مجله تحقیقات حمایت و حفاظت جنگلها و مراتع ایران
سال بیست و یکم شماره 1 (پیاپی 41، بهار و تابستان 1402)

Multiple factors have contributed to rangeland degradation. The present research aims to investigate the impact of policies and interventions by local communities on rangeland reduction through a qualitative approach utilizing the grounded theory method. The participants included 17 experts in natural resources, environment, and agriculture from Zanjan Province, selected purposively and interviewed using a snowball method until theoretical saturation was achieved. Data analysis employing open, axial, and selective coding yielded 427 concepts, which were categorized into 203 initial, 51 principal, and 8 core categories. The core categories encompassed: the decrease in rangeland area and increase in cropland area, the influence of government policies on rural lands and rangelands, shifts in rural socio-economic and farming systems, the impact of human interventions on rangeland degradation, the role of institutions in rangeland conservation, unsustainable exploitation of natural resources by rural communities, changes in rural land ownership, and the effect of collective utilization on rangeland degradation. The paradigmatic model centered around the central phenomenon of the research, "decrease in rangeland area and increase in cropland area," particularly post the 1980s. Government land policies, notably the nationalization of natural resources and land reforms, have significantly contributed to qualitative changes in rangelands, shifts in land ownership, reductions in rangeland area, and expansion of cropland. These changes have triggered shifts in socio-economic systems and land-use patterns in rural areas. Human interventions, especially population growth in rural areas and the intensified livestock population exceeding rangeland capacity, emerge as the most influential factors driving land-use changes, rangeland diminution, and degradation.

This research was conducted in 2020 in order to investigating the species diversity and abundance of oribatid mites in the oak and hornbeam forests of Arasbaran (Ahar and Kaleibar) in East Azerbaijan Province. Soil sampling was carried out in May and June. Oribatid mites present in soil samples were separated using Berlese funnels and clarified in relative solution, followed by preparation of microscope slides. After identification, counting, diversity and evenness indices (Shannon and Simpson), as well as species richness were calculated using Ecological Methodology 6.0 software. In general, 29 species of Oribatid mites from 27 genera and 23 families were identified in this study: Cosmochthonius lanatus Michael, Sphaerochthonius splendidus Berlese, Steganacarus (Tropacarus) carinatus Koch, Papillacarus pseudoaciculatus Mahunka, Rhysotritia ardua Koch, Nothrus biciliatus Koch, Hermanniella septentrionalis Berlese, Plesiodamaeus ornatus Pérez-Íñígo, Belba sp., Xenillus setosus Grobler, Ozman & Cobanoglu, Fosseremus quadripertitus Grandjean, Rhinoppia obsoleta Paoli, Ramusella (Ramusella) puertomonttensis Hammer, Ramusella (R.) sengbuschi Tokyoensis, Ramusella (R.) sengbuschi Str., Graptoppia (G.) sundensis acuta Ayyildiz, Rectoppia sp., Suctobelella sp., Austrocarabodes (Austrocarabodes) foliaceisetus Murvanidze & Weigmann, Tectocepheus velaus Michael, Eupelops acromios Haman, Berlesezetes aegypticus Balogh & Mahunka, Oribatula (O.) tibialis allifera Subías, Protoribates (P.) paracapucinus Mahunka, Scheloribates fimbriatus Thor., Ceratozetes conjunctus Mihelčič, Punctoribates angulatus Bayartogtokh, Grobler & Cobanoglu, Galumna sp., Pilogalumna sp. The highest abundance of mites in Ahar and Kaleibar belonged to Scheloribtes fimbriatus and Oribaiula tibilis, respectively. The calculated species diversity indices in the Kaleibar region during June were higher than those in May. The diversity and species richness of oribatid mites were higher in Kaleibar with oak vegetation, which could be due to the higher humidity and acidity of the soil compared to Ahar.

This study was conducted in 2020 with the objective of identifying dust source areas and soil susceptibility to wind erosion in the eastern part of Kerman Province, through the integration of field and remote sensing methods. In total, ten study areas covering 3007 square kilometers were identified based on remote sensing and field surveys during the winter of 2020. The dust-prone areas and the determination of the dust event frequency in the past 20 years were established using the optical depth index derived from MODIS Terra and Aqua satellites. To assess soil erodibility, wind erosion threshold velocity, and wind erosion rates, soil samples (17 in total) were measured in a wind tunnel at three wind speed classes: 15, 20, and 25 meters per second. Electrical conductivity (EC) values of soil samples (22 in total) were determined in the laboratory to create a soil salinity map using the kriging method. The results of the vegetation cover index were extended, and the linear relationship between EC was computed using Google Earth Engine and compared with kriging results, indicating significant salinity in the studied areas (EC>16). The analysis of prevailing wind directions and wind regimes based on data from five meteorological stations in the region demonstrated that the Rigān and Nasratābād stations, with transport potential of 561 and 1199 kg m^-1 s^-1, respectively, were classified as high-energy wind zones. Wind speeds of 40 knots (20.57 m/s) were prevalent in these areas. The assessment of soil erodibility revealed that the southern parts had the lowest wind erosion threshold velocity (between 6 to 8 m/s), classifying them as wind erosion-sensitive zones, with an accumulated wind erosion rate of 60 kg/m^2/year across the three wind speed classes. Based on the findings, the study areas are considered significant internal dust source areas, requiring management actions to control dust emissions.

Drought phenomenon stands as one of the most significant challenges of the contemporary era, exerting its influence on all ecosystems, including rangelands, at both global and regional scales. The heightened vulnerability of pastoralists underscores the necessity of embracing the concept of resilience. This research aims to investigate existing studies on the resilience of pastoralists under drought conditions and to propose a comprehensive model. A systematic review methodology was employed in this study. The findings of relevant domestic and international research were systematically analyzed using the seven-stage method of Sandelowski and Barroso. Based on inclusion and exclusion criteria, 30 studies were examined. The Waltz and Bausell method was employed to assess the validity of the extracted data. The reliability was also assessed through the Kappa coefficient, yielding a value of 0.87, indicating excellent agreement. The research results led to the formulation of a comprehensive model comprising seven factors: economic, social, individual, institutional, physical, educational-promotional, and ecological. Among these factors, the economic factor emerged as one of the most influential. The resultant model, identifying the factors that impact the resilience of pastoralists under drought conditions, provides the potential for enhancing crisis management, reducing vulnerability, and establishing the necessary groundwork for nationwide rangeland planning.

In light of the inefficiency of conventional and traditional forest conservation systems, the shift from government-centered to community-centered policies in forest management through social forestry becomes increasingly essential. Accordingly, the necessity for employing structural analyses with a futures-oriented approach is emphasized. Based on this premise, the present study aimed to identify and analyze the key drivers influencing the development of social forestry using a futures-oriented approach in the forests of Golestan Province. This research employed a mixed-method (qualitative and quantitative) design and was conducted through survey technique. The study population consisted of experts and forest protection personnel in Golestan Province. A total of 50 participants were purposefully selected as the sample. After data collection, 20 indicators derived from the Delphi method were analyzed using the MicMac software, incorporating cross-impact analysis. The results indicated that the social component has the highest impact, while the economic component has the least impact on the development of social forestry in Golestan Province's forests. Based on the obtained results, two factors, namely "Shifting from Centralized Government-Centered Policy to Integrated Community-Centered Management" and "Benefitting from Governmental Economic and Budgetary Support," from the policy-management component, "Conducting Facilitative Activities and Utilizing Village Promoters for Community-Centered Management" and "Identifying Rural Leaders and Involving Them in Community-Centered Forest Management" from the social component, and "Empowering Local Communities through New Job Opportunities and Strengthening Income Resources" from the economic component, were identified as the most influential key drivers for the development of social forestry in Golestan Province's forest management. In light of the findings, the development of a long-term vision document considering the three dimensions of forest protection, local communities, livelihood, and empowerment, with a future-oriented perspective, is recommended.

Plant reproduction is highly sensitive to stressors caused by both biotic and abiotic factors in nature. The success of plant establishment in the wild depends on various factors such as drought, grazing, availability of water and soil resources, and the mutual interactions among individuals, especially during the seedling stage. The concept of nurse plants, their effects, competition, facilitation, and the facilitative role in land restoration were explained using scientific sources. Through forest surveys and scientific resources, nurse plants and target plants in southern Iran were identified, and the role of each was examined with available scientific references. For this purpose, along the Persian Gulf and the Sea of Oman, accessible pathways were chosen to investigate vegetation cover up to an altitude of 1250 meters above sea level in sample plots of one hectare (100 * 100 meters). Sampling was conducted beneath the canopy of other trees or shrubs, and the plants were identified using scientific sources. The results of this study revealed that nine species belonging to eight genera and six families were identified as nurse plants, and seven species belonging to six genera and six families were identified as target plants. Among the nurse plant group, the genus Ziziphus Mill. from the family Rhamnaceae was the most diverse. Among the target plant group, the most diverse genus was Pistacia L. belonging to the family Anacardiaceae. Further research is recommended to explore the facilitative effects of nurse plant species and suitable methods for their use in the ecological restoration of dry areas in southern Iran in relation to the implementation of restoration and forest development projects.

In order to identify fungal agents associated with juniper trees in the highlands of Tarm County, samples of various tissues from affected trees were collected and subjected to cultivation and isolation using conventional methods. For species identification, both morphological and molecular methods were employed. To achieve this, DNA was extracted from 11 fungal species isolated. The internal transcribed spacer (ITS) region of their ribosomal DNA was amplified using universal primers (ITS-1 and ITS-4). Subsequently, their sequences were determined and compared to sequences available in databases to confirm the identification of species. In total, more than 150 fungal isolates were separated from diseased juniper trees over a span of three years. Based on morphological characteristics and ITS sequence analysis, the following fungal species were confirmed: Nigrospora oryzae (31 isolates), Penicillium spp. (9 isolates), Aspergillus spp. (4 isolates), Trichoderma spp. (5 isolates), Aureobasidium pullulans (33 isolates), Polyporus sp. (3 isolates), Phoma sp. (14 isolates), Phoma medicaginesis (3 isolates), Alternaria alternata (5 isolates), Alternaria sp. (9 isolates), Alternaria consortialis (6 isolates), Hormonema carpetanum (5 isolates), Hormonema sp. (9 isolates), Peyronellaea pinodella (4 isolates), Kabatiella microsticta (3 isolates), and Microsphaeropsis spp. (8 isolates). Most of these species are opportunistic pathogens, reported for the first time on juniper trees in Iran. These agents, in conjunction with host vulnerability due to infestations by phytophagous insects, drought stress, and pest attacks, accelerate the decline of the host trees.

Over time, the development of human settlements and activities has led to an increasing demand for natural resources, including ecosystem services, which subsequently drives changes in land use. As the process of land allocation establishes a link between the natural environment and human resources, the competition among conflicting land uses becomes significantly important in this context. Various tools are employed to address conflicts among land uses and simulate changes in land use. The CLUMONDO model is one such tool that employs various ecosystem services in the allocation and transformation of land uses, allowing for the simulation of land use changes and land cover. In this research, the CLUMONDO model was utilized to predict the extent of changes in demand for major land uses within the Qareh-Sou watershed over a 10-year period (2020-2030). Variables such as slope, aspect, elevation, the number of neighboring urban cells in a 7x7 grid., temperature, precipitation, distance from rivers, distance from urban areas, and distance from roads were incorporated into the model. An optimization approach was implemented to simultaneously enhance carbon sequestration capacity and designate additional residential areas in a specific scenario. The analysis of results was conducted using Idrisi Terrset and ArcGIS software. The findings indicated that over the next 10 years (2020-2030), land use changes for constructed areas and dense forests followed an increasing trend, while semi-dense forests and agricultural lands experienced a decrease due to their conversion into other land uses. This transformation was aimed at enhancing ecosystem services. This study showcases the possibility of harmonizing diverse, and at times conflicting, services in a way that also addresses human needs

The composition and diversity of plant and animal communities change over time due to environmental changes and disturbances. In this study, the impact of short-term disturbance on forest structure in the Daramazu Reserve, located in the Shineh Qallaei region of Lorestan Province, was investigated. For this purpose, 8 forest stands affected by landslides with a total area of 4.5 hectares were identified, and the quantitative and qualitative characteristics of trees (in 4 damage classes) were recorded. Subsequently, changes in tree density, species diversity, and distribution were evaluated. Based on the results, after the disturbance and landslides, half of the trees are in moderate and severe damage classes, and 17.2% of tree bases, as well as 4.1% of canopy cover, have been lost, mostly affecting young trees. Regarding structural indices, species diversity and evenness had a decreasing trend, while the Smith-Wilson index and uniform angle index increased. Despite not observing statistically significant differences in structural indices, the combination of consecutive droughts, irregular and intense rainfall, degradation, and subsequent landslides has led to noticeable changes in the forest structure over a short period of time, and unfortunately, this trend continues. Therefore, it is essential to implement further conservation measures and forest restoration, especially in areas affected by disturbances, to mitigate or halt the destruction of this valuable ecosystem.

Fire is one of the destructive phenomena that have devastated a significant portion of forests and grasslands in Gilan Province in recent years. This study aimed to investigate the temporal and spatial relationship between climatic variables and wildfires in Gilan Province. The wildfire variables included the number and extent of wildfires, and the climatic variables consisted of seven parameters over the past 26 years (2001-2026). Pearson correlation and regression analysis were utilized to examine the temporal relationship. The relative importance of climatic variables in wildfire occurrence was determined using Mean Decrease Gini (MDG) and Mean Decrease Accuracy (MDA) statistics. For modeling and generating probability maps of wildfire occurrence, 70% of wildfire locations and various machine learning models (Logistic Regression, Random Forest, Support Vector Machine, and SVM-RF Hybrid) were employed using the R programming language. Model validation was conducted using 30% of wildfire locations and the Area Under the Curve (AUC) metric. The temporal results showed that during the 26-year period (2001-2026), a significant negative correlation was observed between the number of wildfires and the average seasonal precipitation, while positive correlations were found between the number of wildfires and the average seasonal wind speed and maximum wind speed at a 95% confidence level. Furthermore, a significant negative correlation was observed between the extent of wildfires and the average seasonal precipitation at a 95% confidence level. The spatial relationship analysis indicated that the average maximum temperature, average seasonal precipitation, and average relative humidity had the highest importance in wildfire occurrence within the geographical extent of Gilan Province. Model validation results revealed that the Random Forest model (AUC: 0.82) and the SVM-RF Hybrid model (AUC: 0.79) outperformed others in predicting the occurrence of wildfires. Therefore, predicting wildfires resulting from climatic factors in the forests and grasslands of Gilan Province using the aforementioned maps is feasible and can significantly aid natural resource managers in implementing protective measures in high-risk wildfire areas. Hence, it is imperative that proactive measures be taken by the Natural Resources and Watershed Management Organization of the province to prevent future wildfires with greater sensitivity.

One of the most important pests of boxwood plants in the world is the bux moth, Cydalima perspectalis Walker (Lep.: Crambidae), which is a highly invasive and key pest on the Buxus hyrcana Pojark in the northern forests of Iran. The aim of this study was to determine the LC50 of three botanical insecticides, Neem Azal®, Ruy Agro®, and Bio1®, on the second instar larvae of C. perspectalis in laboratory conditions, as well as to investigate their efficacy on this pest in the forest. The experiments were conducted using a completely randomized design under laboratory conditions (25±1 °C, 65±10% relative humidity, and a 16:8 light-dark photoperiod) with six replicates. In the forest, the study was conducted on branches of 30 cm length in four cardinal directions of the tree, with three replicates in a completely randomized block design. The mortality rate was recorded after 24, 48, and 72 hours at the desired concentrations of each botanical insecticide along with a control (water). The results indicated that the LC50 values for Neem Azal®, Ruy Agro®, and Bio1® after 24 hours were 1.2, 0.90, and 0.50 ppm, respectively, and after 72 hours were 0.51, 0.11, and 0.11 ppm, respectively. In the forest, the recommended laboratory concentrations of 1 and 5.1 ppm for Neem Azal® and 0.50 and 7.5 ppm for Ruy Agro® were tested. Both insecticides exhibited effective control with respective concentrations of 1000 ml and 750 ml per 1000 liters of water in the forest, capable of controlling all larval instars of the box tree moth. Considering the intricate forest ecosystem, the use of insecticides is not recommended. However, in forest parks and areas exclusively inhabited by these plants, the use of less persistent bio-insecticides with limited impact range, such as Neem Azal® and Ruy Agro®, at the specified concentrations, can be recommended.

The role of hemolymph factors, especially hemocytes, in combating foreign invaders introduced into the hemolymph, is crucial, and identifying these cells and their diversity is the first step in insect immune studies. Therefore, the present study aims to investigate the morphology of hemocytes in the larvae of Spodoptera litura. Fifth instar larvae were used in the experiments. The larvae were reared under the conditions of a temperature of 25 ± 1 °C, relative humidity of 50%, and a photoperiod of 14:10 (light:dark). Based on observations using a light microscope at 40× magnification, five types of hemocytes, including prohemocytes, plasmatocytes, granulocytes, oenocytoids, and esferocytes, were found in the hemolymph of the insect larvae. Prohemocytes were rounded with a large central nucleus, and their abundance in the hemolymph of fifth instar larvae was approximately 10%. Plasmatocytes were commonly observed in a binucleated form with distinct elongated and pointed protrusions, as well as in a worm-like shape. These were the largest hemocytes in terms of longitudinal size. They had a centrally positioned distinct nucleus and granular cytoplasm. The abundance of plasmatocytes was approximately 38%. Granulocytes were round and larger than prohemocytes, characterized by numerous granules in their cytoplasm. They exhibited the highest abundance among hemocytes. Oenocytoids had a circular shape and a lateral nucleus, with an abundance of approximately 8%. Esferocytes had a vacuolated cytoplasm and thin cell walls. They had the lowest abundance among hemocytes in the fifth instar S. litura larvae, accounting for less than 1%.