فهرست مطالب صالح کهیانی

Vulnerability context is one of the basic concepts of sustainable livelihood framework. The vulnerability contexts, including shocks, trends, and seasonal variability affect the rangeland users’ livelihoods. This study aims to assess the vulnerability contexts of rangeland users in three villages of Jalal Abad, Haji Abad, and Nahzatabad in Najafabad city. A structured questionnaire was used to measure the vulnerability contexts. From the statistical population of 68 people, 58 people were selected using Cochran's formula. The results showed that about 80% of the respondents evaluated the changes in vulnerable areas as high and 19% as very high. The results of measuring the attitude of the rangeland users of the three studied villages showed the shocks including air pollution and drying of plants and economic shocks with an average of 3.21 and 3.17, trends consisted of inflation and price and rangeland degradation with an average of 3.92 and 3.80 and the seasonality including drought, temperature increase and rapid melting of snow and frost and heat exhaustion of plants with an average of 3.69 and 3.68 had the greatest impact on livelihood vulnerability. Since vulnerability contexts are not one or two, but several factors of vulnerability may occur at the same time, this study suggests policymakers employ a multifaceted approach and a set of adaptive strategies in dealing with vulnerability contexts. In addition, since individuals, households, and communities affected by vulnerability contexts due to the spatial distribution in the geography of the land may not experience risks and vulnerabilities in the same way, future studies can show how different individuals, groups, households, and communities are exposed. In the face of vulnerability, including environmental hazards, and natural disasters.

Livelihood is abilities, assets, and activities that are needed for life and survival. Livelihood, as a means of better understanding the quality of life and well-being, is one a new approach in line with the goals of environmental sustainable management. Livelihood thinking introduces the basic resources through which, people can improve their lives. The main components of the sustainable livelihood framework include livelihood capital (1), vulnerability contexts (2), policies, institutions and processes (3), livelihood strategies (4), and outcomes (5), which have been the subject of various studies. Vulnerability contexts are one of the main components in the sustainable livelihood framework, which directly and indirectly affect livelihood capital. The vulnerability contexts are related to the external environment. The external environment or vulnerability contexts include shocks (i.e. livestock and human diseases and plant and animal pests, environmental hazards such as floods or earthquakes, and economic shocks), trends (i.e. population, biodiversity, migration), and seasonality (i.e. drought, flash floods, rains). One of the areas in which, the livelihoods of individuals and human groups are affected by vulnerability are rangeland resources. They have been reported to be vulnerable to the livelihoods of rangeland users depending on them; at the same time, the vulnerable contexts also affect the sustainability of livelihoods and rangeland resources. This study intends to specifically assess three main criteria and sub-criteria related to the vulnerable contexts of rangeland users in the central part of Najafabad County.

This research measures the criteria related to the vulnerability contexts of livelihoods of rangeland users in three villages of Jalalabad, Hajiabad, and Nahzatabad in the central part of Najafabad County. The statistical population was 68 rangeland users; According to Cochran's formula, 58 users were selected as a statistical sample. To measure the criteria of vulnerability contexts, three main criteria of shock, trend, and seasonality were taken into consideration. Prioritizing and extracting items for measuring the criteria of vulnerability contexts, according to the literature review, in the form of a preliminary questionnaire, was assessed and reviewed by an expert panel. Finally, by analyzing the views of the expert panel and prioritizing the examined items, 5 items in the final questionnaire and 15 items, total in the form of a five-point Likert scale (1-5) including very little (1), little (2), somewhat decreased (3), increased (4) and very increased (5) were investigated. The content validity of the questionnaires was confirmed by using the opinions of the expert panel and its reliability was confirmed by calculating Cronbach's alpha coefficient. After completing the questionnaire and recording the information in the Excel spreadsheet, data analysis was done using SPSS software, and graphs were drawn in the Excel environment. To prioritize and classify the items of vulnerability contexts in the three investigated dimensions, the difference in the standard deviation from the mean or the ISDM standard was used by using the sum of the points.

The results showed that 79.31% of the respondents with the highest frequency evaluated the vulnerability contexts (shock, trend, and seasonality) as high, 18.97% as very high, and 1.72% as moderate during the last 20 years, which affected their livelihood. According to Friedman's test, "drying of plants (rangeland and forest)" and "economic" shocks with an average rating of 3.21 and 3.17, and the shock of "natural disasters and unforeseen events (storms and fires, floods and loss of land)" with an average rating of 2.66, respectively, had the greatest and least impact on livelihoods in the last 20 years. It can be stated that the drying of rangeland plants is an objective and tangible issue due to the decrease in rainfall and extreme weather changes. Regarding dust, the pollution caused by this phenomenon is observed in most parts of Iran, and Najafabad is no exception. According to the Friedman test, the trends of "inflation" and "land degradation" with an average rank of 3.92 and 3.80, and the trend of "immigration of family members to other regions" with the lowest average rank of 1.90 have the highest and lowest impact had on livelihood, respectively. It can be said that according to the current conditions, the state economy dependent on oil, existing sanctions, global inflation, and high prices, are obvious and outstanding issues. According to Friedman's test, the items of seasonality "freezing and heat exhaustion of plants" and "increasing temperature and rapid melting of snow" with average rank values of 3.70 and 3.69 had the highest impact on the rangeland users’ livelihoods. "Occurrence of destructive and sudden floods" with the lowest average rating of 1.51 had the lowest impact on rangeland users. It can be acknowledged that the drought and the increase in temperature largely lead to people's lack of proper productivity of environmental facilities and potentials; including lack of water for various activities and low productivity of crops and many other activities that are directly related to people's livelihood.

Shocks, trends, and seasonality are among the factors and vulnerability contexts, each of which can have negative effects on the livelihood of rangeland users; so the cumulative and combined effects of these vulnerability criteria can permanently affect environmental resources, including rangelands. In the studied area, economic shocks, inflation and high prices, drought, and drying of plants affected the livelihood of rangeland users more than in other cases. In this regard, the study suggests adopting multifaceted approaches and adaptation strategies to deal with vulnerable contexts. Future studies can examine how individuals, groups, households, and communities face different areas of vulnerability, including environmental hazards, natural disasters, and other social and economic vulnerabilities. This helps the policymakers and planners to use a specific strategy in facing risks and crises in every situation, place, and local community and to take basic measures in line with the sustainable management of environmental resources, especially sustainable rangeland management.

Climate change is a global challenge that has had harmful effects on human health, the environment, and natural resources, especially rangelands and rangeland users’ livelihoods. Recognition and perception of local users of the sign’s climate change is a fundamental step in how to face and employ appropriate strategies to mitigate and adapt to the effects of climate change and environmental resources sustainability. This study assesses the awareness and perception of rangeland users on the occurrence of signs of climate change in the central part of Najafabad, including the villages of Jalalabad, Hajiabad, and Nahastabad. The statistical population of the study included 68 rangeland users, according to Cochran's formula, 58 of them were selected as a statistical sample. The perception of local communities about the occurrence of climate change in the three dimensions of rainfall, temperature, and wind was measured with 9, 9, and 5 items, respectively, in the form of a seven-choice Likert scale. After completing the questionnaire and recording the information in the Excel spreadsheet, data analysis was performed using SPSS software, and graphs were drawn in the Excel environment. The results showed that %77.59 of the respondents estimated a high level of understanding of the signs of climate change. From the set of components related to the perception of signs of changes in rainfall, temperature, and wind, the amount of water in springs, aqueducts, and deep wells (1), the intensity of temperature fluctuations in the region (2), and the wind speed (intensification of winds) in the region (3) were assigned the highest priority. In general, it can be concluded that in order to deal with the consequences of climate change and the sustainability of environmental resources, the perception and attitude of rangeland users could be effective in the success of adaptation policies and strategies.

Extreme weather and climate events have received increased attention in the last few years, due to the often-large loss of human life and exponentially increasing costs associated with them. These events have profound impacts on economies and livelihoods of many regions of the world. In this regard, diagnosis of extreme events in terms of intensity, duration, and frequency is crucial in order to frame mitigation and adaptation strategies to counter the impacts due to climate. The purpose of this research is to analyze the trend of changes in precipitation extreme indices to reveal the occurrence of climate change in Najaf Abad using 20-year daily statistics of Najaf Abad synoptic station from 2003 to 2022. For this purpose, the extreme indices of precipitation and the non-parametric Mann-Kendall test were used to investigate the changes. The results showed that the precipitation extreme indices present different patterns of intensity, duration and frequency of precipitation. PRCPTOT, CDD, CWD, R10mm, R20mm, R95p, Rx5day and SDII indices are decreasing and Rnnmm, R99p and Rx1day indices are increasing. But in general, due to the high dispersion and low amount of rainfall, the regional rainfall pattern cannot be clearly identified. The results of the analysis of the threshold indices of precipitation showed that the precipitation does not follow a regular trend and is irregular. The results of this research can provide solutions to workers and managers in line with correct management and use of other capacities to deal with possible situations. In addition, the combination of the results with long-term meteorological data and the perception of local communities affected by climate change can be examined and become a model for managers to make more appropriate and relevant decisions and plans.

Pastoralist lifestyle as the first social system of human society, despite its significant role in the economic, social and cultural development of the country, has faced numerous challenges that have led to its decline. In this regard, awareness of related issues and problems is essential for planning and formulating appropriate policies. In this study, the social- economic situation of some tribes of Chaharmahal Va Bakhtiari province during the past three decades 60, 70 and 80. population, number and types of livestock, fuel consumption, handicrafts and land tenure were analyzed. The required statistics and information were extracted from the data of socio-economic censuses of pastoralists in the years 1366, 1377 and 1387 in the archives of the Iranian Statistics Center. According to the results, the population and the number of households and the amount of fuel consumption of nomadic households in the province in Yilaq and Qashlaq have been decreasing from 1366 to 1387. In addition, the lands under annual cultivation have the highest level used by nomadic households compared to other types of land use. The evolution of traditional livestock systems according to the time and place requirements, strengthening the production infrastructure, organizing the production chain to the sale of handicrafts, forming and strengthening local institutions can act in the direction of the sustainability of the nomadic society and environmental resources through capacity building and empowerment of nomads and continuous training and then continuous monitoring can be followed and realized.

Policy formulation in agriculture and natural resources requires a sufficient understanding of the socioeconomic status of rural and nomadic beneficiaries. Meanwhile, regarding the country's economic growth, the nomadic community has particular importance in livestock production and related side activities.

Purpose of the research:

 In this research, some socioeconomic issues such as population, number and population of livestock, fuel consumption, handicrafts and lands were used to analyze the tribes of Khuzestan Province during the last three decades (60, 70 and 80).

Statistics and information required by the library method from socioeconomic censuses of the nomadic tribes in 1366, 1377 and 1387 in the archives of the Iranian Statistical Center were analyzed.Geographical area of research: The studied area includes Khuzestan Province, which is located in the south of Iran.

According to the results, the population and the number of nomadic families in Khuzestan Province decreased from 1366 to 1387. The results showed that most of the nomadic livestock were goats. The number of livestock nomads is higher in summer highland pastures than in winter pastures. The results also showed that most Khuzestan tribal households use firewood and charcoal for cooking and heat generation, and the fuel consumption of the Khuzestan tribes in different types of fuel consumption decreased from 1366 to 1387. The number of handicrafts produced by nomads increased from 1377 to 1387 and decreased from 1366 to 1377. In particular, the Pelas (tent) production among nomadic households has been higher than other handicrafts.

Developing agricultural activities, other handicrafts and other non-livestock activities can play an important role as sources of alternative and supplementary livelihoods, in which appropriate planning is necessary.

Determination of the sprouting potential of the Quercus brantii, the relationship between the shoots variables with the stump diameter and the number of shoots in each stool are the objectives of this study. For these purposes, a total of 93 stumps in the coppicing stands in Chaharmahal and Bakhtiari Province were selected in a growth period of personal protection. The logistic model was used to determine the potential for sprouting with age and stump diameter variables. The relationship between the shoots variables with a different model (linear and non-linear) was investigated. The results of the logistic model showed that a model including the stump diameter is the appropriate model for determining the potential of sprouting. The polynomial model in terms of model selection criteria among other models showed better results for estimating the three variable include dominant heights, mean height and number of shoots in each stool. The highest coefficient of determination (R²adj = 0.639) and the best result for the selection criteria of the model were the numbers of shoots per stool with the stump diameter. The results of ANOVA analysis showed that there were significant differences between different diameter classes. There is no significant difference between 5-25 cm and 25-55 cm diameters classes.

Stand density management diagram is one of the effective methods for designing, displaying and evaluating various density regime management options in the even-aged stand. The aim of this study was to determine the tools for density management in Quercus brantii even-aged stands. This diagram can be used to manage stand density and estimate the stand volume quickly. For the development of this diagram, four variables were used including dominant heights, number of tree per hectare, quadratic mean diameter and volume per hectare. Data were collected from 15 even-aged stands in 71 plots in the central Zagros located in Charmahal Va Bakhtiari province, Iran. The construction of this diagram was carried out with two equations of the volume and quadratic mean diameter with the dependent variables of the number of tree per hectares and the dominant height. Because of the error in the estimation of left and right sides of the diagram, simultaneous fitting was used. Among different indices of density, relative density index due to its independence on site quality and age of the stand as well as dominant heights as a criterion for determining the interval thinning were used for determining the growth status in this diagram. Finally, in order to clarify the application of this diagram, a practical example of the thinning schedule with a dominant height of 8 m and two thinning intervals was proposed for a stand with medium stocking volume. This diagram can be used for rapid estimation of the volume and to suggest thinning schedules in coppice management planning of Quercus brantii stands.

Awareness of the impact of forest various management methods on forest regeneration is necessary for forest maintenance and sustainable development. Gaps occurs in the forest canopy when trees dry out and die. Canopy gaps have great importance in forest ecosystems and increase the forest biodiversity by establishment of new species and development of natural scenery. This study aimed to investigate the effect of canopy gaps size and dead trees on natural regeneration in control compartment of the Experimental Forest Station of Tarbiat Modares University (Aghozchal district). Therefore، after an initial forest survey and determination of canopy gaps location، plots of 400m2 were sampled in the canopy gaps and adjacent to the existing dead trees and seedlings in the plots were studied in two separate parts: short (50cm height) seedlings. Also، species، number of dead trees، quality status (decay class) and destruction status of canopy gaps were recorded. The results showed that maximum and minimum number of dead trees based on the size of canopy gap was in very large group and small group respectively، and based on decay class is related to class 2 and 4. Logs become much more frequent than snags and the highest and lowest frequency of logs was beech and alder respectively and in contrast، for snags was alder and beech respectively. In comparison with other species، beech has the highest frequency in both parts of natural regeneration. Thus the presence of dead trees in the forest has a significant impact on the natural regeneration and forest biodiversity، high attention should be given for the important role of dead wood in order to achieve forest sustainability.