boiss, L., Cynodon dactylon and Ceratocephalus falcatus L. increases and as the amount of soil cations, electrical conductivity, lime percentage and soil acidity decrease, the abundance of some other species such as Phlomis olivieri Benth, Teucrium polium L., Alyssum minutum Schltdl. and Tanacetum polycephalum Sch.Bip is more common in study sites. Using the results of this research, the growth conditions of the existing species have been determined to some extent, and considering that some species have economic and medicinal value, if the user's goal is to use the species for planting of medicinal plants, it is recommended to pay attention to the soil and topography of the region if they are economic under the conditions of hand planting in similar areas.

Remote sensing data provide a high ability to represent habitat characteristics and use in species distribution models. The purpose of this study is to determine the most important of remote sensing predictors, including climatic indices (precipitation and temperature), primary and secondary topographic indices (elevation, slope, direction, Topographic Position Index (TPI) and Terrain Roughness Index (TRI) and remote sensing indices (Global Environmental Monitoring Index (GEMI), Leaf Area Index (LAI), Modified Normalized Difference Water Index (MNDWI), Modified Simple Ratio Index (MSR), Normalized Burn Ratio Index (NBR) and Visible Atmospherically Resistant Index (VARI)) using two species distribution models (Boosted Regression Tree and Random Forest) to predict the presence of J. excelsa in Khalkhal County of Ardabil province and northern part of Zanjan province using SAHM software. The evaluation of prediction models using AUC chart (Area under curve) showed that it is at an excellent level for both the BRT model (0.991) and the RF model (0.974). The most important affecting habitat desirability based on the BRT method include annual precipitation, slope, digital elevation model, temperature, GEMI index and TRI index variables respectively. The most important variables affecting habitat desirability based on the RF method, respectively, include annual precipitation, digital elevation model, GEMI index, slope, VARI index, temperature, MSR index, TRI index, TPI index, NBR index, MNDWI index, LAI index and aspect. The region mapped in the study as suitable habitats’ for the species could be used in the planning strategies with the aim of evaluating the susceptible habitats, the possibility of conservation, reproduction and breeding. Considering that the modeling method choice is the main source of variability in predictions and choosing the best prediction model is not simple, therefore, it is suggested to use a combination of these models instead of relying on the outputs of a single model.

The pattern of the landscape and its corresponding changes is a comprehensive reflection of the ecology of the environment. The existing ecological processes in different scales cause the fragmentation and disintegration of the landscape structures and cause changes in the spatial distribution and fate of the patches in it. Plant patches are a relatively homogeneous part of the landscape, which have different responses to natural disturbances and management actions, and indicate the history of the management governing the region. It seems necessary to use detection methods to determine the process of changes in the distribution pattern with the passage of time in an ecosystem. Landscape metrics are one of the most important detection methods that provide the basis for quantification of the structure and spatial pattern of the landscape and make the nature of dispersion and distribution of its structural components comparable. The present study was conducted with the aim of investigating the process of changes in the pattern of plant patches in Broujen city, which is located in a heterogeneous landscape in central Zagros. For this purpose, Landsat satellite images from 1990 and 2019 were used and then classified in Idrisi TerrSet software. This has led to the production of classification maps with various patches and placing them in seven different classes in terms of the plant community. In order to quantify landscape pattern at the class level, CA, PLAND, ED, TE, ENN-MN, and SHAPE-MN metrics were calculated using Fragstats software. The results indicate a decrease in degradation and an increase in patch stability in the Astragalus verus, Astragalus verus-Bromus tomentellus, and Astragalus verus-Stipa hohenackeriana classes. On the other hand, the landscape covered by Bromus tomentellus, Bromus tomentellus-Stipa hohenackeriana, and Stipa hohenackeriana classes has been increasing, which shows the expansion of the classes and the reduction of their disintegration. The results also show that except for the Bromus tomentellus class, which shows the increase in complexity and the irregular shape of its patches, the trend of changes in other classes is downward, and it shows that during the period under investigation, the shape of the patches of each class becomes simpler and more regular.