نشریه حفاظت زیست بوم گیاهان
سال دهم شماره 2 (پیاپی 21، پاییز و زمستان 1401)

Intense grazing of rangeland is one of the most important factors affecting rangeland degradation, which causes soil compaction, increased runoff, weakening and degradation of vegetation, and changes in rangeland species composition, and ultimately affects forage and livestock production. The present study was conducted to investigate the different intensities of cattle and sheep grazing and integrated livestock grazing and compare it with rangeland grazing conditions in the pastures of Halichal, Mersark, Shesh Jouleh and Bozkaleh Besout in Savadkuh city. For this purpose, in each of the studied areas, the standard plot of the modified Vitaker was established in two replications and soil samples were taken from a depth of 0-20 cm and transferred to the laboratory. All data analysis was performed in SPSS version 23 software. The results showed a significant difference in moisture, clay percentage, nitrogen, potassium, electrical conductivity (EC) and phosphorus. The highest amount of Nitrogen (0.86 ppm), Potassium (3 ppm), and electrical conductivity (EC, 6.93 ds/m) were observed in the integrated grazing area and the highest percentage of moisture (5.19%) was observed in the enclosed area. While the maximum amounts of Phosphorus (5.51 ppm) were obtained in the area under intense grazing of cattle and the maximum amounts of clay (15.19%) in the area under intense grazing of sheep. According to the results, exclosure had no significant effect on Organic Matter, Organic Carbon, Calcium, Magnesium, Sodium, pH, bulk density and CEC.

The global approach in agricultural production is to increase the quantitative and qualitative yield of plants through management methods such as the use of organic fertilizers and reducing the use of chemical fertilizers. This experiment was conducted as a split factorial arrangement with three replications in two folds in Bandarabbas during 2018 and 2019. The main factor included irrigation intervals at three levels (irrigation 80, 60, and 40% of field capacity) and the subfactor was different fertilizer sources at three levels (poultry manure, sheep manure, and chemical fertilizer based on the results of soil and plant test) and different species of Atriplex (A. canascens, A. leucoclada and A. lentiformis). The results showed that increasing drought stress increased ion and malondialdehyde leakage and decreased relative leaf water content and leaf chlorophyll content of Atriplex. In irrigation of 60 and 40% of field capacity, the use of poultry and sheep manures reduced ion and malondialdehyde leakage of leaves. At 40% of field capacity, plant height in poultry and sheep manures increased by 28% and 38% compared to chemical fertilizer. Also, in 40% of field capacity, biological yield in poultry and sheep manures compared to chemical fertilizer showed a 4 and 8% increase. Increasing the total phenol content in sheep manures compared to chemical fertilizer in irrigation was 40% of field capacity. Overall, the results showed that the use of organic fertilizers by improving physiological traits to some extent increased the resistance to drought stress. Also, in drought stress conditions, organic fertilizers were more effective than chemical fertilizers. In general, based on the findings of this research, it can be concluded that the use of organic fertilizers in order to provide all or part of the nutritional needs of Atriplex maintains the optimal yield of Atriplex plants under water stress conditions.

Identifying environmental factors affecting the habitat preference of medicinal species is a fundamental and valuable action for cultivation and domestication and reducing the pressure on natural resources is a fundamental and valuable action. This study was performed with the purpose of investigate the most important ecological factors affecting the habitat of Stachys lavandulifolia Vahl in eastern Alamut rangelands located in Qazvin province. For this purpose, the maximum entropy in MaxEnt software was used. Species presence points were recorded in field operations. Also, in the habitats of this species, soil samples were collected by random-systematic method (4 transects and 72 soil samples). soil variables were measured in the laboratory. Geostatistical methods were used to make maps of soil variables. Finally, 19 environmental variables maps were entered into MAXENT software including soil, climatic and physiographic. Based on the results, the accuracy of the habitat suitability map was 95%, Also, the most influential environmental factors on the habitat suitability of this species are soil magnesium (0.3-1.3 mM), organic matter, average annual rainfall (more than 400 mm), average annual temperature, altitude (up to about 3100 m). The optimal habitat of this species has been in soils with heavy texture, low electrical conductivity and neutral acidity (7.5) in this region. Also, increasing soil potassium has a positive effect, and increasing the soil sand and lime have a negative effect on the establishment of this species. The results showed that the favorable areas for the growth of the studied species is 5599.67 hectares, which covers 7.93% of the total study area.

The current research is based on the existing ecological conditions in the Zagros forests and knowledge of the response of forest trees to these conditions and the purpose of this study is to investigate the effect of topographic factors, tree characteristics on of fine roots biomass of gal oak (Quercus infectoria Oliv.) and also to compare the amount of nitrogen, phosphorus and potassium in the fine roots of trees in the Shineh region, Lorestan province. Initially, random and regular sampling method used with 100×100 meters of statistical network. Tree characteristics, including diameter at breast height, crown diameter, height/DBH ratio, also the concentration of the NPK on two altitude classes and also the fine root biomass in three directions, at a depth of 0 - 30, slope 15 - 60% and altitude of 1300 - 1500 meter above sea level were measured. The results showed that depth and geographical directions had significant effect on the fine roots biomass. This biomass is greater at a depth of 15-30 cm and in the east direction. Above mean sea level had no significant effect on root biomass. The biomass was greater at a slope of 46-60 percent. Also, crown diameter, height coefficient and amount of NPK have significant effect on root biomass of gal oak. But the DBH and the height of the tree have no significant effect on root biomass. Nitrogen had the highest positive correlation and potassium had the least negative correlation with the amount of fine root biomass. Knowing more about the characteristics of trees according to the state of forest stands can be effective in protection and restoration, especially in their treatment operations.

In order to investigate the effect of different intensities on the quality and quantity of forage in the Bromus tomentellus Boiss species, mountain ranges in the northeastern part of the Delfan city were selected. Three zones with different grazing intensities were selected including the grazing area (reference), medium grazing (key) and heavy grazing (critical). In each region, sampling of surface coatings was done in a systematic randomized way in 30 plots 1*1 square meter during three transects with a length of 100 meters. Vegetation characteristics such as canopy cover and density were calculated and then the production per unit area was calculated by cutting and weighing method. The aerial parts of B. tomentellus, in each treatment, were used to harvest 60 plant aerial parts and transferred to the laboratory. In the laboratory, the samples were dried in the oven at 65 °C and milled and chemical decomposition was performed on them. Analysis of variance and Tukey test were used for comparison of means. The results showed that the percentage of crude protein, potassium, phosphorus, calcium, digestible dry matter and metabolic energy, density, crown cover, and production of the species studied were significant in the areas of grazing, medium grazing and heavy grazing (P <0.01). In both heavy and medium grazing treatments, the protein decreased by 28% and 8%, respectively. Also, potassium, phosphorus, calcium, digestible dry matter and metabolic energy in two treatments under the grazing have a significant decrease compared to the exclosure area. The amount of production, density and canopy in the key area (17, 16 and 31 percent, respectively) and the critical area (42, 69 and 68 percent respectively) are lower than the reference area. The result of this study showed that heavy and medium grazing would reduce the quality and quantity of B. tomentellus species.

Oak mortality is one of the most important management problems in the Zagros forests and the first signs of oak mortality appear in the canopy of trees. The aim of this study was to investigate the trend of oak mortality in trees with different crown-dimensions in the forests of Baneh County (northwest of Kurdistan province). For this study, four sites in the northern slopes (Saraki and Mirhesam sites) and southern (Belveh and Gandman sites) in Baneh county were selected. At each site, floating sample plots (with 100 trees) were selected and the trees were numbered and measured (two large and small diameters of tree crowns). The crowns of the trees were divided into eight classes. At the end of summer of every year (2019 and 2020), the status of trees in the five oak mortality class was reviewed and recorded. The weighted average of decay codes was used to compare the rate of decline in two consecutive years and Wilcoxon non-parametric test was used to compare the decline codes in the crown area classes in two consecutive years. The results of Wilcoxon test showed that in the four sites studied, there was a significant difference between the decline codes from 2019 to 2020. At Sarki and Belveh sites (oak mortality site), the most oak mortality was observed in the crown and 11 and 17 m2 crown classes. In control sites (Mirhesam and Gandman), the highest increase of oak mortality trees was observed in the 5 and 11 m2 crown classes. The results of oak mortality weight of four stands, showed that the highest increase in oak mortality was observed in the 11 m2 crown classes of Sarki site (with 0.67 increase) and 5 m2 classes in Belveh (with 0.33 increase, respectively) and the highest oak mortality in the southern slope. In order to manage forest stands in the study area, it is suggested to focus the breeding operation and remove the dried branches on small to medium-sized trees (trees with a canopy up to 25 m2) and the decay trend of oak trees in the study area be monitored.

Ecophysiography is the geography of the earth and the relationship between physiography and the ecosystem. Ecophysiography is a basis for planning processes to study the characteristics of terrestrial systems concerning the interactions between terrestrial physiography and living organisms. Due to the current state of ecosystems and the increase in natural disasters for ecosystem sustainability, the assessment of ecophysiographic features provides a basis for solving ecosystem problems to provide better ecosystem services. The environment has an important role in determining the affecting factors of the spread, distribution, and survival in forest communities. Therefore, the present study analyzed the relationship between the quantitative characteristics of trees and physiographic factors in slope aspects and elevation ranges. In this study, the data was prepared in six square sample plots with dimensions of 100 m ×100 m in oak and hornbeam-dominated stands in three altitude ranges from 1200 to 1600 meters above sea level and in two slopes aspects. The plots are selected from fully protected areas to minimize the effects of human degradation. The diameter at breast height, total height, and large and small diameters of the canopy of all trees were measured. The parameters of basal area (cm2), canopy area (m2), and average canopy diameter (m) of trees calculated in each sample plot. Statistical tests included analysis of variance and comparison of means performed by Tukey test at the significance level of 0.05 to investigate the effect of elevation and independent t-test to evaluate the effects of geographical aspects in R software. The results showed that the elevation and the slope aspects have not significantly affected the trees’ diameter and basal area (p>0.05), but there was a significant difference in tree height, average canopy diameter, and canopy area (p≤0.05). The northwest slope was more homogeneous in all the studied features, but the changes were more in the northeast slope. The height and canopy of trees from the valley to the peak increased significantly (p≤0.05). There was a significant correlation between the diameter and the basal area, and the canopy area and the average of the canopy diameter (p≤0.05). The study showed that the ecophysiographic factors (including elevation and slope aspect) affected some quantitative characteristics of oak-hornbeam stands in Arasbaran, and the trees had significant changes under the influence of these factors and due to the nature of the tendency to adapt to the environment.  The size of the trees in the top, slope, and valley in the northwest slope was homogeneous, and in the northeast slope from the valley to the top, the trees had larger sizes. This situation also existed for the basal area of trees. But in the northwest direction, they had a larger crown area in the slopes of the trees, and in the northeast direction, the peak trees had a larger crown area. These two regions did not have significant differences in crown characteristics. The trees in these two regions were similar in terms of crown dimensions.

The Moroccan locust (Dociostaurus maroccanus Thunberg) is one of the most important species of locusts in Iran and many parts of the world, which causes great damage to pastures and agricultural products every year. Since a main part of the life cycle of this insect is spent in pastures, recognizing the relationship between locusts and plant properties are important in the rangeland management and locust control programs. The Qaraqar-Bozorg region in Golestan province is one of the centers of Moroccan locusts, parts of which are attacked by this pest every year. The present study - It was done in April 2019- investigates the relationship between Moroccan locust density and biophysical properties of the main vegetation types in this region. Moroccan locust densities were estimated using randomly-systematic plotted samples of 1 square meter at three sites of (without, medium and high locust density) in Qaraqar-Bozorg rangelands. Plant properties based on main vegetative forms (grass and forbs) including canopy cover percentage, density and their heights were estimated in each plot. The correlation between quantities of main vegetative forms and locust density was then tested using Pearson correlation coefficient. The results showed a significant positive correlation between locust densities and the canopy cover percentage, density and height of the grass vegetative forms (with coefficient of determinations of 0.41, 0.45 and 0.34, respectively). Results also showed that Moroccan locust prefers habitats that grasses are dominant. Care should be taken in interpreting the results merely based on the preference of vegetation types by Moroccan locust. It seems the combined effect of environmental factors in dominated grass habitats such as soil texture, moisture availability and shade cast might have an effect on the preference of grass habitats by Moroccan locust in the study area. This results can be useful in planting projects or rangeland improvement, as well as in control programs of Moroccan locust and in finding highly infested areas with this pest.

Understanding ecosystems and their zonation based on their characteristics and sensitivities is an essential step in protecting natural resources and the sustainability of their habitats. The Mediterranean Wetland Habitat Classification System (MEDWET) is used to identify Bakhtegan wetland, Fars Province, Iran, by hierarchical classification of their habitats, in which they are identified and demarcated by dominant vegetation, soil, and hydrology. Remote sensing methods are used to obtain the maximum possible information with the least fieldwork. The data for the water regime were obtained from seasonal satellite images (1997 to 2009) and their analysis in GIS using ArcGis software. Field visits and sampling were performed for sections with little or no information, such as wetland plants and lake bed profiles. After identification, plant samples were classified based on life cycle (annual or perennial), and habitat (submerged or submerged). The digital layers of all information were stacked in ILWIS software to separate different habitats. Habitats were designated with international identifiers, and a habitat zoning map was prepared. A total of 51 different habitats were identified, the most important of which were lacustrine – littoral – emergent – nonpersistent - intermittently flooded - polysaline LLENIP, (607100 m2), water surface - salt crust - intermittently flooded – mesosaline, LLOAIM (154561200 m2), non-vegetated - salt crust - seasonally flooded – mesosaline, LLSASM (15790400 m2), and palustrine - nonvegetated - salt crust - seasonally flooded – mesosaline, P-SASM (25967300 m2), and salt crust - Intermittently flooded – mesosaline, P-SAIM (20503100 m2). The result of this research and the resulting map is the first step for recognizing sensitive and vulnerable areas of the wetland, and further planning for utilization management and protection of the ecosystem, especially the aquatic plant communities.

Considering the current state of the Zagros forests and the necessity of using information related to quantitative characteristics in the management of these forests, it is essential to prepare more accurate information so that the control of this area can be done more accurately. One of the ways to obtain statistical information is linear sampling (transect.( In this regard, the present study aims to compare the efficiency of the length of transects with the inventory method and to investigate the performance of this method in forests with different densities.
To carry out the present research, taking into account the area and topography of the region, a square survey grid with dimensions of 100 x 100 meters was used in the customary forests of Olad -Ghobad located in Lorestan province. Then 30 one-hectare plots were implemented in the area and fully surveyed. In the next step, transect sampling was performed in two modes using tree position simulation in GIS. In the first step, transects with lengths of 25, 50, 75, 100, and 125 meters were harvested inside each one-hectare plot. Then, the quantitative characteristics of the trees that were placed along the desired tracts, such as two diameters perpendicular to each other, were measured. In the second stage, the forest area was divided into three classes low density, medium, and dense, and again transects with the studied lengths were created again. Quantitative characteristics of trees were measured on transects in each class. The results of characteristics comparing the number of trees per hectare and canopy cover showed no significant difference between different transect lengths with a full inventory. The results of estimating the E%2×T index in the study area showed that for both characteristics of the number of trees per hectare and canopy cover, a 25-meter transect with values of (19038.82) and (958338.9) have the highest precision, respectively. The results showed that the value of this index has the highest accuracy for medium numbers in hectare with 75 m transect length, and low canopy covers with transect length of 50 m.

Today, livestock outflows from the forests of the north of the country have created environmental and social challenges and problems that have caused concern to natural resource policy makers.  The re-emergence of livestock and ranchers illegally in the forests for various reasons has created disputes and tensions with conservation systems. In this regard, the present study was conducted to analyze the key drivers affecting the return of livestock in the forests of Golestan province. The sample population in the study consisted of 20 ranchers returning to the forest and were purposefully selected. After collecting information, using the cross-effects technique and using MicMac software, 27 indices extracted from the Delphi method were analyzed. The results of the dispersion of indicators in the axis of impact and effectiveness, indicate the instability of the livestock exit system from the forests of the province and its organization, based on which five variables were identified. Findings obtained from the effect-matrix direct dependence and dispersion of indicators showed that the lack of accurate implementation of the provisions of the plan in the forest, lack of support from government agencies in the area of ​​housing, lack of alternative job opportunities and diversification of income sources, lack of pasture Natural resources for livestock and the high cost of complementary inputs, non-timely payment of salaries by people subject to the plan by the government, various procedures and instructions contrary to the plan, lack of proper planning in housing and livestock farms, as the most important effective indicators and Strategies were evaluated in the return of livestock to forest areas. According to the obtained results, the compilation and preparation of a 10-year transformation document in order to organize the settled forest households is the most important proposal with a forward-looking approach to the subject under study.

In order to manage the forests and optimal and sustainable utilization of the forest, it seems necessary to know the information on the volume of the residual stand. In this study, a systematic randomized inventory was carried out in 186 circular 10-acre plots in the educational and research forest of Darabkola, Sari, Golestan, Iran and the volume of each plot was obtained. In the next step, the physiographic layers of the area were prepared using the topographic map and the vegetation characteristics were prepared using the LISS-III image of the IRS-P6 satellite with a resolution of 23.5. After preparing physiographic layers and vegetation characteristics, their value was calculated for all plots. Then, regarding these variables and using two methods of multilayer perceptron neural network and multiple regression model, modeling was done. The results showed that the multiple linear model could model the volume changes in the region with higher accuracy (R2=0.75 and RMSE=0.3). The results of this research can be used in management planning and as one of the effective factors in the design of logging routes and forest roads so that areas with larger volumes are covered more.

Tamarix sp. Shrub species are extended in steppe and salt marsh areas. These species have adapted to the most hard climatic conditions. Therefore, it is distributed in the driest regions of Iran. The native plants are rarely used for landscape in Iran. So, identifying native plants that has the potential to be ornamental, in addition to the attractiveness of landscape can prevent soil erosion. In this study, 60 Tamarix genotypes from 11 regions in Markazi province were studied during spring and summer and subsequently morphological characteristics were evaluated based on quantitative and qualitative (as codding) traits. Inflorescence length on current shoots, number of flower clusters per shoot, flower cluster length, current shoot color, annual shoot diameter, flower color, tree growth habit, main branch diameter, main branch length, branch density, leaves density, branch flexibility, etc. were studied. The best time for measurement of traits was in late April to early June. Based on the results, there was an excessive diversity between the quantitative and qualitative studied characteristics, which reflected the rich germplasm of this province. In order to choosing native plants in the urban landscape, one should look for species with low water requirements, less maintenance and high ornamental potential. The maximum positive correlation was obtained between tree growth vigor and tree density and the maximum negative correlation was observed between flower cluster diameter and annual stem color. Khosbijan genotype could be introduced as a shrub with ornamental use in landscape due to their appropriate morphological traits such as the longest inflorescence, upright tree form, high density of foliage and brunches.

Land use/cover change is one of the main factors in environmental changes. The changes directly affect the value of ecosystem services. The purpose of this research is to evaluate the effect of land use/land cover change in the Kashkan area on its ecosystem services. This research was carried out in three stages, including the analysis of land cover changes, prediction of changes, and carbon storage and sequestration. Landsat satellite images of TM, ETM+, and OLI sensors were used to prepare land cover maps in three periods of 1370, 1385, and 1400. In the TerrSet software environment, LCM modeler was used to predict land cover change in 1430 and ESM modeler was used for carbon storage and sequestration. Carbon storage data were extracted from IPCC emissions. Validity was evaluated using an error matrix. The results show that forest ecosystems have had the most land cover changes and the most hot spots of carbon loss are in forests. In 1370, about 44.35% of the area, equivalent to 4113.8 square kilometers, was made up of forest ecosystems, while in 1400, it decreased to 26%, equivalent to 2411.7 square kilometers. According to the future study scenario in 1430, about 1205.8 square kilometers of the area will be forest ecosystems, and between 1400 and 1430, about 158,000 mg of carbon will be released. The results can be used by environmental planners and managers to improve and protect the natural covers, especially forests, to protect ecosystem services and their continuity.

Most macronutrient accumulation occurs in tree leaves and there is a strong relationship between leaf nutrient change and tree decline. The aim of this study was to investigate the changes in leaf nutrients in healthy and withered trees in the forests of Marivan and Sarvabad county in Kurdistan province. For this purpose, Garan (Marivan) with declining trees were selected as unhealthy site, while Dezli (Sarvabad) was determined as a control site containing heathy trees. In both sites, trees were selected on the northern and southern slopes, where five healthy trees and five withered trees (totally, 30 trees including 10 trees in control and 20 trees in declining stands) were selected and numbered. 20 leaves were harvested from the four sides of a tree crown in the first week of August 2019 and 2020. The concentrations of nitrogen (N), phosphorus (P) and potassium (K) were measured using digestion method. Due to the normality of the data, one-way analysis of variance, Duncan and paired t-test were used to analyze these data. The results showed that the amount of N in the decline site was higher than that in the control site. In contrast, leaf P and K contents in tress of control was significantly higher that decline stands. and potassium elements, the amount of these elements in the control mass was higher than the decaying mass and had drought. The highest reduction of N and P were observed in withered trees in the northern and southern slopes and one-way analysis of variance test confirmed the significance of the difference between K (2019) and P (2020) in the six groups of studied trees. On the other hand, changes in leaf nutrients between 2019 and 2020 demonstrated a decreasing trend for N and P and an increasing trend for K, where the paired t-test confirmed the significant change in nutrients of tree leaves in two consecutive years. To improve P and K in decline trees, foliar application of these macronutrients could be suggested in a short-time period, and in the long run, susceptible ecosystems should be rehabilitated by reforestation with rainwater catchment system and protection systems.