Zahra Heidari Ghahfarrokhi; Pejman Tahmasebi; Ali Asghar Naghipour
Abstract
Assessing rangeland health is of great importance due to its impact on ecosystem sustainability. This study investigated the relationship between evaluation criteria of rangeland health and functional diversity indices in part of the Sabzkouh Protected Area (Chaharmahal Va Bakhtiari Province, Iran). ...
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Assessing rangeland health is of great importance due to its impact on ecosystem sustainability. This study investigated the relationship between evaluation criteria of rangeland health and functional diversity indices in part of the Sabzkouh Protected Area (Chaharmahal Va Bakhtiari Province, Iran). For this purpose, four rangeland sites with different grazing intensities (reference, light, moderate, and heavy grazing) were selected. In each site, two representative areas were sampled using three 30×30 meter macroplots. Plant functional traits, including plant height, various leaf traits, mean crown diameter, and growth form, were measured. Functional diversity indices, including Functional Richness, Functional Evenness, Functional Dispersion, Rao’s Quadratic entropy and growth forms, were calculated using the FD package in R 4.4.2. Additionally, three evaluation criteria of rangeland health, including soil/site stability, hydrologic functions, and biotic integrity, were evaluated. The data were analyzed using ANOVA, correlation, and univariate regression tests, employing the aov and duncan.test functions and the R packages ggcorrplot, dplyr, reshape2, ggpubr, and ggpmisc for 21 data pairs. Results revealed that soil/site stability, hydrologic function, and biotic integrity had significant positive relationships with certain functional traits such as leaf dry weight (R² = 0.6), leaf area (R² = 0.5), leaf length (R² = 0.5), perennial forb (R² = 0.3), and perennial grass (R² = 0.5). Conversely, negative correlations were observed with other indices including functional divergence (R² = 0.5), functional dispersion (P < 0.05), mean crown diameter (P < 0.05), annual grass (P < 0.05), and shrub (R² = 0.5). These findings emphasize the importance of incorporating quantitative biodiversity indices alongside qualitative assessments to improve rangeland management and develop a quantitative evaluation protocol.
Ali Mohammadian; Esmaeil Asadi Borujeni; Ataollah Ebrahimi; Pejman Tahmasebi; Ali Asghar Naghipour borj
Abstract
Nowadays, using satellite imagery is one of the fastest and lowest-cost methods in rangeland assessment. Also, remote sensing-based vegetation indices are among the most widely used tools to assess and monitor vegetation changes, especially in the post-fire period, and to map the burned regions in rangelands. ...
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Nowadays, using satellite imagery is one of the fastest and lowest-cost methods in rangeland assessment. Also, remote sensing-based vegetation indices are among the most widely used tools to assess and monitor vegetation changes, especially in the post-fire period, and to map the burned regions in rangelands. The present study was conducted considering the importance and extent of rangelands and the recently increased prevalence of fires in the semi-steppe rangelands of Iran, especially in Chaharmahal and Bakhtiari Province. The main objective of this study was to distinguish and identify the burned areas during 1-3 year and 3-5 year periods to adopt an appropriate post-fire management program in these areas using spectral indices. After calculating the spectral indices, the M statistical parameter was determined to designate the separation capability of the burned areas from the adjacent ones. According to the findings, using NBRT, NBR, and CSI indices is recommended to identify and distinguish the burned areas 1-3 years after the fire from the adjacent areas in semi-steppe rangeland regions of Iran. Overall, these indices are of high efficiency in separating these ranges. Moreover, T.C. Brightness and NBRT indices can efficiently identify and separate the burned areas 3-5 years after the fire. Among the studied indices for both periods of fire in the studied semi-steppe rangelands, the NBRT index showed a high potential for identifying the burned area from the adjacent areas.
Azam Karimi; Ataollah Ebrahimi; Esmaeil Asadi borojeni; Pejman Tahmasebi; Rahman Tavakoli
Abstract
One of the important factors threatening forests and rangeland is fires that leads to destruction of a large part of forests and rangelands. Study of this phenomenon and providing management strategies plays a major role to deal with and control such crisis. This study aimed to identify the affecting ...
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One of the important factors threatening forests and rangeland is fires that leads to destruction of a large part of forests and rangelands. Study of this phenomenon and providing management strategies plays a major role to deal with and control such crisis. This study aimed to identify the affecting factors of fire occurrence. The identification of major criteria conducted using a questionnaire as well as gathering information from Natural Resources and Watershed Management Organization in addition to calculation some others. To do so, 3 category of variables including 1- Human factors, 2- Biophysical factors and 3- Instrumental and logistic factors that contained altogether 26 variables are studied. In this research, Geographically Weighted Regression (GWR) method was used for mapping and zonation of the burned areas in the province that were occurred from 2007 to 2013. Results showed that amongst the 26 studied variables, monthly income (R=-0.61 and VIF=8.08) and number of rangeland and forest guardian members (R=-.56 and VIF=10.81), number of guard stations (R=-0.54 and VIF=2.2), guardsmen’s’ average age (R=0.53 and VIF=9.71 ), average of slope (R=0.5 and VIF=8.99) and number of voluntary rangeland and forest guards (R=-0.42 and VIF=15.11) are respectively the most affective variables on the occurred fires in range and forestlands. Finally, based on extracted predicted map Vardenjan, Mizdej-olia, Poshtkouh Ardal, and Aarmand are the most vulnerable counties for fire incident. Whilst, Monj and Mougooei encountered the least vulnerability of number of fire occurrence that is significantly in line with occurred fires.
sepideh fazelian; Pejman tahmasbi; Hamzehali Shirmardi
Abstract
Endozoochory is one of the seed dispersal modes through animal’s digestive systems transmission and the increases rate germination and plant establishment. The aim of this study, investigated the relationship between seed characteristics and the passage through the digestive tract of livestock ...
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Endozoochory is one of the seed dispersal modes through animal’s digestive systems transmission and the increases rate germination and plant establishment. The aim of this study, investigated the relationship between seed characteristics and the passage through the digestive tract of livestock and domestic animals (cattle, sheep and goats) in the 7 species perennial grass 8 species perennial forbs and 3 species annuals forbs in semi-steppe rangelands of Chaharmahal and Bakhtiari. The first, morphological seeds characteristics including: seed weight, length, width and shape of the seeds measured, and Seeds were fed to the livestock (animal treatments) and the excreta collected to order records germination success of plant species in a greenhouse during a four months experiment. Using multiple regression models the relationship between seed characteristics and success germination was evaluated and compared for different animals. Simple linear regression showed that the percentage of germination after passing through the digestive tract of livestock and properties measured, there is no communication and seed size, weight, length and width of the seed does not affect the animal through the gastrointestinal tract. The logarithmic regression showed that for perennial grasses between seed length and germination, exists direct relationship in all animal treatments. The results of this study showed that, there is no Correlation between morphological characteristics of seeds and passing through the digestive tract of livestock.
Pejman Tahmasbi
Abstract
Fire is one of the most important ecological factors in semi-steppe rangelands directing plant community composition, diversity, structure and function of ecosystems. Our primary aim was to examine the effect of fire on plant community composition, diversity, plant species restoration and animal selectivity ...
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Fire is one of the most important ecological factors in semi-steppe rangelands directing plant community composition, diversity, structure and function of ecosystems. Our primary aim was to examine the effect of fire on plant community composition, diversity, plant species restoration and animal selectivity in semi-steppe rangeland in Karsanak region, Chaharmahal & Bakhtiari province in years 2005, 2008 and 2009. To do so, sampling was performed in burned and control areas using quadrates (2*2 m) installed along a 200 meter transect and plant cover, number of restored and grazed plant species estimated within them. There was a significant difference in plant community composition and diversity between the burdened and control areas in years 2008 and 2009. However, no significant difference was observed for year 2005. This may confirm that a four year period is needed to restore vegetation after fire. Most of graminoids species such as Agropron repense and Bromus tomentellus were restored by 90 and 80 percent respectively whereas, shrub species such as Astragalus adcendense and Astragalus susianus restored by 60 and 40 percent just one year after fire. The results also showed that animals selected burdened areas significantly more than controls in areas burned in 2008 and 2009, while the selectivity was the same for control and burned areas in 2005.
