فصلنامه تحقیقات مرتع و بیابان ایران
سال سی‌ام شماره 3 (پیاپی 92، پاییز 1402)

 Salinity is one of the most basic abiotic stresses in arid and semi-arid regions, so it limits plant vegetative and reproductive growth. Soil salinity spreads due to irrigation with salty water, improper drainage, and salt accumulation in desert and semi-desert lands. Licorice (Glycyrrhiza glabra L.; legume family) is one of the most valuable halophyte plants used worldwide as a medicinal-industrial plant. Considering that in the existing studies, the threshold of tolerance to licorice salinity has not been accurately reported, in the present study, the aim was to determine the threshold and investigate some quantitative characteristics of licorice in response to different salinity levels. 

To investigate the salinity tolerance threshold of licorice plants to different levels of salinity stress, an experiment was conducted in the form of a completely randomized design with three replications in the pot environment in the greenhouse of the National Salinity Research Center located in Yazd province. Salinity treatments for irrigation water included 0.6, 3, 6, 9, 12, 15, and 18 dS/m. At planting, all pots were irrigated with tap water until establishment and greening. After four days, salinity levels were increased to reach the desired salinity. In this study, various plant characteristics such as plant height, leaf area, aerial and root parts dry matter, relative water content, ion leakage, and potassium and sodium content were measured. Additionally, salinity tolerance thresholds and a 50% reduction in yield were calculated using the Mass-Hoffman model. Data variance analysis and determination of threshold values and salinity tolerance coefficients were performed using SAS Ver 9.2 statistical software. 

The analysis of variance indicated that all the studied traits in Glycyrrhiza glabra (licorice) were significantly affected by salinity. The increase in water salinity from the control treatment to 18 dS/m resulted in a 90% reduction in plant height, 88% in leaf area, 94% in aerial part dry weight, 73% in root dry weight, 22% in relative water content, 0.42% decrease in potassium content, and an increase of 13% and 2.63%, in ion leakage and sodium content in the plant respectively. The plant salinity tolerance threshold indicated that the plant salinity threshold was calculated based on irrigation water salinity. In addition, it was obtained for root dry matter equal to 2.89 ds m-1. The slope of root dry matter yield reduction per unit of salinity increase in terms of ds m-1 was obtained as 5.50%. Also, the salinity of the irrigation water, which caused a 50% reduction in yield and zero yield, was calculated as 10.98 and 21.06 ds m-1, respectively. Also, the salt tolerance index (ST-index) was estimated at 11.40 ds m-1.

Considering that the salinity level of irrigation water, which caused yield reduction to zero was equal to 21.06 ds m-1, this plant is classified as relatively resistant to salinity stress.

Rangelands provides a wide range of products and services to local communities. In the discussion of rangeland management, it is necessary to note that the monoculture economy is fragile. As long as only attention is paid to rangeland forage for livestock feeding, the users' economy will be very shaky and fragile. Therefore, increasing income, economic stability of rangeland users, creating employment, and sustainable development require multipurpose management and utilization of existing resources. The present research evaluates the relative advantage of various exploitation methods of local communities in the summer rangelands of Hazarjarib Behshahr during 2018-2019. 

In terms of purpose, the research is applied, and regarding the research method, it is classified as descriptive-survey research. It is also a quantitative study, given the nature of the data. The statistical population included all users of the customary summer rangelands of Boznesam, Tirperu, Hashtpader, Mianband, Hajikord, Sefidkhani, Siahkhani, Zereshki, and Shaharam. The research tool is a researcher-made questionnaire whose face validity was confirmed by a panel of experts. Its reliability was calculated between 0.78 and 0.86 for different components based on Cronbach's Alpha formula. Using the census method, 85 people were distributed. After collecting the data and analyzing the questionnaires, Kolmogorov-Smirnov, T-test, and LSD were applied in SPSS software version 24 to answer the research hypotheses. Therefore, a questionnaire was developed in several sections. The first part was related to demographic information, and the second was related to the cost and income of each of the main rangeland users, including animal husbandry, beekeeping, agronomy, medicinal plants, and integrated (multi-purpose) operations. The validity of the questionnaire content was determined using the formal validation method and consulting experts. The priority of usefulness of single subsistence activities and other multi-purpose exploitations was determined using analysis of the income-cost ratio (B/C). 

The results showed that the highest and lowest annual net income from livestock and medicinal plant activities was estimated at 191.1 and 2.3 million Tomans per household (user), respectively. The highest and lowest net profits in multi-activity were estimated at 29.7 and 6.9 million Tomans per household (user), respectively, related to the activities of agronomy-livestock-medicinal plants and agronomy-medicinal plants. The ratio of B/C of all livelihood activities is more than one and economical. In single livelihood activities, beekeeping, with a ratio of 3.7, and multiple livelihoods, agronomy-medicinal plants, with a ratio of 3.1, have the highest income generated about the share of livelihood resources compared to other exploitations. The results showed that livelihood diversity could generate more income for users. The analysis of the annual net income share of mono-livelihood and multi-livelihood operations as a percentage of the total income of the livelihood resources of the operators in the region showed that in the case of optimal use and better management of animal husbandry along with the sub-operations of beekeeping, medicinal plants, and agronomy can provide good income and employment among people. Statistics have rejected the assumption that single-subsistence and multi-subsistence exploitations have the same income. 

Beekeeping and agronomy are among the potential exploitations of the studied rangelands. These exploitations can be combined with livestock farming to compensate for livestock farming shortcomings, both to prevent livestock pressure on rangelands and to increase local communities' income. Therefore, by implementing combined rangeland projects, it is possible to maintain and restore rangelands and increase income for local beneficiaries. Because for many years, the use of rangelands in the study area has been single-purpose and only for providing animal fodder, multi-purpose use according to the capacities of each rangeland can bring many benefits to the users. Also, the high benefit-to-cost ratio of beekeeping can be a strategy for the employment of more people in the region after animal husbandry, to prevent pressure on the rangelands by animal husbandry, and to increase the income of local communities.

According to the law on the protection and exploitation of forests and pastures, any exploitation of natural resources by natural or legal persons must be done with the approval and permission of the country's natural resources and watershed management organization. Issuing grazing and grazing permits is one of the most important permits in the natural resources sector, which has its own implementation process. The evidence shows that there are various issues and problems in the process of issuing this license, and it is necessary to conduct a pathological scientific investigation to improve and correct the said process. The aim of the current research is to identify and categorize the existing damages in the process of issuing and renewing livestock grazing permits in pastures. 

This research is qualitative in nature and the technique of interviewing with focus groups has been used, in this research 96 beneficiaries and 31 experts from 6 provinces of Kerman, Isfahan, Hamadan, Kurdistan, Mazandaran and Semnan were purposefully selected and their opinions about the process and issues of livestock grazing licensing were analyzed using questionnaires and interviews, and the results were collected and analyzed using the content analysis technique.  

The results of this survey led to the identification and confirmation of 30 types of damage and problems in the process of issuing and renewing livestock grazing licenses in the form of three main categories (systemic, legal, and structural-executive), which in the branch of systemic problems, the component of multiple systems and the lack of a system integrated and intelligent, in the branch of legal obstacles, the component of time-consuming investigation of legal violations of applicants for grazing license renewal, division of grazing license among the children after the death of the owner of the grazing license, and in the branch of structural problems, the component of the weakness of monitoring and monitoring systems, lack of update of livestock and pasture statistical information , the low motivation of audit experts of natural resources departments and the lack of provincial credits have played the biggest role in the process of issuing grazing permits. Based on the results of this study, the issuing process in the investigated provinces takes 15 steps and 73 days, and the process of renewing the license is done in 8 days. 

In a general formulation and based on the findings and considering the problems that were stated before, in order to improve the process of issuing and renewing the Kera license, there is a need to take measures, for this purpose, it is necessary to create an integrated system, optimize the notification system, and automatically renew. Grazing license should be prioritized for responsible livestock farmers, updating information on livestock, pastures and determining the exact boundary of pastures and correcting or removing disturbing rules and instructions.

 The history of using American mesquite (Prosopis juliflora) for desertification control especially sand stabilization in Iran, is long. Considering the non-native nature of this species, attention should be paid to its ecological requirements, especially water needs or evapotranspiration (ET). This can contribute to the sustainability of sand stabilization programs and fine dust control and play an influential role in ecosystem development. Determining plants' evapotranspiration rates through lysimetry is one of the most accurate direct measurement methods. 

 The experiment using weighing and drainage lysimeters began in 2021 by planting seedlings inside lysimeters located at the Yazd Shahid Sadoughi Desert Research Station. It continued for two years. Nine lysimeters with a volume of 1.95 m³ (height: 170 cm, diameter: 121 cm) and a surface area of 1.15 m² were used. The ET rates and the crop coefficient (Kc) of Prosopis juliflora were studied under different soil moisture levels, including field capacity (no stress), 67% of field capacity (mild stress), and 34% of field capacity (severe) for various growth stages. Irrigation was performed by drip irrigation based on a fraction of field capacity with an appropriate number of droppers calculated for each treatment. For field capacity, 67% and 34% of field capacity treatments, 6, 4, and 2 droppers with an 8 liters per hour flow rate were used, respectively. Each treatment was irrigated twice with the appropriate amount of water based on soil moisture levels. 

 The results showed that Prosopis juliflora, under lysimeter conditions and the local climate, had an annual ET rate of 496.5 mm and a Kc 0.21. These values for the 67% and 34% field capacity treatments were 445.4 mm with Kc 0.18 and 275.2 mm with Kc 0.11, respectively. The ET rates of Prosopis juliflora at different growth stages revealed that the highest ET occurred during the development period of 124 days. This corresponds to rapid shoot, branch, and leaf growth. The ET rates in different irrigation regimes for field capacity, 67%, and 34% of soil moisture were 322.1 mm, 281.7 mm, and 158.3 mm, respectively. The lowest ET rate was associated with the final growth stage. The Kc for various growth stages in the field capacity treatment were 0.19, 0.24, and 0.14 for the first, second, and third growth periods, respectively. Under these conditions, a sigmoid growth curve (initial growth, development, and end of growth) can be defined for this plant. 

 It is recommended for afforestation with this species in Iran's southern regions, considering its optimal planting density to reduce competition. It is also recommended to pay attention to its ET rate, especially during the hot months of the year when it can exceed 2.5 mm per day. By examining and calculating the ET rates of mature trees with appropriate efficiency in sand stabilization and dust control, it was found that to create a canopy cover area, as mentioned, it is necessary to have 4846 m3 of water per hectare (equivalent to 484.6 mm per year) available to the plant. In other words, with this amount of ET, the plant can expand its canopy cover area to 19.5 m2 and, with 155 individuals per hectare (8×8 meters), cover 30% of the area, which is suitable for sand stabilization.

It seems that there is a mutual relationship between the classes of rangeland conditions and the characteristics of vegetation and biodiversity. However, there is relatively little and contradictory information in this regard. This research was conducted to compare the percentage of cover, litter, density, production, and numerical indicators of biodiversity among 11 types of plants in the Darmian-Sarabisheh protected area. 

After the field survey and identification of plant types, 11 plant types could be identified in the entire area. Sampling was done by the random-systematic method. For this purpose, three key areas were selected for each plant type, three transects were established in each key area, and 20 plots of 4 square meters were sampled in each transect. In each plot, the percentage of vegetation cover, litter, density, and production was measured. Canopy cover and litter percentage were determined visually. Plant density was calculated by counting plants per unit area. Production was estimated through cover vegetation by double sampling. The Adelaide method was used to estimate shrub production. The range condition was evaluated by the modified four-factor method. Species diversity components, including species richness, evenness, and dominance, were calculated by numerical indices. Also, species abundance distribution models (broken-stick, log-normal, log series, and geometric series) were applied to evaluate plant diversity graphically. The chi-square goodness-of-fit test was used to determine the most accurate fit of species distribution to each statistical model. To compare vegetation characteristics and species diversity components among the 11 studied plant types, one-way analysis of variance (ANOVA) and Duncan's multiple range tests were conducted.  

The results of the analysis of variance showed that between the 11 plant types studied in terms of vegetation characteristics, including the percentage of vegetation cover, litter, plant density, and production, and numerical indices related to species diversity, including species richness, evenness, and dominance, there is a significant difference at the p≤0.01. The mean comparison results showed that the highest vegetation cover percentage belongs to Artemisia aucheri - Stipa barbata (51.23%) in good condition. Acantholimon scorpinus - Cousinia eryngioides and Eryngium bungei- Cousinia eryngioides (46.27% and 40.44%, respectively) in poor condition are in the next. The highest plant density belongs to Artemisia aucheri - Stipa barbata (157 individuals) in good condition, followed by Eryngium bungei- Lactuca orientalis (126 individuals) in poor condition. Astragalus verus- Artemisia aucheri in good condition and Acantholimon scorpinus - Cousinia eryngioides in poor condition have higher species diversity (H¢=2.51 and 2.48, respectively). The species abundance of Eryngium bungei- Cousinia eryngioides and Eryngium bungei- Lactuca orientalis types (in poor condition) follows the log-normal series, which represents stable communities. Also, Astragalus verus- Artemisia aucheri and Artemisia aucheri- Stipa barbata, which are in good condition, follow the log series and the geometric series, which represent unstable and fragile communities. 

Range condition was independent of vegetation cover, production, density, species richness, diversity, evenness, and dominance. Some vegetation types are in poor condition despite high vegetation cover, density, and production. The present study also showed that high species diversity is observed even in the poor-condition class of vegetation types and does not necessarily indicate rangeland stability. Determining ecosystem stability and biodiversity based on species abundance distributions (SADs) is also impossible.

The study of vegetation changes under habitat protection conditions has a significant role in rangeland management. The studies confirm that permanent changes in rangelands in terms of plant composition, canopy cover, and forage production are influenced by ecological and management factors. This research was conducted to investigate and monitor the plant vegetation indices of semi-steppe rangelands of central Zagros for five years (2016-2020) at the Zayandehrud watershed management research site (Isfahan province). 

 Vegetation sampling was performed by a systematic random method in each exclosure and grazed site during 2016-2020. Vegetation characteristics, including the percentage of canopy cover of species, the percentage of gravel, bare soil, and litter were determined in each plot. For this purpose, four 100-meter segments were used. Then, ten plots (with 1 x 1-meter dimensions) were established with the same distance. In total, vegetation cover was measured in 80 plots of one square meter in exclosure and grazed sites. To calculate rangeland production, ten samples of each plant species were collected, and their canopy cover percentage was measured. After drying and weighing the samples, by establishing regression equations between the canopy cover percentage and the weight of the dried samples, the amount of production of plant species was determined separately for growth form and palatability class. Rangeland's condition was also evaluated according to the four-factor method and by scoring the factors of soil, vegetation, plant composition and age classes, and plant vigor. After collecting the data in Microsoft Excel, the variance analysis for the vegetation traits was done as a completely random design in a factorial format. This was done through the GLM (General Linear Model) method. Tukey's test investigated vegetation traits mean comparison in MINITAB 16 software. 

The analysis of variance showed a significant difference between vegetation indices, including total canopy cover and production, separately for growth form and palatability class. This was in the exclosure and grazed sites during the assessment period. The average percentage of canopy cover in exclosure sites during different years was 26.7%, 13.7%, 25.84%, 33.74%, and 13.33%. In grazed sites, it was 22.33%, 12.65%, 27.09%, 30.9%, and 11.59%, respectively. Total production at the exclosure site during different years was 624.26, 349.86, 556.79, 894.54, 664.53 kg/ha. Production at the grazed site was 456.45, 243.85, 455.6, 605.47, and 323.44 kg/ha, respectively. The highest values of canopy cover and production belonged to 2019, which was a wet year based on meteorological indices. The lowest canopy cover and production were assigned to 2017 (a drought year). The highest amount of litter was found at the exclosure site. The highest percentage of bare soil and annual plant canopy cover was obtained from the grazed site. The highest percentage of canopy cover and production in the exclosure site belonged to Stipa hohenackeriana. At the grazed site, Hedysarum criniferum and Stipa hohenackeriana accounted for the highest canopy cover and production, respectively. According to the four-factor method, the rangeland condition at the disclosure site was fair in 2016, 2018, and 2019 and poor in 2017 and 2020. At the grazed site, the rangeland condition was fair in 2018 and 2019 and poor in the rest of the years. 

 The comparison of vegetation parameters inside and outside the exclosure shows the good condition of vegetation inside the exclosure. It also shows the effectiveness of the exclosure in rangeland rehabilitation. Balanced livestock grazing on the vegetation caused no significant difference between vegetation characteristics, such as canopy cover in the exclosure and grazed sites. Continuous evaluation and monitoring of rangelands through creating a regular database of vegetation indicators and investigating their changes under different managements. This investigation of their relationship with climatic factors can provide the necessary background for fundamental rangeland planning and management.

Considering the extent of rangeland areas as well as the limited capabilities of the government in managing these areas, the issue of using potentials outside of the government management system to protect national areas has been raised by some experts. One of these abilities is the presence of people who are continuously present in the rangelands. The key question is this, whether rangeland utilizers optimally managed these fields as in the past? The answer to the question required an investigation of the phenomenon under the prevailing conditions. For this purpose, the issue of the "feasibility of reassigning range management to nomads and investigating its effects" in the pilot areas was recognized as reasonable. 

After holding several meetings, the summer rangelands of Dasht Lar, Tehran's Hadavand tribe were chosen as a pilot, and a memorandum of understanding was concluded between the representatives of the nomads and some related government bodies regarding the transfer of the management of the selected rangelands to the representatives of the nomads and the government's support for them. The implementation of the 4-year project started in 2014 with "action research" studies. Evaluations were done using two standard research methods, quantitative and qualitative. Qualitative evaluation of the performance of nomadic representatives in the management of nomads and rangelands. This evaluation quantitatively also included the impact of this management method on vegetation cover indicators. To carry out the last phase after rangeland typing, considering the rangeland area, vegetation changes, accuracy, and study time, 20 plots of 1 square meter were established along two transects of 500 meters. By the random-systematic sampling method, rangeland capacity indicators were calculated by cutting and weighing method, condition trend with trend scale, and exploitation percentage using production difference before the nomads entered and after they left the rangeland. 

The qualitative part of the study revealed that this management method had an average success rate of 40% in the region. The lack of serious volition of the custodian organization in transferring management to the nomads, the lack of allocation of government funds for the implementation of the programs and projects predicted by the nomad representatives, and the protection of the region were analyzed as influential reasons for the complete failure of the management decisions of the nomad representatives. The results of quantitative evaluations also showed that the status of the systems during the research period, the average, and the trend of the situation remained the same. Except for the customary central Kammerdasht (which was negative), all other systems were positive. In each year, the exploitation percentage was higher than the allowed limit (50%), ranging from 0.72 to 1.26. The variance analysis also demonstrated the effect of year on most of the investigated indicators at two levels of 5% and 1% significance. Comparing the averages also showed that, except for utilization percentage, other indicators had an increasing trend. 

In general, the management of nomadic representatives was evaluated as successful in improving the conditions of summer rangelands in the Ghoshkhaneh basin of the Lar Plain, so it seems that establishing the official presence of natural and legal representatives of nomads in the management of rangelands can be effective in improving the coverage of the area.

The present research on Lycium depressum stocks aims to study the vegetative responses (leaf area, leaf specific weight, leaf specific area, dry weight ratio of root to shoot, dry weight of leaf, stem, and root) of the pasture shrub of Kam Tigh against drought stress and the effect of soil amendment on these responses. 

 The experiment was conducted in a factorial design based on a completely randomized design, including the main irrigation treatment at four levels (100, 75, 50, and 25% of crop capacity) and sub-treatment of soil conditioners under semi-controlled greenhouse conditions. The experiment involved five repetitions and 160 pots for each combined irrigation and soil amendment treatment. Sub-treatments of soil conditioners, including Stacosorb hydrogel, were added at 3 grams per kilogram of soil in each pot in the lower part of the plant roots. Mineral Zeolite in 8 grams per pot was placed in the lower part of the plant roots. Nitrobacter was added in the amount of 3 cc in each pot in the upper root area of the plant. Mycorrhiza at 10 grams per pot was added to the lower plant roots. 

Generally, a significant difference (p<0.05) was observed in all irrigation levels between the treatments in each soil amendment material. In zeolite with mycorrhiza, the highest stem dry weight and leaf-specific weight were obtained at a 50% irrigation level. With the increase in leaf-specific gravity and drought stress, plant dry weight increased, and proline content decreased in Nitrobacter and mycorrhizal treatment, which differed from the treatment. Measurements of leaf area revealed that leaf area decreased from 1450 mm2 in 100% and 75% irrigation to 900 mm2 in 25% irrigation. This indicated the impact of drought stress on the leaf area. The highest specific weight of leaves at 25% irrigation was related to Nitrobacter with mycorrhiza. This modifier increased the specific weight of leaves from 0.0025 g/m2 at 100% irrigation level to 0.0028 g/m2 at 25% irrigation level. Leaf surface area in Nitrobacter treatment with mycorrhiza during 100% irrigation decreased from 400 mm2/g to 350 mm2/g during 25% irrigation. In hydrogel treatment without mycorrhiza, the dry weight ratio of root to shoot at 100% irrigation level declined from 2 grams to 1.4 grams in 25% irrigation. The dry weight of the leaf decreased from 1.4 g in 100% irrigation to 1.3 g in 25% irrigation. 

Biofertilizers enhance plant resistance to drought stress by improving vegetative characteristics. Nitrobacter treatments without mycorrhiza, hydrogel, and zeolite with mycorrhiza are recommended for planting this plant due to improved growing conditions. Since the Kam Tig plant is considered a medicinal plant, it can be used as a soil conditioner in the pharmaceutical and medical industries. This will enable better cultivation of the species. All organizations related to the cultivation of Kam Tig species can use the results of this research to enhance cultivation projects.