https://nrsj.malayeru.ac.ir/ New Research in Natural Resources sciences en daily 1 Sat, 21 Feb 2026 00:00:00 +0330 Sat, 21 Feb 2026 00:00:00 +0330 https://nrsj.malayeru.ac.ir/article_241174.html Loranthus europaeus L. is one of the principal parasitic plants threatening the fragile ecosystems of the oak forests in western Iran. Field observations in the Zagros oak forests of Javanroud County revealed a significant increase in the prevalence of this hemiparasitic species in recent years. To investigate this phenomenon, a 200-hectare area with severe mistletoe infestation was selected for detailed study. Through a comprehensive 100% inventory, the infection status, host tree species, and the influence of physiographic factors including slope, elevation, and aspect were analyzed. The highest infection frequency was observed in Quercus brantii (Persian oak) at 67.5%, followed by Crataegus aronia (Hawthorn) at 23.9%, and the lowest in Acer monspessulanum (Montpellier maple) at 0.85%. The analysis confirmed a direct correlation between mistletoe infestation and environmental variables (elevation, slope, and aspect), demonstrating that its distribution and spread are strongly controlled by physiographic conditions. Therefore, it is recommended that monitoring and removal programs for mistletoe be implemented regionally and in a targeted manner, with priority given to susceptible tree species and areas with favorable slope and elevation conditions. https://nrsj.malayeru.ac.ir/article_241175.html Aquaponics is a sustainable plant production system combined with fish farming. In this study, in order to design an aquaponic system for pepper cultivation, two different substrates including glass wool and zeolite, were used for plant establishment and their role on the performance of pepper plant and guppy fish. For this purpose, two aquaponic systems were designed and established. During the period, stable biological conditions were considered for each system in terms of light and temperature. After the end of the period, growth parameters (specific growth rate, weight gain, condition factor and survival) in fish and some plant characteristics (root length, number of leaves and flowering) were measured. The results showed that fish growth was different in both systems and in this respect, the substrate with glass wool had better performance, while the pepper plant showed better efficiency, especially the root length, in the aquaponic system containing zeolite substrate. According to the results, the type of substrate for plant establishment in an aquaponic system can affect the efficiency and performance of plants and fish. Accordingly, glass wool substrate is suitable for fish growth and can lead to improved growth indicators. https://nrsj.malayeru.ac.ir/article_241178.html Indigenous knowledge within each ethnic group represents a body of experience-based understanding that enables communities to meet their needs without depleting natural resources. Such knowledge plays a critical role in the sustainable development of societies. This study aims to examine indigenous knowledge related to rangeland management in two key areas—grazing management, and the rehabilitation and development of rangelands—among nomadic tribes with extensive experience in rangeland stewardship. The study was conducted across selected tribes from the provinces of Gilan, Ardabil, Bushehr, Chaharmahal and Bakhtiari, Lorestan, Razavi Khorasan, Mazandaran, Golestan, Semnan, Hamadan, and Isfahan. A qualitative, exploratory research design was adopted, employing a social constructivist paradigm (Reality constructed by society) with ethnography as the primary strategy. Social Learning Theory served as the theoretical framework, During which the indigenous knowledge of the nomads has continued to this day, through observation and imitation. Data were gathered through purposive and theoretical sampling, with the involvement of key informants to ensure depth and validity. Field data collection relied on semi-structured interviews and participant observation, with data collection and analysis conducted concurrently. Theoretical saturation was achieved after engaging 30 participants. This was the stage when no new data was produced as the interview continued. Audio recordings were transcribed, and findings were systematically organized following a postmodern ethnographic approach using a descriptive model. https://nrsj.malayeru.ac.ir/article_242235.html This study aimed to evaluate the efficiency of the "tabula" package in R for plant sociology studies and to assess the long-term effects of grazing exclusion on biodiversity components in rangelands of Zirkouh, South Khorasan Province. Sampling was conducted in grazed and enclosed (≥30 years) areas by establishing 60 plots of 4 m² using a randomized-systematic method along transects. Alpha diversity indices, beta diversity indices, and similarity coefficients were calculated using the tabula package. The results showed that despite higher basal density in the grazed area (2960 individuals), this area had higher species richness (25 species) compared to the enclosed area (22 species). The Shannon-Wiener (1.26 vs. 0.90), Brillouin (1.25 vs. 0.89), and McIntosh (0.38 vs. 0.21) diversity indices showed significantly higher values in the grazed area (p https://nrsj.malayeru.ac.ir/article_242236.html The aim of this study is to analyze the trend of vegetation changes in Iran over a 20-year period from 2000 to 2020 using the Normalized Difference Vegetation Index (NDVI) obtained from MODIS satellite data. So, the monthly Normalized Difference Vegetation Index (NDVI) of 2000, 2010, and 2020 for the period 2000-2021 is used to study vegetation cover. These images are obtained from the MODIS Terra Sensing Satellite (MOD13A2). Therefore, to analyze the trend of changes in the monthly NDVI time series data and process them in the GIS software environment, the NDVI index was divided into 5 classes. An examination of the average annual changes in the NDVI index from 2000 to 2020 showed that the highest value of this index was observed in different years in the northern, northwestern parts, and sporadically in the western and southwestern parts of Iran. An examination of the changes in the NDVI index over a 20-year period showed that in the entire area of Iran, this index increased in about 25% of the study area and decreased in about 75% of it during the period 2000 to 2010, 2010 to 2020, and 2000 to 2020, respectively. An examination of the NDVI vegetation index in five classes: 0.1 -0.2, 0.2 -0.4, 0.6 -0.4, and more than 0.6 in the years 2000, 2010, and 2020 shows that these classes accounted for 52.61, 39.02, 6.28, 1.21, and 0.88 percent of the study area in 2000, respectively. Also, these classes accounted for 44.28, 35.36, 17.8, 1.62, and 0.94 percent of the study area in 2010, respectively, and 40.05, 39.21,18.08, 1.75, and 0.92 percent of the study area in 2020, respectively. An examination of the percentage changes in the area of different NDVI classes in Iran from 2000 to 2020 showed that during this period, the percentage of the area of classes 0.2-0.4 and 0.6-0.4 increased, and this increase between 2000 and 2020 was about 18.36% and 0.85%, respectively. The study of changes in vegetation classes showed that the NDVI vegetation index was in the classes 0.1-0.2, 0.2-0.4, 0.6-0.4 and more than 0.6, with the highest percentage of vegetation cover in the classes 0.1-0.2, 0.1-0.2, which accounted for 91.63% in 2000, 79.63% in 2010 and 79.25% in 2020, which had a decreasing trend. While the class 0.6-0.4, which included less than 2% of vegetation cover, showed an increasing trend. The highest percentage of vegetation cover was in the classes 0.1-0.2 and 0.1-0.2, which accounted for more than 90% of vegetation cover, and less than 1% of the area of the region was in the class greater than 0.6. In Iran, classes 0.4-0.2 and 0.4-0.6 have had an increasing trend, and class 0.1-0 has had a decreasing trend. The results showed that during this period, a large part of the study area experienced a decrease in vegetation cover, such that only 20.78% increase and 22.79% decrease in NDVI were observed. Also, a decrease in coverage was observed in the lower classes (0.0-1) of NDVI and an increase in the middle classes (0.2-0.4 and 0.4-0.6), indicating an increase in shrub and rangeland cover. This study confirms the effective role of remote sensing in analyzing ecosystem and vegetation changes at large scales. https://nrsj.malayeru.ac.ir/article_244191.html The pattern of the landscape and its corresponding changes is a reflection of environmental ecology. Ecosystem function varies due to biophysical or management heterogeneity and vital responses to these factors in the landscape. The present study aimed to investigate the effect of different aspects of biodiversity on various functions of a heterogeneous landscape in the Central Zagros. For this purpose, Google Earth images were used to classify the area. This has led to producing classification maps with various patches and placing them in seven different classes in the plant community. Then, 4 to 5 patches of each type of plant patches that had a proper distribution in the area were selected for statistics, and depending on the size of each patch, the first 5 to 10 macroplots of 30*30 m2 were established randomly systematically. Sampling of cover and soil factors was done using 3 plots of 2*2 m2 in each macroplot according to the peak growth time of plant species. Ecosystem functioning was quantified based on key performance indicators of plant and soil components. To estimate ecosystem multifunctionality (EMF), standardized values of various performance indicators were calculated using the Z-score method, and their average for each patch was determined as a unified multifunctionality index using the "multifunc" package in R 4.2.2. In the next step, different indices of species diversity, functional diversity, and functional β diversity were extracted using the statistical packages "vegan", "FD" and "betapart" in R software. Finally, using the statistical packages "ggplot2", "ggpubr" and "ggcorrplot" in R software, regression and correlation relationships were investigated and the existing relationships were determined by analyzing the significance level and the value of the explanation coefficient (R2). The results showed that ecosystem functions likely depend on the value of the functional traits of its dominant species. Also, the functional identity of the dominant species influences multi-functionality through similar mechanisms that enhance individual functions.